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Sample records for replica based longitudinal

  1. File-based replica management

    CERN Document Server

    Kunszt, Peter Z; Stockinger, Heinz; Stockinger, Kurt

    2005-01-01

    Data replication is one of the best known strategies to achieve high levels of availability and fault tolerance, as well as minimal access times for large, distributed user communities using a world-wide Data Grid. In certain scientific application domains, the data volume can reach the order of several petabytes; in these domains, data replication and access optimization play an important role in the manageability and usability of the Grid. In this paper, we present the design and implementation of a replica management Grid middleware that was developed within the EDG project left bracket European Data Grid Project (EDG), http://www.eu-egee.org right bracket and is designed to be extensible so that user communities can adjust its detailed behavior according to their QoS requirements.

  2. Storing files in a parallel computing system using list-based index to identify replica files

    Science.gov (United States)

    Faibish, Sorin; Bent, John M.; Tzelnic, Percy; Zhang, Zhenhua; Grider, Gary

    2015-07-21

    Improved techniques are provided for storing files in a parallel computing system using a list-based index to identify file replicas. A file and at least one replica of the file are stored in one or more storage nodes of the parallel computing system. An index for the file comprises at least one list comprising a pointer to a storage location of the file and a storage location of the at least one replica of the file. The file comprises one or more of a complete file and one or more sub-files. The index may also comprise a checksum value for one or more of the file and the replica(s) of the file. The checksum value can be evaluated to validate the file and/or the file replica(s). A query can be processed using the list.

  3. Replica-Based High-Performance Tuple Space Computing

    DEFF Research Database (Denmark)

    Andric, Marina; De Nicola, Rocco; Lluch Lafuente, Alberto

    2015-01-01

    of concurrency and data access. We investigate issues related to replica consistency, provide an operational semantics that guides the implementation of the language, and discuss the main synchronization mechanisms of our prototypical run-time framework. Finally, we provide a performance analysis, which includes...

  4. Replicas Strategy and Cache Optimization of Video Surveillance Systems Based on Cloud Storage

    Directory of Open Access Journals (Sweden)

    Rongheng Li

    2018-04-01

    Full Text Available With the rapid development of video surveillance technology, especially the popularity of cloud-based video surveillance applications, video data begins to grow explosively. However, in the cloud-based video surveillance system, replicas occupy an amount of storage space. Also, the slow response to video playback constrains the performance of the system. In this paper, considering the characteristics of video data comprehensively, we propose a dynamic redundant replicas mechanism based on security levels that can dynamically adjust the number of replicas. Based on the location correlation between cameras, this paper also proposes a data cache strategy to improve the response speed of data reading. Experiments illustrate that: (1 our dynamic redundant replicas mechanism can save storage space while ensuring data security; (2 the cache mechanism can predict the playback behaviors of the users in advance and improve the response speed of data reading according to the location and time correlation of the front-end cameras; and (3 in terms of cloud-based video surveillance, our proposed approaches significantly outperform existing methods.

  5. A Replica Detection Scheme Based on the Deviation in Distance Traveled Sliding Window for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Alekha Kumar Mishra

    2017-01-01

    Full Text Available Node replication attack possesses a high level of threat in wireless sensor networks (WSNs and it is severe when the sensors are mobile. A limited number of replica detection schemes in mobile WSNs (MWSNs have been reported till date, where most of them are centralized in nature. The centralized detection schemes use time-location claims and the base station (BS is solely responsible for detecting replica. Therefore, these schemes are prone to single point of failure. There is also additional communication overhead associated with sending time-location claims to the BS. A distributed detection mechanism is always a preferred solution to the above kind of problems due to significantly lower communication overhead than their counterparts. In this paper, we propose a distributed replica detection scheme for MWSNs. In this scheme, the deviation in the distance traveled by a node and its replica is recorded by the observer nodes. Every node is an observer node for some nodes in the network. Observers are responsible for maintaining a sliding window of recent time-distance broadcast of the nodes. A replica is detected by an observer based on the degree of violation computed from the deviations recorded using the time-distance sliding window. The analysis and simulation results show that the proposed scheme is able to achieve higher detection probability compared to distributed replica detection schemes such as Efficient Distributed Detection (EDD and Multi-Time-Location Storage and Diffusion (MTLSD.

  6. Validation of the replica trick for simple models

    Science.gov (United States)

    Shinzato, Takashi

    2018-04-01

    We discuss the replica analytic continuation using several simple models in order to prove mathematically the validity of the replica analysis, which is used in a wide range of fields related to large-scale complex systems. While replica analysis consists of two analytical techniques—the replica trick (or replica analytic continuation) and the thermodynamical limit (and/or order parameter expansion)—we focus our study on replica analytic continuation, which is the mathematical basis of the replica trick. We apply replica analysis to solve a variety of analytical models, and examine the properties of replica analytic continuation. Based on the positive results for these models we propose that replica analytic continuation is a robust procedure in replica analysis.

  7. Replica consistency in a Data Grid

    International Nuclear Information System (INIS)

    Domenici, Andrea; Donno, Flavia; Pucciani, Gianni; Stockinger, Heinz; Stockinger, Kurt

    2004-01-01

    A Data Grid is a wide area computing infrastructure that employs Grid technologies to provide storage capacity and processing power to applications that handle very large quantities of data. Data Grids rely on data replication to achieve better performance and reliability by storing copies of data sets on different Grid nodes. When a data set can be modified by applications, the problem of maintaining consistency among existing copies arises. The consistency problem also concerns metadata, i.e., additional information about application data sets such as indices, directories, or catalogues. This kind of metadata is used both by the applications and by the Grid middleware to manage the data. For instance, the Replica Management Service (the Grid middleware component that controls data replication) uses catalogues to find the replicas of each data set. Such catalogues can also be replicated and their consistency is crucial to the correct operation of the Grid. Therefore, metadata consistency generally poses stricter requirements than data consistency. In this paper we report on the development of a Replica Consistency Service based on the middleware mainly developed by the European Data Grid Project. The paper summarises the main issues in the replica consistency problem, and lays out a high-level architectural design for a Replica Consistency Service. Finally, results from simulations of different consistency models are presented

  8. Hyper-V Replica essentials

    CERN Document Server

    Krstevski, Vangel

    2013-01-01

    a in various deployment scenarios.Hyper-V Replica Essentials is for Windows Server administrators who want to improve their system availability and speed up disaster recovery. You will need experience in Hyper-V deployment because Hyper-V Replica is built in the Hyper-V platform.

  9. A Dual-Channel Acquisition Method Based on Extended Replica Folding Algorithm for Long Pseudo-Noise Code in Inter-Satellite Links.

    Science.gov (United States)

    Zhao, Hongbo; Chen, Yuying; Feng, Wenquan; Zhuang, Chen

    2018-05-25

    Inter-satellite links are an important component of the new generation of satellite navigation systems, characterized by low signal-to-noise ratio (SNR), complex electromagnetic interference and the short time slot of each satellite, which brings difficulties to the acquisition stage. The inter-satellite link in both Global Positioning System (GPS) and BeiDou Navigation Satellite System (BDS) adopt the long code spread spectrum system. However, long code acquisition is a difficult and time-consuming task due to the long code period. Traditional folding methods such as extended replica folding acquisition search technique (XFAST) and direct average are largely restricted because of code Doppler and additional SNR loss caused by replica folding. The dual folding method (DF-XFAST) and dual-channel method have been proposed to achieve long code acquisition in low SNR and high dynamic situations, respectively, but the former is easily affected by code Doppler and the latter is not fast enough. Considering the environment of inter-satellite links and the problems of existing algorithms, this paper proposes a new long code acquisition algorithm named dual-channel acquisition method based on the extended replica folding algorithm (DC-XFAST). This method employs dual channels for verification. Each channel contains an incoming signal block. Local code samples are folded and zero-padded to the length of the incoming signal block. After a circular FFT operation, the correlation results contain two peaks of the same magnitude and specified relative position. The detection process is eased through finding the two largest values. The verification takes all the full and partial peaks into account. Numerical results reveal that the DC-XFAST method can improve acquisition performance while acquisition speed is guaranteed. The method has a significantly higher acquisition probability than folding methods XFAST and DF-XFAST. Moreover, with the advantage of higher detection

  10. A Dual-Channel Acquisition Method Based on Extended Replica Folding Algorithm for Long Pseudo-Noise Code in Inter-Satellite Links

    Directory of Open Access Journals (Sweden)

    Hongbo Zhao

    2018-05-01

    Full Text Available Inter-satellite links are an important component of the new generation of satellite navigation systems, characterized by low signal-to-noise ratio (SNR, complex electromagnetic interference and the short time slot of each satellite, which brings difficulties to the acquisition stage. The inter-satellite link in both Global Positioning System (GPS and BeiDou Navigation Satellite System (BDS adopt the long code spread spectrum system. However, long code acquisition is a difficult and time-consuming task due to the long code period. Traditional folding methods such as extended replica folding acquisition search technique (XFAST and direct average are largely restricted because of code Doppler and additional SNR loss caused by replica folding. The dual folding method (DF-XFAST and dual-channel method have been proposed to achieve long code acquisition in low SNR and high dynamic situations, respectively, but the former is easily affected by code Doppler and the latter is not fast enough. Considering the environment of inter-satellite links and the problems of existing algorithms, this paper proposes a new long code acquisition algorithm named dual-channel acquisition method based on the extended replica folding algorithm (DC-XFAST. This method employs dual channels for verification. Each channel contains an incoming signal block. Local code samples are folded and zero-padded to the length of the incoming signal block. After a circular FFT operation, the correlation results contain two peaks of the same magnitude and specified relative position. The detection process is eased through finding the two largest values. The verification takes all the full and partial peaks into account. Numerical results reveal that the DC-XFAST method can improve acquisition performance while acquisition speed is guaranteed. The method has a significantly higher acquisition probability than folding methods XFAST and DF-XFAST. Moreover, with the advantage of higher

  11. In Silico Generation of Peptides by Replica Exchange Monte Carlo: Docking-Based Optimization of Maltose-Binding-Protein Ligands.

    Directory of Open Access Journals (Sweden)

    Anna Russo

    Full Text Available Short peptides can be designed in silico and synthesized through automated techniques, making them advantageous and versatile protein binders. A number of docking-based algorithms allow for a computational screening of peptides as binders. Here we developed ex-novo peptides targeting the maltose site of the Maltose Binding Protein, the prototypical system for the study of protein ligand recognition. We used a Monte Carlo based protocol, to computationally evolve a set of octapeptides starting from a polialanine sequence. We screened in silico the candidate peptides and characterized their binding abilities by surface plasmon resonance, fluorescence and electrospray ionization mass spectrometry assays. These experiments showed the designed binders to recognize their target with micromolar affinity. We finally discuss the obtained results in the light of further improvement in the ex-novo optimization of peptide based binders.

  12. Neurovascular Modeling: Small-Batch Manufacturing of Silicone Vascular Replicas

    Science.gov (United States)

    Chueh, J.Y.; Wakhloo, A.K.; Gounis, M.J.

    2009-01-01

    BACKGROUND AND PURPOSE Realistic, population based cerebrovascular replicas are required for the development of neuroendovascular devices. The objective of this work was to develop an efficient methodology for manufacturing realistic cerebrovascular replicas. MATERIALS AND METHODS Brain MR angiography data from 20 patients were acquired. The centerline of the vasculature was calculated, and geometric parameters were measured to describe quantitatively the internal carotid artery (ICA) siphon. A representative model was created on the basis of the quantitative measurements. Using this virtual model, we designed a mold with core-shell structure and converted it into a physical object by fused-deposit manufacturing. Vascular replicas were created by injection molding of different silicones. Mechanical properties, including the stiffness and luminal coefficient of friction, were measured. RESULTS The average diameter, length, and curvature of the ICA siphon were 4.15 ± 0.09 mm, 22.60 ± 0.79 mm, and 0.34 ± 0.02 mm-1 (average ± standard error of the mean), respectively. From these image datasets, we created a median virtual model, which was transformed into a physical replica by an efficient batch-manufacturing process. The coefficient of friction of the luminal surface of the replica was reduced by up to 55% by using liquid silicone rubber coatings. The modulus ranged from 0.67 to 1.15 MPa compared with 0.42 MPa from human postmortem studies, depending on the material used to make the replica. CONCLUSIONS Population-representative, smooth, and true-to-scale silicone arterial replicas with uniform wall thickness were successfully built for in vitro neurointerventional device-testing by using a batch-manufacturing process. PMID:19321626

  13. Reconstruction of Monte Carlo replicas from Hessian parton distributions

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Tie-Jiun [Department of Physics, Southern Methodist University,Dallas, TX 75275-0181 (United States); Gao, Jun [INPAC, Shanghai Key Laboratory for Particle Physics and Cosmology,Department of Physics and Astronomy, Shanghai Jiao-Tong University, Shanghai 200240 (China); High Energy Physics Division, Argonne National Laboratory,Argonne, Illinois, 60439 (United States); Huston, Joey [Department of Physics and Astronomy, Michigan State University,East Lansing, MI 48824 (United States); Nadolsky, Pavel [Department of Physics, Southern Methodist University,Dallas, TX 75275-0181 (United States); Schmidt, Carl; Stump, Daniel [Department of Physics and Astronomy, Michigan State University,East Lansing, MI 48824 (United States); Wang, Bo-Ting; Xie, Ke Ping [Department of Physics, Southern Methodist University,Dallas, TX 75275-0181 (United States); Dulat, Sayipjamal [Department of Physics and Astronomy, Michigan State University,East Lansing, MI 48824 (United States); School of Physics Science and Technology, Xinjiang University,Urumqi, Xinjiang 830046 (China); Center for Theoretical Physics, Xinjiang University,Urumqi, Xinjiang 830046 (China); Pumplin, Jon; Yuan, C.P. [Department of Physics and Astronomy, Michigan State University,East Lansing, MI 48824 (United States)

    2017-03-20

    We explore connections between two common methods for quantifying the uncertainty in parton distribution functions (PDFs), based on the Hessian error matrix and Monte-Carlo sampling. CT14 parton distributions in the Hessian representation are converted into Monte-Carlo replicas by a numerical method that reproduces important properties of CT14 Hessian PDFs: the asymmetry of CT14 uncertainties and positivity of individual parton distributions. The ensembles of CT14 Monte-Carlo replicas constructed this way at NNLO and NLO are suitable for various collider applications, such as cross section reweighting. Master formulas for computation of asymmetric standard deviations in the Monte-Carlo representation are derived. A correction is proposed to address a bias in asymmetric uncertainties introduced by the Taylor series approximation. A numerical program is made available for conversion of Hessian PDFs into Monte-Carlo replicas according to normal, log-normal, and Watt-Thorne sampling procedures.

  14. Creating technical heritage object replicas in a virtual environment

    Science.gov (United States)

    Egorova, Olga; Shcherbinin, Dmitry

    2016-03-01

    The paper presents innovative informatics methods for creating virtual technical heritage replicas, which are of significant scientific and practical importance not only to researchers but to the public in general. By performing 3D modeling and animation of aircrafts, spaceships, architectural-engineering buildings, and other technical objects, the process of learning is achieved while promoting the preservation of the replicas for future generations. Modern approaches based on the wide usage of computer technologies attract a greater number of young people to explore the history of science and technology and renew their interest in the field of mechanical engineering.

  15. The added value of the replica simulators in the exploitation of nuclear power plants; El valor anadido de los simuladores replica en la explotacion de las centrales nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Giron, P. a.; Ortega, F.; Rivero, N.

    2011-07-01

    Nuclear power plants full scope replica simulators were in the past solely designed following operational personnel training criteria. Nevertheless, these simulators not only feature a high replica control room but also provide an accurate process response. Control room replica simulators are presently based on complex technological platforms permitting highest physical and functional fidelity, allowing to be used as versatile and value added tools in diverse plants operation and maintenance activities. In recent years. Tecnatom has extended the use of such simulators to different engineering applications. this article intends to identify the simulators use in training and other applications beyond training. (Author)

  16. Simulated Tempering Distributed Replica Sampling, Virtual Replica Exchange, and Other Generalized-Ensemble Methods for Conformational Sampling.

    Science.gov (United States)

    Rauscher, Sarah; Neale, Chris; Pomès, Régis

    2009-10-13

    Generalized-ensemble algorithms in temperature space have become popular tools to enhance conformational sampling in biomolecular simulations. A random walk in temperature leads to a corresponding random walk in potential energy, which can be used to cross over energetic barriers and overcome the problem of quasi-nonergodicity. In this paper, we introduce two novel methods: simulated tempering distributed replica sampling (STDR) and virtual replica exchange (VREX). These methods are designed to address the practical issues inherent in the replica exchange (RE), simulated tempering (ST), and serial replica exchange (SREM) algorithms. RE requires a large, dedicated, and homogeneous cluster of CPUs to function efficiently when applied to complex systems. ST and SREM both have the drawback of requiring extensive initial simulations, possibly adaptive, for the calculation of weight factors or potential energy distribution functions. STDR and VREX alleviate the need for lengthy initial simulations, and for synchronization and extensive communication between replicas. Both methods are therefore suitable for distributed or heterogeneous computing platforms. We perform an objective comparison of all five algorithms in terms of both implementation issues and sampling efficiency. We use disordered peptides in explicit water as test systems, for a total simulation time of over 42 μs. Efficiency is defined in terms of both structural convergence and temperature diffusion, and we show that these definitions of efficiency are in fact correlated. Importantly, we find that ST-based methods exhibit faster temperature diffusion and correspondingly faster convergence of structural properties compared to RE-based methods. Within the RE-based methods, VREX is superior to both SREM and RE. On the basis of our observations, we conclude that ST is ideal for simple systems, while STDR is well-suited for complex systems.

  17. Replica Fourier Transform: Properties and applications

    International Nuclear Information System (INIS)

    Crisanti, A.; De Dominicis, C.

    2015-01-01

    The Replica Fourier Transform is the generalization of the discrete Fourier Transform to quantities defined on an ultrametric tree. It finds use in conjunction of the replica method used to study thermodynamics properties of disordered systems such as spin glasses. Its definition is presented in a systematic and simple form and its use illustrated with some representative examples. In particular we give a detailed discussion of the diagonalization in the Replica Fourier Space of the Hessian matrix of the Gaussian fluctuations about the mean field saddle point of spin glass theory. The general results are finally discussed for a generic spherical spin glass model, where the Hessian can be computed analytically

  18. The added value of the replica simulators in the exploitation of nuclear power plants

    International Nuclear Information System (INIS)

    Diaz Giron, P. a.; Ortega, F.; Rivero, N.

    2011-01-01

    Nuclear power plants full scope replica simulators were in the past solely designed following operational personnel training criteria. Nevertheless, these simulators not only feature a high replica control room but also provide an accurate process response. Control room replica simulators are presently based on complex technological platforms permitting highest physical and functional fidelity, allowing to be used as versatile and value added tools in diverse plants operation and maintenance activities. In recent years. Tecnatom has extended the use of such simulators to different engineering applications. this article intends to identify the simulators use in training and other applications beyond training. (Author)

  19. Conformational sampling enhancement of replica exchange molecular dynamics simulations using swarm particle intelligence

    International Nuclear Information System (INIS)

    Kamberaj, Hiqmet

    2015-01-01

    In this paper, we present a new method based on swarm particle social intelligence for use in replica exchange molecular dynamics simulations. In this method, the replicas (representing the different system configurations) are allowed communicating with each other through the individual and social knowledge, in additional to considering them as a collection of real particles interacting through the Newtonian forces. The new method is based on the modification of the equations of motion in such way that the replicas are driven towards the global energy minimum. The method was tested for the Lennard-Jones clusters of N = 4,  5, and 6 atoms. Our results showed that the new method is more efficient than the conventional replica exchange method under the same practical conditions. In particular, the new method performed better on optimizing the distribution of the replicas among the thermostats with time and, in addition, ergodic convergence is observed to be faster. We also introduce a weighted histogram analysis method allowing analyzing the data from simulations by combining data from all of the replicas and rigorously removing the inserted bias

  20. An Evaluation of PET Based on Longitudinal Data.

    Science.gov (United States)

    Mandeville, Garrett K.

    Although teacher inservice programs based on Madeline Hunter's Program for Effective Teaching (PET) have become very popular in U.S. schools, there is little evidence that the Hunter model ultimately results in increased student achievement. This longitudinal study attempts to evaluate the effects of Hunter-based staff development programs on…

  1. Data Sets Replicas Placements Strategy from Cost-Effective View in the Cloud

    Directory of Open Access Journals (Sweden)

    Xiuguo Wu

    2016-01-01

    Full Text Available Replication technology is commonly used to improve data availability and reduce data access latency in the cloud storage system by providing users with different replicas of the same service. Most current approaches largely focus on system performance improvement, neglecting management cost in deciding replicas number and their store places, which cause great financial burden for cloud users because the cost for replicas storage and consistency maintenance may lead to high overhead with the number of new replicas increased in a pay-as-you-go paradigm. In this paper, towards achieving the approximate minimum data sets management cost benchmark in a practical manner, we propose a replicas placements strategy from cost-effective view with the premise that system performance meets requirements. Firstly, we design data sets management cost models, including storage cost and transfer cost. Secondly, we use the access frequency and the average response time to decide which data set should be replicated. Then, the method of calculating replicas’ number and their store places with minimum management cost is proposed based on location problem graph. Both the theoretical analysis and simulations have shown that the proposed strategy offers the benefits of lower management cost with fewer replicas.

  2. Longitudinal tire force estimation based on sliding mode observer

    Energy Technology Data Exchange (ETDEWEB)

    El Hadri, A.; Cadiou, J.C.; M' Sirdi, N.K. [Versailles Univ., Paris (France). Lab. de Robotique; Beurier, G.; Delanne, Y. [Lab. Central des Ponts, Centre de Nantes (France)

    2001-07-01

    This paper presents an estimation method for vehicle longitudinal dynamics, particularly the tractive/braking force. The estimation can be used to detect a critical driving situation to improve security. It can be used also in several vehicle control systems. The main characteristics of the vehicle longitudinal dynamics were taken into account in the model used to design an observer and computer simulations. The state variables are the angular wheel velocity, vehicle velocity and the longitudinal tire force. The proposed differential equation of the tractive/braking force is derived using the concept of relaxation length. The observer designed is based on the sliding mode approach using only the angular wheel velocity measurement. The proposed method of estimation is verified through a one-wheel simulation model with a ''Magic formula'' tire model. Simulations results show an excellent reconstruction of the tire force. (orig.)

  3. Replica methods for loopy sparse random graphs

    International Nuclear Information System (INIS)

    Coolen, ACC

    2016-01-01

    I report on the development of a novel statistical mechanical formalism for the analysis of random graphs with many short loops, and processes on such graphs. The graphs are defined via maximum entropy ensembles, in which both the degrees (via hard constraints) and the adjacency matrix spectrum (via a soft constraint) are prescribed. The sum over graphs can be done analytically, using a replica formalism with complex replica dimensions. All known results for tree-like graphs are recovered in a suitable limit. For loopy graphs, the emerging theory has an appealing and intuitive structure, suggests how message passing algorithms should be adapted, and what is the structure of theories describing spin systems on loopy architectures. However, the formalism is still largely untested, and may require further adjustment and refinement. (paper)

  4. Kinetics from Replica Exchange Molecular Dynamics Simulations.

    Science.gov (United States)

    Stelzl, Lukas S; Hummer, Gerhard

    2017-08-08

    Transitions between metastable states govern many fundamental processes in physics, chemistry and biology, from nucleation events in phase transitions to the folding of proteins. The free energy surfaces underlying these processes can be obtained from simulations using enhanced sampling methods. However, their altered dynamics makes kinetic and mechanistic information difficult or impossible to extract. Here, we show that, with replica exchange molecular dynamics (REMD), one can not only sample equilibrium properties but also extract kinetic information. For systems that strictly obey first-order kinetics, the procedure to extract rates is rigorous. For actual molecular systems whose long-time dynamics are captured by kinetic rate models, accurate rate coefficients can be determined from the statistics of the transitions between the metastable states at each replica temperature. We demonstrate the practical applicability of the procedure by constructing master equation (Markov state) models of peptide and RNA folding from REMD simulations.

  5. 3D printed replicas for endodontic education.

    Science.gov (United States)

    Reymus, M; Fotiadou, C; Kessler, A; Heck, K; Hickel, R; Diegritz, C

    2018-06-14

    To assess the feasibility of producing artificial teeth for endodontic training using 3D printing technology, to analyse the accuracy of the printing process, and to evaluate the teeth by students when used during training. Sound extracted human teeth were selected, digitalized by cone beam computed tomography (CBCT) and appropriate software and finally reproduced by a stereolithographic printer. The printed teeth were scanned and compared with the original ones (trueness) and to one another (precision). Undergraduate dental students in the third and fourth years performed root canal treatment on printed molars and were subsequently asked to evaluate their experience with these compared to real teeth. The workflow was feasible for manufacturing 3D printed tooth replicas. The absolute deviation after printing (trueness) ranged from 50.9μm to 104.3μm. The values for precision ranged from 43.5μm to 68.2μm. Students reported great benefits in the use of the replicated teeth for training purposes. The presented workflow is feasible for any dental educational institution who has access to a CBCT unit and a stereolithographic printer. The accuracy of the printing process is suitable for the production of tooth replicas for endodontic training. Undergraduate students favoured the availability of these replicas and the fairness they ensured in training due to standardization. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  6. A critical inventory of preoperative skull replicas.

    Science.gov (United States)

    Fasel, J H D; Beinemann, J; Schaller, K; Gailloud, P

    2013-09-01

    Physical replicas of organs are used increasingly for preoperative planning. The quality of these models is generally accepted by surgeons. In view of the strong trend towards minimally invasive and personalised surgery, however, the aim of this investigation was to assess qualitatively the accuracy of such replicas, using skull models as an example. Skull imaging was acquired for three cadavers by computed tomography using clinical routine parameters. After digital three-dimensional (3D) reconstruction, physical replicas were produced by 3D printing. The facsimilia were analysed systematically and compared with the best gold standard possible: the macerated skull itself. The skull models were far from anatomically accurate. Non-conforming rendering was observed in particular for foramina, sutures, notches, fissures, grooves, channels, tuberosities, thin-walled structures, sharp peaks and crests, and teeth. Surgeons should be aware that preoperative models may not yet render the exact anatomy of the patient under consideration and are advised to continue relying, in specific conditions, on their own analysis of the native computed tomography or magnetic resonance imaging.

  7. Active Splitting in Longitudinal Power Systems based on a WAMPC

    Directory of Open Access Journals (Sweden)

    Felipe Arraño-Vargas

    2017-12-01

    Full Text Available This paper proposes an active splitting scheme especially suitable for longitudinal power systems (LPS. The proposed scheme is based on a modified out-of-step (OOS algorithm combined with an angle difference method using synchrophasor measurements. The remedial actions are based on the detection of possible loss of synchronism due to severe disturbances. The scheme was tested on a detailed dynamic model of the Central Interconnected System of Chile, a good example of extreme LPS. Obtained results show that remedial actions taken by the proposed protection scheme are able to avoid the total collapse of the system during critical contingencies.

  8. Typology of alcohol users based on longitudinal patterns of drinking.

    Science.gov (United States)

    Harrington, Magdalena; Velicer, Wayne F; Ramsey, Susan

    2014-03-01

    Worldwide, alcohol is the most commonly used psychoactive substance. However, heterogeneity among alcohol users has been widely recognized. This paper presents a typology of alcohol users based on an implementation of idiographic methodology to examine longitudinal daily and cyclic (weekly) patterns of alcohol use at the individual level. A secondary data analysis was performed on the pre-intervention data from a large randomized control trial. A time series analysis was performed at the individual level, and a dynamic cluster analysis was employed to identify homogenous longitudinal patterns of drinking behavior at the group level. The analysis employed 180 daily observations of alcohol use in a sample of 177 alcohol users. The first order autocorrelations ranged from -.76 to .72, and seventh order autocorrelations ranged from -.27 to .79. Eight distinct profiles of alcohol users were identified, each characterized by a unique configuration of first and seventh autoregressive terms and longitudinal trajectories of alcohol use. External validity of the profiles confirmed the theoretical relevance of different patterns of alcohol use. Significant differences among the eight subtypes were found on gender, marital status, frequency of drug use, lifetime alcohol dependence, family history of alcohol use and the Short Index of Problems. Our findings demonstrate that individuals can have very different temporal patterns of drinking behavior. The daily and cyclic patterns of alcohol use may be important for designing tailored interventions for problem drinkers. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Microlens fabrication by replica molding of frozen laser-printed droplets

    Science.gov (United States)

    Surdo, Salvatore; Diaspro, Alberto; Duocastella, Martí

    2017-10-01

    In this work, we synergistically combine laser-induced forward transfer (LIFT) and replica molding for the fabrication of microlenses with control of their geometry and size independent of the material or substrate used. Our approach is based on a multistep process in which liquid microdroplets of an aqueous solution are first printed on a substrate by LIFT. Following a freezing step, the microdroplets are used as a master to fabricate a polydimethylsiloxane (PDMS) mold. A subsequent replica molding step enables the creation of microlenses and microlens arrays on arbitrary selected substrates and by using different curable polymers. Thus, our method combines the rapid fabrication capabilities of LIFT and the perfectively smooth surface quality of the generated microdroplets, with the advantages of replica molding in terms of parallelization and materials flexibility. We demonstrate our strategy by generating microlenses of different photocurable polymers and by characterizing their optical and morphological properties.

  10. Acceleration of Lateral Equilibration in Mixed Lipid Bilayers Using Replica Exchange with Solute Tempering.

    Science.gov (United States)

    Huang, Kun; García, Angel E

    2014-10-14

    The lateral heterogeneity of cellular membranes plays an important role in many biological functions such as signaling and regulating membrane proteins. This heterogeneity can result from preferential interactions between membrane components or interactions with membrane proteins. One major difficulty in molecular dynamics simulations aimed at studying the membrane heterogeneity is that lipids diffuse slowly and collectively in bilayers, and therefore, it is difficult to reach equilibrium in lateral organization in bilayer mixtures. Here, we propose the use of the replica exchange with solute tempering (REST) approach to accelerate lateral relaxation in heterogeneous bilayers. REST is based on the replica exchange method but tempers only the solute, leaving the temperature of the solvent fixed. Since the number of replicas in REST scales approximately only with the degrees of freedom in the solute, REST enables us to enhance the configuration sampling of lipid bilayers with fewer replicas, in comparison with the temperature replica exchange molecular dynamics simulation (T-REMD) where the number of replicas scales with the degrees of freedom of the entire system. We apply the REST method to a cholesterol and 1,2-dipalmitoyl- sn -glycero-3-phosphocholine (DPPC) bilayer mixture and find that the lateral distribution functions of all molecular pair types converge much faster than in the standard MD simulation. The relative diffusion rate between molecules in REST is, on average, an order of magnitude faster than in the standard MD simulation. Although REST was initially proposed to study protein folding and its efficiency in protein folding is still under debate, we find a unique application of REST to accelerate lateral equilibration in mixed lipid membranes and suggest a promising way to probe membrane lateral heterogeneity through molecular dynamics simulation.

  11. A Validation Study of the Impression Replica Technique.

    Science.gov (United States)

    Segerström, Sofia; Wiking-Lima de Faria, Johanna; Braian, Michael; Ameri, Arman; Ahlgren, Camilla

    2018-04-17

    To validate the well-known and often-used impression replica technique for measuring fit between a preparation and a crown in vitro. The validation consisted of three steps. First, a measuring instrument was validated to elucidate its accuracy. Second, a specimen consisting of male and female counterparts was created and validated by the measuring instrument. Calculations were made for the exact values of three gaps between the male and female. Finally, impression replicas were produced of the specimen gaps and sectioned into four pieces. The replicas were then measured with the use of a light microscope. The values received from measuring the specimen were then compared with the values received from the impression replicas, and the technique was thereby validated. The impression replica technique overvalued all measured gaps. Depending on location of the three measuring sites, the difference between the specimen and the impression replicas varied from 47 to 130 μm. The impression replica technique overestimates gaps within the range of 2% to 11%. The validation of the replica technique enables the method to be used as a reference when testing other methods for evaluating fit in dentistry. © 2018 by the American College of Prosthodontists.

  12. Evaluation of creep damage development by the replica method; Utvaerdering av krypskadeutveckling med replikmetoden

    Energy Technology Data Exchange (ETDEWEB)

    Storesund, Jan [Det Norske Veritas AB, Stockholm (Sweden); Roennholm, Markku [Fortum (Sweden)

    2002-04-01

    Creep damage development in high temperature components can be monitored by the replica method. Damage is classified and an experience based time period for safe operation is recommended where a re-inspection should be conducted. Original recommendations are still commonly used but there are also developed ones are mostly less conservative. A data base of more than 6000 replicas, collected from welded components in Swedish and Finnish power plants, has been evaluated with respect to damage development in the present project. The results are in general in good agreement to the existing developed recommendations for re-inspections. Important factors that should be considered for use of the recommendations are highlighted: Service history, Material, welding and heat treatment, Measure of pressure and temperature, System stresses, Geometrical stress concentrations, stress distributions, Design of components and welds, Creep crack growth, Starts and stops, Extent and performance of the replica method. These factors have been analysed with respect to the evaluated data resulting in comments to the existing recommendations. In addition, recommendations and conditions for a high reliability of the replica method are described. The comments and recommendations can be read in separate sections in the end of the report.

  13. Coronary heart disease index based on longitudinal electrocardiography

    Science.gov (United States)

    Townsend, J. C.; Cronin, J. P.

    1977-01-01

    A coronary heart disease index was developed from longitudinal ECG (LCG) tracings to serve as a cardiac health measure in studies of working and, essentially, asymptomatic populations, such as pilots and executives. For a given subject, the index consisted of a composite score based on the presence of LCG aberrations and weighted values previously assigned to them. The index was validated by correlating it with the known presence or absence of CHD as determined by a complete physical examination, including treadmill, resting ECG, and risk factor information. The validating sample consisted of 111 subjects drawn by a stratified-random procedure from 5000 available case histories. The CHD index was found to be significantly more valid as a sole indicator of CHD than the LCG without the use of the index. The index consistently produced higher validity coefficients in identifying CHD than did treadmill testing, resting ECG, or risk factor analysis.

  14. Automated magnification calibration in transmission electron microscopy using Fourier analysis of replica images

    International Nuclear Information System (INIS)

    Laak, Jeroen A.W.M. van der; Dijkman, Henry B.P.M.; Pahlplatz, Martin M.M.

    2006-01-01

    The magnification factor in transmission electron microscopy is not very precise, hampering for instance quantitative analysis of specimens. Calibration of the magnification is usually performed interactively using replica specimens, containing line or grating patterns with known spacing. In the present study, a procedure is described for automated magnification calibration using digital images of a line replica. This procedure is based on analysis of the power spectrum of Fourier transformed replica images, and is compared to interactive measurement in the same images. Images were used with magnification ranging from 1,000x to 200,000x. The automated procedure deviated on average 0.10% from interactive measurements. Especially for catalase replicas, the coefficient of variation of automated measurement was considerably smaller (average 0.28%) compared to that of interactive measurement (average 3.5%). In conclusion, calibration of the magnification in digital images from transmission electron microscopy may be performed automatically, using the procedure presented here, with high precision and accuracy

  15. Modeling Vocal Fold Intravascular Flow using Synthetic Replicas

    Science.gov (United States)

    Terry, Aaron D.; Ricks, Matthew T.; Thomson, Scott L.

    2017-11-01

    Vocal fold vibration that is induced by air flowing from the lungs is believed to decrease blood flow through the vocal folds. This is important due to the critical role of blood flow in maintaining tissue health. However, the precise mechanical relationships between vocal fold vibration and blood perfusion remain understudied. A platform for studying liquid perfusion in a synthetic, life-size, self-oscillating vocal fold replica has recently been developed. The replicas are fabricated using molded silicone with material properties comparable to those of human vocal fold tissues and that include embedded microchannels through which liquid is perfused. The replicas are mounted on an air flow supply tube to initiate flow-induced vibration. A liquid reservoir is attached to the microchannel to cause liquid to perfuse through replica in the anterior-posterior direction. As replica vibration is initiated and amplitude increases, perfusion flow rate decreases. In this presentation, the replica design will be presented, along with data quantifying the relationships between parameters such as replica vibration amplitude, stiffness, microchannel diameter, and perfusion flow rate. This work was supported by Grant NIDCD R01DC005788 from the National Institutes of Health.

  16. Comparison of pulsed versus continuous oxygen delivery using realistic adult nasal airway replicas

    Directory of Open Access Journals (Sweden)

    Chen JZ

    2017-08-01

    Full Text Available John Z Chen,1 Ira M Katz,2 Marine Pichelin,2 Kaixian Zhu,3 Georges Caillibotte,2 Michelle L Noga,4 Warren H Finlay,1 Andrew R Martin1 1Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada; 2Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, Les Loges-en-Josas, 3Centre Explor!, Air Liquide Healthcare, Gentilly, France; 4Radiology and Diagnostic Imaging, University of Alberta, Edmonton, AB, Canada Background: Portable oxygen concentrators (POCs typically include pulse flow (PF modes to conserve oxygen. The primary aims of this study were to develop a predictive in vitro model for inhaled oxygen delivery using a set of realistic airway replicas, and to compare PF for a commercial POC with steady flow (SF from a compressed oxygen cylinder. Methods: Experiments were carried out using a stationary compressed oxygen cylinder, a POC, and 15 adult nasal airway replicas based on airway geometries derived from medical images. Oxygen delivery via nasal cannula was tested at PF settings of 2.0 and 6.0, and SF rates of 2.0 and 6.0 L/min. A test lung simulated three breathing patterns representative of a chronic obstructive pulmonary disease patient at rest, during exercise, and while asleep. Volume-averaged fraction of inhaled oxygen (FiO2 was calculated by analyzing oxygen concentrations sampled at the exit of each replica and inhalation flow rates over time. POC pulse volumes were also measured using a commercial O2 conserver test system to attempt to predict FiO2 for PF. Results: Relative volume-averaged FiO2 using PF ranged from 68% to 94% of SF values, increasing with breathing frequency and tidal volume. Three of 15 replicas failed to trigger the POC when used with the sleep breathing pattern at the 2.0 setting, and four of 15 replicas failed to trigger at the 6.0 setting. FiO2 values estimated from POC pulse characteristics followed similar trends but were lower than those derived from

  17. A competency-based longitudinal core curriculum in medical neuroscience.

    Science.gov (United States)

    Merlin, Lisa R; Horak, Holli A; Milligan, Tracey A; Kraakevik, Jeff A; Ali, Imran I

    2014-07-29

    Current medical educational theory encourages the development of competency-based curricula. The Accreditation Council for Graduate Medical Education's 6 core competencies for resident education (medical knowledge, patient care, professionalism, interpersonal and communication skills, practice-based learning, and systems-based practice) have been embraced by medical schools as the building blocks necessary for becoming a competent licensed physician. Many medical schools are therefore changing their educational approach to an integrated model in which students demonstrate incremental acquisition and mastery of all competencies as they progress through medical school. Challenges to medical schools include integration of preclinical and clinical studies as well as development of learning objectives and assessment measures for each competency. The Undergraduate Education Subcommittee (UES) of the American Academy of Neurology (AAN) assembled a group of neuroscience educators to outline a longitudinal competency-based curriculum in medical neuroscience encompassing both preclinical and clinical coursework. In development of this curriculum, the committee reviewed United States Medical Licensing Examination content outlines, Liaison Committee on Medical Education requirements, prior AAN-mandated core curricula for basic neuroscience and clinical neurology, and survey responses from educators in US medical schools. The newly recommended curriculum provides an outline of learning objectives for each of the 6 competencies, listing each learning objective in active terms. Documentation of experiences is emphasized, and assessment measures are suggested to demonstrate adequate achievement in each competency. These guidelines, widely vetted and approved by the UES membership, aspire to be both useful as a stand-alone curriculum and also provide a framework for neuroscience educators who wish to develop a more detailed focus in certain areas of study. © 2014 American Academy

  18. Gamma-ray dosimetry measurements of the Little Boy replica

    International Nuclear Information System (INIS)

    Plassmann, E.A.; Pederson, R.A.

    1984-01-01

    We present the current status of our gamma-ray dosimetry results for the Little Boy replica. Both Geiger-Mueller and thermoluminescent detectors were used in the measurements. Future work is needed to test assumptions made in data analysis

  19. SRF Cavity Surface Topography Characterization Using Replica Techniques

    Energy Technology Data Exchange (ETDEWEB)

    C. Xu, M.J. Kelley, C.E. Reece

    2012-07-01

    To better understand the roll of topography on SRF cavity performance, we seek to obtain detailed topographic information from the curved practical cavity surfaces. Replicas taken from a cavity interior surface provide internal surface molds for fine Atomic Force Microscopy (AFM) and stylus profilometry. In this study, we confirm the replica resolution both on surface local defects such as grain boundary and etching pits and compare the surface uniform roughness with the aid of Power Spectral Density (PSD) where we can statistically obtain roughness parameters at different scales. A series of sampling locations are at the same magnetic field chosen at the same latitude on a single cell cavity to confirm the uniformity. Another series of sampling locations at different magnetic field amplitudes are chosen for this replica on the same cavity for later power loss calculation. We also show that application of the replica followed by rinsing does not adversely affect the cavity performance.

  20. Patrol Detection for Replica Attacks on Wireless Sensor Networks

    OpenAIRE

    Wang, Liang-Min; Shi, Yang

    2011-01-01

    Replica attack is a critical concern in the security of wireless sensor networks. We employ mobile nodes as patrollers to detect replicas distributed in different zones in a network, in which a basic patrol detection protocol and two detection algorithms for stationary and mobile modes are presented. Then we perform security analysis to discuss the defense strategies against the possible attacks on the proposed detection protocol. Moreover, we show the advantages of the proposed protocol by d...

  1. Accuracy of three-dimensional printing for manufacturing replica teeth

    OpenAIRE

    Lee, Keun-Young; Cho, Jin-Woo; Chang, Na-Young; Chae, Jong-Moon; Kang, Kyung-Hwa; Kim, Sang-Cheol; Cho, Jin-Hyoung

    2015-01-01

    Objective Three-dimensional (3D) printing is a recent technological development that may play a significant role in orthodontic diagnosis and treatment. It can be used to fabricate skull models or study models, as well as to make replica teeth in autotransplantation or tooth impaction cases. The aim of this study was to evaluate the accuracy of fabrication of replica teeth made by two types of 3D printing technologies. Methods Fifty extracted molar teeth were selected as samples. They were sc...

  2. Bayesian ensemble refinement by replica simulations and reweighting

    Science.gov (United States)

    Hummer, Gerhard; Köfinger, Jürgen

    2015-12-01

    We describe different Bayesian ensemble refinement methods, examine their interrelation, and discuss their practical application. With ensemble refinement, the properties of dynamic and partially disordered (bio)molecular structures can be characterized by integrating a wide range of experimental data, including measurements of ensemble-averaged observables. We start from a Bayesian formulation in which the posterior is a functional that ranks different configuration space distributions. By maximizing this posterior, we derive an optimal Bayesian ensemble distribution. For discrete configurations, this optimal distribution is identical to that obtained by the maximum entropy "ensemble refinement of SAXS" (EROS) formulation. Bayesian replica ensemble refinement enhances the sampling of relevant configurations by imposing restraints on averages of observables in coupled replica molecular dynamics simulations. We show that the strength of the restraints should scale linearly with the number of replicas to ensure convergence to the optimal Bayesian result in the limit of infinitely many replicas. In the "Bayesian inference of ensembles" method, we combine the replica and EROS approaches to accelerate the convergence. An adaptive algorithm can be used to sample directly from the optimal ensemble, without replicas. We discuss the incorporation of single-molecule measurements and dynamic observables such as relaxation parameters. The theoretical analysis of different Bayesian ensemble refinement approaches provides a basis for practical applications and a starting point for further investigations.

  3. Replica Fourier Tansforms on Ultrametric Trees, and Block-Diagonalizing Multi-Replica Matrices

    Science.gov (United States)

    de Dominicis, C.; Carlucci, D. M.; Temesvári, T.

    1997-01-01

    The analysis of objects living on ultrametric trees, in particular the block-diagonalization of 4-replica matrices M^{α β;γ^δ}, is shown to be dramatically simplified through the introduction of properly chosen operations on those objects. These are the Replica Fourier Transforms on ultrametric trees. Those transformations are defined and used in the present work. On montre que l'analyse d'objets vivant sur un arbre ultramétrique, en particulier, la diagonalisation par blocs d'une matrice M^{α β;γ^δ} dépendant de 4-répliques, se simplifie de façon dramatique si l'on introduit les opérations appropriées sur ces objets. Ce sont les Transformées de Fourier de Répliques sur un arbre ultramétrique. Ces transformations sont définies et utilisées dans le présent travail.

  4. Phonon replica dynamics in high quality GaN epilayers and AlGaN/GaN quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Alderighi, D.; Vinattieri, A.; Colocci, M. [Ist. Nazionale Fisica della Materia, Firenze (Italy); Dipt. di Fisica and LENS, Firenze (Italy); Bogani, F. [Ist. Nazionale Fisica della Materia, Firenze (Italy); Dipt. di Energetica, Firenze (Italy); Gottardo, S. [Dipt. di Fisica and LENS, Firenze (Italy); Grandjean, N.; Massies, J. [Centre de Recherche sur l' Hetero-Epitaxie et ses Applications, CNRS, Valbonne (France)

    2001-01-01

    We present an experimental study of the exciton and phonon replica dynamics in high quality GaN epilayers and AlGaN/GaN quantum wells (QW) by means of picosecond time-resolved photoluminescence (PL) measurements. A non-exponential decay is observed both at the zero phonon line (ZPL) and at the n = 1 LO replica. Time-resolved spectra unambiguously assign the replica to the free exciton A recombination. Optical migration effects are detected both in the epilayer and the QWs samples and disappear as the temperature increases up to 60-90 K. Even though the sample quality is comparable to state-of-the-art samples, localization effects dominate the exciton dynamics at low temperature in the studied GaN based structures. (orig.)

  5. Dynamical self-arrest in symmetric and asymmetric diblock copolymer melts using a replica approach within a local theory.

    Science.gov (United States)

    Wu, Sangwook

    2009-03-01

    We investigate dynamical self-arrest in a diblock copolymer melt using a replica approach within a self-consistent local method based on dynamical mean-field theory (DMFT). The local replica approach effectively predicts (chiN)_{A} for dynamical self-arrest in a block copolymer melt for symmetric and asymmetric cases. We discuss the competition of the cubic and quartic interactions in the Landau free energy for a block copolymer melt in stabilizing a glassy state depending on the chain length. Our local replica theory provides a universal value for the dynamical self-arrest in block copolymer melts with (chiN)_{A} approximately 10.5+64N;{-3/10} for the symmetric case.

  6. Human skulls with turquoise inlays: pre hispanic origin or replicas?

    International Nuclear Information System (INIS)

    Silva V, Y.; Castillo M, M.T.; Bautista M, J.P.; Arenas A, J.

    2006-01-01

    The lack of archaeological context determining if the manufacture of two human skulls adorned with turquoise inlays have pre-Columbian origin or not (replicas), led to perform other studies. Under these conditions, besides orthodox methodology commonly used to assign chronology and cultural aspects as form, style, decoration, iconography, etc., it was necessary to obtain more results based on the use of characterization techniques. The techniques employed were Scanning Electron Microscopy (SEM), X-Ray Energy Dispersive Spectroscopy (EDS), Transmission Electron Microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FTIR), in order to determine the manufacture techniques and chemical composition of the materials used for the cementant. SEM analysis showed the presence of zones composed by Ca, O, C and Al. In some cases Mg, Cl, Fe and Pb were identified. High concentration of Cu was present in all samples, due to residues of turquoise inlays (CuAI 6 (PO 4 ) 4 (OH) 8 (H 2 O) 4 ) with which the skulls were decorated. In the cementant was identified the Ca as base element of the cementant, as well as particles < 100 nm with irregular morphology and other amorphous zones. FTIR spectrums indicated the presence of organic substances that could be used as agglutinating in the cementant. The current work shows a progress identifying involved techniques in the manufacturing of two human skulls with turquoise inlays. (Author)

  7. Preserving the Boltzmann ensemble in replica-exchange molecular dynamics.

    Science.gov (United States)

    Cooke, Ben; Schmidler, Scott C

    2008-10-28

    We consider the convergence behavior of replica-exchange molecular dynamics (REMD) [Sugita and Okamoto, Chem. Phys. Lett. 314, 141 (1999)] based on properties of the numerical integrators in the underlying isothermal molecular dynamics (MD) simulations. We show that a variety of deterministic algorithms favored by molecular dynamics practitioners for constant-temperature simulation of biomolecules fail either to be measure invariant or irreducible, and are therefore not ergodic. We then show that REMD using these algorithms also fails to be ergodic. As a result, the entire configuration space may not be explored even in an infinitely long simulation, and the simulation may not converge to the desired equilibrium Boltzmann ensemble. Moreover, our analysis shows that for initial configurations with unfavorable energy, it may be impossible for the system to reach a region surrounding the minimum energy configuration. We demonstrate these failures of REMD algorithms for three small systems: a Gaussian distribution (simple harmonic oscillator dynamics), a bimodal mixture of Gaussians distribution, and the alanine dipeptide. Examination of the resulting phase plots and equilibrium configuration densities indicates significant errors in the ensemble generated by REMD simulation. We describe a simple modification to address these failures based on a stochastic hybrid Monte Carlo correction, and prove that this is ergodic.

  8. Accuracy of three-dimensional printing for manufacturing replica teeth.

    Science.gov (United States)

    Lee, Keun-Young; Cho, Jin-Woo; Chang, Na-Young; Chae, Jong-Moon; Kang, Kyung-Hwa; Kim, Sang-Cheol; Cho, Jin-Hyoung

    2015-09-01

    Three-dimensional (3D) printing is a recent technological development that may play a significant role in orthodontic diagnosis and treatment. It can be used to fabricate skull models or study models, as well as to make replica teeth in autotransplantation or tooth impaction cases. The aim of this study was to evaluate the accuracy of fabrication of replica teeth made by two types of 3D printing technologies. Fifty extracted molar teeth were selected as samples. They were scanned to generate high-resolution 3D surface model stereolithography files. These files were converted into physical models using two types of 3D printing technologies: Fused deposition modeling (FDM) and PolyJet technology. All replica teeth were scanned and 3D images generated. Computer software compared the replica teeth to the original teeth with linear measurements, volumetric measurements, and mean deviation measurements with best-fit alignment. Paired t-tests were used to statistically analyze the measurements. Most measurements of teeth formed using FDM tended to be slightly smaller, while those of the PolyJet replicas tended to be slightly larger, than those of the extracted teeth. Mean deviation measurements with best-fit alignment of FDM and PolyJet group were 0.047 mm and 0.038 mm, respectively. Although there were statistically significant differences, they were regarded as clinically insignificant. This study confirms that FDM and PolyJet technologies are accurate enough to be usable in orthodontic diagnosis and treatment.

  9. Foundations and latest advances in replica exchange transition interface sampling

    Science.gov (United States)

    Cabriolu, Raffaela; Skjelbred Refsnes, Kristin M.; Bolhuis, Peter G.; van Erp, Titus S.

    2017-10-01

    Nearly 20 years ago, transition path sampling (TPS) emerged as an alternative method to free energy based approaches for the study of rare events such as nucleation, protein folding, chemical reactions, and phase transitions. TPS effectively performs Monte Carlo simulations with relatively short molecular dynamics trajectories, with the advantage of not having to alter the actual potential energy surface nor the underlying physical dynamics. Although the TPS approach also introduced a methodology to compute reaction rates, this approach was for a long time considered theoretically attractive, providing the exact same results as extensively long molecular dynamics simulations, but still expensive for most relevant applications. With the increase of computer power and improvements in the algorithmic methodology, quantitative path sampling is finding applications in more and more areas of research. In particular, the transition interface sampling (TIS) and the replica exchange TIS (RETIS) algorithms have, in turn, improved the efficiency of quantitative path sampling significantly, while maintaining the exact nature of the approach. Also, open-source software packages are making these methods, for which implementation is not straightforward, now available for a wider group of users. In addition, a blooming development takes place regarding both applications and algorithmic refinements. Therefore, it is timely to explore the wide panorama of the new developments in this field. This is the aim of this article, which focuses on the most efficient exact path sampling approach, RETIS, as well as its recent applications, extensions, and variations.

  10. Critiques, replicas and proposals for the New Urbanism Vision

    Directory of Open Access Journals (Sweden)

    Alaide Retana

    2014-03-01

    Full Text Available The new urbanism (NU is a vision of planning and urban design emerged in 1993, which finds its basis in the design of traditional communities. This trend has had various criticisms and replicas, which were reviewed in relation to urban sprawl, transportation, re-densifying, mix of uses of land, design, gentrification, pedestrianization and safety, which were analyzed in the neighborhood of Santa Barbara in Toluca, Mexico. This area was chosen for being traditional and forming part of the historical center of the city, which even though it was not designed under the guidelines of the NU, it has the quality of traditional, from which the NU would theoretically has taken its essence. The objective of this analysis is to establish whether the NU has the essence of a traditional Mexican neighborhood, as well as to check if the criticisms of the NU are informed when applied to a space belonging to a Mexican historic center that has been abandoned by problems of insecurity and degradation. The general conclusion is that the traditional neighborhoods have provided design elements to the NU, which will refute some of the criticisms, however, proposals for NU in neighborhoods of his-toric centers have to be based on the community, the architecture and existing urbanism, since these elements are those that give the identity.

  11. Standard practice for production and evaluation of field metallographic replicas

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2001-01-01

    1.1 This practice covers recognized methods for the preparation and evaluation of cellulose acetate or plastic film replicas which have been obtained from metallographically prepared surfaces. It is designed for the evaluation of replicas to ensure that all significant features of a metallographically prepared surface have been duplicated and preserved on the replica with sufficient detail to permit both LM and SEM examination with optimum resolution and sensitivity. 1.2 This practice may be used as a controlling document in commercial situations. 1.3 The values stated in SI units are to be regarded as the standard. Inch-pound units given in parentheses are for information only. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  12. Replica sizing strategy for aortic valve replacement improves haemodynamic outcome of the epic supra valve.

    Science.gov (United States)

    Gonzalez-Lopez, David; Faerber, Gloria; Diab, Mahmoud; Amorim, Paulo; Zeynalov, Natig; Doenst, Torsten

    2017-10-01

    Current sizing strategies suggest valve selection based on annulus diameter despite supra-annular placement of biological prostheses potentially allowing placement of a larger size. We assessed the frequency of selecting a larger prosthesis if prosthesis size was selected using a replica (upsizing) and evaluated its impact on haemodynamics. We analysed all discharge echocardiograms between June 2012 and June 2014, where a replica sizer was used for isolated aortic valve replacement (Epic Supra: 266 patients, Trifecta: 49 patients). Upsizing was possible in 71% of the Epic Supra valves (by 1 size: 168, by 2 sizes: 20) and in 59% of the Trifectas (by 1 size: 26, by 2 sizes: 3). Patients for whom upsizing was possible had the lowest pressure gradients within their annulus size groups. The difference was significant in annulus diameters of 21-22 or 25-26 mm (Epic Supra) and 23-24 mm (Trifecta). Trifecta gradients were the lowest. However, the ability to upsize the Epic Supra by 2 sizes eliminated the differences between Epic Supra and Trifecta. Upsizing did not cause intraoperative complications. Using replica sizers for aortic prosthesis size selection allows the implantation of bigger prostheses than recommended in most cases and reduces postoperative gradients, specifically for Epic Supra. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  13. Effect of roughness and material strength on the mechanical properties of fracture replicas

    International Nuclear Information System (INIS)

    Wibowo, J.; Amadei, B.; Sture, S.

    1995-08-01

    This report presents the results of 11 rotary shear tests conducted on replicas of three hollow cylinders of natural fractures with JRC values of 7.7, 9.4 and 12.0. The JRC values were determined from the results of laser profilometer measurements. The replicas were created from gypsum cement. By varying the water-to-gypsum cement ratio from 30 to 45%, fracture replicas with different values of compressive strength (JCS) were created. The rotary shear experiments were performed under constant normal (nominal) stresses ranging between 0.2 and 1.6 MPa. In this report, the shear test results are compared with predictions using Barton's empirical peak shear strength equation. observations during the experiments indicate that only certain parts of the fracture profiles influence fracture shear strength and dilatancy. Under relatively low applied normal stresses, the JCS does not seem to have a significant effect on shear behavior. As an alternative, a new procedure for predicting the shear behavior of fractures was developed. The approach is based on basic fracture properties such as fracture surface profile data and the compressive strength, modulus of elasticity, and Poisson's ratio of the fracture walls. Comparison between predictions and actual shear test results shows that the alternative procedure is a reliable method

  14. Patrol Detection for Replica Attacks on Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Yang Shi

    2011-02-01

    Full Text Available Replica attack is a critical concern in the security of wireless sensor networks. We employ mobile nodes as patrollers to detect replicas distributed in different zones in a network, in which a basic patrol detection protocol and two detection algorithms for stationary and mobile modes are presented. Then we perform security analysis to discuss the defense strategies against the possible attacks on the proposed detection protocol. Moreover, we show the advantages of the proposed protocol by discussing and comparing the communication cost and detection probability with some existing methods.

  15. Replica scaling studies of hard missile impacts on reinforced concrete

    International Nuclear Information System (INIS)

    Barr, P.; Carter, P.G.; Howe, W.D.; Neilson, A.J.

    1982-01-01

    Missile and target combinations at three different liners scales have been used in an experimental assessment of the applicability of replica scaling to the dynamic behaviour of reinforced concrete structures impacted by rigid missiles. Experimental results are presented for models with relative linear scales of 1, 0.37 and 0.12. (orig.) [de

  16. Multiscale implementation of infinite-swap replica exchange molecular dynamics.

    Science.gov (United States)

    Yu, Tang-Qing; Lu, Jianfeng; Abrams, Cameron F; Vanden-Eijnden, Eric

    2016-10-18

    Replica exchange molecular dynamics (REMD) is a popular method to accelerate conformational sampling of complex molecular systems. The idea is to run several replicas of the system in parallel at different temperatures that are swapped periodically. These swaps are typically attempted every few MD steps and accepted or rejected according to a Metropolis-Hastings criterion. This guarantees that the joint distribution of the composite system of replicas is the normalized sum of the symmetrized product of the canonical distributions of these replicas at the different temperatures. Here we propose a different implementation of REMD in which (i) the swaps obey a continuous-time Markov jump process implemented via Gillespie's stochastic simulation algorithm (SSA), which also samples exactly the aforementioned joint distribution and has the advantage of being rejection free, and (ii) this REMD-SSA is combined with the heterogeneous multiscale method to accelerate the rate of the swaps and reach the so-called infinite-swap limit that is known to optimize sampling efficiency. The method is easy to implement and can be trivially parallelized. Here we illustrate its accuracy and efficiency on the examples of alanine dipeptide in vacuum and C-terminal β-hairpin of protein G in explicit solvent. In this latter example, our results indicate that the landscape of the protein is a triple funnel with two folded structures and one misfolded structure that are stabilized by H-bonds.

  17. Tunable Laser Plasma Accelerator based on Longitudinal Density Tailoring

    Energy Technology Data Exchange (ETDEWEB)

    Gonsalves, Anthony; Nakamura, Kei; Lin, Chen; Panasenko, Dmitriy; Shiraishi, Satomi; Sokollik, Thomas; Benedetti, Carlo; Schroeder, Carl; Geddes, Cameron; Tilborg, Jeroen van; Osterhoff, Jens; Esarey, Eric; Toth, Csaba; Leemans, Wim

    2011-07-15

    Laser plasma accelerators have produced high-quality electron beams with GeV energies from cm-scale devices and are being investigated as hyperspectral fs light sources producing THz to {gamma}-ray radiation and as drivers for future high-energy colliders. These applications require a high degree of stability, beam quality and tunability. Here we report on a technique to inject electrons into the accelerating field of a laser-driven plasma wave and coupling of this injector to a lower-density, separately tunable plasma for further acceleration. The technique relies on a single laser pulse powering a plasma structure with a tailored longitudinal density profile, to produce beams that can be tuned in the range of 100-400 MeV with percent-level stability, using laser pulses of less than 40 TW. The resulting device is a simple stand-alone accelerator or the front end for a multistage higher-energy accelerator.

  18. Localization-Free Detection of Replica Node Attacks in Wireless Sensor Networks Using Similarity Estimation with Group Deployment Knowledge

    Directory of Open Access Journals (Sweden)

    Chao Ding

    2017-01-01

    Full Text Available Due to the unattended nature and poor security guarantee of the wireless sensor networks (WSNs, adversaries can easily make replicas of compromised nodes, and place them throughout the network to launch various types of attacks. Such an attack is dangerous because it enables the adversaries to control large numbers of nodes and extend the damage of attacks to most of the network with quite limited cost. To stop the node replica attack, we propose a location similarity-based detection scheme using deployment knowledge. Compared with prior solutions, our scheme provides extra functionalities that prevent replicas from generating false location claims without deploying resource-consuming localization techniques on the resource-constraint sensor nodes. We evaluate the security performance of our proposal under different attack strategies through heuristic analysis, and show that our scheme achieves secure and robust replica detection by increasing the cost of node replication. Additionally, we evaluate the impact of network environment on the proposed scheme through theoretic analysis and simulation experiments, and indicate that our scheme achieves effectiveness and efficiency with substantially lower communication, computational, and storage overhead than prior works under different situations and attack strategies.

  19. A psychology based approach for longitudinal development in cognitive robotics

    Directory of Open Access Journals (Sweden)

    James eLaw

    2014-01-01

    Full Text Available A major challenge in robotics is the ability to learn, from novel experiences, new behaviour that is useful for achieving new goals and skills. Autonomous systems must be able to learn solely through the environment, thus ruling out a priori task knowledge, tuning, extensive training, or other forms of pre-programming. Learning must also be cumulative and incremental, as complex skills are built on top of primitive skills. Additionally, it must be driven by intrinsic motivation because formative experience is gained through autonomous activity, even in the absence of extrinsic goals or tasks. This paper presents an approach to these issues through robotic implementations inspired by the learning behaviour of human infants. We describe an approach to developmental learning and present results from a demonstration of longitudinal development on an iCub humanoid robot. The results cover the rapid emergence of staged behaviour, the role of constraints in development, the effect of bootstrapping between stages, and the use of a schema memory of experiential fragments in learning new skills. The context is a longitudinalexperiment in which the robot advanced from uncontrolled motor babbling to skilled hand/eyeintegrated reaching and basic manipulation of objects. This approach offers promise for furtherfast and effective sensory-motor learning techniques for robotic learning.

  20. Longitudinal Assessment of Progress in Reasoning Capacity and Relation with Self-Estimation of Knowledge Base

    Science.gov (United States)

    Collard, Anne; Mélot, France; Bourguignon, Jean-Pierre

    2015-01-01

    The aim of the study was to investigate progress in reasoning capacity and knowledge base appraisal in a longitudinal analysis of data from summative evaluation throughout a medical problem-based learning curriculum. The scores in multidisciplinary discussion of a clinical case and multiple choice questionnaires (MCQs) were studied longitudinally…

  1. The importance of longitudinal studies in family medicine: experiences of two practice-based research networks.

    NARCIS (Netherlands)

    Weel, C. van; Weel-Baumgarten, E.M. van; Mold, J.

    2006-01-01

    BACKGROUND: For evidence-based decision making in family practice, it is essential to know the long-term (natural) course of common diseases and their outcomes under care and treatment. This article, based on a research methodology workshop, aims to raise awareness and interest in longitudinal

  2. Enhanced Sampling in Molecular Dynamics Using Metadynamics, Replica-Exchange, and Temperature-Acceleration

    Directory of Open Access Journals (Sweden)

    Cameron Abrams

    2013-12-01

    Full Text Available We review a selection of methods for performing enhanced sampling in molecular dynamics simulations. We consider methods based on collective variable biasing and on tempering, and offer both historical and contemporary perspectives. In collective-variable biasing, we first discuss methods stemming from thermodynamic integration that use mean force biasing, including the adaptive biasing force algorithm and temperature acceleration. We then turn to methods that use bias potentials, including umbrella sampling and metadynamics. We next consider parallel tempering and replica-exchange methods. We conclude with a brief presentation of some combination methods.

  3. Physical replicas and the Bose glass in cold atomic gases

    International Nuclear Information System (INIS)

    Morrison, S; Kantian, A; Daley, A J; Zoller, P; Katzgraber, H G; Lewenstein, M; Buechler, H P

    2008-01-01

    We study cold atomic gases in a disorder potential and analyse the correlations between different systems subjected to the same disorder landscape. Such independent copies with the same disorder landscape are known as replicas. While, in general, these are not accessible experimentally in condensed matter systems, they can be realized using standard tools for controlling cold atomic gases in an optical lattice. Of special interest is the overlap function which represents a natural order parameter for disordered systems and is a correlation function between the atoms of two independent replicas with the same disorder. We demonstrate an efficient measurement scheme for the determination of this disorder-induced correlation function. As an application, we focus on the disordered Bose-Hubbard model and determine the overlap function within the perturbation theory and a numerical analysis. We find that the measurement of the overlap function allows for the identification of the Bose-glass phase in certain parameter regimes

  4. Physical replicas and the Bose glass in cold atomic gases

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, S; Kantian, A; Daley, A J; Zoller, P [Institute for Theoretical Physics, University of Innsbruck, Technikerstr. 25, A-6020 Innsbruck (Austria); Katzgraber, H G [Theoretische Physik, ETH Zurich, CH-8093 Zuerich (Switzerland); Lewenstein, M [ICAO-Institut de Ciencies Fotoniques, Parc Mediterrani de la Tecnologia, E-08860 Castelldefels, Barcelona (Spain); Buechler, H P [Institute for Theoretical Physics III, University of Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart (Germany)], E-mail: sarah.morrison@uibk.ac.at

    2008-07-15

    We study cold atomic gases in a disorder potential and analyse the correlations between different systems subjected to the same disorder landscape. Such independent copies with the same disorder landscape are known as replicas. While, in general, these are not accessible experimentally in condensed matter systems, they can be realized using standard tools for controlling cold atomic gases in an optical lattice. Of special interest is the overlap function which represents a natural order parameter for disordered systems and is a correlation function between the atoms of two independent replicas with the same disorder. We demonstrate an efficient measurement scheme for the determination of this disorder-induced correlation function. As an application, we focus on the disordered Bose-Hubbard model and determine the overlap function within the perturbation theory and a numerical analysis. We find that the measurement of the overlap function allows for the identification of the Bose-glass phase in certain parameter regimes.

  5. Replica approach to mean-variance portfolio optimization

    Science.gov (United States)

    Varga-Haszonits, Istvan; Caccioli, Fabio; Kondor, Imre

    2016-12-01

    We consider the problem of mean-variance portfolio optimization for a generic covariance matrix subject to the budget constraint and the constraint for the expected return, with the application of the replica method borrowed from the statistical physics of disordered systems. We find that the replica symmetry of the solution does not need to be assumed, but emerges as the unique solution of the optimization problem. We also check the stability of this solution and find that the eigenvalues of the Hessian are positive for r  =  N/T  optimal in-sample variance is found to vanish at the critical point inversely proportional to the divergent estimation error.

  6. Platinum replica electron microscopy: Imaging the cytoskeleton globally and locally.

    Science.gov (United States)

    Svitkina, Tatyana M

    2017-05-01

    Structural studies reveal how smaller components of a system work together as a whole. However, combining high resolution of details with full coverage of the whole is challenging. In cell biology, light microscopy can image many cells in their entirety, but at a lower resolution, whereas electron microscopy affords very high resolution, but usually at the expense of the sample size and coverage. Structural analyses of the cytoskeleton are especially demanding, because cytoskeletal networks are unresolvable by light microscopy due to their density and intricacy, whereas their proper preservation is a challenge for electron microscopy. Platinum replica electron microscopy can uniquely bridge the gap between the "comfort zones" of light and electron microscopy by allowing high resolution imaging of the cytoskeleton throughout the entire cell and in many cells in the population. This review describes the principles and applications of platinum replica electron microscopy for studies of the cytoskeleton. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2011-04-15

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

  8. Difficult Sudoku Puzzles Created by Replica Exchange Monte Carlo Method

    OpenAIRE

    Watanabe, Hiroshi

    2013-01-01

    An algorithm to create difficult Sudoku puzzles is proposed. An Ising spin-glass like Hamiltonian describing difficulty of puzzles is defined, and difficult puzzles are created by minimizing the energy of the Hamiltonian. We adopt the replica exchange Monte Carlo method with simultaneous temperature adjustments to search lower energy states efficiently, and we succeed in creating a puzzle which is the world hardest ever created in our definition, to our best knowledge. (Added on Mar. 11, the ...

  9. Replica treatment of the Calogero-Sutherland model

    International Nuclear Information System (INIS)

    Gangardt, Dimitry M.; Kamenev, Alex

    2001-01-01

    Employing Forrester-Ha method of Jack polynomials, we derive an integral identity connecting certain N-fold coordinate average of the Calogero-Sutherland model with the n-fold replica integral. Subsequent analytical continuation in n leads to asymptotic expressions for the (static and dynamic) density-density correlation function of the model as well as the Green's function for an arbitrary coupling constant λ

  10. Telemedicine-Based Burn Research Initiative: Longitudinal Outcomes of Patients

    National Research Council Canada - National Science Library

    Montalvo, Alfredo

    2003-01-01

    .... All instruments were professionally printed. The consultant for the project was hired and telemedicine equipment was evaluated by the consultant based on clinical requirements defined by the research team...

  11. Video-Based Interaction, Negotiation for Comprehensibility, and Second Language Speech Learning: A Longitudinal Study

    Science.gov (United States)

    Saito, Kazuya; Akiyama, Yuka

    2017-01-01

    This study examined the impact of video-based conversational interaction on the longitudinal development (one academic semester) of second language production by college-level Japanese English-as-a-foreign-language learners. Students in the experimental group engaged in weekly dyadic conversation exchanges with native speakers in the United States…

  12. Computer-Based Learning of Neuroanatomy: A Longitudinal Study of Learning, Transfer, and Retention

    Science.gov (United States)

    Chariker, Julia H.; Naaz, Farah; Pani, John R.

    2011-01-01

    A longitudinal experiment was conducted to evaluate the effectiveness of new methods for learning neuroanatomy with computer-based instruction. Using a three-dimensional graphical model of the human brain and sections derived from the model, tools for exploring neuroanatomy were developed to encourage "adaptive exploration". This is an…

  13. Towards longitudinal activity-based models of travel demand

    NARCIS (Netherlands)

    Arentze, T.A.; Timmermans, H.J.P.; Lo, H.P.; Leung, Stephen C.H.; Tan, Susanna M.L.

    2008-01-01

    Existing activity-based models of travel demand consider a day as the time unit of observation and predict activity patterns of inhviduals for a typical or average day. In this study we argue that the use of a time span of one day severely limits the ability of the models to predict responsive

  14. Replica exchange with solute tempering: A method for sampling biological systems in explicit water

    Science.gov (United States)

    Liu, Pu; Kim, Byungchan; Friesner, Richard A.; Berne, B. J.

    2005-09-01

    An innovative replica exchange (parallel tempering) method called replica exchange with solute tempering (REST) for the efficient sampling of aqueous protein solutions is presented here. The method bypasses the poor scaling with system size of standard replica exchange and thus reduces the number of replicas (parallel processes) that must be used. This reduction is accomplished by deforming the Hamiltonian function for each replica in such a way that the acceptance probability for the exchange of replica configurations does not depend on the number of explicit water molecules in the system. For proof of concept, REST is compared with standard replica exchange for an alanine dipeptide molecule in water. The comparisons confirm that REST greatly reduces the number of CPUs required by regular replica exchange and increases the sampling efficiency. This method reduces the CPU time required for calculating thermodynamic averages and for the ab initio folding of proteins in explicit water. Author contributions: B.J.B. designed research; P.L. and B.K. performed research; P.L. and B.K. analyzed data; and P.L., B.K., R.A.F., and B.J.B. wrote the paper.Abbreviations: REST, replica exchange with solute tempering; REM, replica exchange method; MD, molecular dynamics.*P.L. and B.K. contributed equally to this work.

  15. Research on FBG-based longitudinal-acousto-optic modulator with Fourier mode coupling method.

    Science.gov (United States)

    Li, Zhuoxuan; Pei, Li; Liu, Chao; Ning, Tigang; Yu, Shaowei

    2012-10-20

    Fourier mode coupling model was first applied to achieve the spectra property of a fiber Bragg grating (FBG)-based longitudinal-acousto-optic modulator. Compared with traditional analysis algorithms, such as the transfer matrix method, the Fourier mode coupling model could improve the computing efficiency up to 100 times with a guarantee of accuracy. In this paper, based on the theoretical analysis of this model, the spectra characteristics of the modulator in different frequencies and acoustically induced strains were numerically simulated. In the experiment, a uniform FBG was modulated by acoustic wave (AW) at 12 different frequencies. In particular, the modulator responses at 563 and 885.5 KHz with three different lead zirconate titanate (PZT) loads applied were plotted for illustration, and the linear fitting of experimental data demonstrated a good match with the simulation result. The acoustic excitation of the longitudinal wave is obtained using a conic silica horn attached to the surface of a shear-mode PZT plate paralleled to the fiber axis. This way of generating longitudinal AW with a transversal PZT may shed light on the optimal structural design for the FBG-based longitudinal-acousto-optic modulator.

  16. Software Replica of Minimal Living Processes

    Science.gov (United States)

    Bersini, Hugues

    2010-04-01

    There is a long tradition of software simulations in theoretical biology to complement pure analytical mathematics which are often limited to reproduce and understand the self-organization phenomena resulting from the non-linear and spatially grounded interactions of the huge number of diverse biological objects. Since John Von Neumann and Alan Turing pioneering works on self-replication and morphogenesis, proponents of artificial life have chosen to resolutely neglecting a lot of materialistic and quantitative information deemed not indispensable and have focused on the rule-based mechanisms making life possible, supposedly neutral with respect to their underlying material embodiment. Minimal life begins at the intersection of a series of processes which need to be isolated, differentiated and duplicated as such in computers. Only software developments and running make possible to understand the way these processes are intimately interconnected in order for life to appear at the crossroad. In this paper, I will attempt to set out the history of life as the disciples of artificial life understand it, by placing these different lessons on a temporal and causal axis, showing which one is indispensable to the appearance of the next and how does it connect to the next. I will discuss the task of artificial life as setting up experimental software platforms where these different lessons, whether taken in isolation or together, are tested, simulated, and, more systematically, analyzed. I will sketch some of these existing software platforms: chemical reaction networks, Varela’s autopoietic cellular automata, Ganti’s chemoton model, whose running delivers interesting take home messages to open-minded biologists.

  17. An instrument for the assessment of diarrhoeal severity based on a longitudinal community-based study

    Science.gov (United States)

    Lee, Gwenyth; Peñataro Yori, Pablo; Paredes Olortegui, Maribel; Caulfield, Laura E; Sack, David A; Fischer-Walker, Christa; Black, Robert E; Kosek, Margaret

    2014-01-01

    Objective Diarrhoea is a significant contributer to morbidity and is among the leading causes of death of children living in poverty. As such, the incidence, duration and severity of diarrhoeal episodes in the household are often key variables of interest in a variety of community-based studies. However, there currently exists no means of defining diarrhoeal severity that are (A) specifically designed and adapted for community-based studies, (B) associated with poorer child outcomes and (C) agreed on by the majority of researchers. Clinical severity scores do exist and are used in healthcare settings, but these tend to focus on relatively moderate-to-severe dehydrating and dysenteric disease, require trained observation of the child and, given the variability of access and utilisation of healthcare, fail to sufficiently describe the spectrum of disease in the community setting. Design Longitudinal cohort study. Setting Santa Clara de Nanay, a rural community in the Northern Peruvian Amazon. Participants 442 infants and children 0–72 months of age. Main outcome measures Change in weight over 1-month intervals and change in length/height over 9-month intervals. Results Diarrhoeal episodes with symptoms of fever, anorexia, vomiting, greater number of liquid stools per day and greater number of total stools per day were associated with poorer weight gain compared with episodes without these symptoms. An instrument to measure the severity was constructed based on the duration of these symptoms over the course of a diarrhoeal episode. Conclusions In order to address limitations of existing diarrhoeal severity scores in the context of community-based studies, we propose an instrument comprised of diarrhoea-associated symptoms easily measured by community health workers and based on the association of these symptoms with poorer child growth. This instrument can be used to test the impact of interventions on the burden of diarrhoeal disease. PMID:24907244

  18. Effect of boundary conditions on the strength and deformability of replicas of natural fractures in welded tuff: Comparison between predicted and observed shear behavior using a graphical method

    International Nuclear Information System (INIS)

    Wibowo, J.; Amadei, B.; Sture, S.; Robertson, A.B.

    1993-09-01

    Four series of cyclic direct-shear experiments were conducted on several replicas of three natural fractures and a laboratory-developed tensile fracture of welded tuff from Yucca Mountain to test the graphical load-displacement analysis method proposed by Saeb (1989) and Amadei and Saeb (1990). Based on the results of shear tests conducted on several joint replicas under different levels of constant normal load ranging between 0.6 and 25.6 kips (2.7 and 113.9 kN), the shear behavior of joint replicas under constant normal stiffness ranging between 14.8 and 187.5 kips/in. (25.9 and 328.1 kN/cm) was predicted by using the graphical method. The predictions were compared to the results of actual shear tests conducted for the same range of constant normal stiffness. In general, a good agreement was found between the predicted and the observed shear behavior

  19. How could the replica method improve accuracy of performance assessment of channel coding?

    Energy Technology Data Exchange (ETDEWEB)

    Kabashima, Yoshiyuki [Department of Computational Intelligence and Systems Science, Tokyo Institute of technology, Yokohama 226-8502 (Japan)], E-mail: kaba@dis.titech.ac.jp

    2009-12-01

    We explore the relation between the techniques of statistical mechanics and information theory for assessing the performance of channel coding. We base our study on a framework developed by Gallager in IEEE Trans. Inform. Theory IT-11, 3 (1965), where the minimum decoding error probability is upper-bounded by an average of a generalized Chernoff's bound over a code ensemble. We show that the resulting bound in the framework can be directly assessed by the replica method, which has been developed in statistical mechanics of disordered systems, whereas in Gallager's original methodology further replacement by another bound utilizing Jensen's inequality is necessary. Our approach associates a seemingly ad hoc restriction with respect to an adjustable parameter for optimizing the bound with a phase transition between two replica symmetric solutions, and can improve the accuracy of performance assessments of general code ensembles including low density parity check codes, although its mathematical justification is still open.

  20. Replica field theory for a polymer in random media

    International Nuclear Information System (INIS)

    Goldschmidt, Yadin Y.

    2000-01-01

    In this paper we revisit the problem of a (non-self-avoiding) polymer chain in a random medium which was previously investigated by Edwards and Muthukumar (EM) [J. Chem. Phys. 89, 2435 (1988)]. As noticed by Cates and Ball (CB) [J. Phys. (France) 49, 2009 (1988)] there is a discrepancy between the predictions of the replica calculation of EM and the expectation that in an infinite medium the quenched and annealed results should coincide (for a chain that is free to move) and a long polymer should always collapse. CB argued that only in a finite volume one might see a ''localization transition'' (or crossover) from a stretched to a collapsed chain in three spatial dimensions. Here we carry out the replica calculation in the presence of an additional confining harmonic potential that mimics the effect of a finite volume. Using a variational scheme with five variational parameters we derive analytically for d -1/(4-d) ∼(g ln V) -1/(4-d) , where R is the radius of gyration, g is the strength of the disorder, μ is the spring constant associated with the confining potential, and V is the associated effective volume of the system. Thus the EM result is recovered with their constant replaced by ln V as argued by CB. We see that in the strict infinite volume limit the polymer always collapses, but for finite volume a transition from a stretched to a collapsed form might be observed as a function of the strength of the disorder. For d V ' ∼exp(g 2/(2-d) L (4-d)/(2-d) ) the annealed results are recovered and R∼(Lg) 1/(d-2) , where L is the length of the polymer. Hence the polymer also collapses in the large L limit. The one-step replica symmetry breaking solution is crucial for obtaining the above results. (c) 2000 The American Physical Society

  1. Replica Approach for Minimal Investment Risk with Cost

    Science.gov (United States)

    Shinzato, Takashi

    2018-06-01

    In the present work, the optimal portfolio minimizing the investment risk with cost is discussed analytically, where an objective function is constructed in terms of two negative aspects of investment, the risk and cost. We note the mathematical similarity between the Hamiltonian in the mean-variance model and the Hamiltonians in the Hopfield model and the Sherrington-Kirkpatrick model, show that we can analyze this portfolio optimization problem by using replica analysis, and derive the minimal investment risk with cost and the investment concentration of the optimal portfolio. Furthermore, we validate our proposed method through numerical simulations.

  2. Replica Analysis for Portfolio Optimization with Single-Factor Model

    Science.gov (United States)

    Shinzato, Takashi

    2017-06-01

    In this paper, we use replica analysis to investigate the influence of correlation among the return rates of assets on the solution of the portfolio optimization problem. We consider the behavior of an optimal solution for the case where the return rate is described with a single-factor model and compare the findings obtained from our proposed methods with correlated return rates with those obtained with independent return rates. We then analytically assess the increase in the investment risk when correlation is included. Furthermore, we also compare our approach with analytical procedures for minimizing the investment risk from operations research.

  3. Application of extraction replicas and analytical electron microscopy to precipitate phase studies

    International Nuclear Information System (INIS)

    Kenik, E.A.; Maziasz, P.J.

    1984-01-01

    Extraction replicas provide a powerful extension of AEM techniques for analysis of fine precipitates. In many cases, replicas allow more accurate analyses to be performed and, in some cases, allow unique analyses which cannot be performed in-foil. However, there are limitations to the use of extraction replicas in AEM, of which the analyst must be aware. Many can be eliminated by careful preparation. Often, combined AEM studies of precipitates in-foil and on extraction replicas provide complementary and corroborative information for the fullest analysis of precipitate phases

  4. Replica calibration artefacts for optical 3D scanning of micro parts

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Carmignato, S.; Cantatore, Angela

    2009-01-01

    This work deals with development of calibration artefacts produced by using hard replica materials, achieving high quality geometrical reproduction of suitable reference artefacts, high stability, and high surface cooperativeness. An investigation was carried out using a replica material for dental...... applications to reproduce the geometry of a step artefact, a miniature step gauge, and a curve standard for optical measuring machines. The replica artefacts were calibrated using a tactile coordinate measuring machine and measured on two different optical scanners. Replication quality and applicability...... of the artefacts to verify the accuracy of optical measurements as well as thermal expansion coefficient and stability of the replica artefacts over time were documented....

  5. Using the multi-objective optimization replica exchange Monte Carlo enhanced sampling method for protein-small molecule docking.

    Science.gov (United States)

    Wang, Hongrui; Liu, Hongwei; Cai, Leixin; Wang, Caixia; Lv, Qiang

    2017-07-10

    In this study, we extended the replica exchange Monte Carlo (REMC) sampling method to protein-small molecule docking conformational prediction using RosettaLigand. In contrast to the traditional Monte Carlo (MC) and REMC sampling methods, these methods use multi-objective optimization Pareto front information to facilitate the selection of replicas for exchange. The Pareto front information generated to select lower energy conformations as representative conformation structure replicas can facilitate the convergence of the available conformational space, including available near-native structures. Furthermore, our approach directly provides min-min scenario Pareto optimal solutions, as well as a hybrid of the min-min and max-min scenario Pareto optimal solutions with lower energy conformations for use as structure templates in the REMC sampling method. These methods were validated based on a thorough analysis of a benchmark data set containing 16 benchmark test cases. An in-depth comparison between MC, REMC, multi-objective optimization-REMC (MO-REMC), and hybrid MO-REMC (HMO-REMC) sampling methods was performed to illustrate the differences between the four conformational search strategies. Our findings demonstrate that the MO-REMC and HMO-REMC conformational sampling methods are powerful approaches for obtaining protein-small molecule docking conformational predictions based on the binding energy of complexes in RosettaLigand.

  6. Prevalence, Incidence, and Resolution of Nocturnal Polyuria in a Longitudinal Community-based Study in Older Men : The Krimpen Study

    NARCIS (Netherlands)

    van Doorn, Boris; Blanker, Marco H.; Kok, Esther T.; Westers, Paul; Bosch, J. L. H. Ruud

    Background: Nocturnal polyuria (NP) is common in older men and can lead to nocturia. However, no longitudinal data are available on the natural history of NP. Objective: To determine prevalence, incidence, and resolution rates of NP. Design, setting, and participants: A longitudinal, community-based

  7. Application of carbon extraction replicas in grain-size measurements of high-strength steels using TEM

    International Nuclear Information System (INIS)

    Poorhaydari, Kioumars; Ivey, Douglas G.

    2007-01-01

    In this paper, the application of carbon extraction replicas in grain-size measurements is introduced and discussed. Modern high-strength microalloyed steels, used as structural or pipeline materials, have very small grains with substructures. Replicas used in transmission electron microscopes can resolve the grain boundaries and can be used for systematic measurement of grain size in cases where the small size of the grains pushes the resolution of conventional optical microscopes. The grain-size variations obtained from replicas are compared with those obtained from optical and scanning electron microscopy. An emphasis is placed on the importance of using the correct technique for imaging and the optimal magnification. Grain-size measurements are used for estimation of grain-boundary strengthening contribution to yield strength. The variation in grain size is also correlated with hardness in the base metal of several microalloyed steels, as well as the fine-grained heat-affected zone of a weld structure with several heat inputs

  8. Longitudinal Diffusion Tensor Imaging-Based Assessment of Tract Alterations: An Application to Amyotrophic Lateral Sclerosis

    Directory of Open Access Journals (Sweden)

    Dobri Baldaranov

    2017-12-01

    Full Text Available Objective: The potential of magnetic resonance imaging (MRI as a technical biomarker for cerebral microstructural alterations in neurodegenerative diseases is under investigation. In this study, a framework for the longitudinal analysis of diffusion tensor imaging (DTI-based mapping was applied to the assessment of predefined white matter tracts in amyotrophic lateral sclerosis (ALS, as an example for a rapid progressive neurodegenerative disease.Methods: DTI was performed every 3 months in six patients with ALS (mean (M = 7.7; range 3 to 15 scans and in six controls (M = 3; range 2–5 scans with the identical scanning protocol, resulting in a total of 65 longitudinal DTI datasets. Fractional anisotropy (FA, mean diffusivity (MD, axonal diffusivity (AD, radial diffusivity (RD, and the ratio AD/RD were studied to analyze alterations within the corticospinal tract (CST which is a prominently affected tract structure in ALS and the tract correlating with Braak’s neuropathological stage 1. A correlation analysis was performed between progression rates based on DTI metrics and the revised ALS functional rating scale (ALS-FRS-R.Results: Patients with ALS showed an FA and AD/RD decline along the CST, while DTI metrics of controls did not change in longitudinal DTI scans. The FA and AD/RD decrease progression correlated significantly with ALS-FRS-R decrease progression.Conclusion: On the basis of the longitudinal assessment, DTI-based metrics can be considered as a possible noninvasive follow-up marker for disease progression in neurodegeneration. This finding was demonstrated here for ALS as a fast progressing neurodegenerative disease.

  9. Longitudinal Diffusion Tensor Imaging-Based Assessment of Tract Alterations: An Application to Amyotrophic Lateral Sclerosis.

    Science.gov (United States)

    Baldaranov, Dobri; Khomenko, Andrei; Kobor, Ines; Bogdahn, Ulrich; Gorges, Martin; Kassubek, Jan; Müller, Hans-Peter

    2017-01-01

    Objective : The potential of magnetic resonance imaging (MRI) as a technical biomarker for cerebral microstructural alterations in neurodegenerative diseases is under investigation. In this study, a framework for the longitudinal analysis of diffusion tensor imaging (DTI)-based mapping was applied to the assessment of predefined white matter tracts in amyotrophic lateral sclerosis (ALS), as an example for a rapid progressive neurodegenerative disease. Methods : DTI was performed every 3 months in six patients with ALS (mean (M) = 7.7; range 3 to 15 scans) and in six controls ( M = 3; range 2-5 scans) with the identical scanning protocol, resulting in a total of 65 longitudinal DTI datasets. Fractional anisotropy (FA), mean diffusivity (MD), axonal diffusivity (AD), radial diffusivity (RD), and the ratio AD/RD were studied to analyze alterations within the corticospinal tract (CST) which is a prominently affected tract structure in ALS and the tract correlating with Braak's neuropathological stage 1. A correlation analysis was performed between progression rates based on DTI metrics and the revised ALS functional rating scale (ALS-FRS-R). Results : Patients with ALS showed an FA and AD/RD decline along the CST, while DTI metrics of controls did not change in longitudinal DTI scans. The FA and AD/RD decrease progression correlated significantly with ALS-FRS-R decrease progression. Conclusion : On the basis of the longitudinal assessment, DTI-based metrics can be considered as a possible noninvasive follow-up marker for disease progression in neurodegeneration. This finding was demonstrated here for ALS as a fast progressing neurodegenerative disease.

  10. A research about characteristics of longitudinal variations of ES layers irregularities based on CHAMP occultation measurements

    Science.gov (United States)

    Liao, Sunmin

    2018-04-01

    Based on the data of CHAMP occultation measurements, this paper makes a preliminary analysis of the longitudinal variations of ES irregular structure by using Fourier decomposition and reconstruction technique. It is found that the longitudinal variations of the ES irregular structure show the features of multiple wave-numbers, which is dominated by the wave number 1 to the wave number 5 components, and decrease from the amplitudes of the wave number 6 components. The features of wave number structures are very different in different DIP latitude and different seasons. The number of crests in summer and autumn is mostly 3 or 4 crest structures, while the number of crests in spring achieves 5 at DIP 15°N with small fluctuates, the crests number of winter is the least. In the multiple wave-numbers structure, the wave number 4 component shows a significant dependence on the season, mainly in the summer and autumn, particularly obvious from July to October.

  11. Computer-based learning in neuroanatomy: A longitudinal study of learning, transfer, and retention

    Science.gov (United States)

    Chariker, Julia H.

    A longitudinal experiment was conducted to explore computer-based learning of neuroanatomy. Using a realistic 3D graphical model of neuroanatomy, and sections derived from the model, exploratory graphical tools were integrated into interactive computer programs so as to allow adaptive exploration. 72 participants learned either sectional anatomy alone or learned whole anatomy followed by sectional anatomy. Sectional anatomy was explored either in perceptually continuous animation or discretely, as in the use of an anatomical atlas. Learning was measured longitudinally to a high performance criterion. After learning, transfer to biomedical images and long-term retention was tested. Learning whole anatomy prior to learning sectional anatomy led to a more efficient learning experience. Learners demonstrated high levels of transfer from whole anatomy to sectional anatomy and from sectional anatomy to complex biomedical images. All learning groups demonstrated high levels of retention at 2--3 weeks.

  12. Broken symmetry in the mean field theory of the ising spin glass: replica way and no replica way

    International Nuclear Information System (INIS)

    De Dominicis, C.

    1983-06-01

    We review the type of symmetry breaking involved in the solution discovered by Parisi and in the static derivation of the solution first introduced via dynamics by Sompolinsky. We turn to a formulation of the problem due to Thouless, Anderson and Palmer (TAP) that put a set of equations for the magnetization. A probability law for the magnetization is then built. We consider two cases: (i) a canonical distribution which is shown to give indentical results to the Hamiltonian formulation under a weak and physical assumption and (ii) a white distribution characterized by two matrices and a response. We show what symmetry breaking is necessary to recover Sompolinsky free energy. In section III we supplement replica indices in the Hamiltonian approach by ''time'' indices ans show in particular that the analytic continuation involved in Sompolinsky's equilibrium derivation, is trying to mimick a translational symmetry breaking in ''time'' that incorporates Sompolinsky's ansatz of a long time scale sequence. In section IV we apply the same treatment to the white average approach and show that, replicas can be altogether discorded and replaced by ''time''. Finally, we briefly discuss the attribution of distinct answers for the standard spin glass order parameter depending on the physical situation: equilibrium or non equilibrium associated with canonical or white (non canonical) initial conditions and density matrices

  13. Fabrication of free-standing replicas of fragile, laminar, chitinous biotemplates

    International Nuclear Information System (INIS)

    Lakhtakia, Akhlesh; Motyka, Michael A; MartIn-Palma, Raul J; Pantano, Carlo G

    2009-01-01

    The conformal-evaporated-film-by-rotation technique, followed by the dissolution of chitin in an aqueous solution of orthophosphoric acid, can be used to fabricate free-standing replicas of fragile, laminar, chitinous biotemplates. This novel approach was demonstrated using butterfly wings as biotemplates and GeSeSb chalcogenide glass for replicas. (communication)

  14. Fabrication of free-standing replicas of fragile, laminar, chitinous biotemplates

    Energy Technology Data Exchange (ETDEWEB)

    Lakhtakia, Akhlesh; Motyka, Michael A [Materials Research Institute and Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, PA 16802 (United States); MartIn-Palma, Raul J; Pantano, Carlo G [Materials Research Institute and Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States)], E-mail: akhlesh@psu.edu

    2009-09-01

    The conformal-evaporated-film-by-rotation technique, followed by the dissolution of chitin in an aqueous solution of orthophosphoric acid, can be used to fabricate free-standing replicas of fragile, laminar, chitinous biotemplates. This novel approach was demonstrated using butterfly wings as biotemplates and GeSeSb chalcogenide glass for replicas. (communication)

  15. A Novel General Chemistry Laboratory: Creation of Biomimetic Superhydrophobic Surfaces through Replica Molding

    Science.gov (United States)

    Verbanic, Samuel; Brady, Owen; Sanda, Ahmed; Gustafson, Carolina; Donhauser, Zachary J.

    2014-01-01

    Biomimetic replicas of superhydrophobic lotus and taro leaf surfaces can be made using polydimethylsiloxane. These replicas faithfully reproduce the microstructures of the leaves' surface and can be analyzed using contact angle goniometry, self-cleaning experiments, and optical microscopy. These simple and adaptable experiments were used to…

  16. Replica analysis for the duality of the portfolio optimization problem.

    Science.gov (United States)

    Shinzato, Takashi

    2016-11-01

    In the present paper, the primal-dual problem consisting of the investment risk minimization problem and the expected return maximization problem in the mean-variance model is discussed using replica analysis. As a natural extension of the investment risk minimization problem under only a budget constraint that we analyzed in a previous study, we herein consider a primal-dual problem in which the investment risk minimization problem with budget and expected return constraints is regarded as the primal problem, and the expected return maximization problem with budget and investment risk constraints is regarded as the dual problem. With respect to these optimal problems, we analyze a quenched disordered system involving both of these optimization problems using the approach developed in statistical mechanical informatics and confirm that both optimal portfolios can possess the primal-dual structure. Finally, the results of numerical simulations are shown to validate the effectiveness of the proposed method.

  17. Replica analysis for the duality of the portfolio optimization problem

    Science.gov (United States)

    Shinzato, Takashi

    2016-11-01

    In the present paper, the primal-dual problem consisting of the investment risk minimization problem and the expected return maximization problem in the mean-variance model is discussed using replica analysis. As a natural extension of the investment risk minimization problem under only a budget constraint that we analyzed in a previous study, we herein consider a primal-dual problem in which the investment risk minimization problem with budget and expected return constraints is regarded as the primal problem, and the expected return maximization problem with budget and investment risk constraints is regarded as the dual problem. With respect to these optimal problems, we analyze a quenched disordered system involving both of these optimization problems using the approach developed in statistical mechanical informatics and confirm that both optimal portfolios can possess the primal-dual structure. Finally, the results of numerical simulations are shown to validate the effectiveness of the proposed method.

  18. Beyond Virtual Replicas: 3D Modeling and Maltese Prehistoric Architecture

    Directory of Open Access Journals (Sweden)

    Filippo Stanco

    2013-01-01

    Full Text Available In the past decade, computer graphics have become strategic for the development of projects aimed at the interpretation of archaeological evidence and the dissemination of scientific results to the public. Among all the solutions available, the use of 3D models is particularly relevant for the reconstruction of poorly preserved sites and monuments destroyed by natural causes or human actions. These digital replicas are, at the same time, a virtual environment that can be used as a tool for the interpretative hypotheses of archaeologists and as an effective medium for a visual description of the cultural heritage. In this paper, the innovative methodology and aims and outcomes of a virtual reconstruction of the Borg in-Nadur megalithic temple, carried out by Archeomatica Project of the University of Catania, are offered as a case study for a virtual archaeology of prehistoric Malta.

  19. Pion emission from the T2K replica target: method, results and application

    CERN Document Server

    Abgrall, N.; Anticic, T.; Antoniou, N.; Argyriades, J.; Baatar, B.; Blondel, A.; Blumer, J.; Bogomilov, M.; Bravar, A.; Brooks, W.; Brzychczyk, J.; Bubak, A.; Bunyatov, S.A.; Busygina, O.; Christakoglou, P.; Chung, P.; Czopowicz, T.; Davis, N.; Debieux, S.; Di Luise, S.; Dominik, W.; Dumarchez, J.; Dynowski, K.; Engel, R.; Ereditato, A.; Esposito, L.S.; Feofilov, G.A.; Fodor, Z.; Ferrero, A.; Fulop, A.; Gazdzicki, M.; Golubeva, M.; Grabez, B.; Grebieszkow, K.; Grzeszczuk, A.; Guber, F.; Haesler, A.; Hakobyan, H.; Hasegawa, T.; Idczak, R.; Igolkin, S.; Ivanov, Y.; Ivashkin, A.; Kadija, K.; Kapoyannis, A.; Katrynska, N.; Kielczewska, D.; Kikola, D.; Kirejczyk, M.; Kisiel, J.; Kiss, T.; Kleinfelder, S.; Kobayashi, T.; Kochebina, O.; Kolesnikov, V.I.; Kolev, D.; Kondratiev, V.P.; Korzenev, A.; Kowalski, S.; Krasnoperov, A.; Kuleshov, S.; Kurepin, A.; Lacey, R.; Larsen, D.; Laszlo, A.; Lyubushkin, V.V.; Mackowiak-Pawlowska, M.; Majka, Z.; Maksiak, B.; Malakhov, A.I.; Maletic, D.; Marchionni, A.; Marcinek, A.; Maris, I.; Marin, V.; Marton, K.; Matulewicz, T.; Matveev, V.; Melkumov, G.L.; Messina, M.; Mrowczynski, St.; Murphy, S.; Nakadaira, T.; Nishikawa, K.; Palczewski, T.; Palla, G.; Panagiotou, A.D.; Paul, T.; Peryt, W.; Petukhov, O.; Planeta, R.; Pluta, J.; Popov, B.A.; Posiadala, M.; Pulawski, S.; Puzovic, J.; Rauch, W.; Ravonel, M.; Renfordt, R.; Robert, A.; Rohrich, D.; Rondio, E.; Rossi, B.; Roth, M.; Rubbia, A.; Rustamov, A.; Rybczynski, M.; Sadovsky, A.; Sakashita, K.; Savic, M.; Sekiguchi, T.; Seyboth, P.; Shibata, M.; Sipos, M.; Skrzypczak, E.; Slodkowski, M.; Staszel, P.; Stefanek, G.; Stepaniak, J.; Strabel, C.; Strobele, H.; Susa, T.; Szuba, M.; Tada, M.; Taranenko, A.; Tereshchenko, V.; Tolyhi, T.; Tsenov, R.; Turko, L.; Ulrich, R.; Unger, M.; Vassiliou, M.; Veberic, D.; Vechernin, V.V.; Vesztergombi, G.; Wilczek, A.; Wlodarczyk, Z.; Wojtaszek-Szwarc, A.; Wyszynski, O.; Zambelli, L.; Zipper, W.; Hartz, M.; Ichikawa, A.K.; Kubo, H.; Marino, A.D.; Matsuoka, K.; Murakami, A.; Nakaya, T.; Suzuki, K.; Yuan, T.; Zimmerman, E.D.

    2013-01-01

    The T2K long-baseline neutrino oscillation experiment in Japan needs precise predictions of the initial neutrino flux. The highest precision can be reached based on detailed measurements of hadron emission from the same target as used by T2K exposed to a proton beam of the same kinetic energy of 30 GeV. The corresponding data were recorded in 2007-2010 by the NA61/SHINE experiment at the CERN SPS using a replica of the T2K graphite target. In this paper details of the experiment, data taking, data analysis method and results from the 2007 pilot run are presented. Furthermore, the application of the NA61/SHINE measurements to the predictions of the T2K initial neutrino flux is described and discussed.

  20. Behavioural responses of dogs to asymmetrical tail wagging of a robotic dog replica.

    Science.gov (United States)

    Artelle, K A; Dumoulin, L K; Reimchen, T E

    2011-03-01

    Recent evidence suggests that bilateral asymmetry in the amplitude of tail wagging of domestic dogs (Canis familiaris) is associated with approach (right wag) versus withdrawal (left wag) motivation and may be the by-product of hemispheric dominance. We consider whether such asymmetry in motion of the tail, a crucial appendage in intra-specific communication in all canids, provides visual information to a conspecific leading to differential behaviour. To evaluate this, we experimentally investigated the approach behaviour of free-ranging dogs to the asymmetric tail wagging of a life-size robotic dog replica. Our data, involving 452 separate interactions, showed a significantly greater proportion of dogs approaching the model continuously without stopping when the tail wagged to the left, compared with a right wag, which was more likely to yield stops. While the results indicate that laterality of a wagging tail provides behavioural information to conspecifics, the responses are not readily integrated into the predicted behaviour based on hemispheric dominance.

  1. Stress evaluation of metallic material under steady state based on nonlinear critically refracted longitudinal wave

    Science.gov (United States)

    Mao, Hanling; Zhang, Yuhua; Mao, Hanying; Li, Xinxin; Huang, Zhenfeng

    2018-06-01

    This paper presents the study of applying the nonlinear ultrasonic wave to evaluate the stress state of metallic materials under steady state. The pre-stress loading method is applied to guarantee components with steady stress. Three kinds of nonlinear ultrasonic experiments based on critically refracted longitudinal wave are conducted on components which the critically refracted longitudinal wave propagates along x, x1 and x2 direction. Experimental results indicate the second and third order relative nonlinear coefficients monotonically increase with stress, and the normalized relationship is consistent with simplified dislocation models, which indicates the experimental result is logical. The combined ultrasonic nonlinear parameter is proposed, and three stress evaluation models at x direction are established based on three ultrasonic nonlinear parameters, which the estimation error is below 5%. Then two stress detection models at x1 and x2 direction are built based on combined ultrasonic nonlinear parameter, the stress synthesis method is applied to calculate the magnitude and direction of principal stress. The results show the prediction error is within 5% and the angle deviation is within 1.5°. Therefore the nonlinear ultrasonic technique based on LCR wave could be applied to nondestructively evaluate the stress of metallic materials under steady state which the magnitude and direction are included.

  2. Gamma-ray spectra and doses from the Little Boy replica

    International Nuclear Information System (INIS)

    Moss, C.E.; Lucas, M.C.; Tisinger, E.W.; Hamm, M.E.

    1984-01-01

    Most radiation safety guidelines in the nuclear industry are based on the data concerning the survivors of the nuclear explosions at Hiroshima and Nagasaki. Crucial to determining these guidelines is the radiation from the explosions. We have measured gamma-ray pulse-height distributions from an accurate replica of the Little Boy device used at Hiroshima, operated at low power levels near critical. The device was placed outdoors on a stand 4 m from the ground to minimize environmental effects. The power levels were based on a monitor detector calibrated very carefully in independent experiments. High-resolution pulse-height distributions were acquired with a germanium detector to identify the lines and to obtain line intensities. The 7631 to 7645 keV doublet from neutron capture in the heavy steel case was dominant. Low-resolution pulse-height distributions were acquired with bismuth-germanate detectors. We calculated flux spectra from these distributions using accurately measured detector response functions and efficiency curves. We then calculated dose-rate spectra from the flux spectra using a flux-to-dose-rate conversion procedure. The integral of each dose-rate spectrum gave an integral dose rate. The integral doses at 2 m ranged from 0.46 to 1.03 mrem per 10 13 fissions. The output of the Little Boy replica can be calculated with Monte Carlo codes. Comparison of our experimental spectra, line intensities, and integral doses can be used to verify these calculations at low power levels and give increased confidence to the calculated values from the explosion at Hiroshima. These calculations then can be used to establish better radiation safety guidelines. 7 references, 7 figures, 2 tables

  3. Dynamic Boundaries of Action Based Learning: the Longitudinal Impact (Invited Paper

    Directory of Open Access Journals (Sweden)

    D. Song

    2015-08-01

    Full Text Available How do communities and group-based efforts create, learn and evolve? This paper argues that communities are dynamic, continuously creating connections through cyclical learning processes, regardless of how tight or loosely formulated group based efforts are (Hall et al. 2012. Learning cycles or epicycles processes are relevant for action-based investigation within organizational and social structures. The question of behaviors across boundaries or groups maybe influenced by their positioning within a larger adaptive system, including the type of focus, determined goals and the type of connections that have been developed over time (longitudinally. These types of community or group efforts can be described as autopoietic systems, which operate within larger adaptive societal webs (Nousala 2014. The learning methodologies involved in investigating these types of dynamic phenomena need themselves to be dynamic. These methods can be viewed through longitudinal cycles, (which are essentially feedback loops that include extensive reflective time lines, integration before repetition exposing these epicycles at work. The continuous recording of various processes through epicycles (which are the basis for learning cycles provide a means to "qualitatively measuring" change, which would normally go unseen (Hall et. al 2012; Hall et al. 2005; Nousala and Hall 2008; Wenger and Synder 2000; Garduno et al. 2015.

  4. Capabilities of R Package mixAK for Clustering Based on Multivariate Continuous and Discrete Longitudinal Data

    Directory of Open Access Journals (Sweden)

    Arnošt Komárek

    2014-09-01

    Full Text Available R package mixAK originally implemented routines primarily for Bayesian estimation of finite normal mixture models for possibly interval-censored data. The functionality of the package was considerably enhanced by implementing methods for Bayesian estimation of mixtures of multivariate generalized linear mixed models proposed in Komrek and Komrkov (2013. Among other things, this allows for a cluster analysis (classification based on multivariate continuous and discrete longitudinal data that arise whenever multiple outcomes of a different nature are recorded in a longitudinal study. This package also allows for a data-driven selection of a number of clusters as methods for selecting a number of mixture components were implemented. A model and clustering methodology for multivariate continuous and discrete longitudinal data is overviewed. Further, a step-by-step cluster analysis based jointly on three longitudinal variables of different types (continuous, count, dichotomous is given, which provides a user manual for using the package for similar problems.

  5. Longitudinal population-based studies of affective disorders: Where to from here?

    Directory of Open Access Journals (Sweden)

    Beard John R

    2008-09-01

    Full Text Available Abstract Background Longitudinal, population-based, research is important if we are to better characterize the lifetime patterns and determinants of affective disorders. While studies of this type are becoming increasingly prevalent, there has been little discussion about the limitations of the methods commonly used. Methods Discussion paper including a brief review of key prospective population-based studies as the basis for a critical appraisal of current approaches. Results We identified a number of common methodological weaknesses that restrict the potential of longitudinal research to characterize the diversity, prognosis, and determinants of affective disorders over time. Most studies using comprehensive diagnostic instruments have either been of relatively brief duration, or have suffered from long periods between waves. Most etiologic research has focused on first onset diagnoses, although these may be relatively uncommon after early adulthood and the burden of mental disorders falls more heavily on individuals with recurring disorders. Analysis has tended to be based on changes in diagnostic status rather than anges in symptom levels, limiting study power. Diagnoses have generally been treated as homogeneous entities and few studies have explored whether diagnostic subtypes such as atypical depression vary in their etiology or prognosis. Little research has considered whether there are distinct trajectories of symptoms over time and most has focused on individual disorders such as depression, rather than considering the relationship over time between symptoms of different affective disorders. There has also been limited longitudinal research on factors in the physical or social environment that may influence the onset, recurrence or chronicity of symptoms. Conclusion Many important, and in some respects quite basic, questions remain about the trajectory of depression and anxiety disorders over the life course and the factors that

  6. The use of extraction and electronic diffraction replicas for precipitates characterization in welded Cr-Mo Steels

    International Nuclear Information System (INIS)

    Gutierrez de Saiz-Solabarria, S.; San Juan Nunez, J.M.

    1997-01-01

    The precipitates and phases found in the structure of welded joints of Heat Interchanges Tubes were studied and identified. The base material satisfied the requirements of ASME Sec II, SA 213 Gr T22 (2 1/4 Cr 1 Mo). Compositions of Filler Metals were: 2 1/4 Cr 1 Mo and 2 1/4 Cr 1 Mo 1/4 Nb. The chemical composition of base and weld materials were analyzed by atomic emission spectroscopy in high vacuum electric discharge and by inductive plasma coupled. For the constituents characterization extraction and diffraction microscopy replicas were used. (Author) 65 refs

  7. Internal structure analysis of particle-double network gels used in a gel organ replica

    Science.gov (United States)

    Abe, Mei; Arai, Masanori; Saito, Azusa; Sakai, Kazuyuki; Kawakami, Masaru; Furukawa, Hidemitsu

    2016-04-01

    In recent years, the fabrication of patient organ replicas using 3D printers has been attracting a great deal of attention in medical fields. However, the cost of these organ replicas is very high as it is necessary to employ very expensive 3D printers and printing materials. Here we present a new gel organ replica, of human kidney, fabricated with a conventional molding technique, using a particle-double network hydrogel (P-DN gel). The replica is transparent and has the feel of a real kidney. It is expected that gel organ replicas produced this way will be a useful tool for the education of trainee surgeons and clinical ultrasonography technologists. In addition to developing a gel organ replica, the internal structure of the P-DN gel used is also discussed. Because the P-DN gel has a complex structure comprised of two different types of network, it has not been possible to investigate them internally in detail. Gels have an inhomogeneous network structure. If it is able to get a more uniform structure, it is considered that this would lead to higher strength in the gel. In the present study we investigate the structure of P-DN gel, using the gel organ replica. We investigated the internal structure of P-DN gel using Scanning Microscopic Light Scattering (SMILS), a non-contacting and non-destructive.

  8. Fabrication of the replica templated from butterfly wing scales with complex light trapping structures

    Science.gov (United States)

    Han, Zhiwu; Li, Bo; Mu, Zhengzhi; Yang, Meng; Niu, Shichao; Zhang, Junqiu; Ren, Luquan

    2015-11-01

    The polydimethylsiloxane (PDMS) positive replica templated twice from the excellent light trapping surface of butterfly Trogonoptera brookiana wing scales was fabricated by a simple and promising route. The exact SiO2 negative replica was fabricated by using a synthesis method combining a sol-gel process and subsequent selective etching. Afterwards, a vacuum-aided process was introduced to make PDMS gel fill into the SiO2 negative replica, and the PDMS gel was solidified in an oven. Then, the SiO2 negative replica was used as secondary template and the structures in its surface was transcribed onto the surface of PDMS. At last, the PDMS positive replica was obtained. After comparing the PDMS positive replica and the original bio-template in terms of morphology, dimensions and reflectance spectra and so on, it is evident that the excellent light trapping structures of butterfly wing scales were inherited by the PDMS positive replica faithfully. This bio-inspired route could facilitate the preparation of complex light trapping nanostructure surfaces without any assistance from other power-wasting and expensive nanofabrication technologies.

  9. New force replica exchange method and protein folding pathways probed by force-clamp technique.

    Science.gov (United States)

    Kouza, Maksim; Hu, Chin-Kun; Li, Mai Suan

    2008-01-28

    We have developed a new extended replica exchange method to study thermodynamics of a system in the presence of external force. Our idea is based on the exchange between different force replicas to accelerate the equilibrium process. This new approach was applied to obtain the force-temperature phase diagram and other thermodynamical quantities of the three-domain ubiquitin. Using the C(alpha)-Go model and the Langevin dynamics, we have shown that the refolding pathways of single ubiquitin depend on which terminus is fixed. If the N end is fixed then the folding pathways are different compared to the case when both termini are free, but fixing the C terminal does not change them. Surprisingly, we have found that the anchoring terminal does not affect the pathways of individual secondary structures of three-domain ubiquitin, indicating the important role of the multidomain construction. Therefore, force-clamp experiments, in which one end of a protein is kept fixed, can probe the refolding pathways of a single free-end ubiquitin if one uses either the polyubiquitin or a single domain with the C terminus anchored. However, it is shown that anchoring one end does not affect refolding pathways of the titin domain I27, and the force-clamp spectroscopy is always capable to predict folding sequencing of this protein. We have obtained the reasonable estimate for unfolding barrier of ubiquitin, using the microscopic theory for the dependence of unfolding time on the external force. The linkage between residue Lys48 and the C terminal of ubiquitin is found to have the dramatic effect on the location of the transition state along the end-to-end distance reaction coordinate, but the multidomain construction leaves the transition state almost unchanged. We have found that the maximum force in the force-extension profile from constant velocity force pulling simulations depends on temperature nonlinearly. However, for some narrow temperature interval this dependence becomes

  10. Long-time atomistic simulations with the Parallel Replica Dynamics method

    Science.gov (United States)

    Perez, Danny

    Molecular Dynamics (MD) -- the numerical integration of atomistic equations of motion -- is a workhorse of computational materials science. Indeed, MD can in principle be used to obtain any thermodynamic or kinetic quantity, without introducing any approximation or assumptions beyond the adequacy of the interaction potential. It is therefore an extremely powerful and flexible tool to study materials with atomistic spatio-temporal resolution. These enviable qualities however come at a steep computational price, hence limiting the system sizes and simulation times that can be achieved in practice. While the size limitation can be efficiently addressed with massively parallel implementations of MD based on spatial decomposition strategies, allowing for the simulation of trillions of atoms, the same approach usually cannot extend the timescales much beyond microseconds. In this article, we discuss an alternative parallel-in-time approach, the Parallel Replica Dynamics (ParRep) method, that aims at addressing the timescale limitation of MD for systems that evolve through rare state-to-state transitions. We review the formal underpinnings of the method and demonstrate that it can provide arbitrarily accurate results for any definition of the states. When an adequate definition of the states is available, ParRep can simulate trajectories with a parallel speedup approaching the number of replicas used. We demonstrate the usefulness of ParRep by presenting different examples of materials simulations where access to long timescales was essential to access the physical regime of interest and discuss practical considerations that must be addressed to carry out these simulations. Work supported by the United States Department of Energy (U.S. DOE), Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division.

  11. A Probabilistic Framework for Constructing Temporal Relations in Replica Exchange Molecular Trajectories.

    Science.gov (United States)

    Chattopadhyay, Aditya; Zheng, Min; Waller, Mark Paul; Priyakumar, U Deva

    2018-05-23

    Knowledge of the structure and dynamics of biomolecules is essential for elucidating the underlying mechanisms of biological processes. Given the stochastic nature of many biological processes, like protein unfolding, it's almost impossible that two independent simulations will generate the exact same sequence of events, which makes direct analysis of simulations difficult. Statistical models like Markov Chains, transition networks etc. help in shedding some light on the mechanistic nature of such processes by predicting long-time dynamics of these systems from short simulations. However, such methods fall short in analyzing trajectories with partial or no temporal information, for example, replica exchange molecular dynamics or Monte Carlo simulations. In this work we propose a probabilistic algorithm, borrowing concepts from graph theory and machine learning, to extract reactive pathways from molecular trajectories in the absence of temporal data. A suitable vector representation was chosen to represent each frame in the macromolecular trajectory (as a series of interaction and conformational energies) and dimensionality reduction was performed using principal component analysis (PCA). The trajectory was then clustered using a density-based clustering algorithm, where each cluster represents a metastable state on the potential energy surface (PES) of the biomolecule under study. A graph was created with these clusters as nodes with the edges learnt using an iterative expectation maximization algorithm. The most reactive path is conceived as the widest path along this graph. We have tested our method on RNA hairpin unfolding trajectory in aqueous urea solution. Our method makes the understanding of the mechanism of unfolding in RNA hairpin molecule more tractable. As this method doesn't rely on temporal data it can be used to analyze trajectories from Monte Carlo sampling techniques and replica exchange molecular dynamics (REMD).

  12. Longitudinal assessment of grey matter contraction in amyotrophic lateral sclerosis: A tensor based morphometry study.

    Science.gov (United States)

    Agosta, Federica; Gorno-Tempini, Maria Luisa; Pagani, Elisabetta; Sala, Stefania; Caputo, Domenico; Perini, Michele; Bartolomei, Ilaria; Fruguglietti, Maria Elena; Filippi, Massimo

    2009-06-01

    Our objective was to investigate grey matter (GM) contraction in patients with amyotrophic lateral sclerosis (ALS) using tensor based morphometry (TBM). Using a 1.5 Tesla scanner, T1-weighted MRI scans were obtained at baseline and at follow-up (mean interval, 9 months) from 16 ALS and 10 controls. Standard TBM procedures in Statistical Parametric Mapping (SPM2) were used for image processing and statistical analyses. The frontotemporal cortex and basal ganglia were considered areas of interest, based on pathological studies. Eight patients showed rapid clinical progression of ALS during the follow-up period. Compared to controls, all ALS patients showed progression of GM atrophy in left premotor cortex and right basal ganglia. Patients with rapidly progressing ALS showed GM atrophy changes in a larger motor cortical-subcortical area and in extramotor frontal regions compared to both controls and to non-rapidly progressing cases. Thus, TBM detected longitudinal atrophy changes in the motor network in ALS occurring over less than one year. The faster the clinical progression, the greater was the GM loss in motor and prefrontal areas. Further advances in tracking longitudinal changes in cortical and subcortical regions in ALS may provide an objective marker for monitoring disease progression, and the disease-modifying effect of potential treatments.

  13. Understanding the Longitudinal Variability of Equatorial Electrodynamics using integrated Ground- and Space-based Observations

    Science.gov (United States)

    Yizengaw, E.; Moldwin, M.; Zesta, E.

    2015-12-01

    The currently funded African Meridian B-Field Education and Research (AMBER) magnetometer array comprises more than thirteen magnetometers stationed globally in the vicinity of geomagnetic equator. One of the main objectives of AMBER network is to understand the longitudinal variability of equatorial electrodynamics as function of local time, magnetic activity, and season. While providing complete meridian observation in the region and filling the largest land-based gap in global magnetometer coverage, the AMBER array addresses two fundamental areas of space physics: first, the processes governing electrodynamics of the equatorial ionosphere as a function of latitude (or L-shell), local time, longitude, magnetic activity, and season, and second, ULF pulsation strength at low/mid-latitude regions and its connection with equatorial electrojet and density fluctuation. The global AMBER network can also be used to augment observations from space-based instruments, such us the triplet SWARM mission and the upcoming ICON missions. Thus, in coordination with space-based and other ground-based observations, the AMBER magnetometer network provides a great opportunity to understand the electrodynamics that governs equatorial ionosphere motions. In this paper we present the longitudinal variability of the equatorial electrodynamics using the combination of instruments onboard SWARM and C/NOFS satellites and ground-based AMBER network. Both ground- and pace-based observations show stronger dayside and evening sector equatorial electrodynamics in the American and Asian sectors compared to the African sector. On the other hand, the African sector is home to stronger and year-round ionospheric bubbles/irregularities compared to the American and Asian sectors. This raises the question if the evening sector equatorial electrodynamics (vertical drift), which is believed to be the main cause for the enhancement of Rayleigh-Taylor (RT) instability growth rate, is stronger in the

  14. Commissioning of FPGA-based Transverse and Longitudinal Bunch-by-Bunch Feedback System for the TLS

    International Nuclear Information System (INIS)

    Hu, K. H.; Kuo, C. H.; Lau, W. K.; Yeh, M. S.; Hsu, S. Y.; Chou, P. J.; Wang, M. H.; Lee, Demi; Chen, Jenny; Wang, C. J.; Hsu, K. T.; Kobayashi, K.; Nakamura, T.; Dehler, M.

    2006-01-01

    Multi-bunch instabilities deteriorate beam quality, increasing beam emittance, or even causing beam loss in the synchrotron light source. The feedback system is essential to suppress multi-bunch instabilities caused by the impedances of beam ducts, and trapped ions. A new FPGA based transverse and longitudinal bunch-by-bunch feedback system have been commissioned at the Taiwan Light Source recently, A single feedback loop is used to simultaneously suppress the horizontal and the vertical multi-bunch instabilities. Longitudinal instabilities caused by cavity-like structures are suppressed by the longitudinal feedback loop. The same FPGA processor is employed in the transverse feedback and the longitudinal feedback system respectively. Diagnostic memory is included in the system to capture the bunch oscillation signal, which supports various studies

  15. Neural-Based Compensation of Nonlinearities in an Airplane Longitudinal Model with Dynamic-Inversion Control

    Directory of Open Access Journals (Sweden)

    YanBin Liu

    2017-01-01

    Full Text Available The inversion design approach is a very useful tool for the complex multiple-input-multiple-output nonlinear systems to implement the decoupling control goal, such as the airplane model and spacecraft model. In this work, the flight control law is proposed using the neural-based inversion design method associated with the nonlinear compensation for a general longitudinal model of the airplane. First, the nonlinear mathematic model is converted to the equivalent linear model based on the feedback linearization theory. Then, the flight control law integrated with this inversion model is developed to stabilize the nonlinear system and relieve the coupling effect. Afterwards, the inversion control combined with the neural network and nonlinear portion is presented to improve the transient performance and attenuate the uncertain effects on both external disturbances and model errors. Finally, the simulation results demonstrate the effectiveness of this controller.

  16. Project-based learning in the teaching-learning process university. A longitudinal study

    Directory of Open Access Journals (Sweden)

    Sandoval Hamón Leyla Angélica

    2017-01-01

    Full Text Available The European Higher Education Area promotes the change in teaching-learning, where students have a more active role in their educational process. The main objective of this work is to analyse the use of an alternative proposal, focus in student-based teamwork activities, who seek to favour the acquisition and deepening of knowledge and skills. The implementation of this research was carried out by means of a longitudinal study in the subject of the degree of Economics, with the development of the methodology of Project Based Learning integrating the ICTs and improving the evaluation process (e.g. establishing headings and psychometric analysis of knowledge tests. The results of the research showed an improvement in the learning process from the observation, collection of works, analysis of knowledge tests and the official survey by students to assess the activity and the development of their competitors.

  17. Robust Longitudinal Aircraft- Control Based on an Adaptive Fuzzy-Logic Algorithm

    Directory of Open Access Journals (Sweden)

    Abdel- Latif Elshafei

    2002-06-01

    Full Text Available To study the aircraft response to a fast pull-up manoeuvre, a short period approximation of the longitudinal model is considered. The model is highly nonlinear and includes parametric uncertainties. To cope with a wide range of command signals, a robust adaptive fuzzy logic controller is proposed. The proposed controller adopts a dynamic inversion approach. Since feedback linearization is practically imperfect, robustifying and adaptive components are included in the control law to compensate for modeling errors and achieve acceptable tracking errors. Two fuzzy systems are implemented. The first system models the nominal values of the system’s nonlinearity. The second system is an adaptive one that compensates for modeling errors. The derivation of the control law based on a dynamic game approach is given in detail. Stability of the closed-loop control system is also verified. Simulation results based on an F16-model illustrate a successful tracking performance of the proposed controller.

  18. Electric Vehicle Longitudinal Stability Control Based on a New Multimachine Nonlinear Model Predictive Direct Torque Control

    Directory of Open Access Journals (Sweden)

    M’hamed Sekour

    2017-01-01

    Full Text Available In order to improve the driving performance and the stability of electric vehicles (EVs, a new multimachine robust control, which realizes the acceleration slip regulation (ASR and antilock braking system (ABS functions, based on nonlinear model predictive (NMP direct torque control (DTC, is proposed for four permanent magnet synchronous in-wheel motors. The in-wheel motor provides more possibilities of wheel control. One of its advantages is that it has low response time and almost instantaneous torque generation. Moreover, it can be independently controlled, enhancing the limits of vehicular control. For an EV equipped with four in-wheel electric motors, an advanced control may be envisaged. Taking advantage of the fast and accurate torque of in-wheel electric motors which is directly transmitted to the wheels, a new approach for longitudinal control realized by ASR and ABS is presented in this paper. In order to achieve a high-performance torque control for EVs, the NMP-DTC strategy is proposed. It uses the fuzzy logic control technique that determines online the accurate values of the weighting factors and generates the optimal switching states that optimize the EV drives’ decision. The simulation results built in Matlab/Simulink indicate that the EV can achieve high-performance vehicle longitudinal stability control.

  19. Older adults' experiences of internet-based vestibular rehabilitation for dizziness: A longitudinal study.

    Science.gov (United States)

    Essery, Rosie; Kirby, Sarah; Geraghty, Adam W A; Yardley, Lucy

    2017-11-01

    Factors influencing engagement with self-managed rehabilitation are not well understood, but evidence suggests they may change over time. Despite increasing digitalisation of self-managed interventions, little is known about the role of internet-based interventions in patients' experiences of self-directed rehabilitation. This longitudinal qualitative study investigated individuals' ongoing experiences of internet-guided, self-managed rehabilitation within the context of rehabilitation for dizziness. Eighteen adults aged fifty and over who experienced dizziness used the 'Balance Retraining' internet intervention for six weeks. Participants took part in semi-structured telephone interviews at two-week intervals to explore their experiences. Data were inductively thematically analysed. The internet intervention was reported to facilitate engagement with rehabilitation exercises, providing motivation to continue through symptom reduction and simple but helpful strategies. It was perceived as informative, reassuring, visually pleasing and easy to use. Barriers to engagement included practicalities, symptoms and doubts about exercise efficacy. Participants' perceptions did not always remain consistent over time. The internet intervention may be a feasible method of supporting self-managed vestibular rehabilitation. More generally, longitudinal findings suggest that appearance-related perceptions of online interventions may be especially important for initial engagement. Furthermore, intervention features targeting self-efficacy seem important in overcoming barriers to engagement.

  20. Serum Uric Acid Levels and Risk of Incident Hypertriglyceridemia: A Longitudinal Population-based Epidemiological Study.

    Science.gov (United States)

    Zheng, Rongjiong; Ren, Ping; Chen, Qingmei; Yang, Tianmeng; Chen, Changxi; Mao, Yushan

    2017-09-01

    Hypertriglyceridemia is one of lipid metabolism abnormalities; however, it is still debatable whether serum uric acid is a cause or a consequence of hypertriglyceridemia. We performed the study to investigate the longitudinal association between serum uric acid levels and hypertriglyceridemia. The study included 4190 subjects without hypertriglyceridemia. The subjects had annual health examinations for 8 years to assess incident hyperglyceridemia, and the subjects were divided into groups based on the serum uric acid quartile. Cox regression models were used to analyze the risk factors of development hypertriglyceridemia. During follow-up, 1461 (34.9%) subjects developed hypertriglyceridemia over 8 years of follow-up. The cumulative incidence of hypertriglyceridemia was 28.2%, 29.1%, 36.9%, and 45.6% in quartile 1,2,3 and 4, respectively ( P for trend uric acid levels were independently and positively associated with the risk of incident hypertriglyceridemia. Hypertriglyceridemia has become a serious public health problem. This longitudinal study demonstrates that high serum uric acid levels increase the risk of hypertriglyceridemia. © 2017 by the Association of Clinical Scientists, Inc.

  1. Adapting an evidence-based model to retain adolescent study participants in longitudinal research.

    Science.gov (United States)

    Davis, Erin; Demby, Hilary; Jenner, Lynne Woodward; Gregory, Alethia; Broussard, Marsha

    2016-02-01

    Maintaining contact with and collecting outcome data from adolescent study participants can present a significant challenge for researchers conducting longitudinal studies. Establishing an organized and effective protocol for participant follow-up is crucial to reduce attrition and maintain high retention rates. This paper describes our methods in using and adapting the evidence-based Engagement, Verification, Maintenance, and Confirmation (EVMC) model to follow up with adolescents 6 and 12 months after implementation of a health program. It extends previous research by focusing on two key modifications to the model: (1) the central role of cell phones and texting to maintain contact with study participants throughout the EVMC process and, (2) use of responsive two-way communication between staff and participants and flexible administration modes and methods in the confirmation phase to ensure that busy teens not only respond to contacts, but also complete data collection. These strategies have resulted in high overall retention rates (87-91%) with adolescent study participants at each follow-up data collection point without the utilization of other, more involved tracking measures. The methods and findings presented may be valuable for other researchers with limited resources planning for or engaged in collecting follow-up outcome data from adolescents enrolled in longitudinal studies. Copyright © 2015. Published by Elsevier Ltd.

  2. Parylene C coating for high-performance replica molding.

    Science.gov (United States)

    Heyries, Kevin A; Hansen, Carl L

    2011-12-07

    This paper presents an improvement to the soft lithography fabrication process that uses chemical vapor deposition of poly(chloro-p-xylylene) (parylene C) to protect microfabricated masters and to improve the release of polymer devices following replica molding. Chemical vapor deposition creates nanometre thick conformal coatings of parylene C on silicon wafers having arrays of 30 μm high SU8 pillars with densities ranging from 278 to 10,040 features per mm(2) and aspect ratios (height : width) from 1 : 1 to 6 : 1. A single coating of parylene C was sufficient to permanently promote poly(dimethyl)siloxane (PDMS) mold release and to protect masters for an indefinite number of molding cycles. We also show that the improved release properties of parylene treated masters allow for fabrication with hard polymers, such as poly(urethane), that would otherwise not be compatible with SU8 on silicon masters. Parylene C provides a robust and high performance mold release coating for soft lithography microfabrication that extends the life of microfabricated masters and improves the achievable density and aspect ratio of replicated features.

  3. Replica Exchange Simulations of the Thermodynamics of Aβ Fibril Growth

    Science.gov (United States)

    Takeda, Takako; Klimov, Dmitri K.

    2009-01-01

    Abstract Replica exchange molecular dynamics and an all-atom implicit solvent model are used to probe the thermodynamics of deposition of Alzheimer's Aβ monomers on preformed amyloid fibrils. Consistent with the experiments, two deposition stages have been identified. The docking stage occurs over a wide temperature range, starting with the formation of the first peptide-fibril interactions at 500 K. Docking is completed when a peptide fully adsorbs on the fibril edge at the temperature of 380 K. The docking transition appears to be continuous, and occurs without free energy barriers or intermediates. During docking, incoming Aβ monomer adopts a disordered structure on the fibril edge. The locking stage occurs at the temperature of ≈360 K and is characterized by the rugged free energy landscape. Locking takes place when incoming Aβ peptide forms a parallel β-sheet structure on the fibril edge. Because the β-sheets formed by locked Aβ peptides are typically off-registry, the structure of the locked phase differs from the structure of the fibril interior. The study also reports that binding affinities of two distinct fibril edges with respect to incoming Aβ peptides are different. The peptides bound to the concave edge have significantly lower free energy compared to those bound on the convex edge. Comparison with the available experimental data is discussed. PMID:19167295

  4. Stability and replica symmetry in the ising spin glass: a toy model

    International Nuclear Information System (INIS)

    De Dominicis, C.; Mottishaw, P.

    1986-01-01

    Searching for possible replica symmetric solutions in an Ising spin glass (in the tree approximation) we investigate a toy model whose bond distribution has two non vanishing cumulants (instead of one only as in a gaussian distribution)

  5. Designed-walk replica-exchange method for simulations of complex systems

    OpenAIRE

    Urano, Ryo; Okamoto, Yuko

    2015-01-01

    We propose a new implementation of the replica-exchange method (REM) in which replicas follow a pre-planned route in temperature space instead of a random walk. Our method satisfies the detailed balance condition in the proposed route. The method forces tunneling events between the highest and lowest temperatures to happen with an almost constant period. The number of tunneling counts is proportional to that of the random-walk REM multiplied by the square root of moving distance in temperatur...

  6. Utility of replica techniques for x-ray microanalysis of second phase particles

    International Nuclear Information System (INIS)

    Bentley, J.

    1984-01-01

    X-ray microanalysis of second phase particles in ion-milled or electropolished thin foils is often complicated by the presence of the matrix nearby. Extraction replica techniques provide a means to avoid many of the complications of thin-foil analyses. In this paper, three examples of the analysis of second phase particles are described and illustrate the improvement obtained by the use of extraction replicas for qualitative analysis, quantitative analysis, and analysis of radioactive specimens

  7. Getting Personal with Teacher Burnout: A Longitudinal Study on the Development of Burnout Using a Person-Based Approach

    Science.gov (United States)

    Hultell, Daniel; Melin, Bo; Gustavsson, J. Petter

    2013-01-01

    Studies have suggested that teachers' burnout levels are stable over time. This might be because longitudinal studies on burnout have mainly used a variable-based approach. The purpose of this study was to determine if a person-based approach could provide a more multifaceted perspective to the development of teacher burnout. 816 beginning…

  8. Calculation of absolute protein-ligand binding free energy using distributed replica sampling.

    Science.gov (United States)

    Rodinger, Tomas; Howell, P Lynne; Pomès, Régis

    2008-10-21

    Distributed replica sampling [T. Rodinger et al., J. Chem. Theory Comput. 2, 725 (2006)] is a simple and general scheme for Boltzmann sampling of conformational space by computer simulation in which multiple replicas of the system undergo a random walk in reaction coordinate or temperature space. Individual replicas are linked through a generalized Hamiltonian containing an extra potential energy term or bias which depends on the distribution of all replicas, thus enforcing the desired sampling distribution along the coordinate or parameter of interest regardless of free energy barriers. In contrast to replica exchange methods, efficient implementation of the algorithm does not require synchronicity of the individual simulations. The algorithm is inherently suited for large-scale simulations using shared or heterogeneous computing platforms such as a distributed network. In this work, we build on our original algorithm by introducing Boltzmann-weighted jumping, which allows moves of a larger magnitude and thus enhances sampling efficiency along the reaction coordinate. The approach is demonstrated using a realistic and biologically relevant application; we calculate the standard binding free energy of benzene to the L99A mutant of T4 lysozyme. Distributed replica sampling is used in conjunction with thermodynamic integration to compute the potential of mean force for extracting the ligand from protein and solvent along a nonphysical spatial coordinate. Dynamic treatment of the reaction coordinate leads to faster statistical convergence of the potential of mean force than a conventional static coordinate, which suffers from slow transitions on a rugged potential energy surface.

  9. Electron-longitudinal-acoustic-phonon scattering in double-quantum-dot based quantum gates

    International Nuclear Information System (INIS)

    Zhao Peiji; Woolard, Dwight L.

    2008-01-01

    We propose a nanostructure design which can significantly suppress longitudinal-acoustic-phonon-electron scattering in double-quantum-dot based quantum gates for quantum computing. The calculated relaxation rates vs. bias voltage exhibit a double-peak feature with a minimum approaching 10 5 s -1 . In this matter, the energy conservation law prohibits scattering contributions from phonons with large momenta; furthermore, increasing the barrier height between the double quantum dots reduces coupling strength between the dots. Hence, the joint action of the energy conservation law and the decoupling greatly reduces the scattering rates. The degrading effects of temperatures can be reduced simply by increasing the height of the barrier between the dots

  10. Robust stabilization control based on guardian maps theory for a longitudinal model of hypersonic vehicle.

    Science.gov (United States)

    Liu, Yanbin; Liu, Mengying; Sun, Peihua

    2014-01-01

    A typical model of hypersonic vehicle has the complicated dynamics such as the unstable states, the nonminimum phases, and the strong coupling input-output relations. As a result, designing a robust stabilization controller is essential to implement the anticipated tasks. This paper presents a robust stabilization controller based on the guardian maps theory for hypersonic vehicle. First, the guardian maps theories are provided to explain the constraint relations between the open subsets of complex plane and the eigenvalues of the state matrix of closed-loop control system. Then, a general control structure in relation to the guardian maps theories is proposed to achieve the respected design demands. Furthermore, the robust stabilization control law depending on the given general control structure is designed for the longitudinal model of hypersonic vehicle. Finally, a simulation example is provided to verify the effectiveness of the proposed methods.

  11. Risk factors for common mental disorders in women. Population-based longitudinal study.

    Science.gov (United States)

    Patel, Vikram; Kirkwood, Betty R; Pednekar, Sulochana; Weiss, Helen; Mabey, David

    2006-12-01

    The determinants of common mental disorders in women have not been described in longitudinal studies from a low-income country. Population-based cohort study of 2494 women aged 18 to 50 years, in India. The Revised Clinical Interview Schedule was used for the detection of common mental disorders. There were 39 incident cases of common mental disorder in 2166 participants eligible for analysis (12-month rate 1.8%, 95% CI 1.3-2.4%). The following baseline factors were independently associated with the risk for common mental disorder: poverty (low income and having difficulty making ends meet); being married as compared with being single; use of tobacco; experiencing abnormal vaginal discharge; reporting a chronic physical illness; and having higher psychological symptom scores at baseline. Programmes to reduce the burden of common mental disorder in women should target poorer women, women with chronic physical illness and who have gynaecological symptoms, and women who use tobacco.

  12. A tensor based morphometry study of longitudinal gray matter contraction in FTD

    Science.gov (United States)

    Brambati, Simona M.; Renda, Natasha C.; Rankin, Katherine P.; Rosen, Howard J.; Seeley, William W.; Ashburner, John; Weiner, Michael W.; Miller, Bruce L.; Gorno-Tempini, Maria Luisa

    2008-01-01

    Frontotemporal dementia (FTD) is a neurodegenerative disease characterized by progressive behavioural abnormalities and frontotemporal atrophy. Here we used tensor based morphometry (TBM) to identify regions of longitudinal progression of gray matter atrophy in FTD compared to controls. T1-weighted MRI images were acquired at presentation and 1-year follow-up from 12 patients with mild to moderate FTD and 12 healthy controls. Using TBM as implemented in SPM2, a voxel-wise estimation of regional tissue volume change was derived from the deformation field required to warp a subject’s late to early anatomical images. A whole brain analysis was performed, in which a level of significance of pBased on prior studies, a region of interest (ROI) analysis was also performed, including in the search area bilateral medial and orbital frontal regions, anterior cingulate gyrus, insula, amygdala and hippocampus. Within this ROI a level of significance of p<0.001 uncorrected was accepted. In the whole brain analysis, the anterior cingulate/paracingulate gyri were the only regions that showed significant atrophy change over 1 year. In the ROI analysis, the left ventro-medial frontal cortex, right medial superior frontal gyrus, anterior insulae and left amygdala/hippocampus showed significant longitudinal changes. In conclusion, limbic and paralimbic regions showed detectable gray matter contraction over 1 year in FTD, confirming the susceptibility of these regions to the disease and the consistency with their putative role in causing typical presenting behaviours. These results suggest that TBM might be useful in tracking progression of regional atrophy in FTD. PMID:17350290

  13. Disruption of brain anatomical networks in schizophrenia: A longitudinal, diffusion tensor imaging based study.

    Science.gov (United States)

    Sun, Yu; Chen, Yu; Lee, Renick; Bezerianos, Anastasios; Collinson, Simon L; Sim, Kang

    2016-03-01

    Despite convergent neuroimaging evidence indicating a wide range of brain abnormalities in schizophrenia, our understanding of alterations in the topological architecture of brain anatomical networks and how they are modulated over time, is still rudimentary. Here, we employed graph theoretical analysis of longitudinal diffusion tensor imaging data (DTI) over a 5-year period to investigate brain network topology in schizophrenia and its relationship with clinical manifestations of the illness. Using deterministic tractography, weighted brain anatomical networks were constructed from 31 patients experiencing schizophrenia and 28 age- and gender-matched healthy control subjects. Although the overall small-world characteristics were observed at both baseline and follow-up, a scan-point independent significant deficit of global integration was found in patients compared to controls, suggesting dysfunctional integration of the brain and supporting the notion of schizophrenia as a disconnection syndrome. Specifically, several brain regions (e.g., the inferior frontal gyrus and the bilateral insula) that are crucial for cognitive and emotional integration were aberrant. Furthermore, a significant group-by-longitudinal scan interaction was revealed in the characteristic path length and global efficiency, attributing to a progressive aberration of global integration in patients compared to healthy controls. Moreover, the progressive disruptions of the brain anatomical network topology were associated with the clinical symptoms of the patients. Together, our findings provide insights into the substrates of anatomical dysconnectivity patterns for schizophrenia and highlight the potential for connectome-based metrics as neural markers of illness progression and clinical change with treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. An Evidence-based, Longitudinal Curriculum for Resident Physician Wellness: The 2017 Resident Wellness Consensus Summit.

    Science.gov (United States)

    Arnold, Jacob; Tango, Jennifer; Walker, Ian; Waranch, Chris; McKamie, Joshua; Poonja, Zafrina; Messman, Anne

    2018-03-01

    Physicians are at much higher risk for burnout, depression, and suicide than their non-medical peers. One of the working groups from the May 2017 Resident Wellness Consensus Summit (RWCS) addressed this issue through the development of a longitudinal residency curriculum to address resident wellness and burnout. A 30-person (27 residents, three attending physicians) Wellness Curriculum Development workgroup developed the curriculum in two phases. In the first phase, the workgroup worked asynchronously in the Wellness Think Tank - an online resident community - conducting a literature review to identify 10 core topics. In the second phase, the workgroup expanded to include residents outside the Wellness Think Tank at the live RWCS event to identify gaps in the curriculum. This resulted in an additional seven core topics. Seventeen foundational topics served as the framework for the longitudinal resident wellness curriculum. The curriculum includes a two-module introduction to wellness; a seven-module "Self-Care Series" focusing on the appropriate structure of wellness activities and everyday necessities that promote physician wellness; a two-module section on physician suicide and self-help; a four-module "Clinical Care Series" focusing on delivering bad news, navigating difficult patient encounters, dealing with difficult consultants and staff members, and debriefing traumatic events in the emergency department; wellness in the workplace; and dealing with medical errors and shame. The resident wellness curriculum, derived from an evidence-based approach and input of residents from the Wellness Think Tank and the RWCS event, provides a guiding framework for residency programs in emergency medicine and potentially other specialties to improve physician wellness and promote a culture of wellness.

  15. An Evidence-based, Longitudinal Curriculum for Resident Physician Wellness: The 2017 Resident Wellness Consensus Summit

    Directory of Open Access Journals (Sweden)

    Jacob Arnold

    2018-02-01

    Full Text Available Introduction: Physicians are at much higher risk for burnout, depression, and suicide than their non-medical peers. One of the working groups from the May 2017 Resident Wellness Consensus Summit (RWCS addressed this issue through the development of a longitudinal residency curriculum to address resident wellness and burnout. Methods: A 30-person (27 residents, three attending physicians Wellness Curriculum Development workgroup developed the curriculum in two phases. In the first phase, the workgroup worked asynchronously in the Wellness Think Tank – an online resident community – conducting a literature review to identify 10 core topics. In the second phase, the workgroup expanded to include residents outside the Wellness Think Tank at the live RWCS event to identify gaps in the curriculum. This resulted in an additional seven core topics. Results: Seventeen foundational topics served as the framework for the longitudinal resident wellness curriculum. The curriculum includes a two-module introduction to wellness; a seven-module “Self-Care Series” focusing on the appropriate structure of wellness activities and everyday necessities that promote physician wellness; a two-module section on physician suicide and self-help; a four-module “Clinical Care Series” focusing on delivering bad news, navigating difficult patient encounters, dealing with difficult consultants and staff members, and debriefing traumatic events in the emergency department; wellness in the workplace; and dealing with medical errors and shame. Conclusion: The resident wellness curriculum, derived from an evidence-based approach and input of residents from the Wellness Think Tank and the RWCS event, provides a guiding framework for residency programs in emergency medicine and potentially other specialties to improve physician wellness and promote a culture of wellness.

  16. Multifactorial risk assessment for survival of abutments of removable partial dentures based on practice-based longitudinal study.

    Science.gov (United States)

    Tada, Sayaka; Ikebe, Kazunori; Matsuda, Ken-Ichi; Maeda, Yoshinobu

    2013-12-01

    Predicting the tooth survival is such a great challenge for evidence-based dentistry. To prevent further tooth loss of partially edentulous patients, estimation of individualized risk and benefit for each residual tooth is important to the clinical decision-making. While there are several reports indicating a risk of losing the abutment teeth of RPDs, there are no existing reports exploring the cause of abutment loss by multifactorial analysis. The aim of this practice-based longitudinal study was to determine the prognostic factors affecting the survival period of RPD abutments using a multifactorial risk assessment. One hundred and forty-seven patients had been previously provided with a total of 236 new RPDs at the Osaka University Dental Hospital; the 856 abutments for these RPDs were analyzed. Survival of abutment teeth was estimated using the Kaplan-Meier method. Multivariate analysis was conducted by Cox's proportional hazard modelling. The 5-year survival rates were 86.6% for direct abutments and 93.1% for indirect abutments, compared with 95.8% survival in non-abutment teeth. The multivariate analysis showed that abutment survival was significantly associated with crown-root ratio (hazard ratio (HR): 3.13), root canal treatment (HR: 2.93), pocket depth (HR: 2.51), type of abutments (HR: 2.19) and occlusal support (HR: 1.90). From this practice-based longitudinal study, we concluded that RPD abutment teeth are more likely to be lost than other residual teeth. From the multifactorial risk factor assessment, several prognostic factors, such as occlusal support, crown-root ratio, root canal treatment, and pocket depth were suggested. These results could be used to estimate the individualized risk for the residual teeth, to predict the prognosis of RPD abutments and to facilitate an evidence-based clinical decision making. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Model–Based Techniques for Virtual Sensing of Longitudinal Flight Parameters

    Directory of Open Access Journals (Sweden)

    Seren Cédric

    2015-03-01

    Full Text Available Introduction of fly-by-wire and increasing levels of automation significantly improve the safety of civil aircraft, and result in advanced capabilities for detecting, protecting and optimizing A/C guidance and control. However, this higher complexity requires the availability of some key flight parameters to be extended. Hence, the monitoring and consolidation of those signals is a significant issue, usually achieved via many functionally redundant sensors to extend the way those parameters are measured. This solution penalizes the overall system performance in terms of weight, maintenance, and so on. Other alternatives rely on signal processing or model-based techniques that make a global use of all or part of the sensor data available, supplemented by a model-based simulation of the flight mechanics. That processing achieves real-time estimates of the critical parameters and yields dissimilar signals. Filtered and consolidated information is delivered in unfaulty conditions by estimating an extended state vector, including wind components, and can replace failed signals in degraded conditions. Accordingly, this paper describes two model-based approaches allowing the longitudinal flight parameters of a civil A/C to be estimated on-line. Results are displayed to evaluate the performances in different simulated and real flight conditions, including realistic external disturbances and modeling errors.

  18. Beam Based RF Voltage Measurements and Longitudinal Beam Tomography at the Fermilab Booster

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, C. M. [Fermilab; Bhat, S. [Fermilab

    2017-10-19

    Increasing proton beam power on neutrino production targets is one of the major goals of the Fermilab long term accelerator programs. In this effort, the Fermilab 8 GeV Booster synchrotron plays a critical role for at least the next two decades. Therefore, understanding the Booster in great detail is important as we continue to improve its performance. For example, it is important to know accurately the available RF power in the Booster by carrying out beam-based measurements in order to specify the needed upgrades to the Booster RF system. Since the Booster magnetic field is changing continuously measuring/calibrating the RF voltage is not a trivial task. Here, we present a beam based method for the RF voltage measurements. Data analysis is carried out using computer programs developed in Python and MATLAB. The method presented here is applicable to any RCS which do not have flat-bottom and flat-top in the acceleration magnetic ramps. We have also carried out longitudinal beam tomography at injection and extraction energies with the data used for RF voltage measurements. Beam based RF voltage measurements and beam tomography were never done before for the Fermilab Booster. The results from these investigations will be very useful in future intensity upgrades.

  19. Shockwave-Based Automated Vehicle Longitudinal Control Algorithm for Nonrecurrent Congestion Mitigation

    Directory of Open Access Journals (Sweden)

    Liuhui Zhao

    2017-01-01

    Full Text Available A shockwave-based speed harmonization algorithm for the longitudinal movement of automated vehicles is presented in this paper. In the advent of Connected/Automated Vehicle (C/AV environment, the proposed algorithm can be applied to capture instantaneous shockwaves constructed from vehicular speed profiles shared by individual equipped vehicles. With a continuous wavelet transform (CWT method, the algorithm detects abnormal speed drops in real-time and optimizes speed to prevent the shockwave propagating to the upstream traffic. A traffic simulation model is calibrated to evaluate the applicability and efficiency of the proposed algorithm. Based on 100% C/AV market penetration, the simulation results show that the CWT-based algorithm accurately detects abnormal speed drops. With the improved accuracy of abnormal speed drop detection, the simulation results also demonstrate that the congestion can be mitigated by reducing travel time and delay up to approximately 9% and 18%, respectively. It is also found that the shockwave caused by nonrecurrent congestion is quickly dissipated even with low market penetration.

  20. Precision of fit between implant impression coping and implant replica pairs for three implant systems.

    Science.gov (United States)

    Nicoll, Roxanna J; Sun, Albert; Haney, Stephan; Turkyilmaz, Ilser

    2013-01-01

    The fabrication of an accurately fitting implant-supported fixed prosthesis requires multiple steps, the first of which is assembling the impression coping on the implant. An imprecise fit of the impression coping on the implant will cause errors that will be magnified in subsequent steps of prosthesis fabrication. The purpose of this study was to characterize the 3-dimensional (3D) precision of fit between impression coping and implant replica pairs for 3 implant systems. The selected implant systems represent the 3 main joint types used in implant dentistry: external hexagonal, internal trilobe, and internal conical. Ten impression copings and 10 implant replicas from each of the 3 systems, B (Brånemark System), R (NobelReplace Select), and A (NobelActive) were paired. A standardized aluminum test body was luted to each impression coping, and the corresponding implant replica was embedded in a stone base. A coordinate measuring machine was used to quantify the maximum range of displacement in a vertical direction as a function of the tightening force applied to the guide pin. Maximum angular displacement in a horizontal plane was measured as a function of manual clockwise or counterclockwise rotation. Vertical and rotational positioning was analyzed by using 1-way analysis of variance (ANOVA). The Fisher protected least significant difference (PLSD) multiple comparisons test of the means was applied when the F-test in the ANOVA was significant (α=.05). The mean and standard deviation for change in the vertical positioning of impression copings was 4.3 ±2.1 μm for implant system B, 2.8 ±4.2 μm for implant system R, and 20.6 ±8.8 μm for implant system A. The mean and standard deviation for rotational positioning was 3.21 ±0.98 degrees for system B, 2.58 ±1.03 degrees for system R, and 5.30 ±0.79 degrees for system A. The P-value for vertical positioning between groups A and B and between groups A and R was <.001. No significant differences were found for

  1. Validation of the BUGJEFF311.BOLIB, BUGENDF70.BOLIB and BUGLE-B7 broad-group libraries on the PCA-Replica (H2O/Fe) neutron shielding benchmark experiment

    OpenAIRE

    Pescarini Massimo; Orsi Roberto; Frisoni Manuela

    2016-01-01

    The PCA-Replica 12/13 (H2O/Fe) neutron shielding benchmark experiment was analysed using the TORT-3.2 3D SN code. PCA-Replica reproduces a PWR ex-core radial geometry with alternate layers of water and steel including a pressure vessel simulator. Three broad-group coupled neutron/photon working cross section libraries in FIDO-ANISN format with the same energy group structure (47 n + 20 γ) and based on different nuclear data were alternatively used: the ENEA BUGJEFF311.BOLIB (JEFF-3.1.1) and U...

  2. Effect of boundary conditions on the strength and deformability of replicas of natural fractures in welded tuff: Data analysis

    International Nuclear Information System (INIS)

    Wibowo, J.; Amadei, B.; Sture, S.

    1994-04-01

    Assessing the shear behavior of intact rock ampersand rock fractures is an important issue in the design of a potential nuclear waste repository at Yucca Mountain Nevada. Cyclic direct shear experiments were conducted on replicas of three natural fractures and a laboratory-developed tensile fracture of welded tuff. The tests were carried out under constant normal loads or constant normal stiffnesses with different initial normal load levels. Each test consisted of five cycles of forward and reverse shear motion. Based on the results of the shear tests conducted under constant normal load, the shear behavior of the joint replicas tested under constant normal stiffness was predicted by using the graphical analysis method of Saeb (1989), and Amadei and Saeb (1990). Comparison between the predictions and the actual constant stiffness direct shear experiment results can be found in a report by Wibowo et al. (1993b). Results of the constant normal load shear experiments are analyzed using several constitutive models proposed in the rock mechanics literature for joint shear strength, dilatancy, and joint surface damage. It is shown that some of the existing models have limitations. New constitutive models are proposed and are included in a mathematical analysis tool that can be used to predict joint behavior under various boundary conditions

  3. Plasticity of 150-loop in influenza neuraminidase explored by Hamiltonian replica exchange molecular dynamics simulations.

    Directory of Open Access Journals (Sweden)

    Nanyu Han

    Full Text Available Neuraminidase (NA of influenza is a key target for antiviral inhibitors, and the 150-cavity in group-1 NA provides new insight in treating this disease. However, NA of 2009 pandemic influenza (09N1 was found lacking this cavity in a crystal structure. To address the issue of flexibility of the 150-loop, Hamiltonian replica exchange molecular dynamics simulations were performed on different groups of NAs. Free energy landscape calculated based on the volume of 150-cavity indicates that 09N1 prefers open forms of 150-loop. The turn A (residues 147-150 of the 150-loop is discovered as the most dynamical motif which induces the inter-conversion of this loop among different conformations. In the turn A, the backbone dynamic of residue 149 is highly related with the shape of 150-loop, thus can function as a marker for the conformation of 150-loop. As a contrast, the closed conformation of 150-loop is more energetically favorable in N2, one of group-2 NAs. The D147-H150 salt bridge is found having no correlation with the conformation of 150-loop. Instead the intimate salt bridge interaction between the 150 and 430 loops in N2 variant contributes the stabilizing factor for the closed form of 150-loop. The clustering analysis elaborates the structural plasticity of the loop. This enhanced sampling simulation provides more information in further structural-based drug discovery on influenza virus.

  4. Feedback-type giant magneto-impedance sensor based on longitudinal excitation

    International Nuclear Information System (INIS)

    Zhao Wen; Bu Xiongzhu; Yu Geliang; Xiang Chao

    2012-01-01

    In this paper, the characteristics of Fe-based amorphous ribbon based on the longitudinal excitation are investigated with assistance of the theory of the giant magneto-impedance (GMI) effect. A feedback-type GMI micro-magnetic sensor is designed with regard to the design of the sensing element, the excitation circuit, the conditional circuit and the feedback circuit. With the analysis of the dynamic and static characteristics of the feedback-type GMI sensor, it is concluded that the designed feedback-type GMI sensor has higher linearity, stability and dynamic characteristics than non-feedback-type GMI sensor in −2.5 to +2.5 Oe. - Highlights: ► A feedback-type GMI micro-magnetic sensor is designed. ► Excitation coil and feedback coil of the sensor is designed to be in one. ► The feedback-type sensor has higher linearity and stability than non-feedback type. ► The feedback-type sensor has better dynamic characteristics than non-feedback type.

  5. Combining boundary-based methods with tensor-based morphometry in the measurement of longitudinal brain change.

    Science.gov (United States)

    Fletcher, Evan; Knaack, Alexander; Singh, Baljeet; Lloyd, Evan; Wu, Evan; Carmichael, Owen; DeCarli, Charles

    2013-02-01

    Tensor-based morphometry is a powerful tool for automatically computing longitudinal change in brain structure. Because of bias in images and in the algorithm itself, however, a penalty term and inverse consistency are needed to control the over-reporting of nonbiological change. These may force a tradeoff between the intrinsic sensitivity and specificity, potentially leading to an under-reporting of authentic biological change with time. We propose a new method incorporating prior information about tissue boundaries (where biological change is likely to exist) that aims to keep the robustness and specificity contributed by the penalty term and inverse consistency while maintaining localization and sensitivity. Results indicate that this method has improved sensitivity without increased noise. Thus it will have enhanced power to detect differences within normal aging and along the spectrum of cognitive impairment.

  6. Synthesis and properties of ZnFe2O4 replica with biological hierarchical structure

    International Nuclear Information System (INIS)

    Liu, Hongyan; Guo, Yiping; Zhang, Yangyang; Wu, Fen; Liu, Yun; Zhang, Di

    2013-01-01

    Highlights: • ZFO replica with hierarchical structure was synthesized from butterfly wings. • Biotemplate has a significant impact on the properties of ZFO material. • Our method opens up new avenues for the synthesis of spinel ferrites. -- Abstract: ZnFe 2 O 4 replica with biological hierarchical structure was synthesized from Papilio paris by a sol–gel method followed by calcination. The crystallographic structure and morphology of the obtained samples were characterized by X-ray diffraction, field-emission scanning electron microscope, and transmittance electron microscope. The results showed that the hierarchical structures were retained in the ZFO replica of spinel structure. The magnetic behavior of such novel products was measured by a vibrating sample magnetometer. A superparamagnetism-like behavior was observed due to nanostructuration size effects. In addition, the ZFO replica with “quasi-honeycomb-like structure” showed a much higher specific capacitance of 279.4 F g −1 at 10 mV s −1 in comparison with ZFO powder of 137.3 F g −1 , attributing to the significantly increased surface area. These results demonstrated that ZFO replica is a promising candidate for novel magnetic devices and supercapacitors

  7. A distance-aware replica adaptive data gathering protocol for Delay Tolerant Mobile Sensor Networks.

    Science.gov (United States)

    Feng, Yong; Gong, Haigang; Fan, Mingyu; Liu, Ming; Wang, Xiaomin

    2011-01-01

    In Delay Tolerant Mobile Sensor Networks (DTMSNs) that have the inherent features of intermitted connectivity and frequently changing network topology it is reasonable to utilize multi-replica schemes to improve the data gathering performance. However, most existing multi-replica approaches inject a large amount of message copies into the network to increase the probability of message delivery, which may drain each mobile node's limited battery supply faster and result in too much contention for the restricted resources of the DTMSN, so a proper data gathering scheme needs a trade off between the number of replica messages and network performance. In this paper, we propose a new data gathering protocol called DRADG (for Distance-aware Replica Adaptive Data Gathering protocol), which economizes network resource consumption through making use of a self-adapting algorithm to cut down the number of redundant replicas of messages, and achieves a good network performance by leveraging the delivery probabilities of the mobile sensors as main routing metrics. Simulation results have shown that the proposed DRADG protocol achieves comparable or higher message delivery ratios at the cost of the much lower transmission overhead than several current DTMSN data gathering schemes.

  8. The health Oriented pedagogical project (HOPP) - a controlled longitudinal school-based physical activity intervention program.

    Science.gov (United States)

    Fredriksen, Per Morten; Hjelle, Ole Petter; Mamen, Asgeir; Meza, Trine J; Westerberg, Ane C

    2017-04-28

    The prevalence of non-communicable diseases (NCDs) is increasing worldwide, also among children. Information about primary prevention of NCD's is increasing; however, convincing strategies among children is needed. The present paper describes the design and methods in the Health Oriented Pedagogical Project (HOPP) study. The main objective is to evaluate the effects of a school-based physical activity intervention program on cardio-metabolic risk factors. Secondary objectives include assessment of physical, psychological and academic performance variables. The HOPP study is a 7 years longitudinal large-scale controlled intervention in seven elementary schools (n = 1545) with two control schools (n = 752); all aged 6-11 years at baseline. The school-based physical activity intervention program includes an increase in physical activity (PA) of 225 min/week as an integrated part of theoretical learning, in addition to the curriculum based 90 min/week of ordinary PA. Primary outcomes include cardio-metabolic risk factors measured as PA level, BMI status, waist circumference, muscle mass, percent fat, endurance test performance, total serum cholesterol, high-density lipoprotein (HDL), non-HDL, micro C-reactive protein (mCRP) and long-term blood sugar (HbA1c). In addition, secondary outcomes include anthropometric growth measures, physical fitness, quality of life (QoL), mental health, executive functions, diet and academic performance. HOPP will provide evidence of effects on cardio-metabolic risk factors after a long-term PA intervention program in elementary schoolchildren. School-based PA intervention programs may be an effective arena for health promotion and disease prevention. The study is registered in Clinical trials (ClinicalTrials.gov Identifier: NCT02495714 ) as of June 20 th - 2015, retrospectively registered. The collection of baseline values was initiated in mid-January 2015.

  9. The health Oriented pedagogical project (HOPP - a controlled longitudinal school-based physical activity intervention program

    Directory of Open Access Journals (Sweden)

    Per Morten Fredriksen

    2017-04-01

    Full Text Available Abstract Background The prevalence of non-communicable diseases (NCDs is increasing worldwide, also among children. Information about primary prevention of NCD’s is increasing; however, convincing strategies among children is needed. The present paper describes the design and methods in the Health Oriented Pedagogical Project (HOPP study. The main objective is to evaluate the effects of a school-based physical activity intervention program on cardio-metabolic risk factors. Secondary objectives include assessment of physical, psychological and academic performance variables. Methods The HOPP study is a 7 years longitudinal large-scale controlled intervention in seven elementary schools (n = 1545 with two control schools (n = 752; all aged 6–11 years at baseline. The school-based physical activity intervention program includes an increase in physical activity (PA of 225 min/week as an integrated part of theoretical learning, in addition to the curriculum based 90 min/week of ordinary PA. Primary outcomes include cardio-metabolic risk factors measured as PA level, BMI status, waist circumference, muscle mass, percent fat, endurance test performance, total serum cholesterol, high-density lipoprotein (HDL, non-HDL, micro C-reactive protein (mCRP and long-term blood sugar (HbA1c. In addition, secondary outcomes include anthropometric growth measures, physical fitness, quality of life (QoL, mental health, executive functions, diet and academic performance. Discussion HOPP will provide evidence of effects on cardio-metabolic risk factors after a long-term PA intervention program in elementary schoolchildren. School-based PA intervention programs may be an effective arena for health promotion and disease prevention. Trial registration The study is registered in Clinical trials (ClinicalTrials.gov Identifier: NCT02495714 as of June 20th – 2015, retrospectively registered. The collection of baseline values was initiated in mid-January 2015.

  10. Magnetization reversal of Co-based amorphous wires induced by longitudinal AC magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Perov, N.S.; Antonov, A.S.; Buznikov, N.A.; Granovsky, A.B. E-mail: granov@magn.ru; Iakubov, I.T.; Kartashov, M.A.; Rakhmanov, A.A

    2004-05-01

    The remagnetization process in CoFeSiB amorphous wires under influence of a high-amplitude AC longitudinal magnetic field is studied. The frequency spectra of the voltage at the wire ends are measured as a function of a longitudinal DC magnetic field and the AC field amplitude. A high sensitivity of the voltage harmonics to the DC magnetic field is demonstrated. The experimental results are interpreted within a simple rotational model.

  11. Magnetization reversal of Co-based amorphous wires induced by longitudinal AC magnetic field

    International Nuclear Information System (INIS)

    Perov, N.S.; Antonov, A.S.; Buznikov, N.A.; Granovsky, A.B.; Iakubov, I.T.; Kartashov, M.A.; Rakhmanov, A.A.

    2004-01-01

    The remagnetization process in CoFeSiB amorphous wires under influence of a high-amplitude AC longitudinal magnetic field is studied. The frequency spectra of the voltage at the wire ends are measured as a function of a longitudinal DC magnetic field and the AC field amplitude. A high sensitivity of the voltage harmonics to the DC magnetic field is demonstrated. The experimental results are interpreted within a simple rotational model

  12. A longitudinal and experimental study of the impact of knowledge on the bases of institutional trust.

    Science.gov (United States)

    PytlikZillig, Lisa M; Kimbrough, Christopher D; Shockley, Ellie; Neal, Tess M S; Herian, Mitchel N; Hamm, Joseph A; Bornstein, Brian H; Tomkins, Alan J

    2017-01-01

    This study examined a knowledge-centered theory of institutional trust development. In the context of trust in water regulatory institutions, the moderating impact of knowledge was tested to determine if there were longitudinal changes in the bases of institutional trust as a function of increases in knowledge about a target institution. We hypothesized that as people learn about an institution with which they were previously unfamiliar, they begin to form more nuanced perceptions, distinguishing the new institution from other institutions and relying less upon their generalized trust to estimate their trust in that institution. Prior to having specific, differential information about a new institution, we expected institutional trust to be a function of generalized trust variables such as dispositional trust and trust in government. The longitudinal experiment involved 185 college students randomly assigned to one of three information conditions. Every 3 months for 15 months, participants read information about water regulatory institutions or a control institution. At each time point, participants reported their trust in and perceptions of the trust- and distrust-worthiness of the water regulatory institutions. Participants also completed measures of knowledge of water regulatory institutions, dispositional trust, and governmental trust. Our manipulation check indicated that, as expected, those in the experimental group increased in subjective knowledge of water regulatory institutions to a greater extent than those in the control condition. Consistent with our hypotheses, there was some evidence that, compared to the control group, the experimental group relied less on their general trust in government as a basis for their trust in water regulatory institutions. However, contrary to our hypotheses, there was no evidence the experimental group relied less on dispositional trust as a basis for institutional trust. There also was some evidence the experimental

  13. Ending Intimate Partner Violence after pregnancy: Findings from a community-based longitudinal study in Nicaragua

    Science.gov (United States)

    Salazar, Mariano; Valladares, Eliette; Öhman, Ann; Högberg, Ulf

    2009-01-01

    Background Although reducing intimate partner violence (IPV) is a pervasive public health problem, few longitudinal studies in developing countries have assessed ways to end such abuse. To this end, this paper aims to analyze individual, family, community and societal factors that facilitate reducing IPV. Methods A longitudinal population-based study was conducted in León, Nicaragua at a demographic surveillance site. Women (n = 478) who were pregnant between 2002 and 2003 were interviewed, and 398 were found at follow-up, 2007. Partner abuse was measured using the WHO Multi-country study on women's health and domestic violence questionnaire. Women's socio demographic variables, perceived emotional distress, partner control, social resources, women's norms and attitudes towards IPV and help-seeking behaviours were also assessed. Ending of abuse was defined as having experienced any abuse in a lifetime or during pregnancy but not at follow-up. Crude and adjusted odds ratios were applied. Results Of the women exposed to lifetime or pregnancy IPV, 59% reported that their abuse ended. This finding took place in a context of a substantial shift in women's normative attitudes towards not tolerating abuse. At the family level, no or diminishing partner control [ORadj 6.7 (95%CI 3.5-13)] was associated with ending of abuse. At the societal level, high or improved social resources [ORadj 2.0 (95%CI 1.1.-3.7)] were also associated with the end of abuse. Conclusion A considerable proportion of women reported end of violence. This might be related to a favourable change in women's norms and attitudes toward gender roles and violence and a more positive attitude towards interventions from people outside their family to end abuse. Maintaining and improving social resources and decreasing partner control and isolation are key interventions to ending abuse. Abuse inquiring may also play an important role in this process and must include health care provider's training and a

  14. A longitudinal and experimental study of the impact of knowledge on the bases of institutional trust.

    Directory of Open Access Journals (Sweden)

    Lisa M PytlikZillig

    Full Text Available This study examined a knowledge-centered theory of institutional trust development. In the context of trust in water regulatory institutions, the moderating impact of knowledge was tested to determine if there were longitudinal changes in the bases of institutional trust as a function of increases in knowledge about a target institution. We hypothesized that as people learn about an institution with which they were previously unfamiliar, they begin to form more nuanced perceptions, distinguishing the new institution from other institutions and relying less upon their generalized trust to estimate their trust in that institution. Prior to having specific, differential information about a new institution, we expected institutional trust to be a function of generalized trust variables such as dispositional trust and trust in government. The longitudinal experiment involved 185 college students randomly assigned to one of three information conditions. Every 3 months for 15 months, participants read information about water regulatory institutions or a control institution. At each time point, participants reported their trust in and perceptions of the trust- and distrust-worthiness of the water regulatory institutions. Participants also completed measures of knowledge of water regulatory institutions, dispositional trust, and governmental trust. Our manipulation check indicated that, as expected, those in the experimental group increased in subjective knowledge of water regulatory institutions to a greater extent than those in the control condition. Consistent with our hypotheses, there was some evidence that, compared to the control group, the experimental group relied less on their general trust in government as a basis for their trust in water regulatory institutions. However, contrary to our hypotheses, there was no evidence the experimental group relied less on dispositional trust as a basis for institutional trust. There also was some evidence

  15. Enhancing dry adhesives and replica molding with ethyl cyano-acrylate

    International Nuclear Information System (INIS)

    Bovero, E; Menon, C

    2014-01-01

    The use of cyano-acrylate to improve the performance of dry adhesives and their method of fabrication is investigated. Specifically, the contributions of this work are: (1) a new adhesion method to adhere to a large variety of surfaces, (2) a strategy to increase the compliance of dry adhesives, and (3) an improved fabrication process for micro-structured dry adhesives based on replica molding. For the first contribution, the adhesion method consists of anchoring a micro-structured dry adhesive to a surface through a layer of hardened ethyl cyano-acrylate (ECA). This method increases the adhesion of the orders of magnitude at the expense of leaving residue after detachment. However, this method preserves reusability. For the second contribution, a double-sided dry adhesive is obtained by introducing a substrate with a millimeter-sized pillar structure, which enabled further increasing adhesion. For the third contribution, an ECA layer is used as a mold for the fabrication of new adhesives. These new types of molds proved able to produce dry adhesives with high reproducibility and low degradation. (paper)

  16. Replicas in Cultural Heritage: 3d Printing and the Museum Experience

    Science.gov (United States)

    Ballarin, M.; Balletti, C.; Vernier, P.

    2018-05-01

    3D printing has seen a recent massive diffusion for several applications, not least the field of Cultural Heritage. Being used for different purposes, such as study, analysis, conservation or access in museum exhibitions, 3D printed replicas need to undergo a process of validation also in terms of metrical precision and accuracy. The Laboratory of Photogrammetry of Iuav University of Venice has started several collaborations with Italian museum institutions firstly for the digital acquisition and then for the physical reproduction of objects of historical and artistic interest. The aim of the research is to analyse the metric characteristics of the printed model in relation to the original data, and to optimize the process that from the survey leads to the physical representation of an object. In fact, this could be acquired through different methodologies that have different precisions (multi-image photogrammetry, TOF laser scanner, triangulation based laser scanner), and it always involves a long processing phase. It should not be forgotten that the digital data have to undergo a series of simplifications, which, on one hand, eliminate the noise introduced by the acquisition process, but on the other one, they can lead to discrepancies between the physical copy and the original geometry. In this paper we will show the results obtained on a small archaeological find that was acquired and reproduced for a museum exhibition intended for blind and partially sighted people.

  17. Replica analysis of overfitting in regression models for time-to-event data

    Science.gov (United States)

    Coolen, A. C. C.; Barrett, J. E.; Paga, P.; Perez-Vicente, C. J.

    2017-09-01

    Overfitting, which happens when the number of parameters in a model is too large compared to the number of data points available for determining these parameters, is a serious and growing problem in survival analysis. While modern medicine presents us with data of unprecedented dimensionality, these data cannot yet be used effectively for clinical outcome prediction. Standard error measures in maximum likelihood regression, such as p-values and z-scores, are blind to overfitting, and even for Cox’s proportional hazards model (the main tool of medical statisticians), one finds in literature only rules of thumb on the number of samples required to avoid overfitting. In this paper we present a mathematical theory of overfitting in regression models for time-to-event data, which aims to increase our quantitative understanding of the problem and provide practical tools with which to correct regression outcomes for the impact of overfitting. It is based on the replica method, a statistical mechanical technique for the analysis of heterogeneous many-variable systems that has been used successfully for several decades in physics, biology, and computer science, but not yet in medical statistics. We develop the theory initially for arbitrary regression models for time-to-event data, and verify its predictions in detail for the popular Cox model.

  18. Trillo NPP full scope replica simulator project: The last great NPP simulation challenge in Spain

    International Nuclear Information System (INIS)

    Rivero, N.; Abascal, A.

    2006-01-01

    In the year 2000, Trillo NPP (Spanish PWR-KWU design nuclear power plant) and Tecnatom came to the agreement of developing a Trillo plant specific simulator, having as scope all the plant systems operated either from the main control room or from the emergency panels. The simulator operation should be carried out both through a control room replica and graphical user interface, this latter based on plant schematics and softpanels concept. Trillo simulator is to be primarily utilized as a pedagogical tool for the Trillo operational staff training. Because the engineering grade of the mathematical models, it will also have additional uses, such as: - Operation engineering (POE's validation, New Computerized Operator Support Systems Validation, etc).; - Emergency drills; -Plant design modifications assessment. This project has become the largest simulation task Tecnatom has ever undertaken, being structured in three different subprojects, namely: - Simulator manufacture, Simulator acceptance and Training material production. Most relevant technological innovations the project brings are: Highest accuracy in the Nuclear Island models, Advanced Configuration Management System, Open Software architecture, Human machine interface new design, Latest design I/O system and an Instructor Station with extended functionality. The Trillo simulator 'Ready for Training' event is due on September 2003, having started the Factory Acceptance Tests in Autumn 2002. (author)

  19. Longitudinal behavioral effects of a school-based fruit and vegetable promotion program.

    Science.gov (United States)

    Hoffman, Jessica A; Franko, Debra L; Thompson, Douglas R; Power, Thomas J; Stallings, Virginia A

    2010-01-01

    This study examined the longitudinal effects of a school-based program on kindergarten and first grade children's fruit and vegetable (F&V) consumption. The program included lunchroom, classroom, school-wide, and family components. The primary dependent variable, F&V consumed at lunch, was assessed using weighed plate waste. Hierarchical linear models were used to analyze the differences between intervention and control groups and to account for repeated measurements. Children in the experimental group consumed more F&V (F = 29 g; V = 6 g; 0.43 portions/lunch; 0.28 servings/lunch) at the end of Year 1 compared with children in the control group. At the end of Year 2, children in the experimental group consumed more fruit (21 g; 0.23 portions/lunch; 0.15 servings/lunch), but not more vegetables compared with children in the control group. The intervention resulted in increased F&V consumption, with more pronounced and enduring effects for fruits than vegetables.

  20. The association between intelligence and telomere length: a longitudinal population based study.

    Directory of Open Access Journals (Sweden)

    Eva M Kingma

    Full Text Available Low intelligence has been associated with poor health and mortality, but underlying mechanisms remain obscure. We hypothesized that low intelligence is associated with accelerated biological ageing as reflected by telomere length; we suggested potential mediation of this association by unhealthy behaviors and low socioeconomic position. The study was performed in a longitudinal population-based cohort study of 895 participants (46.8% males. Intelligence was measured with the Generalized Aptitude-Test Battery at mean age 52.8 years (33-79 years, SD=11.3. Leukocyte telomere length was measured by PCR. Lifestyle and socioeconomic factors were assessed using written self-report measures. Linear regression analyses, adjusted for age, sex, and telomere length measured at the first assessment wave (T1, showed that low intelligence was associated with shorter leukocyte telomere length at approximately 2 years follow-up (beta= .081, t=2.160, p= .031. Nearly 40% of this association was explained by an unhealthy lifestyle, while low socioeconomic position did not add any significant mediation. Low intelligence may be a risk factor for accelerated biological ageing, thereby providing an explanation for its association with poor health and mortality.

  1. Disease management programs for patients with asthma in Germany: a longitudinal population-based study.

    Science.gov (United States)

    Mehring, Michael; Donnachie, Ewan; Mutschler, Robert; Hofmann, Frank; Keller, Manfred; Schneider, Antonius

    2013-07-01

    The primary aim of the disease management program (DMP) for patients with asthma is to improve health outcomes and to reduce costs. Five years after its introduction in Germany, no consensus has yet been reached as to whether DMP has been effective in reaching these goals. To evaluate the DMP for asthma in Bavaria using routinely collected subject medical records. A longitudinal population-based study encompassing over 100,000 DMP participants between 2006 (when the program began) and 2010. The prescription rate of oral corticosteroids dropped from 15.7% in 2006 to 13.6% in 2007, and again from 7.5% in 2008 to 5.9% in 2010 (P management education increased from 4.4% to 23.4% (P management. The proportion of subjects requiring hospitalization decreased. Our results suggest that the German DMP for asthma has been effective in enhancing the quality of care in regard to an improved symptom frequency, adherence to guidelines, pharmacotherapy, and hospitalization.

  2. Cost Analysis of Plug-In Hybred Electric Vehicles Using GPS-Based Longitudinal Travel Data

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Xing [Lamar University; Dong, Jing [Iowa State University; Lin, Zhenhong [ORNL

    2014-01-01

    Using spatial, longitudinal travel data of 415 vehicles over 3 18 months in the Seattle metropolitan area, this paper estimates the operating costs of plug-in hybrid electric vehicles (PHEVs) of various electric ranges (10, 20, 30, and 40 miles) for 3, 5, and 10 years of payback period, considering different charging infrastructure deployment levels and gasoline prices. Some key findings were made. (1) PHEVs could help save around 60% or 40% in energy costs, compared with conventional gasoline vehicles (CGVs) or hybrid electric vehicles (HEVs), respectively. However, for motorists whose daily vehicle miles traveled (DVMT) is significant, HEVs may be even a better choice than PHEV40s, particularly in areas that lack a public charging infrastructure. (2) The incremental battery cost of large-battery PHEVs is difficult to justify based on the incremental savings of PHEVs operating costs unless a subsidy is offered for largebattery PHEVs. (3) When the price of gasoline increases from $4/gallon to $5/gallon, the number of drivers who benefit from a larger battery increases significantly. (4) Although quick chargers can reduce charging time, they contribute little to energy cost savings for PHEVs, as opposed to Level-II chargers.

  3. Longitudinal control of aircraft dynamics based on optimization of PID parameters

    Science.gov (United States)

    Deepa, S. N.; Sudha, G.

    2016-03-01

    Recent years many flight control systems and industries are employing PID controllers to improve the dynamic behavior of the characteristics. In this paper, PID controller is developed to improve the stability and performance of general aviation aircraft system. Designing the optimum PID controller parameters for a pitch control aircraft is important in expanding the flight safety envelope. Mathematical model is developed to describe the longitudinal pitch control of an aircraft. The PID controller is designed based on the dynamic modeling of an aircraft system. Different tuning methods namely Zeigler-Nichols method (ZN), Modified Zeigler-Nichols method, Tyreus-Luyben tuning, Astrom-Hagglund tuning methods are employed. The time domain specifications of different tuning methods are compared to obtain the optimum parameters value. The results prove that PID controller tuned by Zeigler-Nichols for aircraft pitch control dynamics is better in stability and performance in all conditions. Future research work of obtaining optimum PID controller parameters using artificial intelligence techniques should be carried out.

  4. Childhood gender-typed behavior and adolescent sexual orientation: A longitudinal population-based study.

    Science.gov (United States)

    Li, Gu; Kung, Karson T F; Hines, Melissa

    2017-04-01

    Lesbian and gay individuals have been reported to show more interest in other-sex, and/or less interest in same-sex, toys, playmates, and activities in childhood than heterosexual counterparts. Yet, most of the relevant evidence comes from retrospective studies or from prospective studies of clinically referred, extremely gender nonconforming children. In addition, findings are mixed regarding the relation between childhood gender-typed behavior and the later sexual orientation spectrum from exclusively heterosexual to exclusively lesbian/gay. The current study drew a sample (2,428 girls and 2,169 boys) from a population-based longitudinal study, and found that the levels of gender-typed behavior at ages 3.5 and 4.75 years, although less so at age 2.5 years, significantly and consistently predicted adolescents' sexual orientation at age 15 years, both when sexual orientation was conceptualized as 2 groups or as a spectrum. In addition, within-individual change in gender-typed behavior during the preschool years significantly related to adolescent sexual orientation, especially in boys. These results suggest that the factors contributing to the link between childhood gender-typed behavior and sexual orientation emerge during early development. Some of those factors are likely to be nonsocial, because nonheterosexual individuals appear to diverge from gender norms regardless of social encouragement to conform to gender roles. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  5. A longitudinal simulation-based ethical-legal curriculum for otolaryngology residents.

    Science.gov (United States)

    Fanous, Amanda; Rappaport, Jamie; Young, Meredith; Park, Yoon Soo; Manoukian, John; Nguyen, Lily H P

    2017-11-01

    To develop, implement, and evaluate a longitudinal, simulation-based ethics and legal curriculum designed specifically for otolaryngology residents. Otolaryngology residents were recruited to participate in a yearly half-day ethical-legal module, the curriculum of which spanned 4 years. Each module included: three simulated scenarios, small-group multisource feedback, and large-group debriefings. Scenarios involved encounters with standardized patients. Residents' ethical-legal knowledge was assessed pre- and postmodule with multiple-choice questions, and ethical reasoning was assessed by a variety of evaluators during the simulated scenario using a locally developed assessment tool. Participants completed an exit survey at the end of each module. Eighteen residents completed four modules from the academic years of 2008 to 2009 to 2011 to 2012. The first year was considered a pilot module, and data were collected for the following 3 years. Knowledge of legal issues improved significantly among residents (mean at pre = 3.40 and post = 4.60, P otolaryngology-head and neck surgery residents. This educational program resulted in a both objective and subjective improvement in legal and ethics knowledge and skills. NA. Laryngoscope, 127:2501-2509, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  6. Are Video Games a Gateway to Gambling? A Longitudinal Study Based on a Representative Norwegian Sample.

    Science.gov (United States)

    Molde, Helge; Holmøy, Bjørn; Merkesdal, Aleksander Garvik; Torsheim, Torbjørn; Mentzoni, Rune Aune; Hanns, Daniel; Sagoe, Dominic; Pallesen, Ståle

    2018-06-05

    The scope and variety of video games and monetary gambling opportunities are expanding rapidly. In many ways, these forms of entertainment are converging on digital and online video games and gambling sites. However, little is known about the relationship between video gaming and gambling. The present study explored the possibility of a directional relationship between measures of problem gaming and problem gambling, while also controlling for the influence of sex and age. In contrast to most previous investigations which are based on cross-sectional designs and non-representative samples, the present study utilized a longitudinal design conducted over 2 years (2013, 2015) and comprising 4601 participants (males 47.2%, age range 16-74) drawn from a random sample from the general population. Video gaming and gambling were assessed using the Gaming Addiction Scale for Adolescents and the Canadian Problem Gambling Index, respectively. Using an autoregressive cross-lagged structural equation model, we found a positive relationship between scores on problematic gaming and later scores on problematic gambling, whereas we found no evidence of the reverse relationship. Hence, video gaming problems appear to be a gateway behavior to problematic gambling behavior. In future research, one should continue to monitor the possible reciprocal behavioral influences between gambling and video gaming.

  7. Spatial complexity of character-based writing systems and arithmetic in primary school: a longitudinal study

    Science.gov (United States)

    Rodic, Maja; Tikhomirova, Tatiana; Kolienko, Tatiana; Malykh, Sergey; Bogdanova, Olga; Zueva, Dina Y.; Gynku, Elena I.; Wan, Sirui; Zhou, Xinlin; Kovas, Yulia

    2015-01-01

    Previous research has consistently found an association between spatial and mathematical abilities. We hypothesized that this link may partially explain the consistently observed advantage in mathematics demonstrated by East Asian children. Spatial complexity of the character-based writing systems may reflect or lead to a cognitive advantage relevant to mathematics. Seven hundered and twenty one 6–9-year old children from the UK and Russia were assessed on a battery of cognitive skills and arithmetic. The Russian children were recruited from specialist linguistic schools and divided into four different language groups, based on the second language they were learning (i.e., English, Spanish, Chinese, and Japanese). The UK children attended regular schools and were not learning any second language. The testing took place twice across the school year, once at the beginning, before the start of the second language acquisition, and once at the end of the year. The study had two aims: (1) to test whether spatial ability predicts mathematical ability in 7–9 year-old children across the samples; (2) to test whether acquisition and usage of a character-based writing system leads to an advantage in performance in arithmetic and related cognitive tasks. The longitudinal link from spatial ability to mathematics was found only in the Russian sample. The effect of second language acquisition on mathematics or other cognitive skills was negligible, although some effect of Chinese language on mathematical reasoning was suggested. Overall, the findings suggest that although spatial ability is related to mathematics at this age, one academic year of exposure to spatially complex writing systems is not enough to provide a mathematical advantage. Other educational and socio-cultural factors might play a greater role in explaining individual and cross-cultural differences in arithmetic at this age. PMID:25859235

  8. Spatial complexity of character based writing systems and arithmetic in primary school: a longitudinal study

    Directory of Open Access Journals (Sweden)

    Maja eRodic

    2015-03-01

    Full Text Available Previous research has consistently found an association between spatial and mathematical abilities. We hypothesised that this link may partially explain the consistently observed advantage in mathematics demonstrated by Asian children. Spatial complexity of the character-based writing systems may reflect or lead to a cognitive advantage relevant to mathematics. 721 6-9 -year old children from the UK and Russia were assessed on a battery of cognitive skills and arithmetic. The Russian children were recruited from specialist linguistic schools and divided into 4 different language groups, based on the second language they were learning (i.e. English, Spanish, Chinese and Japanese. The UK children attended regular schools and were not learning any second language. The testing took place twice across the school year, once at the beginning, before the start of the second language acquisition, and once at the end of the year. The study had two aims: (1 to test whether spatial ability predicts mathematical ability in 7-9 year old children across the samples; (2 to test whether acquisition and usage of a character-based writing system leads to an advantage in performance in arithmetic and related cognitive tasks. The longitudinal link from spatial ability to mathematics was found only in the Russian sample. The effect of second language acquisition on mathematics or other cognitive skills was negligible, although some effect of Chinese language on mathematical reasoning was suggested. Overall, the findings suggest that although spatial ability is related to mathematics at this age, one academic year of exposure to spatially complex writing systems is not enough to provide a mathematical advantage. Other educational and socio-cultural factors might play a greater role in explaining individual and cross-cultural differences in arithmetic at this age.

  9. Spatial complexity of character-based writing systems and arithmetic in primary school: a longitudinal study.

    Science.gov (United States)

    Rodic, Maja; Tikhomirova, Tatiana; Kolienko, Tatiana; Malykh, Sergey; Bogdanova, Olga; Zueva, Dina Y; Gynku, Elena I; Wan, Sirui; Zhou, Xinlin; Kovas, Yulia

    2015-01-01

    Previous research has consistently found an association between spatial and mathematical abilities. We hypothesized that this link may partially explain the consistently observed advantage in mathematics demonstrated by East Asian children. Spatial complexity of the character-based writing systems may reflect or lead to a cognitive advantage relevant to mathematics. Seven hundered and twenty one 6-9-year old children from the UK and Russia were assessed on a battery of cognitive skills and arithmetic. The Russian children were recruited from specialist linguistic schools and divided into four different language groups, based on the second language they were learning (i.e., English, Spanish, Chinese, and Japanese). The UK children attended regular schools and were not learning any second language. The testing took place twice across the school year, once at the beginning, before the start of the second language acquisition, and once at the end of the year. The study had two aims: (1) to test whether spatial ability predicts mathematical ability in 7-9 year-old children across the samples; (2) to test whether acquisition and usage of a character-based writing system leads to an advantage in performance in arithmetic and related cognitive tasks. The longitudinal link from spatial ability to mathematics was found only in the Russian sample. The effect of second language acquisition on mathematics or other cognitive skills was negligible, although some effect of Chinese language on mathematical reasoning was suggested. Overall, the findings suggest that although spatial ability is related to mathematics at this age, one academic year of exposure to spatially complex writing systems is not enough to provide a mathematical advantage. Other educational and socio-cultural factors might play a greater role in explaining individual and cross-cultural differences in arithmetic at this age.

  10. Implementation and performance analysis of the LHCb LFC replica using Oracle streams technology

    CERN Document Server

    Düllmann, D; Martelli, B; Peco, G; Bonifazzi, F; Da Fonte Perez, E; Baranowski, Z; Vagnoni, V

    2007-01-01

    The presentation will describe the architecture and the deployment of the LHCb read-only File Catalogue for the LHC Computing Grid (LFC) replica implemented at the Italian INFN National Centre for Telematics and Informatics (CNAF), and evaluate a series of tests on the LFC with replica. The LHCb computing model foresees the replication of the central LFC database in every Tier-1, in order to assure more scalability and fault tolerance to LHCb applications Scientific data intensive applications use a large collection of files for storing data. In particular, as regards the HEP community, data generated by large detectors will be managed and stored using databases. The intensive access to information stored in databases by the Grid computing applications requires a distributed database replication in order to guarantee the scalability and, in case of failure, redundancy. Besides the results of the tests will be an important reference for all the Grid users This talk will describe the replica implementation of L...

  11. Surgery planning and navigation by laser lithography plastic replica. Features, clinical applications, and advantages

    International Nuclear Information System (INIS)

    Kihara, Tomohiko; Tanaka, Yuuko; Furuhata, Kentaro

    1995-01-01

    The use of three-dimensional replicas created using laserlithography has recently become popular for surgical planning and intraoperative navigation in plastic surgery and oral maxillofacial surgery. In this study, we investigated many clinical applications that we have been involved in regarding the production of three-dimensional replicas. We have also analyzed the features, application classes, and advantages of this method. As a result, clinical applications are categorized into three classes, which are 'three-dimensional shape recognition', 'simulated surgery', and 'template'. The distinct features of three-dimensional replicas are 'direct recognition', 'fast manipulation', and 'free availability'. Meeting the requirements of surgical planning and intraoperative navigation, they have produced satisfactory results in clinical applications. (author)

  12. A procedure to analyze surface profiles of the protein molecules visualized by quick-freeze deep-etch replica electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kimori, Yoshitaka [Division of Biomolecular Imaging, Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo 108-8639 (Japan); Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, Iizuka, Fukuoka 820-8502 (Japan); Oguchi, Yosuke [Department of Electric Engineering, Kogakuin University, Hachioji, Tokyo 192-0015 (Japan); Ichise, Norihiko [Department of Visual Communication, Komazawa Women' s University, Inagi, Tokyo 206-8511 (Japan); Baba, Norio [Department of Electric Engineering, Kogakuin University, Hachioji, Tokyo 192-0015 (Japan); Katayama, Eisaku [Division of Biomolecular Imaging, Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo 108-8639 (Japan)]. E-mail: ekatayam@ims.u-tokyo.ac.jp

    2007-01-15

    Quick-freeze deep-etch replica electron microscopy gives high contrast snapshots of individual protein molecules under physiological conditions in vitro or in situ. The images show delicate internal pattern, possibly reflecting the rotary-shadowed surface profile of the molecule. As a step to build the new system for the 'Structural analysis of single molecules', we propose a procedure to quantitatively characterize the structural property of individual molecules; e.g. conformational type and precise view-angle of the molecules, if the crystallographic structure of the target molecule is available. This paper presents a framework to determine the observed face of the protein molecule by analyzing the surface profile of individual molecules visualized in freeze-replica specimens. A comprehensive set of rotary-shadowed views of the protein molecule was artificially generated from the available atomic coordinates using light-rendering software. Exploiting new mathematical morphology-based image filter, characteristic features were extracted from each image and stored as template. Similar features were extracted from the true replica image and the most likely projection angle and the conformation of the observed particle were determined by quantitative comparison with a set of archived images. The performance and the robustness of the procedure were examined with myosin head structure in defined configuration for actual application.

  13. A procedure to analyze surface profiles of the protein molecules visualized by quick-freeze deep-etch replica electron microscopy

    International Nuclear Information System (INIS)

    Kimori, Yoshitaka; Oguchi, Yosuke; Ichise, Norihiko; Baba, Norio; Katayama, Eisaku

    2007-01-01

    Quick-freeze deep-etch replica electron microscopy gives high contrast snapshots of individual protein molecules under physiological conditions in vitro or in situ. The images show delicate internal pattern, possibly reflecting the rotary-shadowed surface profile of the molecule. As a step to build the new system for the 'Structural analysis of single molecules', we propose a procedure to quantitatively characterize the structural property of individual molecules; e.g. conformational type and precise view-angle of the molecules, if the crystallographic structure of the target molecule is available. This paper presents a framework to determine the observed face of the protein molecule by analyzing the surface profile of individual molecules visualized in freeze-replica specimens. A comprehensive set of rotary-shadowed views of the protein molecule was artificially generated from the available atomic coordinates using light-rendering software. Exploiting new mathematical morphology-based image filter, characteristic features were extracted from each image and stored as template. Similar features were extracted from the true replica image and the most likely projection angle and the conformation of the observed particle were determined by quantitative comparison with a set of archived images. The performance and the robustness of the procedure were examined with myosin head structure in defined configuration for actual application

  14. Effectiveness of "Step into Health" program in Qatar: a pedometer-based longitudinal study.

    Science.gov (United States)

    Al-Kuwari, Mohamed G; Al-Mohannadi, Abdulla S; Sayegh, Suzan

    2017-11-01

    This study examines the impact of a one-year pedometer-based intervention on increasing the physical activity level among adult population in Qatar. This longitudinal study was conducted over a one-year period and included a total of 268 adults aged between 18-64 years old. Data were extracted and used from the "Step into Health" (SIH) program, a community-based program launched in 2012, as an approach to improve physical activity in Qatar. Walking intervention encouraged members of SIH to accumulate 10,000 steps or more per day and monitor their progress through a pedometer supported by a self-monitoring online account and a reinforcement system. This study shows a significant increase in average daily steps from 3933±3240 steps/day at baseline into 7507±5416 steps/week at the 12th month (P<0.001). It was found that 18.6% of participants met the daily target of 10,000 steps or more; however, there was a considerable increase of 39.2% by the 12th month. Females showed an increase in their physical activity; still, they remain less active than males. It was found that non-Arabs subgroup were more active than Arabs. Interestingly, older members (≥50 years old) were more active throughout the study period. Pedometer program was found to be effective in increasing the level of physical activity among participants. A decline in physical activity has been observed during hot weather, while re-enforcement campaign had a positive impact on the number of steps/day.

  15. Replica analysis of partition-function zeros in spin-glass models

    International Nuclear Information System (INIS)

    Takahashi, Kazutaka

    2011-01-01

    We study the partition-function zeros in mean-field spin-glass models. We show that the replica method is useful to find the locations of zeros in a complex parameter plane. For the random energy model, we obtain the phase diagram in the plane and find that there are two types of distributions of zeros: two-dimensional distribution within a phase and one-dimensional one on a phase boundary. Phases with a two-dimensional distribution are characterized by a novel order parameter defined in the present replica analysis. We also discuss possible patterns of distributions by studying several systems.

  16. Anharmonic longitudinal motion of bases and dynamics of nonlinear excitation in DNA.

    Science.gov (United States)

    Di Garbo, Angelo

    2016-01-01

    The dynamics of the transcription bubble in DNA is studied by using a nonlinear model in which torsional and longitudinal conformations of the biomolecule are coupled. In the absence of forcing and dissipation the torsional dynamics is described by a perturbed kink of the Sine-Gordon DNA model, while the longitudinal conformational energy propagate as phonons. It was found that for random initial conditions of the longitudinal conformational field the presence of the kink promotes the creation of phonons propagating along the chain axis. Moreover, the presence of forcing, describing the active role of RNA polymerase, determines in agreement to the experimental data a modulation of the velocity of the transcription bubble. Lastly, it was shown that the presence of dissipation impacts the dynamic of the phonon by reducing the amplitude of the corresponding conformational field. On the contrary, dissipation and forcing modulate the velocity of the transcription bubble alone.

  17. Leisure activities, education, and cognitive impairment in Chinese older adults: a population-based longitudinal study.

    Science.gov (United States)

    Zhu, Xinyi; Qiu, Chengxuan; Zeng, Yi; Li, Juan

    2017-05-01

    We examine the association between leisure-time activities and the risk of developing cognitive impairment among Chinese older people, and further investigate whether the association varies by educational level. This follow-up study included 6,586 participants (aged 79.5 ± 9.8 years, range 65-105 years, 51.7% female) of the Chinese Longitudinal Healthy Longevity Survey who were aged ≥65 years and were free of cognitive impairment in 2002. Incident cognitive impairment was defined at the 2005 or 2008/2009 survey following an education-based cut-off on the adapted Chinese version of Mini-Mental State Examination (MMSE). Participation in cognitive activities (e.g. reading) and non-exercise physical activity (e.g. housework) was assessed by a self-reported scale. Cox proportional hazard models were employed to examine the association of leisure activities with incident cognitive impairment while controlling for age, gender, education, occupation, residence, physical exercise, smoking, drinking, cardiovascular diseases and risk factors, negative well-being, and physical functioning, and baseline MMSE score. During a five-year follow-up, 1,448 participants developed incident cognitive impairment. Overall, a high level of participation in leisure activities was associated with a 41% decreased risk of cognitive impairment compared to low-level engagement in leisure activities after controlling for age, gender, education, and other confounders. Moreover, there was a significant interaction between leisure activity and educational level, such that the beneficial effect of leisure activities on cognitive function was larger in educated elderly than their uneducated counterparts, and only educated elderly benefited from cognitive activities. Late-life leisure activities protect against cognitive impairment among elderly Chinese people, and the protective effects are more profound for educated elderly.

  18. Can Insomnia in Pregnancy Predict Postpartum Depression? A Longitudinal, Population-Based Study

    Science.gov (United States)

    Dørheim, Signe K.; Bjorvatn, Bjørn; Eberhard-Gran, Malin

    2014-01-01

    Background Insomnia and depression are strongly interrelated. This study aimed to describe changes in sleep across childbirth, and to evaluate whether insomnia in pregnancy is a predictor of postpartum depression. Methods A longitudinal, population-based study was conducted among perinatal women giving birth at Akershus University Hospital, Norway. Women received questionnaires in weeks 17 and 32 of pregnancy and eight weeks postpartum. This paper presents data from 2,088 of 4,662 women with complete data for insomnia and depression in week 32 of pregnancy and eight weeks postpartum. Sleep times, wake-up times and average sleep durations were self-reported. The Bergen Insomnia Scale (BIS) was used to measure insomnia. The Edinburgh Postnatal Depression Scale (EPDS) was used to measure depressive symptoms. Results After delivery, sleep duration was reduced by 49 minutes (to 6.5 hours), and mean sleep efficiency was reduced from 84% to 75%. However, self-reported insomnia scores (BIS) improved from 17.2 to 15.4, and the reported prevalence of insomnia decreased from 61.6% to 53.8%. High EPDS scores and anxiety in pregnancy, fear of delivery, previous depression, primiparity, and higher educational level were risk factors for both postpartum insomnia and depression. Insomnia did not predict postpartum depression in women with no prior history of depression, whereas women who recovered from depression had residual insomnia. Limitations Depression and insomnia were not verified by clinical interviews. Women with depressive symptoms were less likely to remain in the study. Conclusions Although women slept fewer hours at night after delivery compared to during late pregnancy, and reported more nights with nighttime awakenings, their self-reported insomnia scores improved, and the prevalence of insomnia according to the DSM-IV criteria decreased. Insomnia in pregnancy may be a marker for postpartum recurrence of depression among women with previous depression. PMID

  19. Cardiovascular events in patients with atherothrombotic disease: a population-based longitudinal study in Taiwan.

    Directory of Open Access Journals (Sweden)

    Wen-Hsien Lee

    Full Text Available BACKGROUND: Atherothrombotic diseases including cerebrovascular disease (CVD, coronary artery disease (CAD, and peripheral arterial disease (PAD, contribute to the major causes of death in the world. Although several studies showed the association between polyvascular disease and poor cardiovascular (CV outcomes in Asian population, there was no large-scale study to validate this relationship in this population. METHODS AND RESULTS: This retrospective cohort study included patients with a diagnosis of CVD, CAD, or PAD from the database contained in the Taiwan National Health Insurance Bureau during 2001-2004. A total of 19954 patients were enrolled in this study. The atherothrombotic disease score was defined according to the number of atherothrombotic disease. The study endpoints included acute coronary syndrome (ACS, all strokes, vascular procedures, in hospital mortality, and so on. The event rate of ischemic stroke (18.2% was higher than that of acute myocardial infarction (5.7% in our patients (P = 0.0006. In the multivariate Cox regression analyses, the adjusted hazard ratios (HRs of each increment of atherothrombotic disease score in predicting ACS, all strokes, vascular procedures, and in hospital mortality were 1.41, 1.66, 1.30, and 1.14, respectively (P≦0.0169. CONCLUSIONS: This large population-based longitudinal study in patients with atherothrombotic disease demonstrated the risk of subsequent ischemic stroke was higher than that of subsequent AMI. In addition, the subsequent adverse CV events including ACS, all stroke, vascular procedures, and in hospital mortality were progressively increased as the increase of atherothrombotic disease score.

  20. Elevated incidence rates of diabetes in Peru: report from PERUDIAB, a national urban population-based longitudinal study

    OpenAIRE

    Seclen, Segundo Nicolas; Rosas, Moises Ernesto; Arias, Arturo Jaime; Medina, Cecilia Alexandra

    2017-01-01

    Objective A recent report from a non-nationally representative, geographically diverse sample in four separate communities in Peru suggests an unusually high diabetes incidence. We aimed to estimate the national diabetes incidence rate using PERUDIAB, a probabilistic, national urban population-based longitudinal study. Research design and methods 662 subjects without diabetes, selected by multistage, cluster, random sampling of households, representing the 24 administrative and the 3 (coast, ...

  1. Older adults’ home- and community-based care service use and residential transitions: a longitudinal study

    Directory of Open Access Journals (Sweden)

    Chen Ya-Mei

    2012-08-01

    Full Text Available Abstract Background As Home-and Community-Based Services (HCBS, such as skilled nursing services or personal care services, have become increasingly available, it has become clear that older adults transit through different residential statuses over time. Older adults may transit through different residential statuses as the various services meet their needs. The purpose of this exploratory study was to better understand the interplay between community-dwelling older adults’ use of home- and community-based services and their residential transitions. Methods The study compared HCBS service-use patterns and residential transitions of 3,085 older adults from the Second Longitudinal Study of Aging. Based on older adults’ residential status at the three follow-up interviews, four residential transitions were tracked: (1 Community-Community-Community (CCC: Resided in community during the entire study period; (2 Community-Institution-Community (CIC: Resided in community at T1, had lived in an institution at some time between T1 and T2, then had returned to community by T3; (3 Community-Community-Institution (CCI: Resided in community between at T1, and betweenT1 and T2, including at T2, but had used institutional services between T2 and T3; (4 Community-Institution-Institution (CII: Resided in community at T1 but in an institution at some time between T1 and T2, and at some time between T2 and T3.. Results Older adults’ use of nondiscretionary and discretionary services differed significantly among the four groups, and the patterns of HCBS use among these groups were also different. Older adults’ use of nondiscretionary services, such as skilled nursing care, may help them to return to communities from institutions. Personal care services (PCS and senior center services may be the key to either support elders to stay in communities longer or help elders to return to their communities from institutions. Different combinations of PCS with other

  2. The Efficacy of Epidemic Algorithms on Detecting Node Replicas in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Narasimha Shashidhar

    2015-12-01

    Full Text Available A node replication attack against a wireless sensor network involves surreptitious efforts by an adversary to insert duplicate sensor nodes into the network while avoiding detection. Due to the lack of tamper-resistant hardware and the low cost of sensor nodes, launching replication attacks takes little effort to carry out. Naturally, detecting these replica nodes is a very important task and has been studied extensively. In this paper, we propose a novel distributed, randomized sensor duplicate detection algorithm called Discard to detect node replicas in group-deployed wireless sensor networks. Our protocol is an epidemic, self-organizing duplicate detection scheme, which exhibits emergent properties. Epidemic schemes have found diverse applications in distributed computing: load balancing, topology management, audio and video streaming, computing aggregate functions, failure detection, network and resource monitoring, to name a few. To the best of our knowledge, our algorithm is the first attempt at exploring the potential of this paradigm to detect replicas in a wireless sensor network. Through analysis and simulation, we show that our scheme achieves robust replica detection with substantially lower communication, computational and storage requirements than prior schemes in the literature.

  3. Three-Dimensional Interpretation of Sculptural Heritage with Digital and Tangible 3D Printed Replicas

    Science.gov (United States)

    Saorin, José Luis; Carbonell-Carrera, Carlos; Cantero, Jorge de la Torre; Meier, Cecile; Aleman, Drago Diaz

    2017-01-01

    Spatial interpretation features as a skill to acquire in the educational curricula. The visualization and interpretation of three-dimensional objects in tactile devices and the possibility of digital manufacturing with 3D printers, offers an opportunity to include replicas of sculptures in teaching and, thus, facilitate the 3D interpretation of…

  4. Systematic expansion in the order parameter for replica theory of the dynamical glass transition.

    Science.gov (United States)

    Jacquin, Hugo; Zamponi, Francesco

    2013-03-28

    It has been shown recently that predictions from mode-coupling theory for the glass transition of hard-spheres become increasingly bad when dimensionality increases, whereas replica theory predicts a correct scaling. Nevertheless if one focuses on the regime around the dynamical transition in three dimensions, mode-coupling results are far more convincing than replica theory predictions. It seems thus necessary to reconcile the two theoretic approaches in order to obtain a theory that interpolates between low-dimensional, mode-coupling results, and "mean-field" results from replica theory. Even though quantitative results for the dynamical transition issued from replica theory are not accurate in low dimensions, two different approximation schemes--small cage expansion and replicated hyper-netted-chain (RHNC)--provide the correct qualitative picture for the transition, namely, a discontinuous jump of a static order parameter from zero to a finite value. The purpose of this work is to develop a systematic expansion around the RHNC result in powers of the static order parameter, and to calculate the first correction in this expansion. Interestingly, this correction involves the static three-body correlations of the liquid. More importantly, we separately demonstrate that higher order terms in the expansion are quantitatively relevant at the transition, and that the usual mode-coupling kernel, involving two-body direct correlation functions of the liquid, cannot be recovered from static computations.

  5. Fast Optimal Replica Placement with Exhaustive Search Using Dynamically Reconfigurable Processor

    Directory of Open Access Journals (Sweden)

    Hidetoshi Takeshita

    2011-01-01

    Full Text Available This paper proposes a new replica placement algorithm that expands the exhaustive search limit with reasonable calculation time. It combines a new type of parallel data-flow processor with an architecture tuned for fast calculation. The replica placement problem is to find a replica-server set satisfying service constraints in a content delivery network (CDN. It is derived from the set cover problem which is known to be NP-hard. It is impractical to use exhaustive search to obtain optimal replica placement in large-scale networks, because calculation time increases with the number of combinations. To reduce calculation time, heuristic algorithms have been proposed, but it is known that no heuristic algorithm is assured of finding the optimal solution. The proposed algorithm suits parallel processing and pipeline execution and is implemented on DAPDNA-2, a dynamically reconfigurable processor. Experiments show that the proposed algorithm expands the exhaustive search limit by the factor of 18.8 compared to the conventional algorithm search limit running on a Neumann-type processor.

  6. A Longitudinal Study of a 5th Grade Science Curriculum Based on the 5E Model

    Science.gov (United States)

    Scott, Timothy P.; Schroeder, Carolyn; Tolson, Homer; Huang, Tse-Yang; Williams, Omah M.

    2014-01-01

    The Center for Mathematics and Science Education at Texas A&M University contracted with Region 4 Education Service Center (ESC) and a large, diverse school district to conduct a longitudinal study from 2005-2009. The state achievement test scores of 5th graders who were taught using a Grade 5 science textbook designed by Region 4 ESC were…

  7. Subtypes of suicide attempters based on longitudinal childhood profiles of co-occurring depressive, anxious and aggressive behavior symptoms.

    Science.gov (United States)

    Hart, Shelley R; Van Eck, Kathryn; Ballard, Elizabeth D; Musci, Rashelle J; Newcomer, Alison; Wilcox, Holly C

    2017-11-01

    Because suicide attempts are multi-determined events, multiple pathways to suicidal behaviors exist. However, as a low-frequency behavior, within group differences in trajectories to attempts may not emerge when examined in samples including non-attempters. We used longitudinal latent profile analysis to identify subtypes specific for suicide attempters based on longitudinal trajectories of childhood clinical symptoms (i.e., depression, anxiety, and aggression measured in 2nd, 4th-7th grades) for 161 young adults (35.6% male; 58.6% African American) who attempted suicide between ages 13-30 from a large, urban community-based, longitudinal prevention trial (n = 2311). Differences in psychiatric diagnoses, suicide attempt characteristics, criminal history and traumatic stress history were studied. Three subtypes emerged: those with all low (n = 32%), all high (n = 16%), and high depressive/anxious, but low aggressive (n = 52%) symptoms. Those with the highest levels of all symptoms were significantly more likely to report a younger age of suicide attempt, and demonstrate more substance abuse disorders and violent criminal histories. Prior studies have found that childhood symptoms of depression, anxiety and aggression are malleable targets; interventions directed at each reduce future risk for suicidal behaviors. Our findings highlight the link of childhood aggression with future suicidal behaviors extending this research by examining childhood symptoms of aggression in the context of depression and anxiety. Copyright © 2017. Published by Elsevier B.V.

  8. Effect of cation nature of zeolite on carbon replicas and their electrochemical capacitance

    International Nuclear Information System (INIS)

    Zhou, Jin; Li, Wen; Zhang, Zhongshen; Wu, Xiaozhong; Xing, Wei; Zhuo, Shuping

    2013-01-01

    Graphical abstract: Cation nature of zeolite influences the porosity, surface chemical properties of carbon replicas of zeolite, resulting in different electrochemical capacitance. Highlights: ► The porosity of carbon replica strongly depends on zeolite's effective pore size. ► The surface chemical properties influence by the cation nature of zeolite. ► The N-doping introduces large pseudo-capacitance. ► The HYC800 carbon showed a high capacitance of up to 312 F g −1 in 1 M H 2 SO 4 . ► The prepared carbons show good durability of galvanostatic cycle. -- Abstract: N-doped carbon replicas of zeolite Y are prepared, and the effect of cation nature of zeolite (H + or Na + ) on the carbon replicas is studied. The morphology, structure and surface properties of the carbon materials are investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), N 2 adsorption, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). The pore regularity, pore parameter and surface chemical properties of the carbons may strongly depend on the cation nature of the zeolite Y. The carbon replicas of zeolite HY (H-form of zeolite Y) possesses higher pore regularity and much larger surface area than those of zeolite NaY (Na-form of zeolite Y), while the latter carbons seem to possess higher carbonization degrees. Electrochemical measurements show a large faradaic capacitance related to the N- or O-containing groups for the prepared carbons. Owing to the large specific surface area, high pore regularity and heteroatom-doping, the HYC800 sample derived from zeolite HY presents very high gravimetric capacitance, up to 312.4 F g −1 in H 2 SO 4 electrolyte, and this carbon can operate at 1.2 V with good retention ratio in the range of 0.25 to 10 A g −1

  9. Coulomb replica-exchange method: handling electrostatic attractive and repulsive forces for biomolecules.

    Science.gov (United States)

    Itoh, Satoru G; Okumura, Hisashi

    2013-03-30

    We propose a new type of the Hamiltonian replica-exchange method (REM) for molecular dynamics (MD) and Monte Carlo simulations, which we refer to as the Coulomb REM (CREM). In this method, electrostatic charge parameters in the Coulomb interactions are exchanged among replicas while temperatures are exchanged in the usual REM. By varying the atom charges, the CREM overcomes free-energy barriers and realizes more efficient sampling in the conformational space than the REM. Furthermore, this method requires only a smaller number of replicas because only the atom charges of solute molecules are used as exchanged parameters. We performed Coulomb replica-exchange MD simulations of an alanine dipeptide in explicit water solvent and compared the results with those of the conventional canonical, replica exchange, and van der Waals REMs. Two force fields of AMBER parm99 and AMBER parm99SB were used. As a result, the CREM sampled all local-minimum free-energy states more frequently than the other methods for both force fields. Moreover, the Coulomb, van der Waals, and usual REMs were applied to a fragment of an amyloid-β peptide (Aβ) in explicit water solvent to compare the sampling efficiency of these methods for a larger system. The CREM sampled structures of the Aβ fragment more efficiently than the other methods. We obtained β-helix, α-helix, 3(10)-helix, β-hairpin, and β-sheet structures as stable structures and deduced pathways of conformational transitions among these structures from a free-energy landscape. Copyright © 2012 Wiley Periodicals, Inc.

  10. Efficient Round-Trip Time Optimization for Replica-Exchange Enveloping Distribution Sampling (RE-EDS).

    Science.gov (United States)

    Sidler, Dominik; Cristòfol-Clough, Michael; Riniker, Sereina

    2017-06-13

    Replica-exchange enveloping distribution sampling (RE-EDS) allows the efficient estimation of free-energy differences between multiple end-states from a single molecular dynamics (MD) simulation. In EDS, a reference state is sampled, which can be tuned by two types of parameters, i.e., smoothness parameters(s) and energy offsets, such that all end-states are sufficiently sampled. However, the choice of these parameters is not trivial. Replica exchange (RE) or parallel tempering is a widely applied technique to enhance sampling. By combining EDS with the RE technique, the parameter choice problem could be simplified and the challenge shifted toward an optimal distribution of the replicas in the smoothness-parameter space. The choice of a certain replica distribution can alter the sampling efficiency significantly. In this work, global round-trip time optimization (GRTO) algorithms are tested for the use in RE-EDS simulations. In addition, a local round-trip time optimization (LRTO) algorithm is proposed for systems with slowly adapting environments, where a reliable estimate for the round-trip time is challenging to obtain. The optimization algorithms were applied to RE-EDS simulations of a system of nine small-molecule inhibitors of phenylethanolamine N-methyltransferase (PNMT). The energy offsets were determined using our recently proposed parallel energy-offset (PEOE) estimation scheme. While the multistate GRTO algorithm yielded the best replica distribution for the ligands in water, the multistate LRTO algorithm was found to be the method of choice for the ligands in complex with PNMT. With this, the 36 alchemical free-energy differences between the nine ligands were calculated successfully from a single RE-EDS simulation 10 ns in length. Thus, RE-EDS presents an efficient method for the estimation of relative binding free energies.

  11. Locus of control and frequency of physician visits: Results of a population-based longitudinal study in Germany.

    Science.gov (United States)

    Hajek, André; König, Hans-Helmut

    2017-09-01

    To examine the role of internal and external locus of control (LOC) in the frequency of physician visits longitudinally. A nationally representative, longitudinal cohort study of German households. Data were used from the years 2005 and 2010. Data were gathered from the German Socio-Economic Panel (GSOEP). The ten internal and external LOC items in the SOEP are based on a scale by Krampen. The number of physician visits in the last 3 months was used as outcome variable. According to Andersen's behavioural model, predisposing characteristics, enabling resources, and need factors were included as control variables. Fixed-effects Poisson regressions showed that physician visits increased with increasing external LOC, whereas changes in internal LOC were not associated with changes in physician visits. Furthermore, physician visits increased with need factors (decreased self-rated health; onset of disability), whereas predisposing characteristics and the enabling resources were not associated with physician visits. Our findings emphasize the meaning of changes in external LOC for physician visits. As there is evidence that interventions can change the LOC, efforts to modify external LOC might be beneficial for the health care system. Statement of contribution What is already known on this subject? A few cross-sectional studies have investigated the association between locus of control (LOC) and health care use. Longitudinal studies are needed to get a deeper understanding of the causal relationship between these factors. What does this study add? Our longitudinal study provides insights into the impact of general internal and external LOC on physician visits. This is the first study examining the long-term relation in Germany using a population-based sample. © 2017 The British Psychological Society.

  12. CardioBengo study protocol: a population based cardiovascular longitudinal study in Bengo Province, Angola

    Directory of Open Access Journals (Sweden)

    João M. Pedro

    2016-03-01

    Full Text Available Abstract Background Cardiovascular diseases and other non-communicable diseases are major causes of morbidity and mortality, responsible for 38 million deaths in 2012, 75 % occurring in low- and middle-income countries. Most of these countries are facing a period of epidemiological transition, being confronted with an increased burden of non-communicable diseases, which challenge health systems mainly designed to deal with infectious diseases. With the adoption of the World Health Organization “Global Action Plan for the Prevention and Control of non-communicable diseases, 2013–2020”, the national dimension of risk factors for non-communicable diseases must be reported on a regular basis. Angola has no national surveillance system for non-communicable diseases, and periodic population-based studies can help to overcome this lack of information. CardioBengo will collect information on risk factors, awareness rates and prevalence of symptoms relevant to cardiovascular diseases, to assist decision makers in the implementation of prevention and treatment policies and programs. Methods CardioBengo is designed as a research structure that comprises a cross-sectional component, providing baseline information and the assembling of a cohort to follow-up the dynamics of cardiovascular diseases risk factors in the catchment area of the Dande Health and Demographic Surveillance System of the Health Research Centre of Angola, in Bengo Province, Angola. The World Health Organization STEPwise approach to surveillance questionnaires and procedures will be used to collect information on a representative sex-age stratified sample, aged between 15 and 64 years old. Discussion CardioBengo will recruit the first population cohort in Angola designed to evaluate cardiovascular diseases risk factors. Using the structures in place of the Dande Health and Demographic Surveillance System and a reliable methodology that generates comparable results with other

  13. Burden of diabetes mellitus estimated with a longitudinal population-based study using administrative databases.

    Directory of Open Access Journals (Sweden)

    Luciana Scalone

    Full Text Available OBJECTIVE: To assess the epidemiologic and economic burden of diabetes mellitus (DM from a longitudinal population-based study. RESEARCH DESIGN AND METHODS: Lombardy Region includes 9.9 million individuals. Its DM population was identified through a data warehouse (DENALI, which matches with a probabilistic linkage demographic, clinical and economic data of different Healthcare Administrative databases. All individuals, who, during the year 2000 had an hospital discharge with a IDC-9 CM code 250.XX, and/or two consecutive prescriptions of drugs for diabetes (ATC code A10XXXX within one year, and/or an exemption from co-payment healthcare costs specific for DM, were selected and followed up to 9 years. We calculated prevalence, mortality and healthcare costs (hospitalizations, drugs and outpatient examinations/visits from the National Health Service's perspective. RESULTS: We identified 312,223 eligible subjects. The study population (51% male had a mean age of 66 (from 0.03 to 105.12 years at the index date. Prevalence ranged from 0.4% among subjects aged ≤45 years to 10.1% among those >85 years old. Overall 43.4 deaths per 1,000 patients per year were estimated, significantly (p<0.001 higher in men than women. Overall, 3,315€/patient-year were spent on average: hospitalizations were the cost driver (54.2% of total cost. Drugs contributed to 31.5%, outpatient claims represented 14.3% of total costs. Thirty-five percent of hospital costs were attributable to cerebro-/cardiovascular reasons, 6% to other complications of DM, and 4% to DM as a main diagnosis. Cardiovascular drugs contributed to 33.5% of total drug costs, 21.8% was attributable to class A (16.7% to class A10 and 4.3% to class B (2.4% to class B01 drugs. CONCLUSIONS: Merging different administrative databases can provide with many data from large populations observed for long time periods. DENALI shows to be an efficient instrument to obtain accurate estimates of burden of

  14. CardioBengo study protocol: a population based cardiovascular longitudinal study in Bengo Province, Angola.

    Science.gov (United States)

    Pedro, João M; Rosário, Edite; Brito, Miguel; Barros, Henrique

    2016-03-01

    Cardiovascular diseases and other non-communicable diseases are major causes of morbidity and mortality, responsible for 38 million deaths in 2012, 75 % occurring in low- and middle-income countries. Most of these countries are facing a period of epidemiological transition, being confronted with an increased burden of non-communicable diseases, which challenge health systems mainly designed to deal with infectious diseases. With the adoption of the World Health Organization "Global Action Plan for the Prevention and Control of non-communicable diseases, 2013-2020", the national dimension of risk factors for non-communicable diseases must be reported on a regular basis. Angola has no national surveillance system for non-communicable diseases, and periodic population-based studies can help to overcome this lack of information. CardioBengo will collect information on risk factors, awareness rates and prevalence of symptoms relevant to cardiovascular diseases, to assist decision makers in the implementation of prevention and treatment policies and programs. CardioBengo is designed as a research structure that comprises a cross-sectional component, providing baseline information and the assembling of a cohort to follow-up the dynamics of cardiovascular diseases risk factors in the catchment area of the Dande Health and Demographic Surveillance System of the Health Research Centre of Angola, in Bengo Province, Angola. The World Health Organization STEPwise approach to surveillance questionnaires and procedures will be used to collect information on a representative sex-age stratified sample, aged between 15 and 64 years old. CardioBengo will recruit the first population cohort in Angola designed to evaluate cardiovascular diseases risk factors. Using the structures in place of the Dande Health and Demographic Surveillance System and a reliable methodology that generates comparable results with other regions and countries, this study will constitute a useful tool for

  15. Course of bereavement over 8-10 years in first degree relatives and spouses of people who committed suicide : longitudinal community based cohort study

    NARCIS (Netherlands)

    de Groot, Marieke; Kollen, Boudewijn J.

    2013-01-01

    Objective To identify factors predicting the long term course of complicated grief, depression, and suicide ideation in a community based sample of relatives bereaved through suicide. Design Longitudinal cohort study. Included in the multilevel regression models were sociodemographic and personality

  16. Course of bereavement over 8-10 years in first degree relatives and spouses of people who committed suicide: longitudinal community based cohort study

    NARCIS (Netherlands)

    de Groot, M.; Kollen, B.J.

    2013-01-01

    Objective To identify factors predicting the long term course of complicated grief, depression, and suicide ideation in a community based sample of relatives bereaved through suicide. Design Longitudinal cohort study. Included in the multilevel regression models were sociodemographic and personality

  17. medplot: a web application for dynamic summary and analysis of longitudinal medical data based on R.

    Directory of Open Access Journals (Sweden)

    Črt Ahlin

    Full Text Available In biomedical studies the patients are often evaluated numerous times and a large number of variables are recorded at each time-point. Data entry and manipulation of longitudinal data can be performed using spreadsheet programs, which usually include some data plotting and analysis capabilities and are straightforward to use, but are not designed for the analyses of complex longitudinal data. Specialized statistical software offers more flexibility and capabilities, but first time users with biomedical background often find its use difficult. We developed medplot, an interactive web application that simplifies the exploration and analysis of longitudinal data. The application can be used to summarize, visualize and analyze data by researchers that are not familiar with statistical programs and whose knowledge of statistics is limited. The summary tools produce publication-ready tables and graphs. The analysis tools include features that are seldom available in spreadsheet software, such as correction for multiple testing, repeated measurement analyses and flexible non-linear modeling of the association of the numerical variables with the outcome. medplot is freely available and open source, it has an intuitive graphical user interface (GUI, it is accessible via the Internet and can be used within a web browser, without the need for installing and maintaining programs locally on the user's computer. This paper describes the application and gives detailed examples describing how to use the application on real data from a clinical study including patients with early Lyme borreliosis.

  18. Zeolite-templated carbon replica: a Grand Canonical Monte-Carlo simulation study

    International Nuclear Information System (INIS)

    Thomas Roussel; Roland J M Pellenq; Christophe Bichara; Roger Gadiou; Antoine Didion; Cathie Vix Guterl; Fabrice Gaslain; Julien Parmentier; Valentin Valtchev; Joel Patarin

    2005-01-01

    Microporous carbon materials are interesting for several applications such as hydrogen storage, catalysis or electrical double layer capacitors. The development of the negative templating method to obtain carbon replicas from ordered templates, has lead to the synthesis of several new materials which have interesting textural properties, attractive for energy storage. Among the possible templates, zeolites can be used to obtain highly microporous carbon materials. Nevertheless, the phenomena involved in the replica synthesis are not fully understood, and the relationships between the structure of the template, the carbon precursor and the resulting carbon material need to be investigated. Experimental results for carbon zeolite-templated nano-structures can be found in a series of papers; see for instance ref. [1] in which Wang et al describe a route to ultra-small Single Wall Carbon Nano-tubes (SWNTs) using the porosity of zeolite AlPO 4 -5. After matrix removal, the resulting structure is a free-standing bundle of 4 Angstroms large nano-tubes. However, it is highly desirable to obtain an ordered porous carbon structure that forms a real 3D network to be used for instance in gas storage applications. Carbon replica of faujasite and EMT zeolites can have these properties since these zeolites have a 3D porous network made of 10 Angstroms cages connected to each other through 7 Angstroms large windows. The first step of this study was to generate a theoretical carbon replica structure of various zeolites (faujasite, EMT, AlPO 4 -5, silicalite). For this purpose, we used the Grand Canonical Monte-Carlo (GCMC) technique in which the carbon-carbon interactions were described within the frame of a newly developed Tight Binding approach and the carbon-zeolite interactions assumed to be characteristic of physi-sorption. The intrinsic stability of the subsequent carbon nano-structures was then investigated after mimicking the removal of the inorganic phase by switching

  19. Subsonic Longitudinal Performance Coefficient Extraction from Shuttle Flight Data: an Accuracy Assessment for Determination of Data Base Updates

    Science.gov (United States)

    Findlay, J. T.; Kelly, G. M.; Mcconnell, J. G.; Compton, H. R.

    1983-01-01

    Longitudinal performance comparisons between flight derived and predicted values are presented for the first five NASA Space Shuttle Columbia flights. Though subsonic comparisons are emphasized, comparisons during the transonic and low supersonic regions of flight are included. Computed air data information based on the remotely sensed atmospheric measurements as well as in situ Orbiter Air Data System (ADS) measurements were incorporated. Each air data source provides for comparisons versus the predicted values from the LaRC data base. Principally, L/D, C sub L, and C sub D, comparisons are presented, though some pitching moment results are included. Similarities in flight conditions and spacecraft configuration during the first five flights are discussed. Contributions from the various elements of the data base are presented and the overall differences observed between the flight and predicted values are discussed in terms of expected variations. A discussion on potential data base updates is presented based on the results from the five flights to date.

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

    Science.gov (United States)

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

    2016-04-01

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

  1. Longitudinal study of alcohol consumption and HDL concentrations: a community-based study.

    Science.gov (United States)

    Huang, Shue; Li, Junjuan; Shearer, Gregory C; Lichtenstein, Alice H; Zheng, Xiaoming; Wu, Yuntao; Jin, Cheng; Wu, Shouling; Gao, Xiang

    2017-04-01

    Background: In cross-sectional studies and short-term clinical trials, it has been suggested that there is a positive dose-response relation between alcohol consumption and HDL concentrations. However, prospective data have been limited. Objective: We sought to determine the association between total alcohol intake, the type of alcohol-containing beverage, and the 6-y (2006-2012) longitudinal change in HDL-cholesterol concentrations in a community-based cohort. Design: A total of 71,379 Chinese adults (mean age: 50 y) who were free of cardiovascular diseases and cancer and did not use cholesterol-lowering agents during follow-up were included in the study. Alcohol intake was assessed via a questionnaire in 2006 (baseline), and participants were classified into the following categories of alcohol consumption: never, past, light (women: 0-0.4 servings/d; men: 0-0.9 servings/d), moderate (women: 0.5-1.0 servings/d; men: 1-2 servings/d), and heavy (women: >1.0 servings/d; men: >2 servings/d). HDL-cholesterol concentrations were measured in 2006, 2008, 2010, and 2012. We used generalized estimating equation models to examine the associations between baseline alcohol intake and the change in HDL-cholesterol concentrations with adjustment for age, sex, smoking, physical activity, obesity, hypertension, diabetes, liver function, and C-reactive protein concentrations. Results: An umbrella-shaped association was observed between total alcohol consumption and changes in HDL-cholesterol concentrations. Compared with never drinkers, past, light, moderate, and heavy drinkers experienced slower decreases in HDL cholesterol of 0.012 mmol · L -1 · y -1 (95% CI: 0.008, 0.016 mmol · L -1 · y -1 ), 0.013 mmol · L -1 · y -1 (95% CI: 0.010, 0.016 mmol · L -1 · y -1 ), 0.017 mmol · L -1 · y -1 (95% CI: 0.009, 0.025 mmol · L -1 · y -1 ), and 0.008 mmol · L -1 · y -1 (95% CI: 0.005, 0.011 mmol · L -1 · y -1 ), respectively ( P alcohol consumption was associated with the

  2. Using longitudinal mixed methods to study the development of professional behaviours during pharmacy work-based training.

    Science.gov (United States)

    Jee, Samuel D; Schafheutle, Ellen I; Noyce, Peter R

    2017-05-01

    Recent longitudinal investigations of professional socialisation and development of professional behaviours during work-based training are lacking. Using longitudinal mixed methods, this study aimed to explore the development of professional behaviours during a year of intensive work-based (pre-registration) training in pharmacy. Twenty trainee pharmacists and their tutors completed semi-structured interview and professional behaviour questionnaires at four time points during 2011/2012: months 1, 4 and 9 during training and 4 months after registration; tutors participated in months 1 and 9. Interviews were analysed thematically using template analysis, and questionnaires were analysed using ANOVA and t-tests. Self-assessed (trainee) and tutor ratings of all elements of professional behaviours measured in questionnaires (appearance, interpersonal/social skills, responsibility, communication skills) increased significantly from the start of pre-registration training to post-registration. Some elements, for example, communication skills, showed more change over time compared with others, such as appearance, and continued to improve post-registration. Qualitative findings highlighted the changing roles of trainees and learning experiences that appeared to facilitate the development of professional behaviours. Trainees' colleagues, and particularly tutors, played an essential part in trainees' development through offering support and role modelling. Trainees noted that they would have benefited from more responsibilities during training to ease the transition into practising as a responsible pharmacist. Longitudinal mixed methods can unpack the way in which professional behaviours develop during work-based training and allow researchers to examine changes in the demonstration of professional behaviours and how they occur. Identifying areas less prone to change allows for more focus to be given to supporting trainees in areas where there is a development need, such as

  3. Subdiffraction-limited imaging based on longitudinal modes in a spatially dispersive slab

    Science.gov (United States)

    Yanai, Avner; Levy, Uriel

    2014-08-01

    It was proposed that a flat silver layer could be used to form a subdiffraction-limited image when illuminated near its surface plasmon resonance frequency [J. B. Pendry, Phys. Rev. Lett. 85, 3966 (2000), 10.1103/PhysRevLett.85.3966]. In this paper, we study the possibility of obtaining sub diffraction resolution using a different mechanism, with no surface plasmons involved. Instead, by taking into account the nonlocal response of a thin silver slab, we show that longitudinal modes contribute to the formation of a subdiffraction-limited image in a frequency regime above the plasma frequency. The differences between these two distinct mechanisms are studied and explained.

  4. Neural Network-Based Model for Landslide Susceptibility and Soil Longitudinal Profile Analyses

    DEFF Research Database (Denmark)

    Farrokhzad, F.; Barari, Amin; Choobbasti, A. J.

    2011-01-01

    The purpose of this study was to create an empirical model for assessing the landslide risk potential at Savadkouh Azad University, which is located in the rural surroundings of Savadkouh, about 5 km from the city of Pol-Sefid in northern Iran. The soil longitudinal profile of the city of Babol......, located 25 km from the Caspian Sea, also was predicted with an artificial neural network (ANN). A multilayer perceptron neural network model was applied to the landslide area and was used to analyze specific elements in the study area that contributed to previous landsliding events. The ANN models were...... studies in landslide susceptibility zonation....

  5. Analyzing age-specific genetic effects on human extreme age survival in cohort-based longitudinal studies

    DEFF Research Database (Denmark)

    Tan, Qihua; Jacobsen, Rune; Sørensen, Mette

    2013-01-01

    The analysis of age-specific genetic effects on human survival over extreme ages is confronted with a deceleration pattern in mortality that deviates from traditional survival models and sparse genetic data available. As human late life is a distinct phase of life history, exploring the genetic...... effects on extreme age survival can be of special interest to evolutionary biology and health science. We introduce a non-parametric survival analysis approach that combines population survival information with individual genotype data in assessing the genetic effects in cohort-based longitudinal studies...

  6. Evaluation of generalized degrees of freedom for sparse estimation by replica method

    Science.gov (United States)

    Sakata, A.

    2016-12-01

    We develop a method to evaluate the generalized degrees of freedom (GDF) for linear regression with sparse regularization. The GDF is a key factor in model selection, and thus its evaluation is useful in many modelling applications. An analytical expression for the GDF is derived using the replica method in the large-system-size limit with random Gaussian predictors. The resulting formula has a universal form that is independent of the type of regularization, providing us with a simple interpretation. Within the framework of replica symmetric (RS) analysis, GDF has a physical meaning as the effective fraction of non-zero components. The validity of our method in the RS phase is supported by the consistency of our results with previous mathematical results. The analytical results in the RS phase are calculated numerically using the belief propagation algorithm.

  7. Neutron and gamma dose and spectra measurements on the Little Boy replica

    International Nuclear Information System (INIS)

    Hoots, S.; Wadsworth, D.

    1984-01-01

    The radiation-measurement team of the Weapons Engineering Division at Lawrence Livermore National Laboratory (LLNL) measured neutron and gamma dose and spectra on the Little Boy replica at Los Alamos National Laboratory (LANL) in April 1983. This assembly is a replica of the gun-type atomic bomb exploded over Hiroshima in 1945. These measurements support the National Academy of Sciences Program to reassess the radiation doses due to atomic bomb explosions in Japan. Specifically, the following types of information were important: neutron spectra as a function of geometry, gamma to neutron dose ratios out to 1.5 km, and neutron attenuation in the atmosphere. We measured neutron and gamma dose/fission from close-in to a kilometer out, and neutron and gamma spectra at 90 and 30 0 close-in. This paper describes these measurements and the results. 12 references, 13 figures, 5 tables

  8. Proactive replica checking to assure reliability of data in cloud storage with minimum replication

    Science.gov (United States)

    Murarka, Damini; Maheswari, G. Uma

    2017-11-01

    The two major issues for cloud storage systems are data reliability and storage costs. For data reliability protection, multi-replica replication strategy which is used mostly in current clouds acquires huge storage consumption, leading to a large storage cost for applications within the loud specifically. This paper presents a cost-efficient data reliability mechanism named PRCR to cut back the cloud storage consumption. PRCR ensures data reliability of large cloud information with the replication that might conjointly function as a price effective benchmark for replication. The duplication shows that when resembled to the standard three-replica approach, PRCR will scale back to consume only a simple fraction of the cloud storage from one-third of the storage, thence considerably minimizing the cloud storage price.

  9. Fabrication of micropillar substrates using replicas of alpha-particle irradiated and chemically etched PADC films

    International Nuclear Information System (INIS)

    Ng, C.K.M.; Chong, E.Y.W.; Roy, V.A.L.; Cheung, K.M.C.; Yeung, K.W.K.; Yu, K.N.

    2012-01-01

    We proposed a simple method to fabricate micropillar substrates. Polyallyldiglycol carbonate (PADC) films were irradiated by alpha particles and then chemically etched to form a cast with micron-scale spherical pores. A polydimethylsiloxane (PDMS) replica of this PADC film gave a micropillar substrate with micron-scale spherical pillars. HeLa cells cultured on such a micropillar substrate had significantly larger percentage of cells entering S-phase, attached cell numbers and cell spreading areas. - Highlights: ► We proposed a simple method to fabricate micropillar substrates. ► Polyallyldiglycol carbonate films were irradiated and etched to form casts. ► Polydimethylsiloxane replica then formed the micropillar substrates. ► Attachment and proliferation of HeLa cells were enhanced on these substrates.

  10. Fabrication of micropillar substrates using replicas of alpha-particle irradiated and chemically etched PADC films

    Energy Technology Data Exchange (ETDEWEB)

    Ng, C.K.M. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); Chong, E.Y.W. [Department of Orthopaedics and Traumatology, University of Hong Kong (Hong Kong); Roy, V.A.L. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); Cheung, K.M.C.; Yeung, K.W.K. [Department of Orthopaedics and Traumatology, University of Hong Kong (Hong Kong); Yu, K.N., E-mail: appetery@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong)

    2012-07-15

    We proposed a simple method to fabricate micropillar substrates. Polyallyldiglycol carbonate (PADC) films were irradiated by alpha particles and then chemically etched to form a cast with micron-scale spherical pores. A polydimethylsiloxane (PDMS) replica of this PADC film gave a micropillar substrate with micron-scale spherical pillars. HeLa cells cultured on such a micropillar substrate had significantly larger percentage of cells entering S-phase, attached cell numbers and cell spreading areas. - Highlights: Black-Right-Pointing-Pointer We proposed a simple method to fabricate micropillar substrates. Black-Right-Pointing-Pointer Polyallyldiglycol carbonate films were irradiated and etched to form casts. Black-Right-Pointing-Pointer Polydimethylsiloxane replica then formed the micropillar substrates. Black-Right-Pointing-Pointer Attachment and proliferation of HeLa cells were enhanced on these substrates.

  11. Neutron and gamma-ray dose-rates from the Little Boy replica

    International Nuclear Information System (INIS)

    Plassmann, E.A.; Pederson, R.A.

    1984-01-01

    We report dose-rate information obtained at many locations in the near vicinity of, and at distances out to 0.64 km from, the Little Boy replica while it was operated as a critical assembly. The measurements were made with modified conventional dosimetry instruments that used an Anderson-Braun detector for neutrons and a Geiger-Mueller tube for gamma rays with suitable electronic modules to count particle-induced pulses. Thermoluminescent dosimetry methods provide corroborative data. Our analysis gives estimates of both neutron and gamma-ray relaxation lengths in air for comparison with earlier calculations. We also show the neutron-to-gamma-ray dose ratio as a function of distance from the replica. Current experiments and further data analysis will refine these results. 7 references, 8 figures

  12. Bayesian quantile regression-based partially linear mixed-effects joint models for longitudinal data with multiple features.

    Science.gov (United States)

    Zhang, Hanze; Huang, Yangxin; Wang, Wei; Chen, Henian; Langland-Orban, Barbara

    2017-01-01

    In longitudinal AIDS studies, it is of interest to investigate the relationship between HIV viral load and CD4 cell counts, as well as the complicated time effect. Most of common models to analyze such complex longitudinal data are based on mean-regression, which fails to provide efficient estimates due to outliers and/or heavy tails. Quantile regression-based partially linear mixed-effects models, a special case of semiparametric models enjoying benefits of both parametric and nonparametric models, have the flexibility to monitor the viral dynamics nonparametrically and detect the varying CD4 effects parametrically at different quantiles of viral load. Meanwhile, it is critical to consider various data features of repeated measurements, including left-censoring due to a limit of detection, covariate measurement error, and asymmetric distribution. In this research, we first establish a Bayesian joint models that accounts for all these data features simultaneously in the framework of quantile regression-based partially linear mixed-effects models. The proposed models are applied to analyze the Multicenter AIDS Cohort Study (MACS) data. Simulation studies are also conducted to assess the performance of the proposed methods under different scenarios.

  13. 1.5 W high efficiency and tunable single-longitudinal-mode Ho:YLF ring laser based on Faraday effect.

    Science.gov (United States)

    Wu, Jing; Ju, Youlun; Dai, Tongyu; Yao, Baoquan; Wang, Yuezhu

    2017-10-30

    We demonstrated an efficient and tunable single-longitudinal-mode Ho:YLF ring laser based on Faraday effect for application to measure atmospheric carbon dioxide (CO 2 ). Single-longitudinal-mode power at 2051.65 nm achieved 528 mW with the slope efficiency of 39.5% and the M 2 factor of 1.07, and the tunable range of about 178 GHz was obtained by inserting a Fabry-Perot (F-P) etalon with the thickness of 0.5 mm. In addition, the maximum single-longitudinal-mode power reached 1.5 W with the injected power of 528 mW at 2051.65 nm by master oscillator power amplifier (MOPA) technique. High efficiency and tunable single-longitudinal-mode based on Faraday effect around 2 μm has not been reported yet to the best of our knowledge.

  14. Quality of life among prostate cancer patients: A prospective longitudinal population-based study

    International Nuclear Information System (INIS)

    Schaake, Wouter; Groot, Martijn de; Krijnen, Wim P.; Langendijk, Johannes A.; Bergh, Alfons C.M. van den

    2013-01-01

    Purpose: To investigate the course of quality of life (QoL) among prostate cancer patients treated with external beam radiotherapy and to compare the results with QoL of a normal age-matched reference population. Patients and methods: The study population was composed of 227 prostate cancer patients, treated with radiotherapy. The EORTC QLQ-C30 was used to assess QoL before radiotherapy and six months, one year, two years and three years after completion of radiotherapy. Mixed model analyses were used to investigate longitudinal changes in QoL. QoL of prostate cancer patients was compared to that of a normative cohort using a multivariate analysis of covariance. Results: A significant decline in QoL was observed after radiotherapy (p < 0.001). The addition of hormonal therapy to radiotherapy was associated with a lower level of role functioning. Patients with coronary heart disease and or chronic obstructive pulmonary disease or asthma had a significantly worse course in QoL. Although statistically significant, all differences were classified as small or trivial. Conclusion: Prostate cancer patients experience a small worsening of QoL as compared with baseline and as compared with a normal reference population. As co-morbidity modulates patients’ post-treatment QoL, a proper assessment of co-morbidity should be included in future longitudinal analyses on QoL

  15. The influence of place on weight gain during early childhood: a population-based, longitudinal study.

    Science.gov (United States)

    Carter, Megan Ann; Dubois, Lise; Tremblay, Mark S; Taljaard, Monica

    2013-04-01

    The objective of this paper was to determine the influence of place factors on weight gain in a contemporary cohort of children while also adjusting for early life and individual/family social factors. Participants from the Québec Longitudinal Study of Child Development comprised the sample for analysis (n = 1,580). A mixed-effects regression analysis was conducted to determine the longitudinal relationship between these place factors and standardized BMI, from age 4 to 10 years. The average relationship with time was found to be quadratic (rate of weight gain increased over time). Neighborhood material deprivation was found to be positively related to weight gain. Social deprivation, social disorder, and living in a medium density area were inversely related, while no association was found for social cohesion. Early life factors and genetic proxies appeared to be important in explaining weight gain in this sample. This study suggests that residential environments may play a role in childhood weight change; however, pathways are likely to be complex and interacting and perhaps not as important as early life factors and genetic proxies. Further work is required to clarify these relationships.

  16. Impact of Channel Estimation Errors on Multiuser Detection via the Replica Method

    Directory of Open Access Journals (Sweden)

    Li Husheng

    2005-01-01

    Full Text Available For practical wireless DS-CDMA systems, channel estimation is imperfect due to noise and interference. In this paper, the impact of channel estimation errors on multiuser detection (MUD is analyzed under the framework of the replica method. System performance is obtained in the large system limit for optimal MUD, linear MUD, and turbo MUD, and is validated by numerical results for finite systems.

  17. Longitudinal categorical data analysis

    CERN Document Server

    Sutradhar, Brajendra C

    2014-01-01

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

  18. Triglyceride and glucose (TyG) index as a predictor of incident hypertension: a 9-year longitudinal population-based study

    OpenAIRE

    Zheng, Rongjiong; Mao, Yushan

    2017-01-01

    Background Hypertension and the triglyceride and glucose index both have been associated with insulin resistance; however, the longitudinal association remains unclear. This study was designed to investigate the longitudinal association between the triglyceride and glucose index and incident hypertension among the Chinese population. Methods We studied 4686 subjects (3177 males and 1509 females) and followed up for 9?years. The subjects were divided into four groups based on the triglyceride ...

  19. Replica Exchange Gaussian Accelerated Molecular Dynamics: Improved Enhanced Sampling and Free Energy Calculation.

    Science.gov (United States)

    Huang, Yu-Ming M; McCammon, J Andrew; Miao, Yinglong

    2018-04-10

    Through adding a harmonic boost potential to smooth the system potential energy surface, Gaussian accelerated molecular dynamics (GaMD) provides enhanced sampling and free energy calculation of biomolecules without the need of predefined reaction coordinates. This work continues to improve the acceleration power and energy reweighting of the GaMD by combining the GaMD with replica exchange algorithms. Two versions of replica exchange GaMD (rex-GaMD) are presented: force constant rex-GaMD and threshold energy rex-GaMD. During simulations of force constant rex-GaMD, the boost potential can be exchanged between replicas of different harmonic force constants with fixed threshold energy. However, the algorithm of threshold energy rex-GaMD tends to switch the threshold energy between lower and upper bounds for generating different levels of boost potential. Testing simulations on three model systems, including the alanine dipeptide, chignolin, and HIV protease, demonstrate that through continuous exchanges of the boost potential, the rex-GaMD simulations not only enhance the conformational transitions of the systems but also narrow down the distribution width of the applied boost potential for accurate energetic reweighting to recover biomolecular free energy profiles.

  20. Biosynthesis of cathodoluminescent zinc oxide replicas using butterfly (Papilio paris) wing scales as templates

    International Nuclear Information System (INIS)

    Zhang Wang; Zhang Di; Fan Tongxiang; Ding Jian; Gu Jiajun; Guo Qixin; Ogawa, Hiroshi

    2009-01-01

    Papilio paris butterflies have an iridescent blue color patch on their hind wings which is visible over a wide viewing angle. Optical and scanning electron microscopy observations of scales from the wings show that the blue color scales have very different microstructure to the matt black ones which also populate the wings. Scanning electron micrographs of the blue scales show that their surfaces comprise a regular two-dimensional array of concavities. By contrast the matt black scales have fine, sponge-like structure, between the ridges and the cross ribs in the scales. Using both types of scale as bio-templates, we obtain zinc oxide (ZnO) replicas of the microstructures of the original scales. Room temperature (T = 300 K) cathodoluminescence spectra of these ZnO replicas have also been studied. Both spectra show a similar sharp near-band-edge emission, but have different green emission, which we associate with the different microstructures of the ZnO replicas

  1. Biosynthesis of cathodoluminescent zinc oxide replicas using butterfly (Papilio paris) wing scales as templates

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Wang [State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, 200240, Shanghai (China); Zhang Di [State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, 200240, Shanghai (China)], E-mail: zhangdi@sjtu.edu.cn; Fan Tongxiang; Ding Jian; Gu Jiajun [State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, 200240, Shanghai (China); Guo Qixin; Ogawa, Hiroshi [Department of Electrical and Electronic Engineering, Saga University, Saga 840-8502 (Japan)

    2009-01-01

    Papilio paris butterflies have an iridescent blue color patch on their hind wings which is visible over a wide viewing angle. Optical and scanning electron microscopy observations of scales from the wings show that the blue color scales have very different microstructure to the matt black ones which also populate the wings. Scanning electron micrographs of the blue scales show that their surfaces comprise a regular two-dimensional array of concavities. By contrast the matt black scales have fine, sponge-like structure, between the ridges and the cross ribs in the scales. Using both types of scale as bio-templates, we obtain zinc oxide (ZnO) replicas of the microstructures of the original scales. Room temperature (T = 300 K) cathodoluminescence spectra of these ZnO replicas have also been studied. Both spectra show a similar sharp near-band-edge emission, but have different green emission, which we associate with the different microstructures of the ZnO replicas.

  2. Characterization of Nb SRF cavity materials by white light interferometry and replica techniques

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Chen [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); The Applied Science Department, The College of William and Mary, Williamsburg, VA 23185 (United States); Reece, Charles [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Kelley, Michael, E-mail: mkelley@jlab.org [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); The Applied Science Department, The College of William and Mary, Williamsburg, VA 23185 (United States)

    2013-06-01

    Much work has shown that the topography of the interior surface is an important contributor to the performance of Nb superconducting radiofrequency (SRF) accelerator cavities. Micron-scale topography is implicated in non-linear loss mechanisms that limit the useful accelerating gradient range and impact cryogenic cost. Aggressive final chemical treatments in cavity production seek to reliably obtain “smoothest” surfaces with superior performance. Process development suffers because the cavity interior surface cannot be viewed directly without cutting out pieces, rendering the cavities unavailable for further study. Here we explore replica techniques as an alternative, providing imprints of cavity internal surface that can be readily examined. A second matter is the topography measurement technique used. Atomic force microscopy (AFM) has proven successful, but too time intensive for routine use in this application. We therefore introduce white light interferometry (WLI) as an alternative approach. We examined real surfaces and their replicas, using AFM and WLI. We find that the replica/WLI is promising to provide the large majority of the desired information, recognizing that a trade-off is being made between best lateral resolution (AFM) and the opportunity to examine much more surface area (WLI).

  3. Tunable hydrodynamic characteristics in microchannels with biomimetic superhydrophobic (lotus leaf replica) walls.

    Science.gov (United States)

    Dey, Ranabir; Raj M, Kiran; Bhandaru, Nandini; Mukherjee, Rabibrata; Chakraborty, Suman

    2014-05-21

    The present work comprehensively addresses the hydrodynamic characteristics through microchannels with lotus leaf replica (exhibiting low adhesion and superhydrophobic properties) walls. The lotus leaf replica is fabricated following an efficient, two-step, soft-molding process and is then integrated with rectangular microchannels. The inherent biomimetic, superhydrophobic surface-liquid interfacial hydrodynamics, and the consequential bulk flow characteristics, are critically analyzed by the micro-particle image velocimetry technique. It is observed that the lotus leaf replica mediated microscale hydrodynamics comprise of two distinct flow regimes even within the low Reynolds number paradigm, unlike the commonly perceived solely apparent slip-stick dominated flows over superhydrophobic surfaces. While the first flow regime is characterized by an apparent slip-stick flow culminating in an enhanced bulk throughput rate, the second flow regime exhibits a complete breakdown of the aforementioned laminar and uni-axial flow model, leading to a predominantly no-slip flow. Interestingly, the critical flow condition dictating the transition between the two hydrodynamic regimes is intrinsically dependent on the micro-confinement effect. In this regard, an energetically consistent theoretical model is also proposed to predict the alterations in the critical flow condition with varying microchannel configurations, by addressing the underlying biomimetic surface-liquid interfacial conditions. Hence, the present research endeavour provides a new design-guiding paradigm for developing multi-functional microfluidic devices involving biomimetic, superhydrophobic surfaces, by judicious exploitation of the tunable hydrodynamic characteristics in the two regimes.

  4. Brain expansion in patients with type II diabetes following insulin therapy: a preliminary study with longitudinal voxel-based morphometry.

    Science.gov (United States)

    Chen, Zhiye; Li, Jinfeng; Sun, Jie; Ma, Lin

    2014-01-01

    We performed a longitudinal analysis based on magnetic resonance (MR) imaging to investigate the brain structural and perfusion changes caused by insulin therapy in patients with type II diabetes. High resolution three-dimensional T1-weighted fast spoiled gradient recalled echo images and flow-sensitive alternating inversion recovery (FAIR) images were obtained from 11 patients with type II diabetes before and 1 year after initiation of insulin therapy and 11 normal controls. Brain volume changes were investigated by a longitudinal voxel-based morphometry (VBM), and perfusion changes were evaluated by FAIR imaging between baseline and follow-up data. Significant regional gray matter (GM) expansion located in bilateral frontal, parietal, and left occipital lobes, and regional white matter (WM) expansion was shown in left precentral subcortical WM and right angular subcortical WM after insulin therapy (P Brain hyperperfusion was detected in bilateral frontal cortex, left occipital cortex, and right temporal cortex after insulin therapy (P brain expansion and hyperperfusion were demonstrated 1 year after initiation of insulin therapy, and insulin therapy could contribute to the brain volume gainment in the patients with type II diabetes. Copyright © 2013 by the American Society of Neuroimaging.

  5. Music training improves speech-in-noise perception: Longitudinal evidence from a community-based music program.

    Science.gov (United States)

    Slater, Jessica; Skoe, Erika; Strait, Dana L; O'Connell, Samantha; Thompson, Elaine; Kraus, Nina

    2015-09-15

    Music training may strengthen auditory skills that help children not only in musical performance but in everyday communication. Comparisons of musicians and non-musicians across the lifespan have provided some evidence for a "musician advantage" in understanding speech in noise, although reports have been mixed. Controlled longitudinal studies are essential to disentangle effects of training from pre-existing differences, and to determine how much music training is necessary to confer benefits. We followed a cohort of elementary school children for 2 years, assessing their ability to perceive speech in noise before and after musical training. After the initial assessment, participants were randomly assigned to one of two groups: one group began music training right away and completed 2 years of training, while the second group waited a year and then received 1 year of music training. Outcomes provide the first longitudinal evidence that speech-in-noise perception improves after 2 years of group music training. The children were enrolled in an established and successful community-based music program and followed the standard curriculum, therefore these findings provide an important link between laboratory-based research and real-world assessment of the impact of music training on everyday communication skills. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Long-term effects of parental divorce timing on depression: A population-based longitudinal study.

    Science.gov (United States)

    Chun, Sung-Youn; Jang, Suk-Yong; Choi, Jae-Woo; Shin, Jaeyong; Park, Eun-Cheol

    2016-09-08

    We examined the long-term effects of parental divorce timing on depression using longitudinal data from the Korean Welfare Panel Study. Depression symptoms were measured using the 11 items of Center for Epidemiologic Scale for Depression (CES-D-11), and we categorized parental divorce timing into 'early childhood', 'adolescent' and 'none'. Although participants who experienced parental divorce during adolescence exhibited a significantly higher CES-D-11 score (p = .0468), 'early childhood' participants displayed the most increased CES-D-11 score compared to the control group (p = .0007). Conversely, among participants who were unsatisfied with their marriage, those who experienced parental divorce in early childhood showed lower CES-D-11 scores, while 'adolescent period' participants exhibited significantly higher CES-D-11 scores (p = .0131). We concluded that timing of parental divorce exerts substantial yet varied effects on long-term depression symptoms and future marriage satisfaction. © The Author(s) 2016.

  7. Replica scale modelling of long rod tank penetrators

    NARCIS (Netherlands)

    Diederen, A.M.; Hoeneveld, J.C.

    2001-01-01

    Experiments and simulations have been conducted using scale size tungsten alloy penetrators at ordnance velocity against an oblique plate array consisting of an inert sandwich and a base armour. The penetrators are made from 2 types of tungsten alloy with different tensile strength. Two scale sizes

  8. Foundations and latest advances in replica exchange transition interface sampling

    NARCIS (Netherlands)

    Cabriolu, R.; Refsnes, K.M.S; Bolhuis, P.G.; van Erp, T.S.

    2017-01-01

    Nearly 20 years ago, transition path sampling (TPS) emerged as an alternative method to free energy based approaches for the study of rare events such as nucleation, protein folding, chemical reactions, and phase transitions. TPS effectively performs Monte Carlo simulations with relatively short

  9. Discrimination Between Cervical Cancer Cells and Normal Cervical Cells Based on Longitudinal Elasticity Using Atomic Force Microscopy.

    Science.gov (United States)

    Zhao, Xueqin; Zhong, Yunxin; Ye, Ting; Wang, Dajing; Mao, Bingwei

    2015-12-01

    The mechanical properties of cells are considered promising biomarkers for the early diagnosis of cancer. Recently, atomic force microscopy (AFM)-based nanoindentation technology has been utilized for the examination of cell cortex mechanics in order to distinguish malignant cells from normal cells. However, few attempts to evaluate the biomechanical properties of cells have focused on the quantification of the non-homogeneous longitudinal elasticity of cellular structures. In the present study, we applied a variation of the method of Carl and Schillers to investigate the differences between longitudinal elasticity of human cervical squamous carcinoma cells (CaSki) and normal cervical epithelial cells (CRL2614) using AFM. The results reveal a three-layer heterogeneous structure in the probing volume of both cell types studied. CaSki cells exhibited a lower whole-cell stiffness and a softer nuclei zone compared to the normal counterpart cells. Moreover, a better differentiated cytoskeleton was found in the inner cytoplasm/nuclei zone of the normal CRL2614 cells, whereas a deeper cytoskeletal distribution was observed in the probing volume of the cancerous counterparts. The sensitive cortical panel of CaSki cells, with a modulus of 0.35~0.47 kPa, was located at 237~225 nm; in normal cells, the elasticity was 1.20~1.32 kPa at 113~128 nm. The present improved method may be validated using the conventional Hertz-Sneddon method, which is widely reported in the literature. In conclusion, our results enable the quantification of the heterogeneous longitudinal elasticity of cancer cells, in particular the correlation with the corresponding depth. Preliminary results indicate that our method may potentially be applied to improve the detection of cancerous cells and provide insights into the pathophysiology of the disease.

  10. Hearing Impairment Affects Dementia Incidence. An Analysis Based on Longitudinal Health Claims Data in Germany

    Science.gov (United States)

    Teipel, Stefan; Óvári, Attila; Kilimann, Ingo; Witt, Gabriele; Doblhammer, Gabriele

    2016-01-01

    Recent research has revealed an association between hearing impairment and dementia. The objective of this study is to determine the effect of hearing impairment on dementia incidence in a longitudinal study, and whether ear, nose, and throat (ENT) specialist care, care level, institutionalization, or depression mediates or moderates this pathway. The present study used a longitudinal sample of 154,783 persons aged 65 and older from claims data of the largest German health insurer; containing 14,602 incident dementia diagnoses between 2006 and 2010. Dementia and hearing impairment diagnoses were defined according to International Classification of Diseases, Tenth Revision, codes. We used a Kaplan Meier estimator and performed Cox proportional hazard models to explore the effect of hearing impairment on dementia incidence, controlling for ENT specialist care, care level, institutionalization, and depression. Gender, age, and comorbidities were controlled for as potential confounders. Patients with bilateral (HR = 1.43, pimpairment had higher risks of dementia incidence than patients without hearing impairment. We found no significant effect for unilateral hearing impairment and other diseases of the ear. The effect of hearing impairment was only partly mediated through ENT specialist utilization. Significant interaction between hearing impairment and specialist care, care level, and institutionalization, respectively, indicated moderating effects. We discuss possible explanations for these effects. This study underlines the importance of the association between hearing impairment and dementia. Preserving hearing ability may maintain social participation and may reduce the burden associated with dementia. The particular impact of hearing aid use should be the subject of further investigations, as it offers potential intervention on the pathway to dementia. PMID:27391486

  11. A population-based longitudinal study of risk factors for suicide attempts in major depressive disorder.

    Science.gov (United States)

    Bolton, James M; Pagura, Jina; Enns, Murray W; Grant, Bridget; Sareen, Jitender

    2010-10-01

    No longitudinal study has examined risk factors for future suicide attempts in major depressive disorder in a nationally representative sample. The objective of this study was to investigate baseline sociodemographic characteristics, comorbid mental disorders, specific depressive symptoms, and previous suicidal behavior as potential risk factors for suicide attempts at 3 years follow-up. Data came from the national epidemiologic survey on alcohol and related conditions (NESARC), a large nationally representative longitudinal survey of mental illness in adults [Wave 1 (2001-2002); Wave 2 (2004-2005) n=34,653]. Logistic regression examined associations between risk factors present at Wave 1 and suicide attempts at Wave 2 (n=169) among individuals with major depressive disorder at baseline assessment (n=6004). Risk factors for incident suicide attempts at Wave 2 (n=63) were identified among those with major depressive disorder at Wave 1 and no lifetime history of suicide attempts (n=5170). Results revealed specific comorbid anxiety, personality, and substance use disorders to be associated with incident suicide attempts at Wave 2. Comorbid borderline personality disorder was strongly associated with suicide attempts in all models. Several comorbid disorders were strongly associated with suicide attempts at Wave 2 even after adjusting for previous suicidal behavior, notably posttraumatic stress disorder (adjusted odds ratio (AOR)=2.20; 95% confidence interval (95% CI) 1.27-3.83) and dependent personality disorder (AOR=4.43; 95% CI 1.93-10.18). These findings suggest that mental illness comorbidity confers an increased risk of future suicide attempts in major depressive disorder that is not solely accounted for by past suicidal behavior.

  12. Detecting mode hopping in single-longitudinal-mode fiber ring lasers based on an unbalanced fiber Michelson interferometer.

    Science.gov (United States)

    Ma, Mingxiang; Hu, Zhengliang; Xu, Pan; Wang, Wei; Hu, Yongming

    2012-10-20

    A method of detecting mode hopping for single-longitudinal-mode (SLM) fiber ring lasers has been proposed and experimentally demonstrated. The method that is based on an unbalanced Michelson interferometer (MI) utilizing phase generated carrier modulation instantly transforms mode-hopping dynamics into steep phase changes of the interferometer. Multiform mode hops in an SLM erbium-doped fiber ring laser with an 18.6 MHz mode spacing have been detected exactly in real-time domain and discussed in detail. Numerical results show that the MI-based method has a high testing sensitivity for identifying mode hopping, which will play a significant role in evaluating the output stability of SLM fiber lasers.

  13. Model predictive controller-based multi-model control system for longitudinal stability of distributed drive electric vehicle.

    Science.gov (United States)

    Shi, Ke; Yuan, Xiaofang; Liu, Liang

    2018-01-01

    Distributed drive electric vehicle(DDEV) has been widely researched recently, its longitudinal stability is a very important research topic. Conventional wheel slip ratio control strategies are usually designed for one special operating mode and the optimal performance cannot be obtained as DDEV works under various operating modes. In this paper, a novel model predictive controller-based multi-model control system (MPC-MMCS) is proposed to solve the longitudinal stability problem of DDEV. Firstly, the operation state of DDEV is summarized as three kinds of typical operating modes. A submodel set is established to accurately represent the state value of the corresponding operating mode. Secondly, the matching degree between the state of actual DDEV and each submodel is analyzed. The matching degree is expressed as the weight coefficient and calculated by a modified recursive Bayes theorem. Thirdly, a nonlinear MPC is designed to achieve the optimal wheel slip ratio for each submodel. The optimal design of MPC is realized by parallel chaos optimization algorithm(PCOA)with computational accuracy and efficiency. Finally, the control output of MPC-MMCS is computed by the weighted output of each MPC to achieve smooth switching between operating modes. The proposed MPC-MMCS is evaluated on eight degrees of freedom(8DOF)DDEV model simulation platform and simulation results of different condition show the benefits of the proposed control system. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  14. Longitudinal and Cross-Sectional Genetic Diversity in the Korean Peninsula Based on the P vivax Merozoite Surface Protein Gene.

    Science.gov (United States)

    Kim, Jung-Yeon; Suh, Eun-Jung; Yu, Hyo-Soon; Jung, Hyun-Sik; Park, In-Ho; Choi, Yien-Kyeoug; Choi, Kyoung-Mi; Cho, Shin-Hyeong; Lee, Won-Ja

    2011-12-01

    Vivax malaria has reemerged and become endemic in Korea. Our study aimed to analyze by both longitudinal and cross-sectional genetic diversity of this malaria based on the P vivax Merozoite Surface Protein (PvMSP) gene parasites recently found in the Korean peninsula. PvMSP-1 gene sequence analysis from P vivax isolates (n = 835) during the 1996-2010 period were longitudinally analyzed and the isolates from the Korean peninsula through South Korea, the demilitarized zone and North Korea collected in 2008-2010 were enrolled in an overall analysis of MSP-1 gene diversity. New recombinant subtypes and severe multiple-cloneinfection rates were observed in recent vivax parasites. Regional variation was also observed in the study sites. This study revealed the great complexity of genetic variation and rapid dissemination of genes in P vivax. It also showed interesting patterns of diversity depending, on the region in the Korean Peninsula. Understanding the parasiteninsula. Under genetic variation may help to analyze trends and assess the extent of endemic malaria in Korea.

  15. Maternal depressive symptoms across early childhood and asthma in school children: findings from a Longitudinal Australian Population Based Study.

    Directory of Open Access Journals (Sweden)

    Rebecca Giallo

    Full Text Available There is a growing body of evidence attesting to links between early life exposure to stress and childhood asthma. However, available evidence is largely based on small, genetically high risk samples. The aim of this study was to explore the associations between the course of maternal depressive symptoms across early childhood and childhood asthma in a nationally representative longitudinal cohort study of Australian children. Participants were 4164 children and their biological mothers from the Longitudinal Study of Australian Children. Latent class analysis identified three trajectories of maternal depressive symptoms across four biennial waves from the first postnatal year to when children were 6-7 years: minimal symptoms (74.6%, sub-clinical symptoms (20.8%, and persistent and increasing high symptoms (4.6%. Logistic regression analyses revealed that childhood asthma at age 6-7 years was associated with persistent and increasing high depressive symptoms after accounting for known risk factors including smoking during pregnancy and maternal history of asthma (adjusted OR 2.36, 95% CI 1.61-3.45, p.001. Our findings from a nationally representative sample of Australian children provide empirical support for a relationship between maternal depressive symptoms across the early childhood period and childhood asthma. The burden of disease from childhood asthma may be reduced by strengthening efforts to promote maternal mental health in the early years of parenting.

  16. Maternal depressive symptoms across early childhood and asthma in school children: findings from a Longitudinal Australian Population Based Study.

    Science.gov (United States)

    Giallo, Rebecca; Bahreinian, Salma; Brown, Stephanie; Cooklin, Amanda; Kingston, Dawn; Kozyrskyj, Anita

    2015-01-01

    There is a growing body of evidence attesting to links between early life exposure to stress and childhood asthma. However, available evidence is largely based on small, genetically high risk samples. The aim of this study was to explore the associations between the course of maternal depressive symptoms across early childhood and childhood asthma in a nationally representative longitudinal cohort study of Australian children. Participants were 4164 children and their biological mothers from the Longitudinal Study of Australian Children. Latent class analysis identified three trajectories of maternal depressive symptoms across four biennial waves from the first postnatal year to when children were 6-7 years: minimal symptoms (74.6%), sub-clinical symptoms (20.8%), and persistent and increasing high symptoms (4.6%). Logistic regression analyses revealed that childhood asthma at age 6-7 years was associated with persistent and increasing high depressive symptoms after accounting for known risk factors including smoking during pregnancy and maternal history of asthma (adjusted OR 2.36, 95% CI 1.61-3.45), p.001). Our findings from a nationally representative sample of Australian children provide empirical support for a relationship between maternal depressive symptoms across the early childhood period and childhood asthma. The burden of disease from childhood asthma may be reduced by strengthening efforts to promote maternal mental health in the early years of parenting.

  17. Implementation of an Outcome-Based Longitudinal Pharmacology Teaching in Undergraduate Dental Curriculum at KSAU-HS Experience

    Directory of Open Access Journals (Sweden)

    Abdulmalik M. Alkatheri

    2018-06-01

    Full Text Available Purpose/objectives: The aim of this study is to present a modification of the structure of the pharmacology educational experience for dental students as a result of the early introduction of a pharmacology course into the pre-professional curriculum. Methods: Three courses of professional dental pharmacology were modified before and/or after delivery by developing general course learning outcomes, lecture-by-lecture learning outcomes and theme mapping to align topics taught within these courses and with those taught in the pre-professional dental program. Results: Final proposals for three professional dental pharmacology courses, which are distributed over three professional years, were prepared based on teaching experience and theme mapping. Topics were added, deleted, transferred from one course to another to afford courses that are fully aligned, relatively comprehensive, longitudinal, with focus on topics relevant to the dental practice without redundancy. In addition, the design of these courses took into consideration the level of coverage of the pre-professional dental pharmacology course. Conclusions: This longitudinal inclusion of pharmacology courses form the second pre-professional year to the third professional year is expected to improve dental students’ pharmacology education experience. Although the last of these courses is a pharmacotherapeutic course, more courses with clinically oriented therapeutic approach are recommended. Keywords: Pharmacology course design, Dental students, Curriculum development, Curriculum mapping

  18. Cannabis use and the course and outcome of major depressive disorder: A population based longitudinal study.

    Science.gov (United States)

    Feingold, Daniel; Rehm, Jürgen; Lev-Ran, Shaul

    2017-05-01

    Cannabis use has been reported to affect the course of various psychiatric disorders, however its effect on the course of major depressive disorder (MDD) is not yet clear. We used data from Wave 1 and Wave 2 of the National Epidemiologic survey on Alcohol and Related Conditions (NESARC). Individuals with baseline MDD (N=2,348) were included in the study. Cannabis users without a Cannabis Use Disorder (CUDs) and individuals with a CUD were compared to nonusers using linear and logistic regression analyses controlling for sociodemographics, psychiatric disorders and substance use disorders at baseline. No differences were found in rates of remission between the groups. Level of cannabis use was associated with significantly more depressive symptoms at follow-up, particularly anhedonia, changes in body weight, insomnia or hypersomnia and psychomotor problems. After adjusting for baseline confounding factors, no associations were found between cannabis use and suicidality, functionality and quality of life. We conclude that many of the associations between cannabis use and a more severe course of MDD do not seem to be attributed to cannabis use itself but to associated sociodemographic and clinical factors. Further longitudinal studies using depression severity indices are required. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  19. Longitudinal Youth-At-Risk Study (LYRIKS): outreach strategies based on a community-engaged framework.

    Science.gov (United States)

    Mitter, Natasha; Nah, Guo Quan Ryan; Bong, Yioe Ling; Lee, Jimmy; Chong, Siow-Ann

    2014-08-01

    Schizophrenia and psychoses are debilitating disorders often leading to serious functional impairments. Early detection efforts have shifted focus to the prodromal phase and the emphasis is now on individuals at risk of developing psychosis. The Longitudinal Youth-At-Risk Study (LYRIKS) seeks to elucidate the biological markers of psychosis. This paper describes the application of a community-engaged framework to the outreach strategies of LYRIKS. It describes the outreach goals, strategies used and their impact, as well as the various challenges faced by the research team and community partners. The target population was defined. Community organizations having close ties with the target population were identified and approached for collaboration. These included educational and healthcare institutions, and government and welfare organizations. Strategies were categorized as active or passive. Active strategies included clinical screening and recruitment, workshops, roadshows and student internships. Passive strategies included utilizing print and social media. Three thousand three hundred twenty-one youth were approached and 401 called the hotline to find out more about the study. Three thousand five hundred one were pre-screened; 864 were further screened using the Comprehensive Assessment of At Risk Mental State. One hundred seventy-eight and 346 were eventually recruited as subjects and controls, respectively. Challenges encountered included differing priorities, maintaining collaborative relationships, stigmatization and inadequate understanding of the profile of at risk youth. Future community-engaged research should be conducted more comprehensively to generate maximum benefits. © 2013 Wiley Publishing Asia Pty Ltd.

  20. Emergency medicine resident crisis resource management ability: a simulation-based longitudinal study

    Directory of Open Access Journals (Sweden)

    Samuel Clarke

    2014-12-01

    Full Text Available Background: Simulation has been identified as a means of assessing resident physicians’ mastery of technical skills, but there is a lack of evidence for its utility in longitudinal assessments of residents’ non-technical clinical abilities. We evaluated the growth of crisis resource management (CRM skills in the simulation setting using a validated tool, the Ottawa Crisis Resource Management Global Rating Scale (Ottawa GRS. We hypothesized that the Ottawa GRS would reflect progressive growth of CRM ability throughout residency. Methods: Forty-five emergency medicine residents were tracked with annual simulation assessments between 2006 and 2011. We used mixed-methods repeated-measures regression analyses to evaluate elements of the Ottawa GRS by level of training to predict performance growth throughout a 3-year residency. Results: Ottawa GRS scores increased over time, and the domains of leadership, problem solving, and resource utilization, in particular, were predictive of overall performance. There was a significant gain in all Ottawa GRS components between postgraduate years 1 and 2, but no significant difference in GRS performance between years 2 and 3. Conclusions: In summary, CRM skills are progressive abilities, and simulation is a useful modality for tracking their development. Modification of this tool may be needed to assess advanced learners’ gains in performance.

  1. Longitudinal connectome-based predictive modeling for REM sleep behavior disorder from structural brain connectivity

    Science.gov (United States)

    Giancardo, Luca; Ellmore, Timothy M.; Suescun, Jessika; Ocasio, Laura; Kamali, Arash; Riascos-Castaneda, Roy; Schiess, Mya C.

    2018-02-01

    Methods to identify neuroplasticity patterns in human brains are of the utmost importance in understanding and potentially treating neurodegenerative diseases. Parkinson disease (PD) research will greatly benefit and advance from the discovery of biomarkers to quantify brain changes in the early stages of the disease, a prodromal period when subjects show no obvious clinical symptoms. Diffusion tensor imaging (DTI) allows for an in-vivo estimation of the structural connectome inside the brain and may serve to quantify the degenerative process before the appearance of clinical symptoms. In this work, we introduce a novel strategy to compute longitudinal structural connectomes in the context of a whole-brain data-driven pipeline. In these initial tests, we show that our predictive models are able to distinguish controls from asymptomatic subjects at high risk of developing PD (REM sleep behavior disorder, RBD) with an area under the receiving operating characteristic curve of 0.90 (pParkinson's Progression Markers Initiative. By analyzing the brain connections most relevant for the predictive ability of the best performing model, we find connections that are biologically relevant to the disease.

  2. Quantitative skeletal evaluation based on cervical vertebral maturation: a longitudinal study of adolescents with normal occlusion.

    Science.gov (United States)

    Chen, L; Liu, J; Xu, T; Long, X; Lin, J

    2010-07-01

    The study aims were to investigate the correlation between vertebral shape and hand-wrist maturation and to select characteristic parameters of C2-C5 (the second to fifth cervical vertebrae) for cervical vertebral maturation determination by mixed longitudinal data. 87 adolescents (32 males, 55 females) aged 8-18 years with normal occlusion were studied. Sequential lateral cephalograms and hand-wrist radiographs were taken annually for 6 consecutive years. Lateral cephalograms were divided into 11 maturation groups according to Fishman Skeletal Maturity Indicators (SMI). 62 morphological measurements of C2-C5 at 11 different developmental stages (SMI1-11) were measured and analysed. Locally weighted scatterplot smoothing, correlation coefficient analysis and variable cluster analysis were used for statistical analysis. Of the 62 cervical vertebral parameters, 44 were positively correlated with SMI, 6 were negatively correlated and 12 were not correlated. The correlation coefficients between cervical vertebral parameters and SMI were relatively high. Characteristic parameters for quantitative analysis of cervical vertebral maturation were selected. In summary, cervical vertebral maturation could be used reliably to evaluate the skeletal stage instead of the hand-wrist radiographic method. Selected characteristic parameters offered a simple and objective reference for the assessment of skeletal maturity and timing of orthognathic surgery. Copyright 2010 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  3. A longitudinal evaluation of performance of automated BCR-ABL1 quantitation using cartridge-based detection system.

    Science.gov (United States)

    Enjeti, Anoop; Granter, Neil; Ashraf, Asma; Fletcher, Linda; Branford, Susan; Rowlings, Philip; Dooley, Susan

    2015-10-01

    An automated cartridge-based detection system (GeneXpert; Cepheid) is being widely adopted in low throughput laboratories for monitoring BCR-ABL1 transcript in chronic myelogenous leukaemia. This Australian study evaluated the longitudinal performance specific characteristics of the automated system.The automated cartridge-based system was compared prospectively with the manual qRT-PCR-based reference method at SA Pathology, Adelaide, over a period of 2.5 years. A conversion factor determination was followed by four re-validations. Peripheral blood samples (n = 129) with international scale (IS) values within detectable range were selected for assessment. The mean bias, proportion of results within specified fold difference (2-, 3- and 5-fold), the concordance rate of major molecular remission (MMR) and concordance across a range of IS values on paired samples were evaluated.The initial conversion factor for the automated system was determined as 0.43. Except for the second re-validation, where a negative bias of 1.9-fold was detected, all other biases fell within desirable limits. A cartridge-specific conversion factor and efficiency value was introduced and the conversion factor was confirmed to be stable in subsequent re-validation cycles. Concordance with the reference method/laboratory at >0.1-≤10 IS was 78.2% and at ≤0.001 was 80%, compared to 86.8% in the >0.01-≤0.1 IS range. The overall and MMR concordance were 85.7% and 94% respectively, for samples that fell within ± 5-fold of the reference laboratory value over the entire period of study.Conversion factor and performance specific characteristics for the automated system were longitudinally stable in the clinically relevant range, following introduction by the manufacturer of lot specific efficiency values.

  4. Research on the Lift-off Effect of Receiving Longitudinal Mode Guided Waves in Pipes Based on the Villari Effect

    Directory of Open Access Journals (Sweden)

    Jiang Xu

    2016-09-01

    Full Text Available The magnetostrictive guided wave technology as a non-contact measurement can generate and receive guided waves with a large lift-off distance up to tens of millimeters. However, the lift-off distance of the receiving coil would affect the coupling efficiency from the elastic energy to the electromagnetic energy. In the existing magnetomechanical models, the change of the magnetic field in the air gap was ignored since the permeability of the rod is much greater than that of air. The lift-off distance of the receiving coil will not affect the receiving signals based on these models. However, the experimental phenomenon is in contradiction with these models. To solve the contradiction, the lift-off effect of receiving the longitudinal mode guided waves in pipes is investigated based on the Villari effect. A finite element model of receiving longitudinal guided waves in pipes is obtained based on the Villari effect, which takes into account the magnetic field in the pipe wall and the air zone at the same time. The relation between the amplitude of the induced signals and the radius (lift-off distance of the receiving coil is obtained, which is verified by experiment. The coupling efficiency of the receiver is a monotonic decline with the lift-off distance increasing. The decay rate of the low frequency wave is slower than the high frequency wave. Additionally, the results show that the rate of change of the magnetic flux in the air zone and in the pipe wall is the same order of magnitude, but opposite. However, the experimental results show that the error of the model in the large lift-off distance is obvious due to the diffusion of the magnetic field in the air, especially for the high frequency guided waves.

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

    Science.gov (United States)

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

    2014-01-01

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

  6. Social desirability and self-reported health risk behaviors in web-based research: three longitudinal studies

    Directory of Open Access Journals (Sweden)

    Göritz Anja S

    2010-11-01

    Full Text Available Abstract Background These studies sought to investigate the relation between social desirability and self-reported health risk behaviors (e.g., alcohol use, drug use, smoking in web-based research. Methods Three longitudinal studies (Study 1: N = 5612, 51% women; Study 2: N = 619, 60%; Study 3: N = 846, 59% among randomly selected members of two online panels (Dutch; German using several social desirability measures (Marlowe-Crowne Scale; Balanced Inventory of Desirable Responding; The Social Desirability Scale-17 were conducted. Results Social desirability was not associated with self-reported current behavior or behavior frequency. Socio-demographics (age; sex; education did not moderate the effect of social desirability on self-reported measures regarding health risk behaviors. Conclusions The studies at hand provided no convincing evidence to throw doubt on the usefulness of the Internet as a medium to collect self-reports on health risk behaviors.

  7. Leadership behavior changes following a theory-based leadership development intervention: A longitudinal study of subordinates' and leaders' evaluations.

    Science.gov (United States)

    Larsson, Gerry; Sandahl, Christer; Söderhjelm, Teresa; Sjövold, Endre; Zander, Ann

    2017-02-01

    The aim was to evaluate effects of leadership courses based on the developmental leadership model at the leadership behavioral level. A longitudinal design was employed with assessments before, one and six months after the leadership courses. The sample consisted of 59 leaders who made self-ratings and were rated by at least three subordinates on each occasion. Leadership behaviors were measured with the Developmental Leadership Questionnaire (DLQ). A limited increase of favorable leadership behaviors and a significant reduction of unfavorable leadership behaviors were found, particularly according to the subordinates' ratings. A cluster analysis yielded three meaningful leader profiles and showed that this pattern was found in all three profiles, irrespective of how favorably they were rated before the onset of the intervention. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  8. Computer-based radiological longitudinal evaluation of meningiomas following stereotactic radiosurgery.

    Science.gov (United States)

    Shimol, Eli Ben; Joskowicz, Leo; Eliahou, Ruth; Shoshan, Yigal

    2018-02-01

    Stereotactic radiosurgery (SRS) is a common treatment for intracranial meningiomas. SRS is planned on a pre-therapy gadolinium-enhanced T1-weighted MRI scan (Gd-T1w MRI) in which the meningioma contours have been delineated. Post-SRS therapy serial Gd-T1w MRI scans are then acquired for longitudinal treatment evaluation. Accurate tumor volume change quantification is required for treatment efficacy evaluation and for treatment continuation. We present a new algorithm for the automatic segmentation and volumetric assessment of meningioma in post-therapy Gd-T1w MRI scans. The inputs are the pre- and post-therapy Gd-T1w MRI scans and the meningioma delineation in the pre-therapy scan. The output is the meningioma delineations and volumes in the post-therapy scan. The algorithm uses the pre-therapy scan and its meningioma delineation to initialize an extended Chan-Vese active contour method and as a strong patient-specific intensity and shape prior for the post-therapy scan meningioma segmentation. The algorithm is automatic, obviates the need for independent tumor localization and segmentation initialization, and incorporates the same tumor delineation criteria in both the pre- and post-therapy scans. Our experimental results on retrospective pre- and post-therapy scans with a total of 32 meningiomas with volume ranges 0.4-26.5 cm[Formula: see text] yield a Dice coefficient of [Formula: see text]% with respect to ground-truth delineations in post-therapy scans created by two clinicians. These results indicate a high correspondence to the ground-truth delineations. Our algorithm yields more reliable and accurate tumor volume change measurements than other stand-alone segmentation methods. It may be a useful tool for quantitative meningioma prognosis evaluation after SRS.

  9. A population-based longitudinal study on the implications of demographics on future blood supply.

    Science.gov (United States)

    Greinacher, Andreas; Weitmann, Kerstin; Lebsa, Anne; Alpen, Ulf; Gloger, Doris; Stangenberg, Wolfgang; Kiefel, Volker; Hoffmann, Wolfgang

    2016-12-01

    Changes in demographics with increases in older age groups and decreases in younger age groups imply an increased demand for blood transfusions paralleled by a decrease in the population eligible for blood donation. However, more restrictive transfusion triggers and the patient blood management initiative also reduce the demand for red blood cells (RBCs). Eastern Germany is a model region for the impact of demographic changes, which manifest in this region approximately 10 years earlier than in other regions due to the 50% birth rate decline after 1989. We report the 2010 longitudinal 5-year follow-up of the study assessing all whole blood donations and RBC transfusions in Mecklenburg-West Pomerania. We compared the projections that were made 5 years ago with: 1) the current age structure of the blood donor and transfusion recipient populations and 2) its impact on blood demand and blood donation numbers in specific age groups. Transfusion rates were lower and blood donation rates were higher than predicted in 2005. Although transfusion rates/1000 decreased in nearly all age groups, the overall annual transfusion rate increased to 66.4 RBC units/1000 (in 2005, 62.2/1000) due to the absolute increase in the elderly population. Despite a 7.4% decline in the population 18 to 65 years of age, whole blood donations increased by 11.7% between 2005 and 2010, but thereafter decreased by 21% (first-time donors by 39.4%), reflecting the effect of the post-1990 birth rate decline on the donor population. Changes in demography and medical practice impact the delicate balance between available blood supply and potential future transfusion needs. In times of pronounced demographic changes, regular monitoring of the blood demand and age structure of blood recipients and donors is required to allow strategic planning to prevent blood shortages or overproduction. © 2016 AABB.

  10. Quantitative OCT-based longitudinal evaluation of intracorneal ring segment implantation in keratoconus.

    Science.gov (United States)

    Pérez-Merino, Pablo; Ortiz, Sergio; Alejandre, Nicolas; Jiménez-Alfaro, Ignacio; Marcos, Susana

    2013-09-09

    To characterize the geometrical properties of keratoconic corneas upon intracorneal ring segments (ICRS) implantation, using custom-developed optical coherence tomography (OCT). Ten keratoconic corneas were measured pre- and post-ICRS surgery (7, 30, and 90 days). Corneal topographic and pachymetric maps were obtained from three-dimensional (3D) images acquired with OCT, provided with custom algorithms for image analysis, distortion correction, and quantification. The 3D positioning of the ICRS was also estimated longitudinally, relative to the pupil center and iris plane. Preoperatively, the average corneal radii of curvature were 7.02 ± 0.54 mm (anterior) and 5.40 ± 0.77 mm (posterior), and the minimum corneal thickness was 384 ± 60 μm. At 90 days, the average corneal radii of curvature were 7.26 ± 0.53 mm (anterior) and 5.44 ± 0.71 mm (posterior), and the minimum corneal thickness was 396 ± 46 μm. ICRS implantation produced a significant decrease of corneal power (by 1.71 ± 1.83 diopters [D] at 90 days). Corneal irregularities (defined by high order Zernike terms of the corneal elevation maps) and the corneal thickness distribution decreased in some patients and increased in others. The 3D ICRS depth matched the planned ICRS depth well (within 23.93 ± 23.49 μm). On average, ICRS showed an overall tilt of -6.8 ± 2.6° (temporal) and -2.1 ± 0.8° (superior) at 7 days. Spectral OCT (sOCT) provided with distortion correction and analysis tools, is an excellent instrument for evaluating the changes produced by ICRS in keratoconic corneas, and for analyzing the 3D ICRS position during the follow up. ICRS produced flattening on the anterior corneal surface, although the benefit for corneal surface regularization varied across patients.

  11. Zeolite-templated carbon replica: a grand canonical Monte-Carlo simulation study

    International Nuclear Information System (INIS)

    Roussel, Th.; Pellenq, R.J.M.; Bichara, Ch.; Gadiou, R.; Didion, A.; Vix-Guterl, C.; Gaslain, F.; Parmentier, J.; Valtchev, V.; Patarin, J.

    2005-01-01

    Microporous carbon materials are interesting for several applications such as hydrogen storage, catalysis or electrical double layer capacitors. The development of the negative templating method to obtain carbon replicas from ordered templates, has lead to the synthesis of several new materials which have interesting textural properties, attractive for energy storage. Among the possible templates, zeolites can be used to obtain highly microporous carbon materials. Nevertheless, the phenomena involved in the replica synthesis are not fully understood, and the relationships between the structure of the template, the carbon precursor and the resulting carbon material need to be investigated. Experimental results for carbon zeolite-templated nano-structures can be found in a series of papers; see for instance ref. [1] in which Wang et al describe a route to ultra-small Single Wall Carbon Nano-tubes (SWNTs) using the porosity of zeolite AlPO 4 -5. After matrix removal, the resulting structure is a free-standing bundle of 4 Angstroms large nano-tubes. However, it is highly desirable to obtain an ordered porous carbon structure that forms a real 3D network to be used for instance in gas storage applications. Carbon replica of faujasite and EMT zeolites can have these properties since these zeolites have a 3D porous network made of 10 Angstroms cages connected to each other through 7 Angstroms large windows. The first step of this study was to generate a theoretical carbon replica structure of various zeolites (faujasite, EMT, AlPO 4 -5, silicalite). For this purpose, we used the Grand Canonical Monte-Carlo (GCMC) technique in which the carbon-carbon interactions were described within the frame of a newly developed Tight Binding approach and the carbon-zeolite interactions assumed to be characteristic of physisorption. The intrinsic stability of the subsequent carbon nano-structures was then investigated after mimicking the removal of the inorganic phase by switching

  12. Eye gaze performance for children with severe physical impairments using gaze-based assistive technology-A longitudinal study.

    Science.gov (United States)

    Borgestig, Maria; Sandqvist, Jan; Parsons, Richard; Falkmer, Torbjörn; Hemmingsson, Helena

    2016-01-01

    Gaze-based assistive technology (gaze-based AT) has the potential to provide children affected by severe physical impairments with opportunities for communication and activities. This study aimed to examine changes in eye gaze performance over time (time on task and accuracy) in children with severe physical impairments, without speaking ability, using gaze-based AT. A longitudinal study with a before and after design was conducted on 10 children (aged 1-15 years) with severe physical impairments, who were beginners to gaze-based AT at baseline. Thereafter, all children used the gaze-based AT in daily activities over the course of the study. Compass computer software was used to measure time on task and accuracy with eye selection of targets on screen, and tests were performed with the children at baseline, after 5 months, 9-11 months, and after 15-20 months. Findings showed that the children improved in time on task after 5 months and became more accurate in selecting targets after 15-20 months. This study indicates that these children with severe physical impairments, who were unable to speak, could improve in eye gaze performance. However, the children needed time to practice on a long-term basis to acquire skills needed to develop fast and accurate eye gaze performance.

  13. Measurements of hadron yields from the T2K replica target in the NA61/SHINE experiment for neutrino flux prediction in T2K

    CERN Document Server

    AUTHOR|(CDS)2086777

    T2K is an accelerator-based long-baseline neutrino experiment in Japan. The main goal of the T2K experiment is a search for CP violation in the lepton sector by measuring electron (anti)neutrino appearance in a muon (anti)neutrino beam. Initial (anti)neutrino flux is produced in decays of hadrons which originate from the interactions and the re-interactions of a $30\\:$GeV proton beam with a $90\\:$cm long graphite target. Knowledge of the T2K neutrino flux is limited due to large hadron production uncertainties. A series of hadron production measurements were done to solve this problem, in the NA61/SHINE experiment at CERN. Measurements were performed with a proton beam and two target types: a thin graphite target and a replica of the T2K target. Work presented in this thesis concentrates on the T2K replica target data taken in 2010 and the development of the analysis and calibration software. The aim of these measurements is to fully constrain production of $\\pi^+$, $\\pi^-$, $K^+$, $K^-$ and $p$ coming from t...

  14. Derivation of the probability distribution function for the local density of states of a disordered quantum wire via the replica trick and supersymmetry

    International Nuclear Information System (INIS)

    Bunder, J.E.J.E.; McKenzie, R.H.Ross H.

    2001-01-01

    We consider the statistical properties of the local density of states of a one-dimensional Dirac equation in the presence of various types of disorder with Gaussian white-noise distribution. It is shown how either the replica trick or supersymmetry can be used to calculate exactly all the moments of the local density of states. Careful attention is paid to how the results change if the local density of states is averaged over atomic length scales. For both the replica trick and supersymmetry the problem is reduced to finding the ground state of a zero-dimensional Hamiltonian which is written solely in terms of a pair of coupled 'spins' which are elements of u(1,1). This ground state is explicitly found for the particular case of the Dirac equation corresponding to an infinite metallic quantum wire with a single conduction channel. The calculated moments of the local density of states agree with those found previously by Al'tshuler and Prigodin [Sov. Phys. JETP 68 (1989) 198] using a technique based on recursion relations for Feynman diagrams

  15. Inferring predator behavior from attack rates on prey-replicas that differ in conspicuousness.

    Directory of Open Access Journals (Sweden)

    Yoel E Stuart

    Full Text Available Behavioral ecologists and evolutionary biologists have long studied how predators respond to prey items novel in color and pattern. Because a predatory response is influenced by both the predator's ability to detect the prey and a post-detection behavioral response, variation among prey types in conspicuousness may confound inference about post-prey-detection predator behavior. That is, a relatively high attack rate on a given prey type may result primarily from enhanced conspicuousness and not predators' direct preference for that prey. Few studies, however, account for such variation in conspicuousness. In a field experiment, we measured predation rates on clay replicas of two aposematic forms of the poison dart frog Dendrobates pumilio, one novel and one familiar, and two cryptic controls. To ask whether predators prefer or avoid a novel aposematic prey form independently of conspicuousness differences among replicas, we first modeled the visual system of a typical avian predator. Then, we used this model to estimate replica contrast against a leaf litter background to test whether variation in contrast alone could explain variation in predator attack rate. We found that absolute predation rates did not differ among color forms. Predation rates relative to conspicuousness did, however, deviate significantly from expectation, suggesting that predators do make post-detection decisions to avoid or attack a given prey type. The direction of this deviation from expectation, though, depended on assumptions we made about how avian predators discriminate objects from the visual background. Our results show that it is important to account for prey conspicuousness when investigating predator behavior and also that existing models of predator visual systems need to be refined.

  16. Evaluation of unrestrained replica-exchange simulations using dynamic walkers in temperature space for protein structure refinement.

    Directory of Open Access Journals (Sweden)

    Mark A Olson

    Full Text Available A central problem of computational structural biology is the refinement of modeled protein structures taken from either comparative modeling or knowledge-based methods. Simulations are commonly used to achieve higher resolution of the structures at the all-atom level, yet methodologies that consistently yield accurate results remain elusive. In this work, we provide an assessment of an adaptive temperature-based replica exchange simulation method where the temperature clients dynamically walk in temperature space to enrich their population and exchanges near steep energetic barriers. This approach is compared to earlier work of applying the conventional method of static temperature clients to refine a dataset of conformational decoys. Our results show that, while an adaptive method has many theoretical advantages over a static distribution of client temperatures, only limited improvement was gained from this strategy in excursions of the downhill refinement regime leading to an increase in the fraction of native contacts. To illustrate the sampling differences between the two simulation methods, energy landscapes are presented along with their temperature client profiles.

  17. Tailored Panel Management: A Theory-Based Approach to Building and Maintaining Participant Commitment to a Longitudinal Study.

    Science.gov (United States)

    Estrada, Mica; Woodcock, Anna; Schultz, P Wesley

    2014-02-01

    Many psychological processes unfold over time, necessitating longitudinal research designs. Longitudinal research poses a host of methodological challenges, foremost of which is participant attrition. Building on Dillman's work, we provide a review of how social influence and relationship research informs retention strategies in longitudinal studies. Objective: We introduce the tailored panel management (TPM) approach, which is designed to establish communal norms that increase commitment to a longitudinal study, and this commitment, in turn, increases response rates and buffers against attrition. Specifically, we discuss practices regarding compensation, communication, consistency, and credibility that increase longer term commitment to panel participation. Research design: Throughout the article, we describe how TPM is being used in a national longitudinal study of undergraduate minority science students. TheScienceStudy is a continuing panel, which has 12 waves of data collected across 6 academic years, with response rates ranging from 70% to 92%. Although more than 90% of participants have either left or graduated from their undergraduate degree program, this highly mobile group of people remains engaged in the study. TheScienceStudy has usable longitudinal data from 96% of the original panel. Conclusion: This article combines social psychological theory, current best practice, and a detailed case study to illustrate the TPM approach to longitudinal data collection. The approach provides guidance for other longitudinal researchers, and advocates for empirical research into longitudinal research methodologies. © The Author(s) 2014.

  18. Anti-stiction coating of PDMS moulds for rapid microchannel fabrication by double replica moulding

    DEFF Research Database (Denmark)

    Zhuang, Guisheng; Kutter, Jörg Peter

    2011-01-01

    ), which resulted in an anti-stiction layer for the improved release after PDMS casting. The deposition of FDTS on an O2 plasma-activated surface of PDMS produced a reproducible and well-performing anti-stiction monolayer of fluorocarbon, and we used the FDTS-coated moulds as micro-masters for rapid......In this paper, we report a simple and precise method to rapidly replicate master structures for fast microchannel fabrication by double replica moulding of polydimethylsiloxane (PDMS). A PDMS mould was surface-treated by vapour phase deposition of 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS...

  19. A sequence of Clifford algebras and three replicas of Dirac particle

    International Nuclear Information System (INIS)

    Krolikowski, W.; Warsaw Univ.

    1990-01-01

    The embedding of Dirac algebra into a sequence N=1, 2, 3,... of Clifford algebras is discussed, leading to Dirac equations with N=1 additional, electromagnetically ''hidden'' spins 1/2. It is shown that there are three and only three replicas N=1, 3, 5 of Dirac particle if the theory of relativity together with the probability interpretation of wave function is applied both to the ''visible'' spin and ''hidden'' spins, and a new ''hidden exclusion principle''is imposed on the wave function (then ''hidden'' spins add up to zero). It is appealing to explore this idea in order to explain the puzzle of three generations of lepton and quarks. (author)

  20. Time-reversal focusing of an expanding soliton gas in disordered replicas

    KAUST Repository

    Fratalocchi, Andrea

    2011-05-31

    We investigate the properties of time reversibility of a soliton gas, originating from a dispersive regularization of a shock wave, as it propagates in a strongly disordered environment. An original approach combining information measures and spin glass theory shows that time-reversal focusing occurs for different replicas of the disorder in forward and backward propagation, provided the disorder varies on a length scale much shorter than the width of the soliton constituents. The analysis is performed by starting from a new class of reflectionless potentials, which describe the most general form of an expanding soliton gas of the defocusing nonlinear Schrödinger equation.

  1. Time-reversal focusing of an expanding soliton gas in disordered replicas

    KAUST Repository

    Fratalocchi, Andrea; Armaroli, A.; Trillo, S.

    2011-01-01

    We investigate the properties of time reversibility of a soliton gas, originating from a dispersive regularization of a shock wave, as it propagates in a strongly disordered environment. An original approach combining information measures and spin glass theory shows that time-reversal focusing occurs for different replicas of the disorder in forward and backward propagation, provided the disorder varies on a length scale much shorter than the width of the soliton constituents. The analysis is performed by starting from a new class of reflectionless potentials, which describe the most general form of an expanding soliton gas of the defocusing nonlinear Schrödinger equation.

  2. The safety of meperidine prescribing in older adults: A longitudinal population-based study.

    Science.gov (United States)

    Friesen, Kevin J; Falk, Jamie; Bugden, Shawn

    2016-05-11

    Meperidine (pethidine) is an opioid analgesic that offers little advantage relative to other opioids and several disadvantages including limited potency, short duration of action, and the production of a neurotoxic metabolite (normeperidine) with a long half-life. Older adults are more sensitive to meperidine's side effects and may have diminished renal function which leads to the accumulation of normeperidine. The Institute for Safe Medication Practices has suggested avoiding meperidine in older adults, limiting its dose (≤600 mg/day) and duration of use (≤48 h). The objective of this study was to determine the level of meperidine use in older adults and assess the dosage and duration of meperidine with reference to these safety recommendations. A longitudinal study using administrative healthcare data was conducted to examine meperidine utilization and levels of high dose and extended duration prescribing among persons ≥65 years of age between April 1, 2001, and March 31, 2014 in Manitoba, Canada. The number of meperidine prescriptions, users, duration of treatment, defined daily doses (DDD) dispensed and number of prescribers were determined over the study period. In the Manitoba older adult population there was a marked decline in meperidine users and prescriptions from 2001 to 2014. There was an average use of 26.4 (95 % CI 24.0-28.8) DDDs of meperidine per user per year. While only 3.7 % of the prescriptions exceeded the 600 mg maximum daily dose, 96.7 % of prescriptions exceeded the recommended 2 days of therapy. For the remaining users of meperidine, the amount of meperidine used per person rose from 18.98 to 56.14 DDDs/user/year over the study period. The number of prescribers of meperidine declined throughout the study, but low DDD prescribers declined more quickly than high DDD prescribers. While meperidine use has declined, the remaining use appears to be decreasing in safety, with more meperidine prescribed per user. This seems to be driven by

  3. Replica Node Detection Using Enhanced Single Hop Detection with Clonal Selection Algorithm in Mobile Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    L. S. Sindhuja

    2016-01-01

    Full Text Available Security of Mobile Wireless Sensor Networks is a vital challenge as the sensor nodes are deployed in unattended environment and they are prone to various attacks. One among them is the node replication attack. In this, the physically insecure nodes are acquired by the adversary to clone them by having the same identity of the captured node, and the adversary deploys an unpredictable number of replicas throughout the network. Hence replica node detection is an important challenge in Mobile Wireless Sensor Networks. Various replica node detection techniques have been proposed to detect these replica nodes. These methods incur control overheads and the detection accuracy is low when the replica is selected as a witness node. This paper proposes to solve these issues by enhancing the Single Hop Detection (SHD method using the Clonal Selection algorithm to detect the clones by selecting the appropriate witness nodes. The advantages of the proposed method include (i increase in the detection ratio, (ii decrease in the control overhead, and (iii increase in throughput. The performance of the proposed work is measured using detection ratio, false detection ratio, packet delivery ratio, average delay, control overheads, and throughput. The implementation is done using ns-2 to exhibit the actuality of the proposed work.

  4. Synthesis and properties of ZnFe{sub 2}O{sub 4} replica with biological hierarchical structure

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hongyan; Guo, Yiping, E-mail: ypguo@sjtu.edu.cn; Zhang, Yangyang; Wu, Fen; Liu, Yun; Zhang, Di, E-mail: zhangdi@sjtu.edu.cn

    2013-09-20

    Highlights: • ZFO replica with hierarchical structure was synthesized from butterfly wings. • Biotemplate has a significant impact on the properties of ZFO material. • Our method opens up new avenues for the synthesis of spinel ferrites. -- Abstract: ZnFe{sub 2}O{sub 4} replica with biological hierarchical structure was synthesized from Papilio paris by a sol–gel method followed by calcination. The crystallographic structure and morphology of the obtained samples were characterized by X-ray diffraction, field-emission scanning electron microscope, and transmittance electron microscope. The results showed that the hierarchical structures were retained in the ZFO replica of spinel structure. The magnetic behavior of such novel products was measured by a vibrating sample magnetometer. A superparamagnetism-like behavior was observed due to nanostructuration size effects. In addition, the ZFO replica with “quasi-honeycomb-like structure” showed a much higher specific capacitance of 279.4 F g{sup −1} at 10 mV s{sup −1} in comparison with ZFO powder of 137.3 F g{sup −1}, attributing to the significantly increased surface area. These results demonstrated that ZFO replica is a promising candidate for novel magnetic devices and supercapacitors.

  5. Pilot study of a 'RIME'-based tool for giving feedback in a multi-specialty longitudinal clerkship.

    Science.gov (United States)

    DeWitt, Dawn; Carline, Jan; Paauw, Douglas; Pangaro, Louis

    2008-12-01

    The Reporter-Interpreter-Manager-Educator (RIME) evaluation framework is intuitive and reliable. Our preceptors' frustration with using summative tools for formative feedback and the hypothesis that the RIME vocabulary might improve students' and preceptors' experiences with feedback prompted us to develop and pilot a RIME-based feedback tool. The tool was based on the RIME vocabulary, which has previously been used for evaluation. As interpersonal skills and professionalism are difficult areas in which to give feedback, we added these as explicit categories. We piloted the tool in a longitudinal, 5-month, multi-specialty clerkship. Preceptors completed pre- and post-introductory workshop surveys. Students completed post-workshop and post-clerkship surveys. Preceptors (n = 14) and students (n = 8) preferred RIME-based feedback to 'usual feedback' (previously given using end-of-clerkship evaluation forms). After the initial workshop, preceptors expected that giving feedback, including critical feedback, would be easier. After the 5-month clerkship, students reported receiving more feedback than in previous clerkships and rated feedback given using this tool more highly (P = 0.002; effect size 1.2). Students also felt it helped them understand specifically how to improve their performance (P = 0.003; effect size 1.2). In this pilot study, preceptors and students preferred feedback with a specific RIME-based tool. Students felt such feedback was more useful and helped them identify specifically how to improve. Whether this method can improve student performance through improved feedback remains an area for further research.

  6. Error Estimate of the Ares I Vehicle Longitudinal Aerodynamic Characteristics Based on Turbulent Navier-Stokes Analysis

    Science.gov (United States)

    Abdol-Hamid, Khaled S.; Ghaffari, Farhad

    2011-01-01

    Numerical predictions of the longitudinal aerodynamic characteristics for the Ares I class of vehicles, along with the associated error estimate derived from an iterative convergence grid refinement, are presented. Computational results are based on the unstructured grid, Reynolds-averaged Navier-Stokes flow solver USM3D, with an assumption that the flow is fully turbulent over the entire vehicle. This effort was designed to complement the prior computational activities conducted over the past five years in support of the Ares I Project with the emphasis on the vehicle s last design cycle designated as the A106 configuration. Due to a lack of flight data for this particular design s outer mold line, the initial vehicle s aerodynamic predictions and the associated error estimates were first assessed and validated against the available experimental data at representative wind tunnel flow conditions pertinent to the ascent phase of the trajectory without including any propulsion effects. Subsequently, the established procedures were then applied to obtain the longitudinal aerodynamic predictions at the selected flight flow conditions. Sample computed results and the correlations with the experimental measurements are presented. In addition, the present analysis includes the relevant data to highlight the balance between the prediction accuracy against the grid size and, thus, the corresponding computer resource requirements for the computations at both wind tunnel and flight flow conditions. NOTE: Some details have been removed from selected plots and figures in compliance with the sensitive but unclassified (SBU) restrictions. However, the content still conveys the merits of the technical approach and the relevant results.

  7. High School Longitudinal Study of 2009 (HSLS:09): Base-Year Data File Documentation. NCES 2011-328

    Science.gov (United States)

    Ingels, Steven J.; Pratt, Daniel J.; Herget, Deborah R.; Burns, Laura J.; Dever, Jill A.; Ottem, Randolph; Rogers, James E.; Jin, Ying; Leinwand, Steve

    2011-01-01

    The High School Longitudinal Study of 2009 (HSLS:09) is the fifth in a series of National Center for Education Statistics (NCES) secondary longitudinal studies. The core research questions for HSLS:09 explore secondary to postsecondary transition plans and the evolution of those plans; the paths into and out of science, technology, engineering,…

  8. PHYSICAL DISABILITY, STIGMA, AND PHYSICAL ACTIVITY IN CHILDREN: A REPLICA STUDY

    Directory of Open Access Journals (Sweden)

    Markus GEBHARDT

    2016-04-01

    Full Text Available Introduction: Stereotypes can be reduced through positive descriptions. A stigma that able-bodied adults have towards children with physical disability can be reduced when the child is portrayed as being active. The study found out that a sporty active child, who uses a wheelchair, is perceived as more competent than the sporty active able-bodied child. Objective: This study is a replica study to support the hypotheses and to examine the stereotypes of able-bodied adults towards children with and without (physical disabilities. Methods: This study presents two experimental replica studies using a 2 (physical activity x 2 (sporty activities. The dependent variables were the perception of competencies and warmth according to Stereotype Content Model (SCM. Study 1 is an online experiment with 355 students of the Open University of Hagen. Study 2 surveys 1176 participants (from Munich and Graz with a paper-pencil-questionnaire. Results: The significant interaction effect was not supported by our studies. The sporty able-bodied child was rated higher in competences than the sporty child, who use a wheelchair. Sporting activity only reduces the stigma towards children with a physical disability slightly. Conclusion: The stigma towards children with physical disability can be reduced when the child is portrayed as being active, but the effect was not strong enough to chance the original classification by the SCM.

  9. Nuclear research emulsion neutron spectrometry at the Little-Boy replica

    International Nuclear Information System (INIS)

    Gold, R.; Roberts, J.H.; Preston, C.C.

    1985-10-01

    Nuclear research emulsions (NRE) have been used to characterize the neutron spectrum emitted by the Little-Boy replica. NRE were irradiated at the Little-Boy surface as well as approximately 2 m from the center of the Little-Boy replica using polar angles of 0 0 , 30 0 , 60 0 and 90 0 . For the NRE exposed at 2 m, neutron background was determined using shadow shields of borated polyethylene. Emulsion scanning to date has concentrated exclusively on the 2-m, 0 0 and 2-m, 90 0 locations. Approximately 5000 proton-recoil tracks have been measured in NRE irradiated at each of these locations. Neutron spectra obtained from these NRE proton-recoil spectra are compared with both liquid scintillator neutron spectrometry and Monte Carlo calculations. NRE and liquid scintillator neutron spectra generally agree within experimental uncertainties at the 2-m, 90 0 location. However, at the 2-m, 0 0 location, the neutron spectra derived from these two independent experimental methods differ significantly. NRE spectra and Monte Carlo calculations exhibit general agreement with regard to both intensity as well as energy dependence. Better agreement is attained between theory and experiment at the 2-m, 90 0 location, where the neutron intensity is considerably higher. 14 refs., 18 figs., 11 tabs

  10. One step replica symmetry breaking and extreme order statistics of logarithmic REMs

    Directory of Open Access Journals (Sweden)

    Xiangyu Cao, Yan V. Fyodorov, Pierre Le Doussal

    2016-12-01

    Full Text Available Building upon the one-step replica symmetry breaking formalism, duly understood and ramified, we show that the sequence of ordered extreme values of a general class of Euclidean-space logarithmically correlated random energy models (logREMs behave in the thermodynamic limit as a randomly shifted decorated exponential Poisson point process. The distribution of the random shift is determined solely by the large-distance ("infra-red", IR limit of the model, and is equal to the free energy distribution at the critical temperature up to a translation. the decoration process is determined solely by the small-distance ("ultraviolet", UV limit, in terms of the biased minimal process. Our approach provides connections of the replica framework to results in the probability literature and sheds further light on the freezing/duality conjecture which was the source of many previous results for log-REMs. In this way we derive the general and explicit formulae for the joint probability density of depths of the first and second minima (as well its higher-order generalizations in terms of model-specific contributions from UV as well as IR limits. In particular, we show that the second min statistics is largely independent of details of UV data, whose influence is seen only through the mean value of the gap. For a given log-correlated field this parameter can be evaluated numerically, and we provide several numerical tests of our theory using the circular model of $1/f$-noise.

  11. A new creep-strain-replica method for evaluating the remaining life time of components

    International Nuclear Information System (INIS)

    Joas, H.D.

    2001-01-01

    To realise a safe and economic operation of older power- or chemical plants a strategy for maintenance is necessary, which makes it possible to operate a component or the plant longer than 300,000 operating hours, this also for the situation that the mode of operation has changed meanwhile. In Germany a realistic evaluation of the remaining life-time is done by comparing the actual calculated test data of a component with the code TRD 301 and TRD 508 and additional non-destructive tests or other codes like ASME, Sec. II, BS 5500, AFCEN (1985). According to many boundary conditions, the calculated data are inaccurate and the measuring of creep-strain at temperatures of about 600 o C with capacitive strain-gauges very expensive. Description of the approach of the problems: spotwelding of two gauges to the surface of a component (in a defined distance), forming a gap, producing of replica of the gap after certain operating hours at shut-down conditions by trained personal, evaluation of the replica to gain the amount of creep-strain using a scanning electron microscope, assessment of the creep-strain data. (Author)

  12. Efficacy of independence sampling in replica exchange simulations of ordered and disordered proteins.

    Science.gov (United States)

    Lee, Kuo Hao; Chen, Jianhan

    2017-11-15

    Recasting temperature replica exchange (T-RE) as a special case of Gibbs sampling has led to a simple and efficient scheme for enhanced mixing (Chodera and Shirts, J. Chem. Phys., 2011, 135, 194110). To critically examine if T-RE with independence sampling (T-REis) improves conformational sampling, we performed T-RE and T-REis simulations of ordered and disordered proteins using coarse-grained and atomistic models. The results demonstrate that T-REis effectively increase the replica mobility in temperatures space with minimal computational overhead, especially for folded proteins. However, enhanced mixing does not translate well into improved conformational sampling. The convergences of thermodynamic properties interested are similar, with slight improvements for T-REis of ordered systems. The study re-affirms the efficiency of T-RE does not appear to be limited by temperature diffusion, but by the inherent rates of spontaneous large-scale conformational re-arrangements. Due to its simplicity and efficacy of enhanced mixing, T-REis is expected to be more effective when incorporated with various Hamiltonian-RE protocols. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  13. Laboratory studies of groundwater degassing in replicas of natural fractured rock for linear flow geometry

    International Nuclear Information System (INIS)

    Geller, J.T.

    1998-02-01

    Laboratory experiments to simulate two-phase (gas and water) flow in fractured rock evolving from groundwater degassing were conducted in transparent replicas of natural rock fractures. These experiments extend the work by Geller et al. (1995) and Jarsjo and Geller (1996) that tests the hypothesis that groundwater degassing caused observed flow reductions in the Stripa Simulated Drift Experiment (SDE). Understanding degassing effects over a range of gas contents is needed due to the uncertainty in the gas contents of the water at the SDE. The main objectives of this study were to: (1) measure the effect of groundwater degassing on liquid flow rates for lower gas contents than the values used in Geller for linear flow geometry in the same fracture replicas of Geller; (2) provide a data set to develop a predictive model of two-phase flow in fractures for conditions of groundwater degassing; and (3) improve the certainty of experimental gas contents (this effort included modifications to the experimental system used by Geller et al. and separate gas-water equilibration tests). The Stripa site is being considered for a high-level radioactive waste repository

  14. High School Longitudinal Study of 2009 (HSLS:09) Base Year to First Follow-Up Data File Documentation. NCES 2014-361

    Science.gov (United States)

    Ingels, Steven J.; Pratt, Daniel J.; Herget, Deborah R.; Dever, Jill A.; Fritch, Laura Burns; Ottem, Randolph; Rogers, James E.; Kitmitto, Sami; Leinwand, Steve

    2013-01-01

    This manual has been produced to familiarize data users with the design, and the procedures followed for data collection and processing, in the base year and first follow-up of the High School Longitudinal Study of 2009 (HSLS:09), with emphasis on the first follow-up. It also provides the necessary documentation for use of the public-use data…

  15. High School Longitudinal Study of 2009 (HSLS:09) Base Year to First Follow-Up Data File Documentation. Appendixes. NCES 2014-361

    Science.gov (United States)

    Ingels, Steven J.; Pratt, Daniel J.; Herget, Deborah R.; Dever, Jill A.; Fritch, Laura Burns; Ottem, Randolph; Rogers, James E.; Kitmitto, Sami; Leinwand, Steve

    2013-01-01

    The manual that accompanies these appendices was produced to familiarize data users with the design, and the procedures followed for data collection and processing, in the base year and first follow-up of the High School Longitudinal Study of 2009 (HSLS:09), with emphasis on the first follow-up. It also provides the necessary documentation for use…

  16. A replica exchange Monte Carlo algorithm for protein folding in the HP model

    Directory of Open Access Journals (Sweden)

    Shmygelska Alena

    2007-09-01

    Full Text Available Abstract Background The ab initio protein folding problem consists of predicting protein tertiary structure from a given amino acid sequence by minimizing an energy function; it is one of the most important and challenging problems in biochemistry, molecular biology and biophysics. The ab initio protein folding problem is computationally challenging and has been shown to be NP MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaat0uy0HwzTfgDPnwy1egaryqtHrhAL1wy0L2yHvdaiqaacqWFneVtcqqGqbauaaa@3961@-hard even when conformations are restricted to a lattice. In this work, we implement and evaluate the replica exchange Monte Carlo (REMC method, which has already been applied very successfully to more complex protein models and other optimization problems with complex energy landscapes, in combination with the highly effective pull move neighbourhood in two widely studied Hydrophobic Polar (HP lattice models. Results We demonstrate that REMC is highly effective for solving instances of the square (2D and cubic (3D HP protein folding problem. When using the pull move neighbourhood, REMC outperforms current state-of-the-art algorithms for most benchmark instances. Additionally, we show that this new algorithm provides a larger ensemble of ground-state structures than the existing state-of-the-art methods. Furthermore, it scales well with sequence length, and it finds significantly better conformations on long biological sequences and sequences with a provably unique ground-state structure, which is believed to be a characteristic of real proteins. We also present evidence that our REMC algorithm can fold sequences which exhibit significant interaction between termini in the hydrophobic core relatively easily. Conclusion We demonstrate that REMC utilizing the pull move

  17. Parity and 11-Year Serum Thyrotropin and Thyroid Autoantibody Change: A Longitudinal Population-Based Study

    DEFF Research Database (Denmark)

    Bjergved, Lena; Carlé, Allan; Jørgensen, Torben

    2016-01-01

    thyrotropin (TSH), as well as change in thyroid peroxidase autoantibody (TPOAb) status. A random sample of 4649 people aged 18-65 years participated in a population-based study in the period 1997-1998. In the study presented here, 1749 non-pregnant women with no history of thyroid disease were included who...

  18. Mindfulness Based Stress Reduction for Academic Evaluation Anxiety: A Naturalistic Longitudinal Study

    Science.gov (United States)

    Dundas, Ingrid; Thorsheim, Torbjørn; Hjeltnes, Aslak; Binder, Per Einar

    2016-01-01

    Mindfulness based stress reduction (MBSR) for academic evaluation anxiety and self-confidence in 70 help-seeking bachelor's and master's students was examined. A repeated measures analysis of covariance on the 46 students who completed pretreatment and posttreatment measures (median age = 24 years, 83% women) showed that evaluation anxiety and…

  19. Enhancing Student Motivation: A Longitudinal Intervention Study Based on Future Time Perspective Theory

    Science.gov (United States)

    Schuitema, Jaap; Peetsma, Thea; van der Veen, Ineke

    2014-01-01

    The authors investigated the effects of an intervention developed to enhance student motivation in the first years of secondary education. The intervention, based on future time perspective (FTP) theory, has been found to be effective in prevocational secondary education (T. T. D. Peetsma & I. Van der Veen, 2008, 2009). The authors extend the…

  20. Emotional development in children with tics : a longitudinal population-based study

    NARCIS (Netherlands)

    Hoekstra, P. J.; Lundervold, A. J.; Lie, S. A.; Gillberg, C.; Plessen, Kerstin J.

    Children with tics often experience accompanying problems that may have more impact on their well being and quality of life than the tics themselves. The present study investigates characteristics and the course of associated problems. In a population-based follow-up study, we investigated the

  1. Contrast enhancement by lipid-based MRI contrast agents in mouse atherosclerotic plaques; a longitudinal study

    NARCIS (Netherlands)

    den Adel, Brigit; van der Graaf, Linda M.; Que, Ivo; Strijkers, Gustav J.; Löwik, Clemens W.; Poelmann, Robert E.; van der Weerd, Louise

    2013-01-01

    The use of contrast-enhanced MRI to enable in vivo specific characterization of atherosclerotic plaques is increasing. In this study the intrinsic ability of two differently sized gadolinium-based contrast agents to enhance atherosclerotic plaques in ApoE(-/-) mice was evaluated with MRI. We

  2. Vedic Science Based Education and Nonverbal Intelligence: A Preliminary Longitudinal Study in Cambodia.

    Science.gov (United States)

    Fergusson, Lee C.; And Others

    1996-01-01

    A study investigated the effects on students' nonverbal intelligence of implementing an approach to higher education based on Vedic science, developed by Maharishi Mahesh Yogi and including transcendental meditation. The approach was implemented in two Cambodian universities and its effects assessed in 70 undergraduate students. An increase in…

  3. A theory of longitudinally polarised piezocomposite rod based on Mindlin-Herrmann model

    CSIR Research Space (South Africa)

    Shatalov, M

    2010-09-01

    Full Text Available The conventional theory of the piezoelectric rod is based on an assumption that its lateral vibrations are negligible. In this case the rod, vibration could be described in terms of one-dimensional wave equation and a set of mechanical and electric...

  4. FEM-based neural-network approach to nonlinear modeling with application to longitudinal vehicle dynamics control.

    Science.gov (United States)

    Kalkkuhl, J; Hunt, K J; Fritz, H

    1999-01-01

    An finite-element methods (FEM)-based neural-network approach to Nonlinear AutoRegressive with eXogenous input (NARX) modeling is presented. The method uses multilinear interpolation functions on C0 rectangular elements. The local and global structure of the resulting model is analyzed. It is shown that the model can be interpreted both as a local model network and a single layer feedforward neural network. The main aim is to use the model for nonlinear control design. The proposed FEM NARX description is easily accessible to feedback linearizing control techniques. Its use with a two-degrees of freedom nonlinear internal model controller is discussed. The approach is applied to modeling of the nonlinear longitudinal dynamics of an experimental lorry, using measured data. The modeling results are compared with local model network and multilayer perceptron approaches. A nonlinear speed controller was designed based on the identified FEM model. The controller was implemented in a test vehicle, and several experimental results are presented.

  5. The impact of covariance misspecification in group-based trajectory models for longitudinal data with non-stationary covariance structure.

    Science.gov (United States)

    Davies, Christopher E; Glonek, Gary Fv; Giles, Lynne C

    2017-08-01

    One purpose of a longitudinal study is to gain a better understanding of how an outcome of interest changes among a given population over time. In what follows, a trajectory will be taken to mean the series of measurements of the outcome variable for an individual. Group-based trajectory modelling methods seek to identify subgroups of trajectories within a population, such that trajectories that are grouped together are more similar to each other than to trajectories in distinct groups. Group-based trajectory models generally assume a certain structure in the covariances between measurements, for example conditional independence, homogeneous variance between groups or stationary variance over time. Violations of these assumptions could be expected to result in poor model performance. We used simulation to investigate the effect of covariance misspecification on misclassification of trajectories in commonly used models under a range of scenarios. To do this we defined a measure of performance relative to the ideal Bayesian correct classification rate. We found that the more complex models generally performed better over a range of scenarios. In particular, incorrectly specified covariance matrices could significantly bias the results but using models with a correct but more complicated than necessary covariance matrix incurred little cost.

  6. Group-based developmental BMI trajectories, polycystic ovary syndrome, and gestational diabetes: a community-based longitudinal study.

    Science.gov (United States)

    Kakoly, Nadira Sultana; Earnest, Arul; Moran, Lisa J; Teede, Helena J; Joham, Anju E

    2017-11-06

    Obesity is common in young women, increasing insulin resistance (IR) and worsening pregnancy complications, including gestational diabetes (GDM). Women with polycystic ovary syndrome (PCOS) are commonly obese, which aggravates the severity of PCOS clinical expression. Relationships between these common insulin-resistant conditions, however, remain unclear. We conducted a secondary analysis of the Australian Longitudinal Study on Women's Health (ALSWH) database, including data from 8009 women aged 18-36 years across six surveys. We used latent-curve growth modelling to identify distinct body mass index (BMI) trajectories and multinomial logistic regression to explore sociodemographic and health variables characterizing BMI group membership. Logistic regression was used to assess independent risk of GDM. A total of 662 women (8.29%, 95% CI 7.68-8.89) reported PCOS. Three distinct BMI trajectories emerged, namely low stable (LSG) (63.8%), defined as an average trajectory remaining at ~25 kg/m 2 ; moderately rising (MRG) (28.8%), a curvilinear trajectory commencing in a healthy BMI and terminating in the overweight range; and high-rising (HRG) (7.4%), a curvilinear trajectory starting and terminating in the obese range. A high BMI in early reproductive life predicted membership in higher trajectories. The HRG BMI trajectory was independently associated with GDM (OR 2.50, 95% CI 1.80-3.48) and was a stronger correlate than PCOS (OR 1.89, 95% CI 1.41-2.54), maternal age, socioeconomic status, or parity. Our results suggest heterogeneity in BMI change among Australian women of reproductive age, with and without PCOS. Reducing early adult life weight represents an ideal opportunity to intervene at an early stage of reproductive life and decreases the risk of long-term metabolic complications such as GDM.

  7. Evaluation of elastix-based propagated align algorithm for VOI- and voxel-based analysis of longitudinal F-18-FDG PET/CT data from patients with non-small cell lung cancer (NSCLC)

    OpenAIRE

    Kerner, Gerald S. M. A.; Fischer, Alexander; Koole, Michel J. B.; Pruim, Jan; Groen, Harry J. M.

    2015-01-01

    Background: Deformable image registration allows volume of interest (VOI)- and voxel-based analysis of longitudinal changes in fluorodeoxyglucose (FDG) tumor uptake in patients with non-small cell lung cancer (NSCLC). This study evaluates the performance of the elastix toolbox deformable image registration algorithm for VOI and voxel-wise assessment of longitudinal variations in FDG tumor uptake in NSCLC patients. Methods: Evaluation of the elastix toolbox was performed using F-18-FDG PET/CT ...

  8. Mimicking the action of folding chaperones by Hamiltonian replica-exchange molecular dynamics simulations : Application in the refinement of de novo models

    NARCIS (Netherlands)

    Fan, Hao; Periole, Xavier; Mark, Alan E.

    The efficiency of using a variant of Hamiltonian replica-exchange molecular dynamics (Chaperone H-replica-exchange molecular dynamics [CH-REMD]) for the refinement of protein structural models generated de novo is investigated. In CH-REMD, the interaction between the protein and its environment,

  9. Correlates of physical activity among colorectal cancer survivors : Results from the longitudinal population-based profiles registry

    NARCIS (Netherlands)

    van Putten, Margreet; Husson, O.; Mols, F.; Luyer, Misha D P; van de Poll-Franse, L.V.; Ezendam, N.P.M.

    2016-01-01

    PURPOSE: Physical activity can improve health of cancer survivors. To increase physical activity levels among colorectal cancer (CRC) survivors, we need to understand which factors affect physical activity. Therefore, this study examined the longitudinal relationship between symptom-related,

  10. Correlates of physical activity among colorectal cancer survivors: results from the longitudinal population-based profiles registry

    NARCIS (Netherlands)

    Putten, M van; Husson, O.; Mols, F.; Luyer, M.D.; Poll-Franse, L.V. van de; Ezendam, N.P.

    2016-01-01

    PURPOSE: Physical activity can improve health of cancer survivors. To increase physical activity levels among colorectal cancer (CRC) survivors, we need to understand which factors affect physical activity. Therefore, this study examined the longitudinal relationship between symptom-related,

  11. Characteristics of menstrual versus non-menstrual migraine during pregnancy: a longitudinal population-based study.

    Science.gov (United States)

    Petrovski, Beáta Éva; Vetvik, Kjersti G; Lundqvist, Christofer; Eberhard-Gran, Malin

    2018-04-02

    Migraine is a common headache disorder that affects mostly women. In half of these, migraine is menstrually associated, and ranges from completely asymptomatic to frequent pain throughout pregnancy. The aim of the study was to define the pattern (frequency, intensity, analgesics use) of migrainous headaches among women with and without menstural migraine (MM) during pregnancy, and define how hormonally-related factors affect its intensity. The analysis was based upon data from 280 women, 18.6% of them having a self-reported MM. Women with MM described a higher headache intensity during early pregnancy and postpartum compared those without MM, but both groups showed improvement during the second half of pregnancy and directly after delivery. Hormonal factors and pre-menstrual syndrome had no effect upon headache frequency, but may affect headache intensity. Individual treatment plan is necessary for women with migrainous headaches during pregnancy, especially for those suffering highest symptoms load.

  12. Longitudinal stability of MRI for mapping brain change using tensor-based morphometry

    Science.gov (United States)

    Leow, Alex D.; Klunder, Andrea D.; Jack, Clifford R.; Toga, Arthur W.; Dale, Anders M.; Bernstein, Matt A.; Britson, Paula J.; Gunter, Jeffrey L.; Ward, Chadwick P.; Whitwell, Jennifer L.; Borowski, Bret J.; Fleisher, Adam S.; Fox, Nick C.; Harvey, Danielle; Kornak, John; Schuff, Norbert; Studholme, Colin; Alexander, Gene E.; Weiner, Michael W.; Thompson, Paul M.

    2007-01-01

    Measures of brain change can be computed from sequential MRI scans, providing valuable information on disease progression, e.g., for patient monitoring and drug trials. Tensor-based morphometry (TBM) creates maps of these brain changes, visualizing the 3D profile and rates of tissue growth or atrophy, but its sensitivity depends on the contrast and geometric stability of the images. A s part of the Alzheimer’s Disease Neuroimaging Initiative (ADNI), 17 normal elderly subjects were scanned twice (at a 2-week interval) with several 3D 1.5 T MRI pulse sequences: high and low flip angle SPGR/FLASH (from which Synthetic T1 images were generated), MP-RAGE, IR-SPGR (N = 10) and MEDIC (N = 7) scans. For each subject and scan type, a 3D deformation map aligned baseline and follow-up scans, computed with a nonlinear, inverse-consistent elastic registration algorithm. Voxelwise statistics, in ICBM stereotaxic space, visualized the profile of mean absolute change and its cross-subject variance; these maps were then compared using permutation testing. Image stability depended on: (1) the pulse sequence; (2) the transmit/receive coil type (birdcage versus phased array); (3) spatial distortion corrections (using MEDIC sequence information); (4) B1-field intensity inhomogeneity correction (using N3). SPGR/FLASH images acquired using a birdcage coil had least overall deviation. N3 correction reduced coil type and pulse sequence differences and improved scan reproducibility, except for Synthetic T1 images (which were intrinsically corrected for B1-inhomogeneity). No strong evidence favored B0 correction. Although SPGR/FLASH images showed least deviation here, pulse sequence selection for the ADNI project was based on multiple additional image analyses, to be reported elsewhere. PMID:16480900

  13. Experiences from implementing value-based healthcare at a Swedish University Hospital - an longitudinal interview study.

    Science.gov (United States)

    Nilsson, Kerstin; Bååthe, Fredrik; Andersson, Annette Erichsen; Wikström, Ewa; Sandoff, Mette

    2017-02-28

    Implementing the value-based healthcare concept (VBHC) is a growing management trend in Swedish healthcare organizations. The aim of this study is to explore how representatives of four pilot project teams experienced implementing VBHC in a large Swedish University Hospital over a period of 2 years. The project teams started their work in October 2013. An explorative and qualitative design was used, with interviews as the data collection method. All the participants in the four pilot project teams were individually interviewed three times, with interviews starting in March 2014 and ending in November 2015. All the interviews were transcribed and analyzed using qualitative analysis. Value for the patients was experienced as the fundamental drive for implementing VBHC. However, multiple understandings of what value for patients' means existed in parallel. The teams received guidance from consultants during the first 3 months. There were pros and cons to the consultant's guidance. This period included intensive work identifying outcome measurements based on patients' and professionals' perspectives, with less interest devoted to measuring costs. The implementation process, which both gave and took energy, developed over time and included interventions. In due course it provided insights to the teams about the complexity of healthcare. The necessity of coordination, cooperation and working together inter-departmentally was critical. Healthcare organizations implementing VBHC will benefit from emphasizing value for patients, in line with the intrinsic drive in healthcare, as well as managing the process of implementation on the basis of understanding the complexities of healthcare. Paying attention to the patients' voice is a most important concern and is also a key towards increased engagement from physicians and care providers for improvement work.

  14. Revisiting the association of blood pressure with mortality in oldest old people in China: community based, longitudinal prospective study

    Science.gov (United States)

    Lv, Yue-Bin; Gao, Xiang; Yin, Zhao-Xue; Chen, Hua-Shuai; Luo, Jie-Si; Brasher, Melanie Sereny; Kraus, Virginia Byers; Li, Tian-Tian; Zeng, Yi

    2018-01-01

    Abstract Objective To examine the associations of blood pressure with all cause mortality and cause specific mortality at three years among oldest old people in China. Design Community based, longitudinal prospective study. Setting 2011 and 2014 waves of the Chinese Longitudinal Healthy Longevity Survey, conducted in 22 Chinese provinces. Participants 4658 oldest old individuals (mean age 92.1 years). Main outcome measures All cause mortality and cause specific mortality assessed at three year follow-up. Results 1997 deaths were recorded at three year follow-up. U shaped associations of mortality with systolic blood pressure, mean arterial pressure, and pulse pressure were identified; values of 143.5 mm Hg, 101 mm Hg, and 66 mm Hg conferred the minimum mortality risk, respectively. After adjustment for covariates, the U shaped association remained only for systolic blood pressure (minimum mortality risk at 129 mm Hg). Compared with a systolic blood pressure value of 129 mm Hg, risk of all cause mortality decreased for values lower than 107 mm Hg (from 1.47 (95% confidence interval 1.01 to 2.17) to 1.08 (1.01 to 1.17)), and increased for values greater than 154 mm Hg (from 1.08 (1.01 to 1.17) to 1.27 (1.02 to 1.58)). In the cause specific analysis, compared with a middle range of systolic blood pressure (107-154 mm Hg), higher values (>154 mm Hg) were associated with a higher risk of cardiovascular mortality (adjusted hazard ratio 1.51 (95% confidence interval 1.12 to 2.02)); lower values (blood pressure and all cause mortality at three years among oldest old people in China. This association could be explained by the finding that higher systolic blood pressure predicted a higher risk of death from cardiovascular disease, and that lower systolic blood pressure predicted a higher risk of death from non-cardiovascular causes. These results emphasise the importance of revisiting blood pressure management or establishing specific guidelines for management among oldest

  15. Prevalence, incidence, and resolution of nocturnal polyuria in a longitudinal community-based study in older men: the Krimpen study.

    Science.gov (United States)

    van Doorn, Boris; Blanker, Marco H; Kok, Esther T; Westers, Paul; Bosch, J L H Ruud

    2013-03-01

    Nocturnal polyuria (NP) is common in older men and can lead to nocturia. However, no longitudinal data are available on the natural history of NP. To determine prevalence, incidence, and resolution rates of NP. A longitudinal, community-based study was conducted among 1688 men aged 50-78 yr in Krimpen aan den IJssel, The Netherlands (reference date: 1995), with planned follow-up rounds at 2, 4, and 6 yr. NP was determined with frequency-volume charts. Two definitions of NP were used: (1) a nocturnal urine production (NUP) of >90 ml/h (NUP90) and (2) the nocturnal voided volume plus first morning void being >33% of the 24-h voided volume (NUV33). Nocturia was defined as two or more voids per night. We determined the prevalence of NP at each study round. At first follow-up, we determined the incidence in men without baseline NP and the resolution in men with baseline NP. Prevalence of NP in men with or without nocturia was also determined. At baseline, the prevalence of NUP90 was 15.0% and increased to 21.7% after 6.5 yr, whereas the prevalence of NUV33 was 77.8% at baseline and 80.5% after 6.5 yr. At 2.1 yr of follow-up, the incidences of NUP90 and NUV33 were 13.6% and 60.3%, respectively, and the resolution rates were 57.0% and 17.8%, respectively. Because of this fluctuation in NP, no reliable long-term incidences could be calculated. At baseline, NUP90 was prevalent in 27.7% of men with nocturia and in 8.0% of those without nocturia. At baseline, NUV33 was prevalent in 91.9% of men with nocturia and in 70.1% of men without nocturia. Due to the fluctuation of NP, it is advisable to first determine its chronicity and cause before starting treatment. Because of the high prevalence of NP in men without nocturia, NUV33 should be reconsidered as a discriminative definition of NP. Copyright © 2012. Published by Elsevier B.V.

  16. Elevated incidence rates of diabetes in Peru: report from PERUDIAB, a national urban population-based longitudinal study.

    Science.gov (United States)

    Seclen, Segundo Nicolas; Rosas, Moises Ernesto; Arias, Arturo Jaime; Medina, Cecilia Alexandra

    2017-01-01

    A recent report from a non-nationally representative, geographically diverse sample in four separate communities in Peru suggests an unusually high diabetes incidence. We aimed to estimate the national diabetes incidence rate using PERUDIAB, a probabilistic, national urban population-based longitudinal study. 662 subjects without diabetes, selected by multistage, cluster, random sampling of households, representing the 24 administrative and the 3 (coast, highlands and jungle) natural regions across the country, from both sexes, aged 25+ years at baseline, enrolled in 2010-2012, were followed for 3.8 years. New diabetes cases were defined as fasting blood glucose ≥126 mg/dL or on medical diabetes treatment. There were 49 cases of diabetes in 2408 person-years follow-up. The weighted cumulative incidence of diabetes was 7.2% while the weighted incidence rate was estimated at 19.5 (95% CI 13.9 to 28.3) new cases per 1000 person-years. Older age, obesity and technical or higher education were statistically associated with the incidence of diabetes. Our results confirm that the incidence of diabetes in Peru is among the highest reported globally. The fast economic growth in the last 20 years, high overweight and obesity rates may have triggered this phenomenon.

  17. Predicting healthy and unhealthy behaviors through physical education: A self-determination theory-based longitudinal approach.

    Science.gov (United States)

    Ferriz, R; González-Cutre, D; Sicilia, Á; Hagger, M S

    2016-05-01

    The aim of this study was to evaluate the relations between three dimensions of the structured teaching environment (promotion of theoretical knowledge, physical learning, and health improvement) in physical education (PE) and the adoption of health-related behaviors by students. The study adopted a two-occasion longitudinal design based on self-determination theory (SDT). PE students (N = 654, mean age = 16.13, SD = .77) completed measures of perceived structured teaching environment, satisfaction of basic psychological needs and motivation for PE, and healthy (physical activity, sport participation, and healthy eating) and unhealthy (consumption of tobacco, alcohol, and drugs) behaviors at the beginning and end of the first year of post-compulsory secondary education. Path analysis of the proposed relations among variables supported SDT tenets and showed positive relations between the three dimensions of the structured teaching environment, the satisfaction of basic psychological needs, and autonomous motivation in PE. Autonomous motivation contributed to an explanation of variance in two healthy behaviors, physical activity and sport participation. However, no relation was found among motivation in PE, healthy eating, and consumption of tobacco, alcohol, and drugs. These results show negligible trans-contextual influence of SDT motivational factors in PE on other healthy behaviors beyond physical activity. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. A Population-based Longitudinal Study of Childhood Neurodevelopmental Disorders, IQ and Subsequent Risk of Psychotic Experiences in Adolescence

    Science.gov (United States)

    Khandaker, Golam M.; Stochl, Jan; Zammit, Stanley; Lewis, Glyn; Jones, Peter B

    2014-01-01

    Background Schizophrenia has a neurodevelopmental component to its origin, and may share overlapping pathogenic mechanisms with childhood neurodevelopmental disorders (ND). Yet longitudinal studies of psychotic outcomes among individuals with ND are limited. We report a population-based prospective study of six common childhood ND, subsequent neurocognitive performance and the risk of psychotic experiences (PEs) in early adolescence. Methods PEs were assessed by semi-structured interviews at age 13 years. IQ and working memory were measured between ages 9 and 11 years. The presence of six neurodevelopmental disorders (autism spectrum, dyslexia, dyspraxia, dysgraphia, dysorthographia, dyscalculia) was determined from parent-completed questionnaire at age 9 years. Linear regression calculated mean difference in cognitive scores between those with and without ND. The association between ND and PEs was expressed as odds ratio (OR); effects of cognitive deficits were examined. Potential confounders included age, gender, father’s social class, ethnicity and maternal education. Results Out of 8,220 children, 487 (5.9%) were reported to have ND at age 9 years. Children with, compared with those without ND performed worse on all cognitive measures; adjusted mean difference in total IQ 6.84 (95% CI 5.00- 8.69). The association between total IQ and ND was linear (pneurodevelopmental hypothesis of schizophrenia. PMID:25066026

  19. Classifying MCI Subtypes in Community-Dwelling Elderly Using Cross-Sectional and Longitudinal MRI-Based Biomarkers

    Directory of Open Access Journals (Sweden)

    Hao Guan

    2017-09-01

    Full Text Available Amnestic MCI (aMCI and non-amnestic MCI (naMCI are considered to differ in etiology and outcome. Accurately classifying MCI into meaningful subtypes would enable early intervention with targeted treatment. In this study, we employed structural magnetic resonance imaging (MRI for MCI subtype classification. This was carried out in a sample of 184 community-dwelling individuals (aged 73–85 years. Cortical surface based measurements were computed from longitudinal and cross-sectional scans. By introducing a feature selection algorithm, we identified a set of discriminative features, and further investigated the temporal patterns of these features. A voting classifier was trained and evaluated via 10 iterations of cross-validation. The best classification accuracies achieved were: 77% (naMCI vs. aMCI, 81% (aMCI vs. cognitively normal (CN and 70% (naMCI vs. CN. The best results for differentiating aMCI from naMCI were achieved with baseline features. Hippocampus, amygdala and frontal pole were found to be most discriminative for classifying MCI subtypes. Additionally, we observed the dynamics of classification of several MRI biomarkers. Learning the dynamics of atrophy may aid in the development of better biomarkers, as it may track the progression of cognitive impairment.

  20. Validation of adult height prediction based on automated bone age determination in the Paris Longitudinal Study of healthy children

    Energy Technology Data Exchange (ETDEWEB)

    Martin, David D. [Tuebingen University Children' s Hospital, Tuebingen (Germany); Filderklinik, Filderstadt (Germany); Schittenhelm, Jan [Tuebingen University Children' s Hospital, Tuebingen (Germany); Thodberg, Hans Henrik [Visiana, Holte (Denmark)

    2016-02-15

    An adult height prediction model based on automated determination of bone age was developed and validated in two studies from Zurich, Switzerland. Varied living conditions and genetic backgrounds might make the model less accurate. To validate the adult height prediction model on children from another geographical location. We included 51 boys and 58 girls from the Paris Longitudinal Study of children born 1953 to 1958. Radiographs were obtained once or twice a year in these children from birth to age 18. Bone age was determined using the BoneXpert method. Radiographs in children with bone age greater than 6 years were considered, in total 1,124 images. The root mean square deviation between the predicted and the observed adult height was 2.8 cm for boys in the bone age range 6-15 years and 3.1 cm for girls in the bone age range 6-13 years. The bias (the average signed difference) was zero, except for girls below bone age 12, where the predictions were 0.8 cm too low. The accuracy of the BoneXpert method in terms of root mean square error was as predicted by the model, i.e. in line with what was observed in the Zurich studies. (orig.)

  1. Sociocultural Determinants of Risky Sexual Behaviors among Adult Latinas: A Longitudinal Study of a Community-Based Sample.

    Science.gov (United States)

    Rojas, Patria; Huang, Hui; Li, Tan; Ravelo, Gira J; Sanchez, Mariana; Dawson, Christyl; Brook, Judith; Kanamori, Mariano; De La Rosa, Mario

    2016-11-23

    Few studies have examined the sociocultural determinants of risky sexual behavior trajectories among adult Latinas. To longitudinally examine the link between sociocultural determinants of risky sexual behaviors, we followed a sample of adult Latina mother-daughter dyads ( n = 267) across a 10-year span through four waves of data collection. The present study investigates how risky sexual behavior (operationalized as sex under the influence of alcohol or other drugs, sex without a condom, or multiple sex partners) is affected by: (a) socioeconomic conditions; (b) mental health; (c) medical health; (d) acculturation to U.S. culture; (e) interpersonal support; (f) relationship stress; (g) mother-daughter attachment; (h) intimate partner violence; (i) religious involvement; and (j) criminal justice involvement. Results indicate the following factors are negatively associated with risky sexual behavior: drug and alcohol use, treating a physical problem with prescription drugs, religious involvement, and mother-daughter attachment. The following factors are positively associated with risky sexual behavior: higher number of mental health symptoms, being U.S.-born, and criminal justice involvement. We discuss implications for the future development of culturally relevant interventions based on the study findings.

  2. Spinal cord injury and Parkinson's disease: a population-based, propensity score-matched, longitudinal follow-up study.

    Science.gov (United States)

    Yeh, T-S; Huang, Y-P; Wang, H-I; Pan, S-L

    2016-12-01

    To investigate whether patients with spinal cord injury (SCI) are at an increased risk of developing Parkinson's disease (PD). A population-based, propensity score-matched, longitudinal follow-up cohort study. The study was conducted using the National Health Insurance (NHI) Research Database. A total of 10 125 patients with at least 2 ambulatory visits with a diagnosis of SCI in 2001 were enrolled in the SCI group. The non-SCI group comprised 10 125 propensity score-matched patients without SCI. The propensity scores were computed using a logistic regression model that included age, sex, comorbidities and socioeconomic status. The PD-free survival rates of the two groups were estimated using the Kaplan-Meier method. Stratified Cox proportional hazard regression was used to estimate the effect of SCI on subsequent occurrence of PD. During the 3-year follow-up period, 99 subjects in the SCI group and 59 in the non-SCI group developed PD. The hazard ratio of PD for the SCI group compared with the non-SCI group was 1.65 (95% confidence interval 1.16-2.33, P=0.0049). The PD-free survival rate for the SCI group was lower than that for the non-SCI group (P=0.0017). This study shows that SCI is associated with a subsequent increased risk of PD. Further studies are needed to elucidate the mechanism underlying this association.

  3. Validation of adult height prediction based on automated bone age determination in the Paris Longitudinal Study of healthy children

    International Nuclear Information System (INIS)

    Martin, David D.; Schittenhelm, Jan; Thodberg, Hans Henrik

    2016-01-01

    An adult height prediction model based on automated determination of bone age was developed and validated in two studies from Zurich, Switzerland. Varied living conditions and genetic backgrounds might make the model less accurate. To validate the adult height prediction model on children from another geographical location. We included 51 boys and 58 girls from the Paris Longitudinal Study of children born 1953 to 1958. Radiographs were obtained once or twice a year in these children from birth to age 18. Bone age was determined using the BoneXpert method. Radiographs in children with bone age greater than 6 years were considered, in total 1,124 images. The root mean square deviation between the predicted and the observed adult height was 2.8 cm for boys in the bone age range 6-15 years and 3.1 cm for girls in the bone age range 6-13 years. The bias (the average signed difference) was zero, except for girls below bone age 12, where the predictions were 0.8 cm too low. The accuracy of the BoneXpert method in terms of root mean square error was as predicted by the model, i.e. in line with what was observed in the Zurich studies. (orig.)

  4. Longitudinal change in the neural bases of adolescent social self-evaluations: effects of age and pubertal development.

    Science.gov (United States)

    Pfeifer, Jennifer H; Kahn, Lauren E; Merchant, Junaid S; Peake, Shannon J; Veroude, Kim; Masten, Carrie L; Lieberman, Matthew D; Mazziotta, John C; Dapretto, Mirella

    2013-04-24

    Self-evaluations undergo significant transformation during early adolescence, developing in parallel with the heightened complexity of teenagers' social worlds. Intuitive theories of adolescent development, based in part on animal work, suggest that puberty is associated with neural-level changes that facilitate a "social reorientation" (Nelson et al., 2005). However, direct tests of this hypothesis using neuroimaging are limited in humans. This longitudinal fMRI study examined neurodevelopmental trajectories associated with puberty, self-evaluations, and the presumed social reorientation during the transition from childhood to adolescence. Participants (N = 27, mean age = 10.1 and 13.1 years at time points one and two, respectively) engaged in trait evaluations of two targets (the self and a familiar fictional other), across two domains of competence (social and academic). Responses in ventromedial PFC increased with both age and pubertal development during self-evaluations in the social domain, but not in the academic domain. These results suggest that changes in social self-evaluations are intimately connected with biology, not just peer contexts, and provide important empirical support for the relationship between neurodevelopment, puberty, and social functioning.

  5. Does International Migration Pay Off? The Labor Market Situation of Finnish Return Migrants Based on Longitudinal Register Data

    Directory of Open Access Journals (Sweden)

    Saara Koikkalainen

    2016-12-01

    Full Text Available International mobility is a form of flexible labor market adaptation available for young Nordic nationals who have the privilege of relatively easy return if life abroad does not work out. The article considers mobility as a labor market transition and examines the pre- and post-migration situation of two Finnish return migrant groups—those who lived abroad in 1999 and in 2004—based on longitudinal register data. It considers the consequences of return for an individual migrant: is it a form of failure in labor market integration in the country of destination or rather a sign of success whereby the skills, resources, and experiences gained abroad are brought back to the country of origin. Migrants who leave Finland nowadays often opt to move to other Nordic countries and are younger, more educated, and have a better socio-economic status than previous migrant generations. The article demonstrates that international migration does not deteriorate the returnees’ labor market status. While re-entry into the Finnish labor market may take some time and flexibility, mobility seems to pay off and have beneficial consequences: return migrants earn higher taxable incomes and have lower unemployment rates than their peers who only stayed in the national labor markets..

  6. A population-based longitudinal study on the implication of demographic changes on blood donation and transfusion demand.

    Science.gov (United States)

    Greinacher, Andreas; Weitmann, Kerstin; Schönborn, Linda; Alpen, Ulf; Gloger, Doris; Stangenberg, Wolfgang; Stüpmann, Kerstin; Greger, Nico; Kiefel, Volker; Hoffmann, Wolfgang

    2017-06-13

    Transfusion safety includes the risk of transmission of pathogens, appropriate transfusion thresholds, and sufficient blood supply. All industrialized countries experience major ongoing demographic changes resulting from low birth rates and aging of the baby boom generation. Little evidence exists about whether future blood supply and demand correlate with these demographic changes. The ≥50% decline in birth rate in the eastern part of Germany after 1990 facilitates systematic study of the effects of pronounced demographic changes on blood donation and demand. In this prospective, 10-year longitudinal study, we enrolled all whole blood donors and all patients receiving red blood cell transfusions in the state of Mecklenburg-West Pomerania. We compared projections made in 2005 based on the projected demographic changes with: (1) number and age distribution of blood donors and transfusion recipients in 2015 and (2) blood demand within specific age and patient groups. Blood donation rates closely followed the demographic changes, showing a decrease of -18% (vs projected -23%). In contrast, 2015 transfusion rates were -21.3% lower than projected. We conclude that although changes in demography are highly predictive for the blood supply, transfusion demand is strongly influenced by changes in medical practice. Given ongoing pronounced demographic change, regular monitoring of the donor/recipient age distributions and associated impact on blood demand/supply relationships is required to allow strategic planning to prevent blood shortages or overproduction.

  7. Screen-Based Sedentary Behavior, Physical Activity, and Muscle Strength in the English Longitudinal Study of Ageing

    Science.gov (United States)

    Hamer, Mark; Stamatakis, Emmanuel

    2013-01-01

    Background Sarcopenia is associated with loss of independence and ill-health in the elderly although the causes remain poorly understood. We examined the association between two screen-based leisure time sedentary activities (daily TV viewing time and internet use) and muscle strength. Methods and Results We studied 6228 men and women (aged 64.9±9.1 yrs) from wave 4 (2008-09) of the English Longitudinal Study of Ageing, a prospective study of community dwelling older adults. Muscle strength was assessed by a hand grip test and the time required to complete five chair rises. TV viewing and internet usage were inversely associated with one another. Participants viewing TV ≥6hrs/d had lower grip strength (Men, B = −1.20 kg, 95% CI, −2.26, −0.14; Women, −0.75 kg, 95% CI, −1.48, −0.03) in comparison to behavior. PMID:23755302

  8. How Effective Is Help on the Doorstep? A Longitudinal Evaluation of Community-Based Organisation Support.

    Directory of Open Access Journals (Sweden)

    Lorraine Sherr

    Full Text Available Community-based responses have a lengthy history. The ravages of HIV on family functioning has included a widespread community response. Although much funding has been invested in front line community-based organisations (CBO, there was no equal investment in evaluations. This study was set up to compare children aged 9-13 years old, randomly sampled from two South African provinces, who had not received CBO support over time (YC with a group of similarly aged children who were CBO attenders (CCC. YC baseline refusal rate was 2.5% and retention rate was 97%. CCC baseline refusal rate was 0.7% and retention rate was 86.5%. 1848 children were included-446 CBO attenders compared to 1402 9-13 year olds drawn from a random sample of high-HIV prevalence areas. Data were gathered at baseline and 12-15 months follow-up. Standardised measures recorded demographics, violence and abuse, mental health, social and educational factors. Multivariate regression analyses revealed that children attending CBOs had lower odds of experiencing weekly domestic conflict between adults in their home (OR 0.17; 95% CI 0.09, 0.32, domestic violence (OR 0.22; 95% CI 0.08, 0.62, or abuse (OR 0.11; 95% CI 0.05, 0.25 at follow-up compared to participants without CBO contact. CBO attenders had lower odds of suicidal ideation (OR 0.41; 95% CI 0.18, 0.91, fewer depressive symptoms (B = -0.40; 95% CI -0.62, -0.17, less perceived stigma (B = -0.37; 95% CI -0.57, -0.18, fewer peer problems (B = -1.08; 95% CI -1.29, -0.86 and fewer conduct problems (B = -0.77; 95% CI -0.95, -0.60 at follow-up. In addition, CBO contact was associated with more prosocial behaviours at follow-up (B = 1.40; 95% CI 1.13, 1.67. No associations were observed between CBO contact and parental praise or post-traumatic symptoms. These results suggest that CBO exposure is associated with behavioural and mental health benefits for children over time. More severe psychopathology was not affected by attendance and

  9. Resistance Patterns of Typhoid Fever in Children: A Longitudinal Community-Based Study.

    Science.gov (United States)

    Vala, Snehal; Shah, Urvesh; Ahmad, Syed Amir; Scolnik, Dennis; Glatstein, Miguel

    2016-01-01

    Salmonella typhi and S. paratyphi are important causes of bacteremia in children, especially those from the developing world. There is a lack of standardized treatment protocols for such patients in the literature, and there are also reports of therapeutic failure related to resistance to commonly used antibiotics. We analyzed the epidemiological, clinical, and antimicrobiological sensitivity patterns of disease in patients diagnosed with blood culture-positive typhoid fever over a 6-month period in a tertiary-care pediatric hospital in western India. Data were retrospectively analyzed for all patients with Salmonella isolates on blood culture between January 1 and June 30, 2011 at the Synergy Neonatal and Pediatric Hospital. Susceptibility of isolates to antimicrobials and minimum inhibitory concentrations were determined. Demographic data, symptoms and signs, basic laboratory results, treatment courses, and clinical outcomes were collected from clinical charts. All of the 61 isolates of S. typhi were sensitive to cefepime (fourth-generation cephalosporin), 96% to third-generation cephalosporins, and 95% to quinolones. There was intermediate sensitivity to ampicillin (92%) and chloramphenicol (80%). Notably, azithromycin resistance was observed in 63% of isolates. All patients ultimately made full recoveries. There is an urgent need for large scale, community-based clinical trials to evaluate the effectiveness of different antibiotics in enteric fever. Our antimicrobial susceptibility data suggest that quinolones and third-generation cephalosporins should be used as first-line antimicrobials in enteric fever. Although fourth-generation cephalosporins are useful, we feel their use should be restricted to complicated or resistant cases.

  10. Accurate measurement of brain changes in longitudinal MRI scans using tensor-based morphometry.

    Science.gov (United States)

    Hua, Xue; Gutman, Boris; Boyle, Christina P; Rajagopalan, Priya; Leow, Alex D; Yanovsky, Igor; Kumar, Anand R; Toga, Arthur W; Jack, Clifford R; Schuff, Norbert; Alexander, Gene E; Chen, Kewei; Reiman, Eric M; Weiner, Michael W; Thompson, Paul M

    2011-07-01

    This paper responds to Thompson and Holland (2011), who challenged our tensor-based morphometry (TBM) method for estimating rates of brain changes in serial MRI from 431 subjects scanned every 6 months, for 2 years. Thompson and Holland noted an unexplained jump in our atrophy rate estimates: an offset between 0 and 6 months that may bias clinical trial power calculations. We identified why this jump occurs and propose a solution. By enforcing inverse-consistency in our TBM method, the offset dropped from 1.4% to 0.28%, giving plausible anatomical trajectories. Transitivity error accounted for the minimal remaining offset. Drug trial sample size estimates with the revised TBM-derived metrics are highly competitive with other methods, though higher than previously reported sample size estimates by a factor of 1.6 to 2.4. Importantly, estimates are far below those given in the critique. To demonstrate a 25% slowing of atrophic rates with 80% power, 62 AD and 129 MCI subjects would be required for a 2-year trial, and 91 AD and 192 MCI subjects for a 1-year trial. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Longitudinal volumetric changes following traumatic brain injury: a tensor-based morphometry study.

    Science.gov (United States)

    Farbota, Kimberly D M; Sodhi, Aparna; Bendlin, Barbara B; McLaren, Donald G; Xu, Guofan; Rowley, Howard A; Johnson, Sterling C

    2012-11-01

    After traumatic injury, the brain undergoes a prolonged period of degenerative change that is paradoxically accompanied by cognitive recovery. The spatiotemporal pattern of atrophy and the specific relationships of atrophy to cognitive changes are ill understood. The present study used tensor-based morphometry and neuropsychological testing to examine brain volume loss in 17 traumatic brain injury (TBI) patients and 13 controls over a 4-year period. Patients were scanned at 2 months, 1 year, and 4 years post-injury. High-dimensional warping procedures were used to create change maps of each subject's brain for each of the two intervals. TBI patients experienced volume loss in both cortical areas and white matter regions during the first interval. We also observed continuing volume loss in extensive regions of white matter during the second interval. Neuropsychological correlations indicated that cognitive tasks were associated with subsequent volume loss in task-relevant regions. The extensive volume loss in brain white matter observed well beyond the first year post-injury suggests that the injured brain remains malleable for an extended period, and the neuropsychological relationships suggest that this volume loss may be associated with subtle cognitive improvements.

  12. Progression of brain atrophy in spinocerebellar ataxia type 2: a longitudinal tensor-based morphometry study.

    Science.gov (United States)

    Mascalchi, Mario; Diciotti, Stefano; Giannelli, Marco; Ginestroni, Andrea; Soricelli, Andrea; Nicolai, Emanuele; Aiello, Marco; Tessa, Carlo; Galli, Lucia; Dotti, Maria Teresa; Piacentini, Silvia; Salvatore, Elena; Toschi, Nicola

    2014-01-01

    Spinocerebellar ataxia type 2 (SCA2) is the second most frequent autosomal dominant inherited ataxia worldwide. We investigated the capability of magnetic resonance imaging (MRI) to track in vivo progression of brain atrophy in SCA2 by examining twice 10 SCA2 patients (mean interval 3.6 years) and 16 age- and gender-matched healthy controls (mean interval 3.3 years) on the same 1.5 T MRI scanner. We used T1-weighted images and tensor-based morphometry (TBM) to investigate volume changes and the Inherited Ataxia Clinical Rating Scale to assess the clinical deficit. With respect to controls, SCA2 patients showed significant higher atrophy rates in the midbrain, including substantia nigra, basis pontis, middle cerebellar peduncles and posterior medulla corresponding to the gracilis and cuneatus tracts and nuclei, cerebellar white matter (WM) and cortical gray matter (GM) in the inferior portions of the cerebellar hemisphers. No differences in WM or GM volume loss were observed in the supratentorial compartment. TBM findings did not correlate with modifications of the neurological deficit. In conclusion, MRI volumetry using TBM is capable of demonstrating the progression of pontocerebellar atrophy in SCA2, supporting a possible role of MRI as biomarker in future trials.

  13. Emotional development in children with tics: a longitudinal population-based study.

    Science.gov (United States)

    Hoekstra, P J; Lundervold, A J; Lie, S A; Gillberg, C; Plessen, Kerstin J

    2013-03-01

    Children with tics often experience accompanying problems that may have more impact on their well being and quality of life than the tics themselves. The present study investigates characteristics and the course of associated problems. In a population-based follow-up study, we investigated the developmental trajectory of children with and without tics when they were 7-9 years old. Parents and teachers completed the strengths and difficulties questionnaire (SDQ) when the children were 7-9 years (wave 1) and 4 years later (wave 2). Using strict criteria, we identified 38 children with tics in the cohort of 4,025 children (0.94% of the total cohort) with a preponderance of boys (78.9%). 22 children (57.9%) in the group with tics had only motor tics, and 16 (42.1%) had both motor and vocal tics. Children with tics had significantly higher parent- and teacher-rated SDQ total difficulty scores and subscale scores in both waves. Children with tics experienced an increase in emotional problems and in peer problems between the first and the second wave. This study in a general population indicates that the presence of tics is associated with a range of internalizing and externalizing difficulties, as well as problems in peer relationships. Moreover, our study indicates that emotional and peer problems tend to increase over time in the group of children with tics.

  14. Progression of brain atrophy in spinocerebellar ataxia type 2: a longitudinal tensor-based morphometry study.

    Directory of Open Access Journals (Sweden)

    Mario Mascalchi

    Full Text Available Spinocerebellar ataxia type 2 (SCA2 is the second most frequent autosomal dominant inherited ataxia worldwide. We investigated the capability of magnetic resonance imaging (MRI to track in vivo progression of brain atrophy in SCA2 by examining twice 10 SCA2 patients (mean interval 3.6 years and 16 age- and gender-matched healthy controls (mean interval 3.3 years on the same 1.5 T MRI scanner. We used T1-weighted images and tensor-based morphometry (TBM to investigate volume changes and the Inherited Ataxia Clinical Rating Scale to assess the clinical deficit. With respect to controls, SCA2 patients showed significant higher atrophy rates in the midbrain, including substantia nigra, basis pontis, middle cerebellar peduncles and posterior medulla corresponding to the gracilis and cuneatus tracts and nuclei, cerebellar white matter (WM and cortical gray matter (GM in the inferior portions of the cerebellar hemisphers. No differences in WM or GM volume loss were observed in the supratentorial compartment. TBM findings did not correlate with modifications of the neurological deficit. In conclusion, MRI volumetry using TBM is capable of demonstrating the progression of pontocerebellar atrophy in SCA2, supporting a possible role of MRI as biomarker in future trials.

  15. Evaluation of an automated knowledge-based textual summarization system for longitudinal clinical data, in the intensive care domain.

    Science.gov (United States)

    Goldstein, Ayelet; Shahar, Yuval; Orenbuch, Efrat; Cohen, Matan J

    2017-10-01

    To examine the feasibility of the automated creation of meaningful free-text summaries of longitudinal clinical records, using a new general methodology that we had recently developed; and to assess the potential benefits to the clinical decision-making process of using such a method to generate draft letters that can be further manually enhanced by clinicians. We had previously developed a system, CliniText (CTXT), for automated summarization in free text of longitudinal medical records, using a clinical knowledge base. In the current study, we created an Intensive Care Unit (ICU) clinical knowledge base, assisted by two ICU clinical experts in an academic tertiary hospital. The CTXT system generated free-text summary letters from the data of 31 different patients, which were compared to the respective original physician-composed discharge letters. The main evaluation measures were (1) relative completeness, quantifying the data items missed by one of the letters but included by the other, and their importance; (2) quality parameters, such as readability; (3) functional performance, assessed by the time needed, by three clinicians reading each of the summaries, to answer five key questions, based on the discharge letter (e.g., "What are the patient's current respiratory requirements?"), and by the correctness of the clinicians' answers. Completeness: In 13/31 (42%) of the letters the number of important items missed in the CTXT-generated letter was actually less than or equal to the number of important items missed by the MD-composed letter. In each of the MD-composed letters, at least two important items that were mentioned by the CTXT system were missed (a mean of 7.2±5.74). In addition, the standard deviation in the number of missed items in the MD letters (STD=15.4) was much higher than the standard deviation in the CTXT-generated letters (STD=5.3). Quality: The MD-composed letters obtained a significantly better grade in three out of four measured parameters

  16. Childhood ADHD and Risk for Substance Dependence in Adulthood: A Longitudinal, Population-Based Study

    Science.gov (United States)

    Levy, Sharon; Katusic, Slavica K.; Colligan, Robert C.; Weaver, Amy L.; Killian, Jill M.; Voigt, Robert G.; Barbaresi, William J.

    2014-01-01

    Background Adolescents with attention-deficit/hyperactivity disorder (ADHD) are known to be at significantly greater risk for the development of substance use disorders (SUD) compared to peers. Impulsivity, which could lead to higher levels of drug use, is a known symptom of ADHD and likely accounts, in part, for this relationship. Other factors, such as a biologically increased susceptibility to substance dependence (addiction), may also play a role. Objective This report further examines the relationships between childhood ADHD, adolescent- onset SUD, and substance abuse and substance dependence in adulthood. Method Individuals with childhood ADHD and non-ADHD controls from the same population-based birth cohort were invited to participate in a prospective outcome study. Participants completed a structured neuropsychiatric interview with modules for SUD and a psychosocial questionnaire. Information on adolescent SUD was obtained retrospectively, in a previous study, from medical and school records. Associations were summarized using odds ratios (OR) and 95% CIs estimated from logistic regression models adjusted for age and gender. Results A total of 232 ADHD cases and 335 non-ADHD controls participated (mean age, 27.0 and 28.6 years, respectively). ADHD cases were more likely than controls to have a SUD diagnosed in adolescence and were more likely to have alcohol (adjusted OR 14.38, 95% CI 1.49–138.88) and drug (adjusted OR 3.48, 95% CI 1.38–8.79) dependence in adulthood. The subgroup of participating ADHD cases who did not have SUD during adolescence were no more likely than controls to develop new onset alcohol dependence as adults, although they were significantly more likely to develop new onset drug dependence. Conclusions Our study found preliminary evidence that adults with childhood ADHD are more susceptible than peers to developing drug dependence, a disorder associated with neurological changes in the brain. The relationship between ADHD and

  17. Hypnosis-based psychodynamic treatment in ALS: a longitudinal study on patients and their caregivers.

    Directory of Open Access Journals (Sweden)

    Johann Roland Kleinbub

    2015-06-01

    Full Text Available Background: Evidence of psychological treatment efficacy is strongly needed in ALS, particularly regarding long-term effects.Methods: Fifteen patients participated in a hypnosis treatment and self-hypnosis training protocol after an in-depth psychological and neurological evaluation. Patients’ primary caregivers and 15 one-by-one matched control patients were considered in the study.Measurements of anxiety, depression and quality of life were collected at the baseline, post-treatment, and after 3 and 6 months from the intervention. Bayesian linear mixed-models were used to evaluate the impact of treatment and defense style on patients’ anxiety, depression, quality of life, and functional impairment (ALSFRS-r, as well as on caregivers’ anxiety and depression.Results: The statistical analyses revealed an improvement in psychological variables’ scores immediately after the treatment. Amelioration in patients’ and caregivers’ anxiety as well as caregivers’ depression, were found to persist at 3 and 6 months follow-ups. The observed massive use of primitive defense mechanisms was found to have a reliable and constant buffer effect on psychopathological symptoms in both patients and caregivers. Notably, treated patients decline in ALSFRS-r score was observed to be slower than that of control group’s patients.Discussion: Our brief psychodynamic hypnosis-based treatment showed efficacy both at psychological and physical levels in patients with ALS, and was indirectly associated to long-lasting benefits in caregivers. The implications of peculiar psychodynamic factors and mind-body techniques are discussed. Future directions should be oriented toward a convergence of our results and further psychological interventions, in order to delineate clinical best practices for ALS.

  18. Geometry anisotropy and mechanical property isotropy in titanium foam fabricated by replica impregnation method

    Energy Technology Data Exchange (ETDEWEB)

    Manonukul, Anchalee, E-mail: anchalm@mtec.or.th [National Metal and Materials Technology Center (MTEC), National Science and Technology Development Agency (NSTDA), 114 Thailand Science Park, Paholyothin Rd., Klong 1, Klong Luang, Pathumthani 12120 (Thailand); Srikudvien, Pathompoom [National Metal and Materials Technology Center (MTEC), National Science and Technology Development Agency (NSTDA), 114 Thailand Science Park, Paholyothin Rd., Klong 1, Klong Luang, Pathumthani 12120 (Thailand); Tange, Makiko [Taisei Kogyo Thailand Co., Ltd., Room INC2d-409, Innovation Cluster 2 Building, Tower D, 141 Thailand Science Park, Paholyothin Rd., Klong 1, Klong Luang, Pathumthani 12120 (Thailand); Puncreobutr, Chedtha [Department of Metallurgical Engineering, Faculty of Engineering, Chulalongkorn University, Pathumwan, Bangkok 10330 (Thailand)

    2016-02-08

    Polyurethane (PU) foams have both geometry and mechanical property anisotropy. Metal foams, which are manufacturing by investment casting or melt deposition method and using PU foam as a template, also have mechanical property anisotropy. This work studied the mechanical properties in two directions of titanium foam with four different cell sizes fabricated using the replica impregnation method. The two directions are (1) the loading direction parallel to the foaming direction where the cells are elongated (EL direction) and (2) the loading direction perpendicular to the foaming direction where the cell are equiaxed (EQ direction). The results show that the compression responses for both EL and EQ directions are isotropy. Micrographs and X-ray micro-computed tomography show that the degree of geometry anisotropy is not strong enough to results in mechanical property anisotropy.

  19. Geometry anisotropy and mechanical property isotropy in titanium foam fabricated by replica impregnation method

    International Nuclear Information System (INIS)

    Manonukul, Anchalee; Srikudvien, Pathompoom; Tange, Makiko; Puncreobutr, Chedtha

    2016-01-01

    Polyurethane (PU) foams have both geometry and mechanical property anisotropy. Metal foams, which are manufacturing by investment casting or melt deposition method and using PU foam as a template, also have mechanical property anisotropy. This work studied the mechanical properties in two directions of titanium foam with four different cell sizes fabricated using the replica impregnation method. The two directions are (1) the loading direction parallel to the foaming direction where the cells are elongated (EL direction) and (2) the loading direction perpendicular to the foaming direction where the cell are equiaxed (EQ direction). The results show that the compression responses for both EL and EQ directions are isotropy. Micrographs and X-ray micro-computed tomography show that the degree of geometry anisotropy is not strong enough to results in mechanical property anisotropy.

  20. Computing Relative Free Energies of Solvation using Single Reference Thermodynamic Integration Augmented with Hamiltonian Replica Exchange.

    Science.gov (United States)

    Khavrutskii, Ilja V; Wallqvist, Anders

    2010-11-09

    This paper introduces an efficient single-topology variant of Thermodynamic Integration (TI) for computing relative transformation free energies in a series of molecules with respect to a single reference state. The presented TI variant that we refer to as Single-Reference TI (SR-TI) combines well-established molecular simulation methodologies into a practical computational tool. Augmented with Hamiltonian Replica Exchange (HREX), the SR-TI variant can deliver enhanced sampling in select degrees of freedom. The utility of the SR-TI variant is demonstrated in calculations of relative solvation free energies for a series of benzene derivatives with increasing complexity. Noteworthy, the SR-TI variant with the HREX option provides converged results in a challenging case of an amide molecule with a high (13-15 kcal/mol) barrier for internal cis/trans interconversion using simulation times of only 1 to 4 ns.

  1. Causes of death among females-investigating beyond maternal causes: a community-based longitudinal study.

    Science.gov (United States)

    Melaku, Yohannes Adama; Weldearegawi, Berhe; Aregay, Alemseged; Tesfay, Fisaha Haile; Abreha, Loko; Abera, Semaw Ferede; Bezabih, Afework Mulugeta

    2014-09-10

    In developing countries, investigating mortality levels and causes of death among all age female population despite the childhood and maternal related deaths is important to design appropriate and tailored interventions and to improve survival of female residents. Under Kilite-Awlealo Health and Demographic Surveillance System, we investigated mortality rates and causes of death in a cohort of female population from 1st of January 2010 to 31st of December 2012. At the baseline, 33,688 females were involved for the prospective follow-up study. Households under the study were updated every six months by fulltime surveillance data collectors to identify vital events, including deaths. Verbal Autopsy (VA) data were collected by separate trained data collectors for all identified deaths in the surveillance site. Trained physicians assigned underlining causes of death using the 10th edition of International Classification of Diseases (ICD). We assessed overall, age- and cause-specific mortality rates per 1000 person-years. Causes of death among all deceased females and by age groups were ranked based on cause specific mortality rates. Analysis was performed using Stata Version 11.1. During the follow-up period, 105,793.9 person-years of observation were generated, and 398 female deaths were recorded. This gave an overall mortality rate of 3.76 (95% confidence interval (CI): 3.41, 4.15) per 1,000 person-years. The top three broad causes of death were infectious and parasitic diseases (1.40 deaths per 1000 person-years), non-communicable diseases (0.98 deaths per 1000 person-years) and external causes (0.36 per 1000 person-years). Most deaths among reproductive age female were caused by Human Deficiency Virus/Acquired Immune Deficiency Virus (HIV/AIDS) and tuberculosis (0.14 per 1000 person-years for each cause). Pregnancy and childbirth related causes were responsible for few deaths among women of reproductive age--3 out of 73 deaths (4.1%) or 5.34 deaths per 1,000 person

  2. The association between stress and headache: A longitudinal population-based study.

    Science.gov (United States)

    Schramm, Sara H; Moebus, Susanne; Lehmann, Nils; Galli, Ursula; Obermann, Mark; Bock, Eva; Yoon, Min-Suk; Diener, Hans-Christoph; Katsarava, Zaza

    2015-09-01

    We studied the association between stress intensity and headache frequency for tension-type headache (TTH), migraine and migraine with coexisting TTH (MigTTH). We studied a population-based sample of 5159 participants (21-71 years) who were asked quarterly between March 2010 and April 2012 about headache and stress. Log-linear regression in the framework of generalized estimating equations was used to estimate regression coefficients presented as percent changes to describe the association between stress intensity (modified visual analog scale (VAS) from 0 to 100) and headache frequency (days/month) stratified by headache subtypes and age groups and adjusted for sex, age, frequent intake of acute pain drugs, drinking, smoking, BMI and education. TTH was reported in 31% participants (48.1 ± 12.5years, 51.5% women, 2.2 ± 3.9 mean headache days/month, 52.3 ± 26.7 mean stress), migraine in 14% (44.8 ± 11.3years, 73.3%, 4.5 ± 5.2 days/month, 62.4 ± 23.3), MigTTH in 10.6% (43.5 ± 11.5 years, 61.0%, 3.6 ± 4.8 days/month, 58.6 ± 24.1), 23.6% were unclassifiable, and 20.8% had no headache. In participants with TTH an increase of 10 points on VAS was associated with an increase of headaches days/month of 6.0% (adjusted). Higher effects were observed in younger age groups (21-30/31-40/41-50/51-60/61-71 years: 9.8/10.2/7.0/6.5/3.5%). Slightly lower effects were observed for migraine (4.3%, 8.1/5.1/3.4/6.3/0.3%) and MigTTH (4.2%, 5.5/6.8/6.9/5.8/-0.7%). Our study provides evidence for an association between stress intensity and headache frequency. © International Headache Society 2014.

  3. An innovative design for using flexible printed coils for magnetostrictive-based longitudinal guided wave sensors in steel strand inspection

    International Nuclear Information System (INIS)

    Tse, P W; Liu, X C; Wang, X J; Liu, Z H; Wu, B; He, C F

    2011-01-01

    Magnetostrictive sensors (MsSs) that can excite and receive guided waves are commonly used in detecting defects that may occur in cables and strands for supporting heavy structures. A conventional MsS has a hard sensing coil that is wound onto a bobbin with electric wires to generate the necessary dynamic magnetic field to excite the desired guided waves. This tailor-made hard coil is usually bulky and is not flexible enough to fit steel strands of various sizes. The conventional MsS also cannot be mounted to any steel strand that does not have a free end to allow the bobbin to pass through the structure of the tested strand. Such inflexibilities limit the use of conventional MsSs in practical situations. To solve these limitations, an innovative type of coil, called a flexible printed coil (FPC), which is made out of flexible printed film, has been designed to replace the inflexible hard coil. The flexible structure of the FPC ensures that the new MsS can be easily installed on and removed from steel strands with different diameters and without free ends. Moreover, the FPC-based MsS can be wrapped into multiple layers due to its thin and flexible design. Although multi-layer FPC creates a minor asymmetry in the dynamic magnetic field, the results of finite element analysis and experiments confirm that the longitudinal guided waves excited by a FPC-based MsS are comparable to those excited by a conventional hard coil MsS. No significant reduction in defect inspection performance was found; in fact, further advantages were identified when using the FPC-based MsS. When acting as the transmitter, the innovative FPC-based MsS can cover a longer inspection length of strand. When acting as the receiver, the FPC-based MsS is more sensitive to smaller defects that are impossible to detect using a hard coil MsS. Hence, the multi-layer FPC-based MsS has great potential for replacing the conventional hard coil MsS because of its convenient installation, and ease of fitting to

  4. Multisite longitudinal reliability of tract-based spatial statistics in diffusion tensor imaging of healthy elderly subjects.

    Science.gov (United States)

    Jovicich, Jorge; Marizzoni, Moira; Bosch, Beatriz; Bartrés-Faz, David; Arnold, Jennifer; Benninghoff, Jens; Wiltfang, Jens; Roccatagliata, Luca; Picco, Agnese; Nobili, Flavio; Blin, Oliver; Bombois, Stephanie; Lopes, Renaud; Bordet, Régis; Chanoine, Valérie; Ranjeva, Jean-Philippe; Didic, Mira; Gros-Dagnac, Hélène; Payoux, Pierre; Zoccatelli, Giada; Alessandrini, Franco; Beltramello, Alberto; Bargalló, Núria; Ferretti, Antonio; Caulo, Massimo; Aiello, Marco; Ragucci, Monica; Soricelli, Andrea; Salvadori, Nicola; Tarducci, Roberto; Floridi, Piero; Tsolaki, Magda; Constantinidis, Manos; Drevelegas, Antonios; Rossini, Paolo Maria; Marra, Camillo; Otto, Josephin; Reiss-Zimmermann, Martin; Hoffmann, Karl-Titus; Galluzzi, Samantha; Frisoni, Giovanni B

    2014-11-01

    Large-scale longitudinal neuroimaging studies with diffusion imaging techniques are necessary to test and validate models of white matter neurophysiological processes that change in time, both in healthy and diseased brains. The predictive power of such longitudinal models will always be limited by the reproducibility of repeated measures acquired during different sessions. At present, there is limited quantitative knowledge about the across-session reproducibility of standard diffusion metrics in 3T multi-centric studies on subjects in stable conditions, in particular when using tract based spatial statistics and with elderly people. In this study we implemented a multi-site brain diffusion protocol in 10 clinical 3T MRI sites distributed across 4 countries in Europe (Italy, Germany, France and Greece) using vendor provided sequences from Siemens (Allegra, Trio Tim, Verio, Skyra, Biograph mMR), Philips (Achieva) and GE (HDxt) scanners. We acquired DTI data (2 × 2 × 2 mm(3), b = 700 s/mm(2), 5 b0 and 30 diffusion weighted volumes) of a group of healthy stable elderly subjects (5 subjects per site) in two separate sessions at least a week apart. For each subject and session four scalar diffusion metrics were considered: fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD) and axial (AD) diffusivity. The diffusion metrics from multiple subjects and sessions at each site were aligned to their common white matter skeleton using tract-based spatial statistics. The reproducibility at each MRI site was examined by looking at group averages of absolute changes relative to the mean (%) on various parameters: i) reproducibility of the signal-to-noise ratio (SNR) of the b0 images in centrum semiovale, ii) full brain test-retest differences of the diffusion metric maps on the white matter skeleton, iii) reproducibility of the diffusion metrics on atlas-based white matter ROIs on the white matter skeleton. Despite the differences of MRI scanner

  5. Flow field analysis in a compliant acinus replica model using particle image velocimetry (PIV).

    Science.gov (United States)

    Berg, Emily J; Weisman, Jessica L; Oldham, Michael J; Robinson, Risa J

    2010-04-19

    Inhaled particles reaching the alveolar walls have the potential to cross the blood-gas barrier and enter the blood stream. Experimental evidence of pulmonary dosimetry, however, cannot be explained by current whole lung dosimetry models. Numerical and experimental studies shed some light on the mechanisms of particle transport, but realistic geometries have not been investigated. In this study, a three dimensional expanding model including two generations of respiratory bronchioles and five terminal alveolar sacs was created from a replica human lung cast. Flow visualization techniques were employed to quantify the fluid flow while utilizing streamlines to evaluate recirculation. Pathlines were plotted to track the fluid motion and estimate penetration depth of inhaled air. This study provides evidence that the two generations immediately proximal to the terminal alveolar sacs do not have recirculating eddies, even for intense breathing. Results of Peclet number calculations indicate that substantial convective motion is present in vivo for the case of deep breathing, which significantly increases particle penetration into the alveoli. However, particle diffusion remains the dominant mechanism of particle transport over convection, even for intense breathing because inhaled particles do not reach the alveolar wall in a single breath by convection alone. Examination of the velocity fields revealed significant uneven ventilation of the alveoli during a single breath, likely due to variations in size and location. This flow field data, obtained from replica model geometry with realistic breathing conditions, provides information to better understand fluid and particle behavior in the acinus region of the lung. Copyright 2009 Elsevier Ltd. All rights reserved.

  6. Large sample NAA of a pottery replica utilizing thermal neutron flux at AHWR critical facility and X-Z rotary scanning unit

    International Nuclear Information System (INIS)

    Acharya, R.; Dasari, K.B.; Pujari, P.K.; Swain, K.K.; Shinde, A.D.; Reddy, A.V.R.

    2013-01-01

    Large sample neutron activation analysis (LSNAA) of a clay pottery replica from Peru was carried out using low neutron flux graphite reflector position of Advanced Heavy Water Reactor (AHWR) critical facility. This work was taken up as a part of inter-comparison exercise under IAEA CRP on LSNAA of archaeological objects. Irradiated large size sample, placed on an X-Z rotary scanning unit, was assayed using a 40% relative efficiency HPGe detector. The k 0 -based internal monostandard NAA (IM-NAA) in conjunction with insitu relative detection efficiency was used to calculate concentration ratios of 12 elements with respect to Na. Analyses of both small and large size samples were carried out to check homogeneity and to arrive at absolute concentrations. (author)

  7. Child and Family Antecedents of Pain During the Transition to Adolescence: A Longitudinal Population-Based Study.

    Science.gov (United States)

    Incledon, Emily; O'Connor, Meredith; Giallo, Rebecca; Chalkiadis, George A; Palermo, Tonya M

    2016-11-01

    Pediatric persistent pain is associated with poorer physical and psychosocial functioning in children, as well as immediate and long-term societal costs. Onset typically occurs in early adolescence, suggesting that late childhood is a key window for identifying potential intervention targets before pain symptoms become entrenched. This study used population-based data from the Longitudinal Study of Australian Children (n = 3,812) and adopted a biopsychosocial and ecological systems approach to investigate child, family, and sociodemographic factors associated with pain problems in children transitioning to adolescence. The prevalence of at least weekly parent-reported pain in the study sample was approximately 5% at 10 to 11 years of age, and pain continued at 12 to 13 years of age for 40% of these children. Key factors at 10 to 11 years that uniquely predicted parent-reported pain problems at 12 to 13 years were frequency of previous pain (1-3 times weekly: odds ratio [OR] = 7.49; 95% confidence interval [CI], 4.3-13.0; 4-7 times weekly: OR = 17.8; 95% CI, 8.7-36.5) and sleep difficulties (OR = 1.86; 95% CI, 1.16-2.97). This study highlights the importance of early intervention for persistent pain in childhood, because pain complaints in late childhood tend to persist into early adolescence. This article used a biopsychosocial and ecological systems approach to understanding predictors of pain problems during the transition to adolescence within a nationally representative community-based cohort. Sleep difficulties at 10 to 11 years uniquely predicted pain at ages 12 to 13 years, suggesting that early intervention using sleep interventions may be a promising direction for future research. Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

  8. The longitudinal relationship between control over working hours and depressive symptoms: Results from SLOSH, a population-based cohort study.

    Science.gov (United States)

    Albrecht, Sophie C; Kecklund, Göran; Rajaleid, Kristiina; Leineweber, Constanze

    2017-06-01

    Psychosocial work factors can affect depressive moods, but research is inconclusive if flexibility to self-determine working hours (work-time control, WTC) is associated with depressive symptoms over time. We investigated if either sub-dimension of WTC, control over daily hours and control over time off, was related to depressive symptoms over time and examined causal, reversed-causal, and reciprocal pathways. The study was based on four waves of the Swedish Longitudinal Occupational Survey of Health which is a follow-up of representative samples of the Swedish working population. WTC was measured using a 5-item index. Depressive symptoms were assessed with a brief subscale of the Symptom Checklist. Latent growth curve models and cross-lagged panel models were tested. Best fit was found for a model with correlated intercepts (control over daily hours) and both correlated intercepts and slopes (control over time off) between WTC and depressive symptoms, with stronger associations for control over time off. Causal models estimating impacts from WTC to subsequent depressive symptoms were best fitting, with a standardised coefficient between -0.023 and -0.048. Results were mainly based on self-report data and mean age in the study sample was relatively high. Higher WTC was related to fewer depressive symptoms over time albeit small effects. Giving workers control over working hours - especially over taking breaks and vacation - may improve working conditions and buffer against developing depression, potentially by enabling workers to recover more easily and promoting work-life balance. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Reckoning HIV/AIDS care: A longitudinal study of community home-based caregivers and clients in Swaziland.

    Science.gov (United States)

    Root, Robin; Van Wyngaard, Arnau; Whiteside, Alan

    2015-01-01

    The article is a descriptive case study of a community home-based care (CHBC) organisation in Swaziland that depicts the convergence of CHBC expansion with substantially improved health outcomes. Comprised of 993 care supporters who tend to 3 839 clients in 37 communities across southern Swaziland, Shiselweni Home-based Care (SHBC) is illustrative of many resource-limited communities throughout Africa that have mobilised, at varying degrees of formality, to address the individual and household suffering associated with HIV/AIDS. To better understand the potential significance of global and national health policy/programming reliance on community health workers (task shifting), we analysed longitudinal data on both care supporter and client cohorts from 2008 to 2013. Most CHBC studies report data from only one cohort. Foremost, our analysis demonstrated a dramatic decline (71.4%) among SHBC clients in overall mortality from 32.2% to 9.2% between 2008 and 2013. Although the study was not designed to establish statistical significance or causality between SHBC expansion and health impact, our findings detail a compelling convergence among CHBC, improved HIV health practices, and declines in client mortality. Our analysis indicated (1) the potential contributions of community health workers to individual and community wellbeing, (2) the challenges of task-shifting agendas, above all comprehensive support of community health workers/care supporters, and (3) the importance of data collection to monitor and strengthen the critical health services assigned to CHBC. Detailed study of CHBC operations and practices is helpful also for advancing government and donor HIV/AIDS strategies, especially with respect to health services decentralisation, in Swaziland and similarly profiled settings.

  10. Analysis of temporal-longitudinal-latitudinal characteristics in the global ionosphere based on tensor rank-1 decomposition

    Science.gov (United States)

    Lu, Shikun; Zhang, Hao; Li, Xihai; Li, Yihong; Niu, Chao; Yang, Xiaoyun; Liu, Daizhi

    2018-03-01

    Combining analyses of spatial and temporal characteristics of the ionosphere is of great significance for scientific research and engineering applications. Tensor decomposition is performed to explore the temporal-longitudinal-latitudinal characteristics in the ionosphere. Three-dimensional tensors are established based on the time series of ionospheric vertical total electron content maps obtained from the Centre for Orbit Determination in Europe. To obtain large-scale characteristics of the ionosphere, rank-1 decomposition is used to obtain U^{(1)}, U^{(2)}, and U^{(3)}, which are the resulting vectors for the time, longitude, and latitude modes, respectively. Our initial finding is that the correspondence between the frequency spectrum of U^{(1)} and solar variation indicates that rank-1 decomposition primarily describes large-scale temporal variations in the global ionosphere caused by the Sun. Furthermore, the time lags between the maxima of the ionospheric U^{(2)} and solar irradiation range from 1 to 3.7 h without seasonal dependence. The differences in time lags may indicate different interactions between processes in the magnetosphere-ionosphere-thermosphere system. Based on the dataset displayed in the geomagnetic coordinates, the position of the barycenter of U^{(3)} provides evidence for north-south asymmetry (NSA) in the large-scale ionospheric variations. The daily variation in such asymmetry indicates the influences of solar ionization. The diurnal geomagnetic coordinate variations in U^{(3)} show that the large-scale EIA (equatorial ionization anomaly) variations during the day and night have similar characteristics. Considering the influences of geomagnetic disturbance on ionospheric behavior, we select the geomagnetic quiet GIMs to construct the ionospheric tensor. The results indicate that the geomagnetic disturbances have little effect on large-scale ionospheric characteristics.

  11. Whole brain MP2RAGE-based mapping of the longitudinal relaxation time at 9.4T.

    Science.gov (United States)

    Hagberg, G E; Bause, J; Ethofer, T; Ehses, P; Dresler, T; Herbert, C; Pohmann, R; Shajan, G; Fallgatter, A; Pavlova, M A; Scheffler, K

    2017-01-01

    Mapping of the longitudinal relaxation time (T 1 ) with high accuracy and precision is central for neuroscientific and clinical research, since it opens up the possibility to obtain accurate brain tissue segmentation and gain myelin-related information. An ideal, quantitative method should enable whole brain coverage within a limited scan time yet allow for detailed sampling with sub-millimeter voxel sizes. The use of ultra-high magnetic fields is well suited for this purpose, however the inhomogeneous transmit field potentially hampers its use. In the present work, we conducted whole brain T 1 mapping based on the MP2RAGE sequence at 9.4T and explored potential pitfalls for automated tissue classification compared with 3T. Data accuracy and T 2 -dependent variation of the adiabatic inversion efficiency were investigated by single slice T 1 mapping with inversion recovery EPI measurements, quantitative T 2 mapping using multi-echo techniques and simulations of the Bloch equations. We found that the prominent spatial variation of the transmit field at 9.4T (yielding flip angles between 20% and 180% of nominal values) profoundly affected the result of image segmentation and T 1 mapping. These effects could be mitigated by correcting for both flip angle and inversion efficiency deviations. Based on the corrected T 1 maps, new, 'flattened', MP2RAGE contrast images were generated, that were no longer affected by variations of the transmit field. Unlike the uncorrected MP2RAGE contrast images acquired at 9.4T, these flattened images yielded image segmentations comparable to 3T, making bias-field correction prior to image segmentation and tissue classification unnecessary. In terms of the T 1 estimates at high field, the proposed correction methods resulted in an improved precision, with test-retest variability below 1% and a coefficient-of-variation across 25 subjects below 3%. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Tensions in mentoring medical students toward self-directed and reflective learning in a longitudinal portfolio-based mentoring system - An activity theory analysis.

    Science.gov (United States)

    Heeneman, Sylvia; de Grave, Willem

    2017-04-01

    In medical education, students need to acquire skills to self-direct(ed) learning (SDL), to enable their development into self-directing and reflective professionals. This study addressed the mentor perspective on how processes in the mentor-student interaction influenced development of SDL. n = 22 mentors of a graduate-entry medical school with a problem-based curriculum and longitudinal mentoring system were interviewed (n = 1 recording failed). Using activity theory (AT) as a theoretical framework, thematic analysis was applied to the interview data to identify important themes. Four themes emerged: centered around the role of the portfolio, guiding of students' SDL in the context of assessment procedures, mentor-role boundaries and longitudinal development of skills by both the mentor and mentee. Application of AT showed that in the interactions between themes tensions or supportive factors could emerge for activities in the mentoring process. The mentors' perspective on coaching and development of reflection and SDL of medical students yielded important insights into factors that can hinder or support students' SDL, during a longitudinal mentor-student interaction. Coaching skills of the mentor, the interaction with a portfolio and the context of a mentor community are important factors in a longitudinal mentor-student interaction that can translate to students' SDL skills.

  13. Tracking control of WMRs on loose soil based on mixed H2/H∞ control with longitudinal slip ratio estimation

    Science.gov (United States)

    Gao, Haibo; Chen, Chao; Ding, Liang; Li, Weihua; Yu, Haitao; Xia, Kerui; Liu, Zhen

    2017-11-01

    Wheeled mobile robots (WMRs) often suffer from the longitudinal slipping when moving on the loose soil of the surface of the moon during exploration. Longitudinal slip is the main cause of WMRs' delay in trajectory tracking. In this paper, a nonlinear extended state observer (NESO) is introduced to estimate the longitudinal velocity in order to estimate the slip ratio and the derivative of the loss of velocity which are used in modelled disturbance compensation. Owing to the uncertainty and disturbance caused by estimation errors, a multi-objective controller using the mixed H2/H∞ method is employed to ensure the robust stability and performance of the WMR system. The final inputs of the trajectory tracking consist of the feedforward compensation, compensation for the modelled disturbances and designed multi-objective control inputs. Finally, the simulation results demonstrate the effectiveness of the controller, which exhibits a satisfactory tracking performance.

  14. Jendl-3.1 iron validation on the PCA-REPLICA (H2O/Fe) shielding benchmark experiment

    International Nuclear Information System (INIS)

    Pescarini, M.; Borgia, M. G.

    1997-03-01

    The PCA-REPLICA (H 2 O/Fe) neutron shielding benchmarks experiment is analysed using the SN 2-D DOT 3.5-E code and the 3-D-equivalent flux synthesis method. This engineering benchmark reproduces the ex-core radial geometry of a PWR, including a mild steel reactor pressure vessel (RPV) simulator, and is designed to test the accuracy of the calculation of the in-vessel neutron exposure parameters. This accuracy is strongly dependent on the quality of the iron neutron cross sections used to describe the nuclear reactions within the RPV simulator. In particular, in this report, the cross sections based on the JENDL-3.1 iron data files are tested, through a comparison of the calculated integral and spectral results with the corresponding experimental data. In addition, the present results are compared, on the same benchmark experiment, with those of a preceding ENEA-Bologna validation of the ENDF/B VI iron cross sections. The integral result comparison indicates that, for all the threshold detectors considered (Rh-103 (n, n') Rh-103m, In-115 (n, n') In-115m and S-32 (n, p) P-32), the JENDL-3.1 natural iron data produce satisfactory results similar to those obtained with the ENDF/B VI iron data. On the contrary, when the JENDL/3.1 Fe-56 data file is used, strongly underestimated results are obtained for the lower energy threshold detectors, Rh-103 and In-115. This fact, in particular, becomes more evident with increasing the neutron penetration depth in the RPV simulator

  15. Screen-based sedentary behavior, physical activity, and muscle strength in the English longitudinal study of ageing.

    Directory of Open Access Journals (Sweden)

    Mark Hamer

    Full Text Available Sarcopenia is associated with loss of independence and ill-health in the elderly although the causes remain poorly understood. We examined the association between two screen-based leisure time sedentary activities (daily TV viewing time and internet use and muscle strength.We studied 6228 men and women (aged 64.9 ± 9.1 yrs from wave 4 (2008-09 of the English Longitudinal Study of Ageing, a prospective study of community dwelling older adults. Muscle strength was assessed by a hand grip test and the time required to complete five chair rises. TV viewing and internet usage were inversely associated with one another. Participants viewing TV ≥ 6 hrs/d had lower grip strength (Men, B = -1.20 kg, 95% CI, -2.26, -0.14; Women, -0.75 kg, 95% CI, -1.48, -0.03 in comparison to <2 hrs/d TV, after adjustment for age, physical activity, smoking, alcohol, chronic disease, disability, depressive symptoms, social status, and body mass index. In contrast, internet use was associated with higher grip strength (Men, B = 2.43 kg, 95% CI, 1.74, 3.12; Women, 0.76 kg, 95% CI, 0.32, 1.20. These associations persisted after mutual adjustment for both types of sedentary behaviour.In older adults, the association between sedentary activities and physical function is context specific (TV viewing vs. computer use. Adverse effects of TV viewing might reflect the prolonged sedentary nature of this behavior.

  16. Lifestyle factors, medication use and risk for ischaemic heart disease hospitalisation: a longitudinal population-based study.

    Directory of Open Access Journals (Sweden)

    Anthony S Gunnell

    Full Text Available BACKGROUND: Lifestyle factors have been implicated in ischaemic heart disease (IHD development however a limited number of longitudinal studies report results stratified by cardio-protective medication use. PURPOSE: This study investigated the influence of self-reported lifestyle factors on hospitalisation for IHD, stratified by blood pressure and/or lipid-lowering therapy. METHODS: A population-based cohort of 14,890 participants aged 45+ years and IHD-free was identified from the Western Australian Health and wellbeing Surveillance System (2004 to 2010 inclusive, and linked with hospital administrative data. Adjusted hazard ratios for future IHD-hospitalisation were estimated using Cox regression. RESULTS: Current smokers remained at higher risk for IHD-hospitalisation (adjusted HR=1.57; 95% CI: 1.22-2.03 after adjustment for medication use, as did those considered overweight (BMI=25-29 kg/m(2; adjusted HR=1.28; 95% CI: 1.04-1.57 or obese (BMI of ≥30 kg/m(2; adjusted HR=1.31; 95% CI: 1.03-1.66. Weekly leisure-time physical activity (LTPA of 150 minutes or more and daily intake of 3 or more fruit/vegetable servings reduced risk by 21% (95% CI: 0.64-0.97 and 26% (95% CI: 0.58-0.96 respectively. Benefits of LTPA appeared greatest in those on blood pressure lowering medication (adjusted HR=0.50; 95% CI: 0.31-0.82 [for LTPA=150 mins]. IHD risk in smokers was most pronounced in those taking neither medication (adjusted HR=2.00; 95% CI: 1.41-2.83. CONCLUSION: This study confirms the contribution of previously reported lifestyle factors towards IHD hospitalisation, even after adjustment for antihypertensive and lipid-lowering medication use. Medication stratified results suggest that IHD risks related to LTPA and smoking may differ according to medication use.

  17. Increased risk of ischemic stroke in young patients with ankylosing spondylitis: a population-based longitudinal follow-up study.

    Directory of Open Access Journals (Sweden)

    Chia-Wei Lin

    Full Text Available BACKGROUND: Prospective data on the association between ischemic stroke and ankylosing spondylitis (AS in the young are sparse. The purpose of this population-based, age- and sex-matched longitudinal follow-up study was to investigate the risk of developing ischemic stroke in young patients with AS. METHODS: A total of 4562 patients aged 18- to 45-year-old with at least two ambulatory visits in 2001 with a principal diagnosis of AS were enrolled in the AS group. The non-AS group consisted of 22810 age- and sex-matched, randomly sampled subjects without AS. The two-year ischemic stroke-free survival rate for each group were calculated using the Kaplan-Meier method. Cox proportional hazards regression analysis was used to estimate the hazard ratio of ischemic stroke after adjusting for demographic and clinical covariates. RESULTS: During follow-up, 21 patients in the AS group and 53 in the non-AS group developed ischemic stroke. The ischemic stroke-free survival rate over the 2 year follow-up was lower in the AS group than the non-AS group (p = 0.0021. The crude hazard ratio of ischemic stroke for the AS group was 1.98 (95% CI, 1.20-3.29; p = 0.0079 and the adjusted hazard ratio after controlling for demographic and comorbid medical disorders was 1.93 (95% CI, 1.16-3.20; p = 0.0110. CONCLUSION: Our study showed an increased risk of developing ischemic stroke in young patients with AS.

  18. Increased risk of ischemic stroke in young patients with ankylosing spondylitis: a population-based longitudinal follow-up study.

    Science.gov (United States)

    Lin, Chia-Wei; Huang, Ya-Ping; Chiu, Yueh-Hsia; Ho, Yu-Tsun; Pan, Shin-Liang

    2014-01-01

    Prospective data on the association between ischemic stroke and ankylosing spondylitis (AS) in the young are sparse. The purpose of this population-based, age- and sex-matched longitudinal follow-up study was to investigate the risk of developing ischemic stroke in young patients with AS. A total of 4562 patients aged 18- to 45-year-old with at least two ambulatory visits in 2001 with a principal diagnosis of AS were enrolled in the AS group. The non-AS group consisted of 22810 age- and sex-matched, randomly sampled subjects without AS. The two-year ischemic stroke-free survival rate for each group were calculated using the Kaplan-Meier method. Cox proportional hazards regression analysis was used to estimate the hazard ratio of ischemic stroke after adjusting for demographic and clinical covariates. During follow-up, 21 patients in the AS group and 53 in the non-AS group developed ischemic stroke. The ischemic stroke-free survival rate over the 2 year follow-up was lower in the AS group than the non-AS group (p = 0.0021). The crude hazard ratio of ischemic stroke for the AS group was 1.98 (95% CI, 1.20-3.29; p = 0.0079) and the adjusted hazard ratio after controlling for demographic and comorbid medical disorders was 1.93 (95% CI, 1.16-3.20; p = 0.0110). Our study showed an increased risk of developing ischemic stroke in young patients with AS.

  19. UV-laser-based longitudinal illuminated diffuser (LID) incorporating diffractive and Lambertian reflectance for the disinfection of beverages

    Science.gov (United States)

    Lizotte, Todd

    2010-08-01

    A novel laser beam shaping system was designed to demonstrate the potential of using high power UV laser sources for large scale disinfection of liquids used in the production of food products, such as juices, beer, milk and other beverage types. The design incorporates a patented assembly of optical components including a diffractive beam splitting/shaping element and a faceted pyramidal or conically shaped Lambertian diffuser made from a compression molded PTFE compounds. When properly sintered to an appropriate density, as an example between 1.10 and 1.40 grams per cubic centimeter, the compressed PTFE compounds show a ~99% reflectance at wavelengths ranging from 300 nm to 1500 nm, and a ~98.5% refection of wavelengths from 250 nm to 2000 nm [1]. The unique diffuser configuration also benefits from the fact that the PTFE compounds do not degrade when exposed to ultraviolet radiation as do barium sulfate materials and silver or aluminized mirror coatings [2]. These components are contained within a hermetically sealed quartz tube. Once assembled a laser beam is directed through one end of the tube. This window takes the form of a computer generated diffractive splitter or other diffractive shaper element to split the laser beam into a series of spot beamlets, circular rings or other geometric shapes. As each of the split beamlets or rings cascade downward, they illuminate various points along the tapered PTFE cone or faceted pyramidal form. As they strike the surface they each diffuse in a Lambertian reflectance pattern creating a pseudo-uniform circumferential illuminator along the length of the quartz tube enclosing the assembly. The compact tubular structure termed Longitudinal Illuminated Diffuser (LID) provides a unique UV disinfection source that can be placed within a centrifugal reactor or a pipe based reactor chamber. This paper will review the overall design principle, key component design parameters, preliminary analytic and bench operational testing

  20. No sustained attention differences in a longitudinal randomized trial comparing mindfulness based stress reduction versus active control.

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    Donal G MacCoon

    Full Text Available Mindfulness Based Stress Reduction (MBSR is a secular form of meditation training. The vast majority of the extant literature investigating the health effects of mindfulness interventions relies on wait-list control comparisons. Previous studies have found that meditation training over several months is associated with improvements in cognitive control and attention.We used a visual continuous performance task (CPT to test the effects of eight weeks of mindfulness training on sustained attention by comparing MBSR to the Health Enhancement Program (HEP, a structurally equivalent, active control condition in a randomized, longitudinal design (ClinicalTrials.gov, NCT01301105 focusing on a non-clinical population typical of MBSR participants. Researchers were blind to group assignment. 63 community participants were randomized to either MBSR (n = 31 or HEP (n = 32. CPT analyses were conducted on 29 MBSR participants and 25 HEP participants. We predicted that MBSR would improve visual discrimination ability and sustained attention over time on the CPT compared to HEP, with more home practice associated with greater improvements. Our hypotheses were not confirmed but we did find some evidence for improved visual discrimination similar to effects in partial replication of other research. Our study had sufficient power to demonstrate that intervention groups do not differ in their improvement over time in sustained attention performance. One of our primary predictions concerning the effects of intervention on attentional fatigue was significant but not interpretable.Attentional sensitivity is not affected by mindfulness practice as taught in MBSR, but it is unclear whether mindfulness might positively affect another aspect of attention, vigilance. These results also highlight the relevant procedural modifications required by future research to correctly investigate the role of sustained attention in similar samples.ClinicalTrials.gov, NCT

  1. Patient perceptions of innovative longitudinal integrated clerkships based in regional, rural and remote primary care: a qualitative study

    Directory of Open Access Journals (Sweden)

    Hudson Judith N

    2012-07-01

    Full Text Available Abstract Background Medical students at the University of Wollongong experience continuity of patient care and clinical supervision during an innovative year-long integrated (community and hospital clinical clerkship. In this model of clinical education, students are based in a general practice ‘teaching microsystem’ and participate in patient care as part of this community of practice (CoP. This study evaluates patients’ perceptions of the clerkship initiative, and their perspectives on this approach to training ‘much-needed’ doctors in their community. Methods Semi-structured, face-to-face, interviews with patients provided data on the clerkship model in three contexts: regional, rural and remote health care settings in Australia. Two researchers independently thematically analysed transcribed data and organised emergent categories into themes. Results The twelve categories that emerged from the analysis of transcribed data were clustered into four themes: learning as doing; learning as shared experience; learning as belonging to a community; and learning as ‘becoming’. Patients viewed the clerkship learning environment as patient- and student-centred, emphasising that the patient-student-doctor relationship triad was important in facilitating active participation by patients as well as students. Patients believed that students became central, rather than peripheral, members of the CoP during an extended placement, value-adding and improving access to patient care. Conclusions Regional, rural and remote patients valued the long-term engagement of senior medical students in their health care team(s. A supportive CoP such as the general practice ‘teaching microsystem’ allowed student and patient to experience increasing participation and identity transformation over time. The extended student-patient-doctor relationship was seen as influential in this progression. Patients revealed unique insights into the longitudinal

  2. A longitudinal population-based study exploring treatment utilization and suicidal ideation and behavior in major depressive disorder.

    Science.gov (United States)

    Chartrand, Hayley; Robinson, Jennifer; Bolton, James M

    2012-12-10

    This study aimed to longitudinally examine the relationship between treatment utilization and suicidal behavior among people with major depressive disorder in a nationally representative sample. Data came from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) (Wave 1: N=43,093; Wave 2: N=34,653). Suicidal and non-suicidal individuals at Wave 1 were compared based on subsequent treatment utilization. Suicidal behavior at Wave 2 was compared between people with major depressive disorder who had sought treatment at Wave 1 versus those that had not. Individuals with past year major depressive disorder at Wave 1 who attempted suicide were more likely to be hospitalized at follow up compared to non-suicidal people with major depressive disorder [adjusted odds ratio (AOR)=4.46; 95% confidence interval [95% CI]: 2.54-7.85]; however, they were not more likely to seek other forms of treatment. Among those with past year major depressive disorder who sought treatment at baseline, visiting an emergency room (AOR=3.08; 95% CI: 1.61-5.89) and being hospitalized (AOR=2.41; 95% CI: 1.13-5.14), was associated with an increased likelihood of attempting suicide within 3 years even after adjusting for mental disorder comorbidity, depression severity, and previous suicidal behavior. Unable to draw conclusions about completed suicide or adequacy of treatment. Suicidal behavior does not lead individuals with major depressive disorder to seek treatment with professionals or use antidepressant medications; instead, they are more likely to use emergency services. These findings suggest that treatment efforts for people with major depressive disorder who are suicidal need improvement. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. The Association of Poor Academic Performance with Tic Disorders: A Longitudinal, Mainstream School-Based Population Study.

    Science.gov (United States)

    Cubo, Esther; Gonzalez, Cristina; Ausin, Vanesa; Delgado, Vanesa; Saez, Sara; Calvo, Sara; Garcia Soto, Xose; Cordero, José; Kompoliti, Katie; Louis, Elan D; de la Fuente Anuncibay, Raquel

    2017-01-01

    Little is known about the academic performance of students with tic disorders (TD). Our aim was to investigate the association of TD and poor academic performance over time. Longitudinal, observational study of mainstream schoolchildren comparing grade retention (GR) and learning disorders (LD) in students with vs. without TD between 2010 and 2014. Students with vs. without TD based on DSM-IV-TR criteria, or with vs. without GR and LD were compared in terms of comorbidities, school, and environmental characteristics. The association of TD with GR was analyzed using hazard ratios (HRs) with 95% CIs, and with LD using logistic regression analysis [Odds ratio (OR)]. Two hundred fifty-eight students were included (mean age 14.0 ± 1.71 years, 143 [55.4%] males). The incident rate for TD and GR was 2.6 and 3.3 per 100 persons-year, respectively. LD found in 21 (9.9%) students was associated with TD (OR 11.62, 95% CI 2.21-60.90, p = 0.004), and attention deficit hyperactivity disorder (ADHD; OR 6.63, 95% CI 1.55-28.37, p = 0.01). Low psychological support (HRs 12.79, 95% CI 3.39-48.17) and low sport participation (HRs 6.41, 95% CI 1.54-26.78) were risk factors for GR. TD was associated with academic difficulties, namely, LD in conjunction with ADHD but not GR. The diagnosis of TD and comorbidities, and the initiation of proper treatment could have a favorable impact on school performance, and consequently on social development. © 2017 S. Karger AG, Basel.

  4. Exposure to pesticide as a risk factor for depression: A population-based longitudinal study in Korea.

    Science.gov (United States)

    Koh, Sang-Baek; Kim, Tae Hui; Min, Seongho; Lee, Kyungsuk; Kang, Dae Ryong; Choi, Jung Ran

    2017-09-01

    Exposure to pesticides is associated with mental disorders, including depression, especially among occupationally exposed populations, such as farmers. The results of experimental studies ascribed the negative effects of pesticides on mental health to their neurotoxic and endocrine-disrupting activities. This study aimed to investigate the association between the risk of depression and high- or low-level exposure to pesticides in a rural population. This longitudinal study was performed in 2005-2008 (baseline) and 2008-2012 (follow-up) to evaluate the risk of depression among 2151 Korean adults. A standardized questionnaire was used to obtain information on depression upon self-reported exposure to pesticide based on the Center for Epidemiologic Studies Depression Scale. Logistic regression analysis was performed to evaluate the association between pesticide exposure and depression. We adjusted the data for age, cigarette smoking status, current alcohol use, monthly income, educational level, marriage status, and religion. Among the individuals who reported depression, the number of participants who used pesticides was significantly higher than that who did not (N=61 [7.2%] vs. N=54 [4.2%], P=0.003). A positive association was noted between >20-year period of pesticide use and depression (odds ratio [OR], 2.35; 95% confidence interval [CI], 1.41-3.88). Individuals who reported depression showed greater odds of being exposed to higher pesticide concentrations (OR, 2.33; 95% CI, 1.40-3.88) and experiencing pesticide poisoning (OR, 5.83; 95% CI, 1.80-18.86) than those who did not. Exposure to pesticides at a high concentration was found to be associated with depressive symptoms among Korean adults. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Revisiting typhoid fever surveillance in low and middle income countries: lessons from systematic literature review of population-based longitudinal studies.

    Science.gov (United States)

    Mogasale, Vittal; Mogasale, Vijayalaxmi V; Ramani, Enusa; Lee, Jung Seok; Park, Ju Yeon; Lee, Kang Sung; Wierzba, Thomas F

    2016-01-29

    The control of typhoid fever being an important public health concern in low and middle income countries, improving typhoid surveillance will help in planning and implementing typhoid control activities such as deployment of new generation Vi conjugate typhoid vaccines. We conducted a systematic literature review of longitudinal population-based blood culture-confirmed typhoid fever studies from low and middle income countries published from 1(st) January 1990 to 31(st) December 2013. We quantitatively summarized typhoid fever incidence rates and qualitatively reviewed study methodology that could have influenced rate estimates. We used meta-analysis approach based on random effects model in summarizing the hospitalization rates. Twenty-two papers presented longitudinal population-based and blood culture-confirmed typhoid fever incidence estimates from 20 distinct sites in low and middle income countries. The reported incidence and hospitalizations rates were heterogeneous as well as the study methodology across the sites. We elucidated how the incidence rates were underestimated in published studies. We summarized six categories of under-estimation biases observed in these studies and presented potential solutions. Published longitudinal typhoid fever studies in low and middle income countries are geographically clustered and the methodology employed has a potential for underestimation. Future studies should account for these limitations.

  6. Internato Longitudinal

    Directory of Open Access Journals (Sweden)

    Marcelo Marcos Piva Demarzo

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

  7. Annual incidence rate of schizophrenia and schizophrenia spectrum disorders in a longitudinal population-based cohort study

    NARCIS (Netherlands)

    Sutterland, Arjen L.; Dieleman, Jeanne; Storosum, Jitschak G.; Voordouw, Bettie A. C.; Kroon, Jojanneke; Veldhuis, Joris; Denys, Damiaan A. J. P.; de Haan, Lieuwe; Sturkenboom, Miriam C. J. M.

    2013-01-01

    Longitudinal incidence studies of schizophrenia spectrum disorders (SSD) performed in mental health service organizations are prone to confounding factors not found in research performed in the general population. To estimate the incidence rates (IRs) over a 10-year period of SSD (broadly defined)

  8. Progression, incidence, and risk factors for intervertebral disc degeneration in a longitudinal population-based cohort: the Wakayama Spine Study.

    Science.gov (United States)

    Teraguchi, M; Yoshimura, N; Hashizume, H; Yamada, H; Oka, H; Minamide, A; Nagata, K; Ishimoto, Y; Kagotani, R; Kawaguchi, H; Tanaka, S; Akune, T; Nakamura, K; Muraki, S; Yoshida, M

    2017-07-01

    The present study examined the progression, incidence, and risk factors for intervertebral disc degeneration (DD) throughout the lumbar spine using magnetic resonance imaging (MRI) in a large population-based cohort. We followed up 617 subjects for more than 4 years as part of the Wakayama Spine Study. 1) "Progression of DD" in each of the entire, upper (L1/2 to L3/4) and lower (L4/5 and L5/S1) lumbar spine was defined as Pfirrmann grade progression at follow-up in at least one disc in the affected region. 2) "Incidence of DD" in each of these regions was defined if all discs were grade 3 or lower (white disc) at baseline, and at least one disc had progressed to grade 4 or higher (black disc) at follow-up. Logistic regression analyses were used to determine the risk factors for progression and incidence of DD. DD progression and incidence in the entire lumbar spine were 52.0% and 31.6% in men, and 60.4% and 44.7% in women, respectively. Women was associated with DD progression in the upper lumbar spine (odds ratio [OR] = 1.68, 95% confidence interval [CI] = 1.18-2.42). Aging was associated with the incidence of DD in each region (entire: OR = 1.14, CI = 1.06-1.14; upper: OR = 1.10, CI = 1.05-1.15; lower: OR = 1.11, CI = 1.05-1.19). Diabetes mellitus (DM) was associated with the incidence of DD in the upper lumbar spine (OR = 6.83, CI = 1.07-133.7). This 4-year longitudinal study is the first to demonstrate DD progression and incidence in the lumbar spine and their risk factors in a large population-based cohort. Copyright © 2017 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  9. Additive Manufacturing: A Comparative Analysis of Dimensional Accuracy and Skin Texture Reproduction of Auricular Prostheses Replicas.

    Science.gov (United States)

    Unkovskiy, Alexey; Spintzyk, Sebastian; Axmann, Detlef; Engel, Eva-Maria; Weber, Heiner; Huettig, Fabian

    2017-11-10

    The use of computer-aided design/computer-aided manufacturing (CAD/CAM) and additive manufacturing in maxillofacial prosthetics has been widely acknowledged. Rapid prototyping can be considered for manufacturing of auricular prostheses. Therefore, so-called prostheses replicas can be fabricated by digital means. The objective of this study was to identify a superior additive manufacturing method to fabricate auricular prosthesis replicas (APRs) within a digital workflow. Auricles of 23 healthy subjects (mean age of 37.8 years) were measured in vivo with respect to an anthropometrical protocol. Landmarks were volumized with fiducial balls for 3D scanning using a handheld structured light scanner. The 3D CAD dataset was postprocessed, and the same anthropometrical measurements were made in the CAD software with the digital lineal. Each CAD dataset was materialized using fused deposition modeling (FDM), selective laser sintering (SLS), and stereolithography (SL), constituting 53 APR samples. All distances between the landmarks were measured on the APRs. After the determination of the measurement error within the five data groups (in vivo, CAD, FDM, SLS, and SL), the mean values were compared using matched pairs method. To this, the in vivo and CAD dataset were set as references. Finally, the surface structure of the APRs was qualitatively evaluated with stereomicroscopy and profilometry to ascertain the level of skin detail reproduction. The anthropometrical approach showed drawbacks in measuring the protrusion of the ear's helix. The measurement error within all groups of measurements was calculated between 0.20 and 0.28 mm, implying a high reproducibility. The lowest mean differences of 53 produced APRs were found in FDM (0.43%) followed by SLS (0.54%) and SL (0.59%)--compared to in vivo, and again in FDM (0.20%) followed by SL (0.36%) and SLS (0.39%)--compared to CAD. None of these values exceed the threshold of clinical relevance (1.5%); however, the qualitative

  10. The role of self-efficacy, self-esteem and optimism for using routine health check-ups in a population-based sample. A longitudinal perspective.

    Science.gov (United States)

    Hajek, André; Hans-Helmut-König

    2017-12-01

    While several cross-sectional studies have shown that self-efficacy, self-esteem and optimism are associated with the use of routine health check-ups, little is known about this relationship based on longitudinal studies. Consequently, the purpose of this study was to examine whether these factors are associated with routine health check-ups longitudinally. Data were retrieved from a population-based longitudinal study of individuals (≥40years of age) residing in private households in Germany (two waves: 2008 and 2011). Widely established scales were used to quantify self-efficacy, self-esteem, and optimism. Respondents reported whether they used a health check-up in the last two years. Conditional fixed-effects logistic regressions were used (n=1504), adjusting for socio-demographic, lifestyle and health-related variables. After adjusting for various potential confounders, regression analysis revealed that the use of routine health check-ups increased with self-efficacy [OR: 1.71 (95%-CI: 1.14-2.55)], self-esteem [OR: 1.78 (1.16-2.73)], and optimism [OR: 1.37 (1.01-1.86)]. Furthermore, the use of routine health check-ups increased with changes from employment to retirement [OR: 2.60 (1.34-5.03)], whereas it was not associated with changes in age, marital status, smoking status, the number of physical illnesses, self-rated health and body-mass index. The current study stresses the importance of an association between screening behavior and self-efficacy, self-esteem and optimism longitudinally. Interventions aiming at modifying these psychological factors might help to increase the use of routine health check-ups. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Disease management programs for patients with type 2 diabetes mellitus in Germany: a longitudinal population-based descriptive study.

    Science.gov (United States)

    Mehring, Michael; Donnachie, Ewan; Bonke, Florian Cornelius; Werner, Christoph; Schneider, Antonius

    2017-01-01

    The primary aim of the disease management program (DMP) for patients with diabetes mellitus type 2 is to improve the quality of health care and the treatment process. 12 years after its introduction in Germany, there is still no consensus as to whether DMP has been effective in reaching these goals. A retrospective longitudinal population-based study between 2004 and 2015 were conducted to evaluate the DMP for type 2 diabetes in Bavaria using routinely collected patient medical records hold from the National Association of Statutory Health Insurance Physicians of Bavaria. During the first 12 years of DMP, the number of participants increased continually to reach 580,222 in 2015. The proportion of participants older than 70 years increased during the observation from 41.6 to 51.1%. The percentage of smokers increased slightly from 9 to 11%. Similarly, the distribution of body mass index remained constant with approximately 50% of patients having a body mass index >30 kg/m 2 . Control of HbA1c was without an appreciable change over the course, with between 8.3 and 9.4% of all patients with uncontrolled values higher than 8.5%. Prescription of metformin increased from 40.5% in 2004 to 54.1% in 2015. Among patients receiving insulin, the proportion receiving a combined therapy with metformin increased from 28.4% in 2004 to 50.8% in 2015. In contrast, the percentage with insulin monotherapy decreased from 55.4 to 33.7%. The proportion of patients with a diabetic education increased within the course from 12.8 to 29.3%. Data from the German DMP for type 2 diabetes demonstrates an improvement in the quality of care with respect to pharmacotherapy and patient education and therefore to an improved adherence to guidelines. However, no appreciable improvement was observed with regard to smoking status, obesity or HbA1c control.

  12. On the Application of Replica Molding Technology for the Indirect Measurement of Surface and Geometry of Micromilled Components

    DEFF Research Database (Denmark)

    Baruffi, Federico; Parenti, Paolo; Cacciatore, Francesco

    2017-01-01

    the replica molding technology. The method consists of obtaining a replica of the feature that is inaccessible for standard measurement devices and performing its indirect measurement. This paper examines the performance of a commercial replication media applied to the indirect measurement of micromilled...... components. Two specifically designed micromilled benchmark samples were used to assess the accuracy in replicating both surface texture and geometry. A 3D confocal microscope and a focus variation instrument were employed and the associated uncertainties were evaluated. The replication method proved...... to be suitable for characterizing micromilled surface texture even though an average overestimation in the nano-metric level of the Sa parameter was observed. On the other hand, the replicated geometry generally underestimated that of the master, often leading to a different measurement output considering...

  13. An implementation of the maximum-caliber principle by replica-averaged time-resolved restrained simulations.

    Science.gov (United States)

    Capelli, Riccardo; Tiana, Guido; Camilloni, Carlo

    2018-05-14

    Inferential methods can be used to integrate experimental informations and molecular simulations. The maximum entropy principle provides a framework for using equilibrium experimental data, and it has been shown that replica-averaged simulations, restrained using a static potential, are a practical and powerful implementation of such a principle. Here we show that replica-averaged simulations restrained using a time-dependent potential are equivalent to the principle of maximum caliber, the dynamic version of the principle of maximum entropy, and thus may allow us to integrate time-resolved data in molecular dynamics simulations. We provide an analytical proof of the equivalence as well as a computational validation making use of simple models and synthetic data. Some limitations and possible solutions are also discussed.

  14. Evaluation of elastix-based propagated align algorithm for VOI- and voxel-based analysis of longitudinal F-18-FDG PET/CT data from patients with non-small cell lung cancer (NSCLC)

    NARCIS (Netherlands)

    Kerner, Gerald S. M. A.; Fischer, Alexander; Koole, Michel J. B.; Pruim, Jan; Groen, Harry J. M.

    2015-01-01

    Background: Deformable image registration allows volume of interest (VOI)- and voxel-based analysis of longitudinal changes in fluorodeoxyglucose (FDG) tumor uptake in patients with non-small cell lung cancer (NSCLC). This study evaluates the performance of the elastix toolbox deformable image

  15. Narrow intra-individual variation of maternal thyroid function in pregnancy based on a longitudinal study on 132 women

    DEFF Research Database (Denmark)

    Boas, M.; Forman, Julie Lyng; Juul, A.

    2009-01-01

    BACKGROUND: Adaptive alterations in maternal physiology cause changes in thyroid hormone levels throughout pregnancy, and precise biochemical evaluation is thus highly dependent on gestation-specific reference intervals and expected intra-individual variation. OBJECTIVE: The aim of the study...... was the assessment of the intra-individual variation as well as the longitudinal course of thyroid hormones during normal pregnancy and factors that influence the normal reference range for thyroid function. For this purpose, a longitudinal statistical model was applied. DESIGN: In a cohort of 132 pregnant women......, serial blood samples were obtained and ultrasound scans were performed throughout pregnancy. METHODS: Serum levels of TSH, free and total thyroxine (T(4)), free and total triiodothyronine (T(3)) as well as autoantibodies against thyroid peroxidase and thyroglobulin were measured in 979 serum samples...

  16. Metallic microwires obtained as replicas of etched ion tracks in polymer matrixes: Microscopy and emission properties

    International Nuclear Information System (INIS)

    Zagorski, D.L.; Bedin, S.A.; Oleinikov, V.A.; Polyakov, N.B.; Rybalko, O.G.; Mchedlishvili, B.V.

    2009-01-01

    Specially prepared porous matrixes (with through and dead-end pores of cylindrical or conical forms) were used as the templates for making ensembles of microwires. The process of electrodeposition of metal (Cu) into these pores was investigated. AFM technique was used for studying the 'composite material' (metal microwires embedded into the polymer matrix). It was shown that the combination of different modes of AFM (tapping with phase-contrast mode, contact with lateral force mode) makes it possible to detect metal in the polymer matrix. Additional spread resistance mode in the contact regime allowed to measure the electrical conductivity of a single wire. The ensembles of free-standing microwires (metallic replicas of the pores obtained after removing of the polymer matrix) were used as the substrates (for deposition of the probe) for ion emission in the mass-spectrometer. It was shown that the intensity of formed ion beam increases with increasing of power of the laser pulse and with increasing of the mass of the probe. The intensity of mass-spectra signal on the power of laser pulse has a threshold character with saturation accompanied with the appearance of dimer ions. At the same time this intensity decreases with the increasing of the surface density of wires. The effect of degradation of wires during the laser pulse irradiation was found.

  17. From Dalek half balls to Daft Punk helmets: Mimetic fandom and the crafting of replicas

    Directory of Open Access Journals (Sweden)

    Matt Hills

    2014-06-01

    Full Text Available Mimetic fandom is a surprisingly understudied mode of (culturally masculinized fan activity in which fans research and craft replica props. Mimetic fandom can be considered as (inauthentic and (immaterial, combining noncommercial status with grassroots marketing or brand reinforcement as well as fusing an emphasis on material artifacts with Web 2.0 collective intelligence. Simply analyzing mimetic fandom as part of fannish material culture fails to adequately assess the nonmaterial aspects of this collaborative creativity. Two fan cultures are taken as case studies: Dalek building groups and Daft Punk helmet constructors. These diverse cases indicate that mimetic fandom has a presence and significance that moves across media fandoms and is not restricted to the science fiction, fantasy, and horror followings with which it is most often associated. Mimetic fandom may be theorized as an oscillatory activity that confuses binaries and constructions of (academic/fan authenticity. This fan practice desires and pursues a kind of ontological bridging or unity—from text to reality—that is either absent or less dominant in many other fan activities such as cosplay, screen-used prop collecting, and geographical pilgrimage. Fan studies may benefit from reassessing the place of mimesis, especially in order to theorize fan practices that are less clearly transformative in character.

  18. Conformational Ensembles of α-Synuclein Derived Peptide with Different Osmolytes from Temperature Replica Exchange Sampling

    Directory of Open Access Journals (Sweden)

    Salma Jamal

    2017-12-01

    Full Text Available Intrinsically disordered proteins (IDP are a class of proteins that do not have a stable three-dimensional structure and can adopt a range of conformations playing various vital functional role. Alpha-synuclein is one such IDP which can aggregate into toxic protofibrils and has been associated largely with Parkinson's disease (PD along with other neurodegenerative diseases. Osmolytes are small organic compounds that can alter the environment around the proteins by acting as denaturants or protectants for the proteins. In the present study, we have conducted a series of replica exchange molecular dynamics simulations to explore the role of osmolytes, urea which is a denaturant and TMAO (trimethylamine N-oxide, a protecting osmolyte, in aggregation and conformations of the synuclein peptide. We observed that both the osmolytes have significantly distinct impacts on the peptide and led to transitions of the conformations of the peptide from one state to other. Our findings highlighted that urea attenuated peptide aggregation and resulted in the formation of extended peptide structures whereas TMAO led to compact and folded forms of the peptide.

  19. Partial replicas of uv-irradiated bacteriophage T4 genomes and their role in multiplicity reactivation

    International Nuclear Information System (INIS)

    Rayssiguier, C.; Kozinski, A.W.; Doermann, A.H.

    1980-01-01

    A physicochemical study was made of the replication and transmission of uv-irradiated T4 genomes. The data presented in this paper justify the following conclusions. (i) For both low and high multiplicity of infection there was abundant replication from uv-irradiated parental templates. It exceeded by far the efficiency predicted by the hypothesis that a single lethal hit completely prevents replication of the killed phage DNA: i.e., some dead phage particles must replicate parts of their DNA. (ii) Replication of the uv-irradiated DNA was repetitive as shown by density reversal experiments. (iii) Newly synthesized progeny DNA originating from uv-irradiated templates appeared as significantly shorter segments of the genomes than progeny DNA produced from non-uv-irradiated templates. A good correlation existed between the number of uv hits and the number of random cuts that would be needed to reduce replication fragments to the length observed. (iv) The contribution of uv-irradiated parental DNA among progeny phage in multiplicity reactivation was disposed in shorter subunits than was the DNA from unirradiated parental phage. It is important to emphasize that it was mainly in the form of replicative hybrid. These conclusions appear to justify excluding interparental recombination as a prerequisite for multiplicity reactivation. They lead directly to some form of partial replica hypothesis for multiplicity reactivation

  20. Replica of human dentin treated with different desensitizing agents: a methodological SEM study in vitro

    Directory of Open Access Journals (Sweden)

    Pereira Jose Carlos

    2002-01-01

    Full Text Available This is a preliminary study to determine a methodological sequence in vitro which may allow the reproduction of dentin for SEM analysis, after the use of different desensitizing agents. Dentin discs obtained from extracted human third molars were etched with 6% citric acid, an artificial smear layer was created and the surface dentin discs were divided into four quadrants. Quadrants 2, 3 and 4 of each disc were conditioned with 6% citric acid. The desensitizing agents (Oxa-Gel®, Gluma Desensitizer and an experimental agent were applied to quadrants 3 and 4. To evaluate the acid resistance of the treatment, quadrant 4 was etched again with 6% citric acid. An impression was then taken with Aquasil ULV. After a setting period of 6 min, each disc was removed from the impression and stored in a moist-free environment for 24 h at 37ºC. After that time, a low-viscosity epoxy resin (Araltec GY 1109 BR was poured into the impression and cured for 24 h. All specimens were metal-coated for SEM analysis. Comparison of the photomicrographs of dentin discs with their respective impressions and resin replicas showed that this technique can reproduce the characteristics of the dentin surface treated with desensitizing agents.

  1. Simulated tempering distributed replica sampling: A practical guide to enhanced conformational sampling

    Energy Technology Data Exchange (ETDEWEB)

    Rauscher, Sarah; Pomes, Regis, E-mail: pomes@sickkids.ca

    2010-11-01

    Simulated tempering distributed replica sampling (STDR) is a generalized-ensemble method designed specifically for simulations of large molecular systems on shared and heterogeneous computing platforms [Rauscher, Neale and Pomes (2009) J. Chem. Theor. Comput. 5, 2640]. The STDR algorithm consists of an alternation of two steps: (1) a short molecular dynamics (MD) simulation; and (2) a stochastic temperature jump. Repeating these steps thousands of times results in a random walk in temperature, which allows the system to overcome energetic barriers, thereby enhancing conformational sampling. The aim of the present paper is to provide a practical guide to applying STDR to complex biomolecular systems. We discuss the details of our STDR implementation, which is a highly-parallel algorithm designed to maximize computational efficiency while simultaneously minimizing network communication and data storage requirements. Using a 35-residue disordered peptide in explicit water as a test system, we characterize the efficiency of the STDR algorithm with respect to both diffusion in temperature space and statistical convergence of structural properties. Importantly, we show that STDR provides a dramatic enhancement of conformational sampling compared to a canonical MD simulation.

  2. Perovskite Quantum Dots Modeled Using ab Initio and Replica Exchange Molecular Dynamics

    KAUST Repository

    Buin, Andrei; Comin, Riccardo; Ip, Alexander H.; Sargent, Edward H.

    2015-01-01

    © 2015 American Chemical Society. Organometal halide perovskites have recently attracted tremendous attention at both the experimental and theoretical levels. Much of this work has been dedicated to bulk material studies, yet recent experimental work has shown the formation of highly efficient quantum-confined nanocrystals with tunable band edges. Here we investigate perovskite quantum dots from theory, predicting an upper bound of the Bohr radius of 45 Å that agrees well with literature values. When the quantum dots are stoichiometric, they are trap-free and have nearly symmetric contributions to confinement from the valence and conduction bands. We further show that surface-associated conduction bandedge states in perovskite nanocrystals lie below the bulk states, which could explain the difference in Urbach tails between mesoporous and planar perovskite films. In addition to conventional molecular dynamics (MD), we implement an enhanced phase-space sampling algorithm, replica exchange molecular dynamics (REMD). We find that in simulation of methylammonium orientation and global minima, REMD outperforms conventional MD. To the best of our knowledge, this is the first REMD implementation for realistic-sized systems in the realm of DFT calculations.

  3. Perovskite Quantum Dots Modeled Using ab Initio and Replica Exchange Molecular Dynamics

    KAUST Repository

    Buin, Andrei

    2015-06-18

    © 2015 American Chemical Society. Organometal halide perovskites have recently attracted tremendous attention at both the experimental and theoretical levels. Much of this work has been dedicated to bulk material studies, yet recent experimental work has shown the formation of highly efficient quantum-confined nanocrystals with tunable band edges. Here we investigate perovskite quantum dots from theory, predicting an upper bound of the Bohr radius of 45 Å that agrees well with literature values. When the quantum dots are stoichiometric, they are trap-free and have nearly symmetric contributions to confinement from the valence and conduction bands. We further show that surface-associated conduction bandedge states in perovskite nanocrystals lie below the bulk states, which could explain the difference in Urbach tails between mesoporous and planar perovskite films. In addition to conventional molecular dynamics (MD), we implement an enhanced phase-space sampling algorithm, replica exchange molecular dynamics (REMD). We find that in simulation of methylammonium orientation and global minima, REMD outperforms conventional MD. To the best of our knowledge, this is the first REMD implementation for realistic-sized systems in the realm of DFT calculations.

  4. Obtain ceramic porous alumina-zirconia by replica method calcium phosphate coated

    International Nuclear Information System (INIS)

    Silva, A.D.R.; Rigoli, W.R.; Osiro, Denise; Pallone, E.M.J.A.

    2016-01-01

    Biomaterials used in bone replacement, including porous bioceramics, are often used as support structure for bone formation and repair. The porous bioceramics are used because present features as biocompatibility, high porosity and pore morphology that confer adequate mechanical strength and induce bone growth. In this work were obtained porous specimens of alumina containing 5% by inclusion of volume of zirconia produced by the replica method. The porous specimens had its surface chemically treated with phosphoric acid and were coated with calcium phosphate. The coating was performed using the biomimetic method during 14 days and an initial pH of 6.1. The porous specimens were characterized using the follow techniques: porosity, axial compression tests, microtomography, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and pH measurements SBF solution. The results showed specimens with suitable pore morphology for application as biomaterial, and even a reduced time of incubation favored the calcium phosphate phases formation on the material surfaces. (author)

  5. Parallel replica dynamics method for bistable stochastic reaction networks: Simulation and sensitivity analysis

    Science.gov (United States)

    Wang, Ting; Plecháč, Petr

    2017-12-01

    Stochastic reaction networks that exhibit bistable behavior are common in systems biology, materials science, and catalysis. Sampling of stationary distributions is crucial for understanding and characterizing the long-time dynamics of bistable stochastic dynamical systems. However, simulations are often hindered by the insufficient sampling of rare transitions between the two metastable regions. In this paper, we apply the parallel replica method for a continuous time Markov chain in order to improve sampling of the stationary distribution in bistable stochastic reaction networks. The proposed method uses parallel computing to accelerate the sampling of rare transitions. Furthermore, it can be combined with the path-space information bounds for parametric sensitivity analysis. With the proposed methodology, we study three bistable biological networks: the Schlögl model, the genetic switch network, and the enzymatic futile cycle network. We demonstrate the algorithmic speedup achieved in these numerical benchmarks. More significant acceleration is expected when multi-core or graphics processing unit computer architectures and programming tools such as CUDA are employed.

  6. Parallel replica dynamics method for bistable stochastic reaction networks: Simulation and sensitivity analysis.

    Science.gov (United States)

    Wang, Ting; Plecháč, Petr

    2017-12-21

    Stochastic reaction networks that exhibit bistable behavior are common in systems biology, materials science, and catalysis. Sampling of stationary distributions is crucial for understanding and characterizing the long-time dynamics of bistable stochastic dynamical systems. However, simulations are often hindered by the insufficient sampling of rare transitions between the two metastable regions. In this paper, we apply the parallel replica method for a continuous time Markov chain in order to improve sampling of the stationary distribution in bistable stochastic reaction networks. The proposed method uses parallel computing to accelerate the sampling of rare transitions. Furthermore, it can be combined with the path-space information bounds for parametric sensitivity analysis. With the proposed methodology, we study three bistable biological networks: the Schlögl model, the genetic switch network, and the enzymatic futile cycle network. We demonstrate the algorithmic speedup achieved in these numerical benchmarks. More significant acceleration is expected when multi-core or graphics processing unit computer architectures and programming tools such as CUDA are employed.

  7. Approaches in methodology for population-based longitudinal study on neuroprotective model for healthy longevity (TUA) among Malaysian Older Adults.

    Science.gov (United States)

    Shahar, Suzana; Omar, Azahadi; Vanoh, Divya; Hamid, Tengku Aizan; Mukari, Siti Zamratol Mai-Sarah; Din, Normah Che; Rajab, Nor Fadilah; Mohammed, Zainora; Ibrahim, Rahimah; Loo, Won Hui; Meramat, Asheila; Kamaruddin, Mohd Zul Amin; Bagat, Mohamad Fazdillah; Razali, Rosdinom

    2016-12-01

    A number of longitudinal studies on aging have been designed to determine the predictors of healthy longevity, including the neuroprotective factors, however, relatively few studies included a wide range of factors and highlighted the challenges faced during data collection. Thus, the longitudinal study on neuroprotective model for healthy longevity (LRGS TUA) has been designed to prospectively investigate the magnitude of cognitive decline and its risk factors through a comprehensive multidimensional assessment comprising of biophysical health, auditory and visual function, nutrition and dietary pattern and psychosocial aspects. At baseline, subjects were interviewed for their status on sociodemographic, health, neuropsychological test, psychosocial and dietary intake. Subjects were also measured for anthropometric and physical function and fitness. Biospecimens including blood, buccal swap, hair and toenail were collected, processed and stored. A subsample was assessed for sensory function, i.e., vision and auditory. During follow-up, at 18 and 36 months, most of the measurements, along with morbidity and mortality outcomes will be collected. The description of mild cognitive impairment, successful aging and usual aging process is presented here. A total 2322 respondents were recruited in the data analysis at baseline. Most of the respondents were categorized as experiencing usual aging (73 %), followed by successful aging (11 %) and mild cognitive impairment (16 %). The LRGS TUA study is the most comprehensive longitudinal study on aging in Malaysia, and will contribute to the understanding of the aging process and factors associated with healthy aging and mental well-being of a multiethnic population in Malaysia.

  8. Order parameter free enhanced sampling of the vapor-liquid transition using the generalized replica exchange method.

    Science.gov (United States)

    Lu, Qing; Kim, Jaegil; Straub, John E

    2013-03-14

    The generalized Replica Exchange Method (gREM) is extended into the isobaric-isothermal ensemble, and applied to simulate a vapor-liquid phase transition in Lennard-Jones fluids. Merging an optimally designed generalized ensemble sampling with replica exchange, gREM is particularly well suited for the effective simulation of first-order phase transitions characterized by "backbending" in the statistical temperature. While the metastable and unstable states in the vicinity of the first-order phase transition are masked by the enthalpy gap in temperature replica exchange method simulations, they are transformed into stable states through the parameterized effective sampling weights in gREM simulations, and join vapor and liquid phases with a succession of unimodal enthalpy distributions. The enhanced sampling across metastable and unstable states is achieved without the need to identify a "good" order parameter for biased sampling. We performed gREM simulations at various pressures below and near the critical pressure to examine the change in behavior of the vapor-liquid phase transition at different pressures. We observed a crossover from the first-order phase transition at low pressure, characterized by the backbending in the statistical temperature and the "kink" in the Gibbs free energy, to a continuous second-order phase transition near the critical pressure. The controlling mechanisms of nucleation and continuous phase transition are evident and the coexistence properties and phase diagram are found in agreement with literature results.

  9. The Children’s Attention Project: a community-based longitudinal study of children with ADHD and non-ADHD controls

    Directory of Open Access Journals (Sweden)

    Sciberras Emma

    2013-01-01

    Full Text Available Abstract Background Attention-Deficit/Hyperactivity Disorder (ADHD affects approximately 5% of children worldwide and results in significant impairments in daily functioning. Few community-ascertained samples of children with ADHD have been studied prospectively to identify factors associated with differential outcomes. The Children’s Attention Project is the first such study in Australia, examining the mental health, social, academic and quality of life outcomes for children with diagnostically-confirmed ADHD compared to non-ADHD controls. The study aims to map the course of ADHD symptoms over time and to identify risk and protective factors associated with differential outcomes. Methods/design The sample for this prospective longitudinal study is being recruited across 43 socio-economically diverse primary schools across Melbourne, Australia. All children in Grade 1, the second year of formal schooling (6–8 years, are screened for ADHD symptoms using independent parent and teacher reports on the Conners’ 3 ADHD index (~N = 5260. Children screening positive for ADHD by both parent and teacher report, and a matched sample (gender, school screening negative, are invited to participate in the longitudinal study. At baseline this involves parent completion of the NIMH Diagnostic Interview Schedule for Children IV (DISC-IV to confirm likely ADHD diagnostic status and identify other mental health difficulties, direct child assessments (cognitive, academic, language and executive functioning; height and weight and questionnaires for parents and teachers assessing outcomes, as well as a broad range of risk and protective factors (child, parent/family, teacher/school, and socio-economic factors. Families will be initially followed up for 3 years. Discussion This study is the first Australian longitudinal study of children with ADHD and one of the first community-based longitudinal studies of diagnostically confirmed children with ADHD. The

  10. The impact of New Zealand's 2008 prohibition of piperazine-based party pills on young people's substance use: results of a longitudinal, web-based study.

    Science.gov (United States)

    Sheridan, Janie; Dong, Christine Yang; Butler, Rachael; Barnes, Joanne

    2013-09-01

    The last decade has seen the emergence of a new phenomenon in recreational substance use with the availability of herbal and synthetic, unregulated, psychoactive drugs in the market place; alongside this, international concern has developed in relation to their use and associated harms. New Zealand (NZ) was one of the first countries to experience this new phenomenon, with products containing chemicals of the piperazine group - mainly benzylpiperazine (BZP) and trifluoromethylphenylpiperazine (TFMPP). In 2008, the NZ Government prohibited these substances, but allowed a 6-month amnesty period for possession. Our study aimed to obtain a measure of change in BZP use over time. This study used a longitudinal, web-based survey, with data collected at two time points from the same participants. The first survey was carried out 3 months after BZP prohibition, and included retrospective questions for the 6 months preceding the survey. The second survey was conducted 9 months after prohibition and also included retrospective questions for the 6 months preceding the survey. 273 sets of paired data were identified. The use of BZP party pills (pparty pills obtained them from friends or from their own stockpiled supplies. The misuse of prescription drugs (p=0.02) increased over time, whereas statistically significant increases in stimulant or alcohol use were not noted. Following prohibition of piperazine-based party pills, we noted a significant reduction in the proportions of participants using them. The observed increase in the misuse of prescription medicines may relate to their perceived 'quality', or as being less 'illegal' than illicit drugs. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Trends in traumatic brain injury mortality in China, 2006-2013: A population-based longitudinal study.

    Science.gov (United States)

    Cheng, Peixia; Yin, Peng; Ning, Peishan; Wang, Lijun; Cheng, Xunjie; Liu, Yunning; Schwebel, David C; Liu, Jiangmei; Qi, Jinlei; Hu, Guoqing; Zhou, Maigeng

    2017-07-01

    Traumatic brain injury (TBI) is a significant global public health problem, but has received minimal attention from researchers and policy-makers in low- and middle-income countries (LMICs). Epidemiological evidence of TBI morbidity and mortality is absent at the national level for most LMICs, including China. Using data from China's Disease Surveillance Points (DSPs) system, we conducted a population-based longitudinal analysis to examine TBI mortality, and mortality differences by sex, age group, location (urban/rural), and external cause of injury, from 1 January 2006 to 31 December 2013 in China. Mortality data came from the national DSPs system of China, which has coded deaths using the International Classification of Diseases-10th Revision (ICD-10) since 2004. Crude and age-standardized mortality with 95% CIs were estimated using the census population in 2010 as a reference population. The Cochran-Armitage trend test was used to examine the significance of trends in mortality from 2006 to 2013. Negative binomial models were used to examine the associations of TBI mortality with location, sex, and age group. Subgroup analysis was performed by external cause of TBI. We found the following: (1) Age-adjusted TBI mortality increased from 13.23 per 100,000 population in 2006 to 17.06 per 100,000 population in 2008 and then began to fall slightly. In 2013, age-adjusted TBI mortality was 12.99 per 100,000 population (SE = 0.13). (2) Compared to females and urban residents, males and rural residents had higher TBI mortality risk, with adjusted mortality rate ratios of 2.57 and 1.71, respectively. TBI mortality increased substantially with older age. (3) Motor vehicle crashes and falls were the 2 leading causes of TBI mortality between 2006 and 2013. TBI deaths from motor vehicle crashes in children aged 0-14 years and adults aged 65 years and older were most often in pedestrians, and motorcyclists were the first or second leading category of road user for the other

  12. Trends in traumatic brain injury mortality in China, 2006-2013: A population-based longitudinal study.

    Directory of Open Access Journals (Sweden)

    Peixia Cheng

    2017-07-01

    Full Text Available Traumatic brain injury (TBI is a significant global public health problem, but has received minimal attention from researchers and policy-makers in low- and middle-income countries (LMICs. Epidemiological evidence of TBI morbidity and mortality is absent at the national level for most LMICs, including China. Using data from China's Disease Surveillance Points (DSPs system, we conducted a population-based longitudinal analysis to examine TBI mortality, and mortality differences by sex, age group, location (urban/rural, and external cause of injury, from 1 January 2006 to 31 December 2013 in China.Mortality data came from the national DSPs system of China, which has coded deaths using the International Classification of Diseases-10th Revision (ICD-10 since 2004. Crude and age-standardized mortality with 95% CIs were estimated using the census population in 2010 as a reference population. The Cochran-Armitage trend test was used to examine the significance of trends in mortality from 2006 to 2013. Negative binomial models were used to examine the associations of TBI mortality with location, sex, and age group. Subgroup analysis was performed by external cause of TBI. We found the following: (1 Age-adjusted TBI mortality increased from 13.23 per 100,000 population in 2006 to 17.06 per 100,000 population in 2008 and then began to fall slightly. In 2013, age-adjusted TBI mortality was 12.99 per 100,000 population (SE = 0.13. (2 Compared to females and urban residents, males and rural residents had higher TBI mortality risk, with adjusted mortality rate ratios of 2.57 and 1.71, respectively. TBI mortality increased substantially with older age. (3 Motor vehicle crashes and falls were the 2 leading causes of TBI mortality between 2006 and 2013. TBI deaths from motor vehicle crashes in children aged 0-14 years and adults aged 65 years and older were most often in pedestrians, and motorcyclists were the first or second leading category of road user for

  13. Trends in suicide risk associated with hospitalized psychiatric illness: a case-control study based on danish longitudinal registers

    DEFF Research Database (Denmark)

    Qin, Ping; Nordentoft, Merete; Hansen Høyer, Eyd

    2006-01-01

    longitudinal registers. Data were analyzed using conditional logistic regression. RESULTS: This study shows that the reduction in suicide rate is generally faster among individuals with a history of psychiatric admission than among individuals without such a history. However, this substantial reduction...... at the time of suicide or the index date, the reduction in suicide rate is relatively slower. Such trends hold for all diagnostic groups. Further analyses stratified by age indicate that the faster reduction in suicide rate associated with history of hospitalized psychiatric illness is more pronounced among...

  14. ENDF/B VI iron validation onpca-replica (H2O/FE) shielding benchmark experiment

    Energy Technology Data Exchange (ETDEWEB)

    Pescarini, M. [ENEA, Bologna (Italy). Centro Ricerche Energia `E. Clementel` - Area Energia e Innovazione

    1994-05-01

    The PCA-REPLICA (H2O/Fe) neutron shielding benchmark experiment is analysed using the SN 2-D DOT 3.5 code and the 3-D-equivalent flux synthesis method. This engineering benchmark reproduces the ex-core radial geometry of a PWR, including a mild steel reactor pressure vessel (RPV) simulator, and is dsigned to test the accuracy of the calculation of the in-vessel neutron exposure parameters (fast fluence and iron displacement rates). This accuracy is strongly dependent on the quality of the iron neutron cross section used to describe the nuclear reactions within the RPV simulator. In particular, in this report, the cross sections based on the ENDF/B VI iron data files are tested, through a comparison of the calculated integral and spectral results with the corresponding experimental data. In addition, the present results are compared, on the same benchmark experiment, with those of a preceding ENEA (Italian Agency for Energy, New Technologies and Environment)-Bologna validation of the JEF-2.1 iron cross sections. The integral result comparison indicates that, for all the thresold detectors considered (Rh-103 (n,n) Rh-103m, In-115 (n,n) In-115 (n,n) In-115m and S-32 (n.p) P-32), the ENDF/B VI iron data produce better results than the JEF-2.1 iron data. In particular, in the ENDF/B VI calcultaions, an improvement of the in-vessel C/E (Calculated/Experimental) activity ratios for the lower energy threshold detectors, Rh-103 and In-115, is observed. This improvement becomes more evident with increasing neutron penetration depth in the vessel. This is probably attributable to the fact that the inelastic scattering cross section values of the ENDF/B VI Fe-56 data file, approximately in the 0.86 - 1.5 MeV energy range, are lower then the corresponding values of the JEF-2.1 data file.

  15. FTIR study of ageing of fast drying oil colour (FDOC) alkyd paint replicas

    Science.gov (United States)

    Duce, Celia; Della Porta, Valentina; Tiné, Maria Rosaria; Spepi, Alessio; Ghezzi, Lisa; Colombini, Maria Perla; Bramanti, Emilia

    2014-09-01

    We propose ATR-FTIR spectroscopy for the characterization of the spectral changes in alkyd resin from the Griffin Alkyd Fast Drying Oil Colour range (Winsor & Newton), occurring over 550 days (˜18 months) of natural ageing and over six months of artificial ageing under an acetic acid atmosphere. Acetic acid is one of the atmospheric pollutants found inside museums in concentrations that can have a significant effect on the works exhibited. During natural ageing we observed an increase and broadening of the OH group band around 3300 cm-1 and an increase in bands in the region 1730-1680 cm-1 due to carbonyl stretching. We found a broad band around 1635 cm-1 likely due to Cdbnd O stretching vibrations of β dichetons. These spectral changes are the result of autooxidation reactions during natural ageing and crosslinking, which then form f alcohols and carbonyl species. The increase in absorbance at 1635 cm-1 was selected as a parameter to monitor the ageing process of paintings prepared with FDOC, without the need for any extractive procedure. FTIR spectra of paint replicas kept under an acetic acid atmosphere indicated the chemical groups involved in the reaction with acid, thus suggesting which spectral FTIR regions could be investigated in order to follow any degradation in real paintings. A red paint sample from a hyper-realistic artwork (“Racconta storie”, 2003) by the Italian painter Patrizia Zara was investigated by FTIR in order to evaluate the effects of 10 years natural ageing on alkyd colours. The results obtained suggested that after the end of chemical drying (autooxidation), alkyd colours are very stable.

  16. The Brain Health Registry: An internet-based platform for recruitment, assessment, and longitudinal monitoring of participants for neuroscience studies.

    Science.gov (United States)

    Weiner, Michael W; Nosheny, Rachel; Camacho, Monica; Truran-Sacrey, Diana; Mackin, R Scott; Flenniken, Derek; Ulbricht, Aaron; Insel, Philip; Finley, Shannon; Fockler, Juliet; Veitch, Dallas

    2018-05-08

    Recruitment, assessment, and longitudinal monitoring of participants for neuroscience studies and clinical trials limit the development of new treatments. Widespread Internet use allows data capture from participants in an unsupervised setting. The Brain Health Registry, a website and online registry, collects data from participants and their study partners. The Brain Health Registry obtains self and study partner report questionnaires and neuropsychological data, including the Cogstate Brief Battery, Lumos Labs Neurocognitive Performance Test, and MemTrax Memory Test. Participants provide informed consent before participation. Baseline and longitudinal data were obtained from nearly 57,000 and 28,000 participants, respectively. Over 18,800 participants were referred to, and nearly 1800 were enrolled in, clinical Alzheimer's disease and aging studies, including five observational studies and seven intervention trials. Online assessments of participants and study partners provide useful information at relatively low cost for neuroscience studies and clinical trials and may ultimately be used in routine clinical practice. Copyright © 2018 the Alzheimer's Association. All rights reserved.

  17. The role of personality in health care use: Results of a population-based longitudinal study in Germany.

    Directory of Open Access Journals (Sweden)

    André Hajek

    Full Text Available To determine the role of personality in health care use longitudinally.Data were derived from the German Socio-Economic Panel (GSOEP, a nationally representative, longitudinal cohort study of German households starting in 1984. Concentrating on the role of personality, we used data from the years 2005, 2009 and 2013. Personality was measured by using the GSOEP Big Five Inventory (BFI-S. Number of physician visits in the last 3 months and hospital stays in the last year were used as measures of health care use.Adjusting for predisposing factors, enabling resources, and need factors, fixed effects regressions revealed that physician visits increased with increasing neuroticism, whereas extraversion, openness to experience, agreeableness and conscientiousness did not affect physician visits in a significant way. The effect of self-rated health on physician visits was significantly moderated by neuroticism. Moreover, fixed effects regressions revealed that the probability of hospitalization in the past year increased with increasing extraversion, whereas the other personality factors did not affect this outcome measure significantly.Our findings suggest that changes in neuroticism are associated with changes in physician visits and that changes in extraversion are associated with the probability of hospitalization. Since recent studies have shown that treatments can modify personality traits, developing interventional strategies should take into account personality factors. For example, efforts to intervene in changing neuroticism might have beneficial effects for the healthcare system.

  18. The role of personality in health care use: Results of a population-based longitudinal study in Germany.

    Science.gov (United States)

    Hajek, André; Bock, Jens-Oliver; König, Hans-Helmut

    2017-01-01

    To determine the role of personality in health care use longitudinally. Data were derived from the German Socio-Economic Panel (GSOEP), a nationally representative, longitudinal cohort study of German households starting in 1984. Concentrating on the role of personality, we used data from the years 2005, 2009 and 2013. Personality was measured by using the GSOEP Big Five Inventory (BFI-S). Number of physician visits in the last 3 months and hospital stays in the last year were used as measures of health care use. Adjusting for predisposing factors, enabling resources, and need factors, fixed effects regressions revealed that physician visits increased with increasing neuroticism, whereas extraversion, openness to experience, agreeableness and conscientiousness did not affect physician visits in a significant way. The effect of self-rated health on physician visits was significantly moderated by neuroticism. Moreover, fixed effects regressions revealed that the probability of hospitalization in the past year increased with increasing extraversion, whereas the other personality factors did not affect this outcome measure significantly. Our findings suggest that changes in neuroticism are associated with changes in physician visits and that changes in extraversion are associated with the probability of hospitalization. Since recent studies have shown that treatments can modify personality traits, developing interventional strategies should take into account personality factors. For example, efforts to intervene in changing neuroticism might have beneficial effects for the healthcare system.

  19. The Network for Analysing Longitudinal Population-based HIV/AIDS data on Africa (ALPHA): Data on mortality, by HIV status and stage on the HIV care continuum, among the general population in seven longitudinal studies between 1989 and 2014.

    Science.gov (United States)

    Slaymaker, Emma; McLean, Estelle; Wringe, Alison; Calvert, Clara; Marston, Milly; Reniers, Georges; Kabudula, Chodziwadziwa Whiteson; Crampin, Amelia; Price, Alison; Michael, Denna; Urassa, Mark; Kwaro, Daniel; Sewe, Maquins; Eaton, Jeffrey W; Rhead, Rebecca; Nakiyingi-Miiro, Jessica; Lutalo, Tom; Nabukalu, Dorean; Herbst, Kobus; Hosegood, Victoria; Zaba, Basia

    2017-11-06

    Timely progression of people living with HIV (PLHIV) from the point of infection through the pathway from diagnosis to treatment is important in ensuring effective care and treatment of HIV and preventing HIV-related deaths and onwards transmission of infection.  Reliable, population-based estimates of new infections are difficult to obtain for the generalised epidemics in sub-Saharan Africa.  Mortality data indicate disease burden and, if disaggregated along the continuum from diagnosis to treatment, can also reflect the coverage and quality of different HIV services.  Neither routine statistics nor observational clinical studies can estimate mortality prior to linkage to care nor following disengagement from care.  For this, population-based data are required. The Network for Analysing Longitudinal Population-based HIV/AIDS data on Africa brings together studies in Kenya, Malawi, South Africa, Tanzania, Uganda, and Zimbabwe.  Eight studies have the necessary data to estimate mortality by HIV status, and seven can estimate mortality at different stages of the HIV care continuum.  This data note describes a harmonised dataset containing anonymised individual-level information on survival by HIV status for adults aged 15 and above. Among PLHIV, the dataset provides information on survival during different periods: prior to diagnosis of infection; following diagnosis but before linkage to care; in pre-antiretroviral treatment (ART) care; in the first six months after ART initiation; among people continuously on ART for 6+ months; and among people who have ever interrupted ART.

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

    Science.gov (United States)

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

    2017-10-16

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

  1. Machine Learning-based Individual Assessment of Cortical Atrophy Pattern in Alzheimer's Disease Spectrum: Development of the Classifier and Longitudinal Evaluation.

    Science.gov (United States)

    Lee, Jin San; Kim, Changsoo; Shin, Jeong-Hyeon; Cho, Hanna; Shin, Dae-Seock; Kim, Nakyoung; Kim, Hee Jin; Kim, Yeshin; Lockhart, Samuel N; Na, Duk L; Seo, Sang Won; Seong, Joon-Kyung

    2018-03-07

    To develop a new method for measuring Alzheimer's disease (AD)-specific similarity of cortical atrophy patterns at the individual-level, we employed an individual-level machine learning algorithm. A total of 869 cognitively normal (CN) individuals and 473 patients with probable AD dementia who underwent high-resolution 3T brain MRI were included. We propose a machine learning-based method for measuring the similarity of an individual subject's cortical atrophy pattern with that of a representative AD patient cohort. In addition, we validated this similarity measure in two longitudinal cohorts consisting of 79 patients with amnestic-mild cognitive impairment (aMCI) and 27 patients with probable AD dementia. Surface-based morphometry classifier for discriminating AD from CN showed sensitivity and specificity values of 87.1% and 93.3%, respectively. In the longitudinal validation study, aMCI-converts had higher atrophy similarity at both baseline (p < 0.001) and first year visits (p < 0.001) relative to non-converters. Similarly, AD patients with faster decline had higher atrophy similarity than slower decliners at baseline (p = 0.042), first year (p = 0.028), and third year visits (p = 0.027). The AD-specific atrophy similarity measure is a novel approach for the prediction of dementia risk and for the evaluation of AD trajectories on an individual subject level.

  2. Initial Career Paths and Inequality in Uruguay. An Analysis Based on the PISA-L Longitudinal Study 2003-2012

    Directory of Open Access Journals (Sweden)

    Tabaré Fernández

    2017-01-01

    Full Text Available This article aims to identify and explain the initial career paths of young Uruguayans. It emphasizes three elements: labour protection, timing and qualifications in the context of the new uncertainty generated by globalization and the role of institutional filters provided by the employment and education systems. We use PISA 2003 -2012 longitudinal project data. An optimal solution of seven clusters reveals a medium level of heterogeneity in the transition. The multinomial regression on social class, gender and human capital reports modest but significant marginal effects for the last two. It is evident the reproduction of gender inequality in this "dense period", particularly affecting women with children. Human capital has also a clear protective effect towards vulnerable paths, but does not generate advantages to follow paths of rising job skills.

  3. Prolonged job strain and subsequent risk of cancer in women–a longitudinal study, based on the Danish Nurse Cohort

    DEFF Research Database (Denmark)

    Vesterlund, Gitte K.; Høeg, Beverley L.; Johansen, Christoffer

    2017-01-01

    Background: The role of psychological stress in cancer risk is continuously debated. Stress at work is the most common form of stress and previous studies have shown inconsistent results regarding cancer risk. In this longitudinal study, we examined the association between prolonged job strain......-related, digestive and lung cancers according to level of prolonged job strain. The women were followed from 1 January 2000 until cancer diagnosis, emigration, death or 31 December 2013 (mean follow-up 13 years) and models were adjusted for potential confounders. Effect modification was examined according to working...... nightshifts and full time. Results: No significant differences in the risk of overall cancer or any of the cancer subgroups were identified in relation to prolonged busyness, speed, influence, or overall job strain. Effect modification by working full time was observed when examining job influence in relation...

  4. Keep Talking & Monitoring: the importance of longitudinal research & community-based monitoring to support sustainable land management in southern Africa

    Science.gov (United States)

    Dougill, Andrew; Stringer, Lindsay

    2015-04-01

    Projects come and go with researchers, development practioners and government staff initiating new forms of community engagement in environmental monitoring and land management practices. We analyse interventions from Botswana and Swaziland and highlight that for benefits to be long-lived and lead to sustainable land management, requires community engagement in project design, implementation and for project outputs to be used in developing community-led environmental monitoring tools that can then help to guide local decision-making systems. We stress the vital importance of continued participatory engagement of researchers with community leaders and key government staff beyond the timeframe of their initial research such that longitudinal research approaches can realise significant benefits to all concerned. In dynamic (non-equilibrium) dryland environments, it is vitally important that research approaches address temporal and spatial variability by mapping patterns of change, using a range of participatory tools to enhance understandings of the causes of land degradation and the opportunities for shifts towards more sustainable land management. Decision-support tools, such as rangeland assessment guides produced for various Kalahari rangeland settings in Botswana (via a UNEP project and affiliated research), provide opportunities to support more sustainable land management. However, at present benefits are not being fully realised as project and research staff move on after projects end. Similarly, findings from mixed farming systems in Swaziland (assessing a JICA-funded project) show problems in maintaining new institutional structures to manage rangeland degradation, whilst issues on arable areas associated with parasitic weeds (Striga asiatica) remain problematic. Findings from longitudinal research in Swaziland also show that community understandings of environmental problems have evolved over 10 years and identify new problems associated with intensified

  5. Longitudinal predictors of health-related quality of life in middle-aged and older adults with hypertension: results of a population-based study.

    Science.gov (United States)

    Maatouk, Imad; Wild, Beate; Herzog, Wolfgang; Wesche, Daniela; Schellberg, Dieter; Schöttker, Ben; Müller, Heiko; Rothenbacher, Dietrich; Stegmaier, Christa; Brenner, Hermann

    2012-07-01

    The aim of the study was to assess the longitudinal association between cardiovascular risk factors including albuminuria and other variables (e.g. awareness of hypertension, number of types of antihypertensive drugs, comorbidity), and health-related quality of life (HRQOL) in a large cohort of patients with hypertension, over a follow-up period of 5 years. Nine thousand nine hundred and fifty-three participants of the ESTHER (Epidemiologische Studie zu Chancen der Verhütung, Früherkennung und optimierten Therapie chronischer Erkrankungen) study - a population-based cohort study of middle-aged and older adults aged 50-74 years at baseline - were recruited by general practitioners (GPs) in 2000-2002 and included in the follow-up (2005-2007). HRQOL at baseline and follow-up was measured using the Short-Form General Health Survey (SF-12). Mental component scores (MCS) and physical component scores (PCS) were calculated. Multiple linear regression models were used to determine longitudinal predictors of HRQOL at follow-up. Four thousand, two hundred and three patients with hypertension (98.2%) responded to the SF-12 both at baseline and after 5 years and were therefore included in the study. Smoking status, BMI, diabetes, macroalbuminuria, comorbid diseases, history of depression, and lower HRQOL at baseline predicted lower PCS at the 5-year follow-up. Lower MCS after 5 years was predicted by smoking status, dyslipidaemia, a reported history of depression, and HRQOL at baseline. No significant association was detected between awareness of hypertension and any HRQOL component score after 5 years. Macroalbuminuria and other variables related to increased cardiovascular risk have a negative impact on PCS. Suggestions of a link of treatment and awareness of hypertension with HRQOL from previous cross-sectional studies are not supported by our longitudinal findings.

  6. Informal Caregiving and Subjective Well-Being: Evidence of a Population-Based Longitudinal Study of Older Adults in Germany.

    Science.gov (United States)

    Hajek, André; König, Hans-Helmut

    2016-04-01

    The aim of this study was to examine whether informal caregiving affects subjective well-being (SWB) of the caregivers in the long run. The German Ageing Survey (DEAS) is a nationwide, representative longitudinal study of community-dwelling individuals living in Germany aged 40 and older. The surveys in 2002, 2008, and 2011 were used (11,264 observations). Several components of SWB were used, covering functional and mental health, and affective (positive affect and negative affect) as well as cognitive well-being. Although functional health was quantified by the subscale "physical functioning" of the 36-Item Short Form Health Survey (SF-36), mental health was assessed by using the Center for Epidemiologic Studies Depression Scale (CES-D). Life satisfaction (cognitive well-being) was quantified by using the Satisfaction with Life Scale (SWLS) and positive and negative affect (affective well-being) was assessed using the Positive and Negative Affect Schedule (PANAS). Longitudinal regressions revealed that informal care affected (1) mental health in the total sample and in both sexes as well as (2) cognitive well-being in women. The effect of informal care on mental health was significantly moderated by self-efficacy in the total sample. Our findings emphasize the role of informal caregiving for mental health and cognitive well-being (women). Moreover, our findings highlight the role of self-efficacy in the relation between informal care and mental health. Thus, to prevent declines in mental health due to informal care, it might be a fruitful approach to strengthen self-efficacy. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

  7. Risk Factors for Malnutrition in Older Adults: A Systematic Review of the Literature Based on Longitudinal Data123

    Science.gov (United States)

    Vereecken, Carine; Vanhauwaert, Erika; Bekkering, Geertruida Elsiena

    2016-01-01

    The present systematic review critically examines the available scientific literature on risk factors for malnutrition in the older population (aged ≥65 y). A systematic search was conducted in MEDLINE, reviewing reference lists from 2000 until March 2015. The 2499 papers identified were subjected to inclusion criteria that evaluated the study quality according to items from validated guidelines. Only papers that provided information on a variable’s effect on the development of malnutrition, which requires longitudinal data, were included. A total of 6 longitudinal studies met the inclusion criteria and were included in the systematic review. These studies reported the following significant risk factors for malnutrition: age (OR: 1.038; P = 0.045), frailty in institutionalized persons (β: 0.22; P = 0.036), excessive polypharmacy (β: −0.62; P = 0.001), general health decline including physical function (OR: 1.793; P = 0.008), Parkinson disease (OR: 2.450; P = 0.047), constipation (OR: 2.490; P = 0.015), poor (OR: 3.30; P value not given) or moderate (β: −0.27; P = 0.016) self-reported health status, cognitive decline (OR: 1.844; P = 0.001), dementia (OR: 2.139; P = 0.001), eating dependencies (OR: 2.257; P = 0.001), loss of interest in life (β: −0.58; P = 0.017), poor appetite (β: −1.52; P = 0.000), basal oral dysphagia (OR: 2.72; P = 0.010), signs of impaired efficacy of swallowing (OR: 2.73; P = 0.015), and institutionalization (β: −1.89; P malnutrition in older adults may be considered by health care professionals when developing new integrated assessment instruments to identify older adults’ risk of malnutrition and to support the development of preventive and treatment strategies. PMID:27184278

  8. DOT 3.5-E (DOT 3.5-E/JEF-1) analysis of the PCA-Replica (H2O/FE) shielding benchmark for the LWR-PV damage prediction

    International Nuclear Information System (INIS)

    Pescarini, M.

    1991-01-01

    The results of a DOT 3.5-E/JEF-1 validation on the (H2O/Fr) PCA-REPLICA (UKAEA-Winfith) low-flux shielding benchmark are presented. The PCA-REPLICA experiments reproduces the excore radial geometry of a PWR and is closely related to LWR safety since it is dedicated to test the accuracy of the calculated neutron exposure parameters (fast fluence and iron displacement rates) in a pressure vessel simulator. The NJOY/THEMIS data processing system is employed to obtain the neutron damage-energy cross sections for the JEF-1 iron file. The SN 1-D ANISN code is used to collapse cross sections from the VITAMIN-J (175 n) shielding library, based on the JEF-1 data, to a 28 group working library for 2-D calculations. A 3-D-equivalent synthesis (X,Y,Z) of 2-D and 1-D DOT 3.5-E SN calculations in a plane geometry, gives the integral and spectral results for comparison with the respective experimental data. The underprediction of the in-vessel dosimeter experimental activities depends probably on an overestimation of the iron inelastic scattering cross section of the JEF-1 file

  9. Validation of the BUGJEFF311.BOLIB, BUGENDF70.BOLIB and BUGLE-B7 broad-group libraries on the PCA-Replica (H2O/Fe neutron shielding benchmark experiment

    Directory of Open Access Journals (Sweden)

    Pescarini Massimo

    2016-01-01

    Full Text Available The PCA-Replica 12/13 (H2O/Fe neutron shielding benchmark experiment was analysed using the TORT-3.2 3D SN code. PCA-Replica reproduces a PWR ex-core radial geometry with alternate layers of water and steel including a pressure vessel simulator. Three broad-group coupled neutron/photon working cross section libraries in FIDO-ANISN format with the same energy group structure (47 n + 20 γ and based on different nuclear data were alternatively used: the ENEA BUGJEFF311.BOLIB (JEFF-3.1.1 and UGENDF70.BOLIB (ENDF/B-VII.0 libraries and the ORNL BUGLE-B7 (ENDF/B-VII.0 library. Dosimeter cross sections derived from the IAEA IRDF-2002 dosimetry file were employed. The calculated reaction rates for the Rh-103(n,n′Rh-103m, In-115(n,n′In-115m and S-32(n,pP-32 threshold activation dosimeters and the calculated neutron spectra are compared with the corresponding experimental results.

  10. Validation of the BUGJEFF311.BOLIB, BUGENDF70.BOLIB and BUGLE-B7 broad-group libraries on the PCA-Replica (H2O/Fe) neutron shielding benchmark experiment

    Science.gov (United States)

    Pescarini, Massimo; Orsi, Roberto; Frisoni, Manuela

    2016-03-01

    The PCA-Replica 12/13 (H2O/Fe) neutron shielding benchmark experiment was analysed using the TORT-3.2 3D SN code. PCA-Replica reproduces a PWR ex-core radial geometry with alternate layers of water and steel including a pressure vessel simulator. Three broad-group coupled neutron/photon working cross section libraries in FIDO-ANISN format with the same energy group structure (47 n + 20 γ) and based on different nuclear data were alternatively used: the ENEA BUGJEFF311.BOLIB (JEFF-3.1.1) and UGENDF70.BOLIB (ENDF/B-VII.0) libraries and the ORNL BUGLE-B7 (ENDF/B-VII.0) library. Dosimeter cross sections derived from the IAEA IRDF-2002 dosimetry file were employed. The calculated reaction rates for the Rh-103(n,n')Rh-103m, In-115(n,n')In-115m and S-32(n,p)P-32 threshold activation dosimeters and the calculated neutron spectra are compared with the corresponding experimental results.

  11. Are screen-based sedentary behaviors longitudinally associated with dietary behaviors and leisure-time physical activity in the transition into adolescence?

    Science.gov (United States)

    Gebremariam, Mekdes K; Bergh, Ingunn H; Andersen, Lene F; Ommundsen, Yngvar; Totland, Torunn H; Bjelland, Mona; Grydeland, May; Lien, Nanna

    2013-01-25

    There is a need for more longitudinal studies investigating the associations between screen-based sedentary behaviors (SB), dietary behaviors and leisure-time physical activity (PA). In the HEIA cohort study, 908 children were followed from age 11 to age 13 (September 2007-May 2009). The children self-reported their intake of fruits, vegetables, soft drinks with sugar and snacks. TV/DVD use, computer/game use and leisure-time PA were also self-reported. Multilevel generalized linear mixed model analysis was used to assess longitudinal associations between the screen-based SB and each of the two other behaviors. Twenty-month changes in TV/DVD use and computer/game use were positively associated with changes in the consumption of soft drinks with sugar and unhealthy snacks in the same period; and inversely associated with change in vegetable consumption. Change in computer/game use was also inversely related to change in fruit consumption. An inverse but non-substantive association was found between change in TV/DVD use and change in leisure-time PA. Change in computer/game use was not significantly associated with change in leisure-time PA. Changes in screen-based SB were associated with multiple unfavorable changes in dietary habits, although the associations were weak. These associations need to be further investigated in intervention/experimental studies, to assess whether changing screen-based SB will result in clinically relevant changes in dietary behaviors. However, the findings of this study suggest that screen-based SB and leisure-time PA are largely independent behaviors which should be addressed separately in health promotion activities.

  12. Replica symmetry breaking solution for two-sublattice fermionic Ising spin glass models in a transverse field

    International Nuclear Information System (INIS)

    Zimmer, F.M.; Magalhaes, S.G.

    2007-01-01

    The one-step replica symmetry breaking is used to study the competition between spin glass (SG) and antiferromagnetic order (AF) in two-sublattice fermionic Ising SG models in the presence of a transverse Γ and a parallel H magnetic fields. Inter- and intra-sublattice exchange interactions following Gaussian distributions are considered. The problem is formulated in a Grassmann path integral formalism within the static ansatz. Results show that H favors the non-ergodic mixed phase (AF+SG) and it destroys the AF. The Γ suppresses the magnetic orders, and the intra-sublattice interaction can introduce a discontinuous phase transition

  13. Utilization of Stimulants and Atomoxetine for Attention-Deficit/Hyperactivity Disorder among 5.4 Million Children Using Population-Based Longitudinal Data

    DEFF Research Database (Denmark)

    Furu, Kari; Karlstad, Øystein; Zoëga, Helga

    2017-01-01

    Use of stimulants to treat attention-deficit/hyperactivity disorder (ADHD) has increased over the past two decades and varies substantially between countries. The objective of this multinational population-based study was to examine utilization of ADHD drugs (stimulants and atomoxetine) including...... the importance of close monitoring of treatment for ADHD among children.......Use of stimulants to treat attention-deficit/hyperactivity disorder (ADHD) has increased over the past two decades and varies substantially between countries. The objective of this multinational population-based study was to examine utilization of ADHD drugs (stimulants and atomoxetine) including...... comedication with other psychotropic drugs in the entire child population in the five Nordic countries. We included longitudinal data on dispensed ADHD drugs from five Nordic prescription registers during 2008-2012, which in 2012 comprised 48,296 individuals among 5.42 million inhabitants aged 0-17 years...

  14. Impact of the Project P.A.T.H.S. in the Junior Secondary School Years: Objective Outcome Evaluation Based on Eight Waves of Longitudinal Data

    Directory of Open Access Journals (Sweden)

    Daniel T. L. Shek

    2012-01-01

    Full Text Available To assess the effectiveness of the Tier 1 Program of the Project P.A.T.H.S., a randomized group trial with eight waves of data collected was carried out. At the fifth year of data collection, 19 experimental schools (n=2, 662 students and 24 control schools (n=3, 272 students participated in the study. Analyses based on individual growth curve modeling showed that participants in the experimental schools displayed better positive youth development than did participants in the control schools in terms of different indicators derived from the Chinese Positive Youth Development Scale, including moral competence and behavioral competence and cognitive behavioral competencies. Significant results were also found when examining the trajectories of psychological development among control and experimental participants who perceived the program to be beneficial. Findings based on longitudinal objective outcome evaluation strongly suggest that the Project P.A.T.H.S. is effective in promoting positive development in Hong Kong secondary school students.

  15. Impact of the Project P.A.T.H.S. in the junior secondary school years: objective outcome evaluation based on eight waves of longitudinal data.

    Science.gov (United States)

    Shek, Daniel T L; Ma, Cecilia M S

    2012-01-01

    To assess the effectiveness of the Tier 1 Program of the Project P.A.T.H.S., a randomized group trial with eight waves of data collected was carried out. At the fifth year of data collection, 19 experimental schools (n = 2, 662 students) and 24 control schools (n = 3, 272 students) participated in the study. Analyses based on individual growth curve modeling showed that participants in the experimental schools displayed better positive youth development than did participants in the control schools in terms of different indicators derived from the Chinese Positive Youth Development Scale, including moral competence and behavioral competence and cognitive behavioral competencies. Significant results were also found when examining the trajectories of psychological development among control and experimental participants who perceived the program to be beneficial. Findings based on longitudinal objective outcome evaluation strongly suggest that the Project P.A.T.H.S. is effective in promoting positive development in Hong Kong secondary school students.

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

    Science.gov (United States)

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

    2016-10-01

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

  17. Triglyceride and glucose (TyG) index as a predictor of incident hypertension: a 9-year longitudinal population-based study.

    Science.gov (United States)

    Zheng, Rongjiong; Mao, Yushan

    2017-09-13

    Hypertension and the triglyceride and glucose index both have been associated with insulin resistance; however, the longitudinal association remains unclear. This study was designed to investigate the longitudinal association between the triglyceride and glucose index and incident hypertension among the Chinese population. We studied 4686 subjects (3177 males and 1509 females) and followed up for 9 years. The subjects were divided into four groups based on the triglyceride and glucose index. Univariate and multivariate Cox regression models were used to analyse the risk factors of hypertension. After 9 years of follow-up, 2047 subjects developed hypertension. The overall 9-year cumulative incidence of hypertension was 43.7%, ranging from 28.5% in quartile 1 to 36.9% in quartile 2, 49.2% in quartile 3 and 59.8% in quartile 4 (p for trend triglyceride and glucose index was associated with an increased risk of subsequent incident hypertension. The triglyceride and glucose index can predict the incident hypertension among the Chinese population.

  18. Validation of a Radiography-Based Quantification Designed to Longitudinally Monitor Soft Tissue Calcification in Skeletal Muscle.

    Science.gov (United States)

    Moore, Stephanie N; Hawley, Gregory D; Smith, Emily N; Mignemi, Nicholas A; Ihejirika, Rivka C; Yuasa, Masato; Cates, Justin M M; Liu, Xulei; Schoenecker, Jonathan G

    2016-01-01

    Soft tissue calcification, including both dystrophic calcification and heterotopic ossification, may occur following injury. These lesions have variable fates as they are either resorbed or persist. Persistent soft tissue calcification may result in chronic inflammation and/or loss of function of that soft tissue. The molecular mechanisms that result in the development and maturation of calcifications are uncertain. As a result, directed therapies that prevent or resorb soft tissue calcifications remain largely unsuccessful. Animal models of post-traumatic soft tissue calcification that allow for cost-effective, serial analysis of an individual animal over time are necessary to derive and test novel therapies. We have determined that a cardiotoxin-induced injury of the muscles in the posterior compartment of the lower extremity represents a useful model in which soft tissue calcification develops remote from adjacent bones, thereby allowing for serial analysis by plain radiography. The purpose of the study was to design and validate a method for quantifying soft tissue calcifications in mice longitudinally using plain radiographic techniques and an ordinal scoring system. Muscle injury was induced by injecting cardiotoxin into the posterior compartment of the lower extremity in mice susceptible to developing soft tissue calcification. Seven days following injury, radiographs were obtained under anesthesia. Multiple researchers applied methods designed to standardize post-image processing of digital radiographs (N = 4) and quantify soft tissue calcification (N = 6) in these images using an ordinal scoring system. Inter- and intra-observer agreement for both post-image processing and the scoring system used was assessed using weighted kappa statistics. Soft tissue calcification quantifications by the ordinal scale were compared to mineral volume measurements (threshold 450.7mgHA/cm3) determined by μCT. Finally, sample-size calculations necessary to discriminate

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

    Science.gov (United States)

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

    2015-01-01

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

  20. Replication Strategy for Spatiotemporal Data Based on Distributed Caching System.

    Science.gov (United States)

    Xiong, Lian; Yang, Liu; Tao, Yang; Xu, Juan; Zhao, Lun

    2018-01-14

    The replica strategy in distributed cache can effectively reduce user access delay and improve system performance. However, developing a replica strategy suitable for varied application scenarios is still quite challenging, owing to differences in user access behavior and preferences. In this paper, a replication strategy for spatiotemporal data (RSSD) based on a distributed caching system is proposed. By taking advantage of the spatiotemporal locality and correlation of user access, RSSD mines high popularity and associated files from historical user access information, and then generates replicas and selects appropriate cache node for placement. Experimental results show that the RSSD algorithm is simple and efficient, and succeeds in significantly reducing user access delay.

  1. Replication Strategy for Spatiotemporal Data Based on Distributed Caching System

    Science.gov (United States)

    Xiong, Lian; Tao, Yang; Xu, Juan; Zhao, Lun

    2018-01-01

    The replica strategy in distributed cache can effectively reduce user access delay and improve system performance. However, developing a replica strategy suitable for varied application scenarios is still quite challenging, owing to differences in user access behavior and preferences. In this paper, a replication strategy for spatiotemporal data (RSSD) based on a distributed caching system is proposed. By taking advantage of the spatiotemporal locality and correlation of user access, RSSD mines high popularity and associated files from historical user access information, and then generates replicas and selects appropriate cache node for placement. Experimental results show that the RSSD algorithm is simple and efficient, and succeeds in significantly reducing user access delay. PMID:29342897

  2. Current strategies for monitoring men with localised prostate cancer lack a strong evidence base: observational longitudinal study.

    Science.gov (United States)

    Metcalfe, C; Tilling, K; Davis, M; Lane, J A; Martin, R M; Kynaston, H; Powell, P; Neal, D E; Hamdy, F; Donovan, J L

    2009-08-04

    The UK National Institute for Health and Clinical Excellence (NICE) guidance recommends conservative management of men with 'low-risk' localised prostate cancer, monitoring the disease using prostate-specific antigen (PSA) kinetics and re-biopsy. However, there is little evidence of the changes in PSA level that should alert to the need for clinical re-assessment. This study compares the alerts resulting from PSA kinetics and a novel longitudinal reference range approach, which incorporates age-related changes, during the monitoring of 408 men with localised prostate cancer. Men were monitored by regular PSA tests over a mean of 2.9 years, recording when a man's PSA doubling time fell below 2 years, PSA velocity exceeded 2 ng ml(-1) per year, or when his upper 10% reference range was exceeded. Prostate-specific antigen doubling time and PSA velocity alerted a high proportion of men initially but became unresponsive to changes with successive tests. Calculating doubling time using recent PSA measurements reduced the decline in response. The reference range method maintained responsiveness to changes in PSA level throughout the monitoring. The increasing unresponsiveness of PSA kinetics is a consequence of the underlying regression model. Novel methods are needed for evaluation in cohorts currently being managed by monitoring. Meanwhile, the NICE guidance should be cautious.

  3. Stable single longitudinal mode erbium-doped silica fiber laser based on an asymmetric linear three-cavity structure

    International Nuclear Information System (INIS)

    Feng Ting; Yan Feng-Ping; Li Qi; Peng Wan-Jing; Feng Su-Chun; Tan Si-Yu; Wen Xiao-Dong

    2013-01-01

    We present a stable linear-cavity single longitudinal mode (SLM) erbium-doped silica fiber laser. It consists of four fiber Bragg gratings (FBGs) directly written in a section of photosensitive erbium-doped fiber (EDF) to form an asymmetric three-cavity structure. The stable SLM operation at a wavelength of 1545.112 nm with a 3-dB bandwidth of 0.012 nm and an optical signal-to-noise ratio (OSNR) of about 60 dB is verified experimentally. Under laboratory conditions, the performance of a power fluctuation of less than 0.05 dB observed from the power meter for 6 h and a wavelength variation of less than 0.01 nm obtained from the optical spectrum analyzer (OSA) for about 1.5 h are demonstrated. The gain fiber length is no longer limited to only several centimeters for SLM operation because of the excellent mode-selecting ability of the asymmetric three-cavity structure. The proposed scheme provides a simple and cost-effective approach to realizing a stable SLM fiber laser. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  4. Childhood physical maltreatment, perceived social isolation, and internalizing symptoms: a longitudinal, three-wave, population-based study.

    Science.gov (United States)

    Sheikh, Mashhood Ahmed

    2018-04-01

    A number of cross-sectional studies have consistently shown a correlation between childhood physical maltreatment, perceived social isolation and internalizing symptoms. Using a longitudinal, three-wave design, this study sought to assess the mediating role of perceived social isolation in adulthood in the association between childhood physical maltreatment and internalizing symptoms in adulthood. The study has a three-wave design. We used data collected from 1994 to 2008 within the framework of the Tromsø Study (N = 4530), a representative prospective cohort study of men and women. Perceived social isolation was measured at a mean age of 54.7 years, and internalizing symptoms were measured at a mean age of 61.7 years. The difference-in-coefficients method was used to assess the indirect effects and the proportion (%) of mediated effects. Childhood physical maltreatment was associated with an up to 68% [relative risk (RR) = 1.68, 95% confidence interval (CI): 1.33-2.13] higher risk of perceived social isolation in adulthood. Childhood physical maltreatment and perceived social isolation in adulthood were associated with greater levels of internalizing symptoms in adulthood (p social isolation in adulthood mediated up to 14.89% (p social isolation into account when considering the impact of childhood physical maltreatment on internalizing symptoms.

  5. Changes in job strain and subsequent weight gain: a longitudinal study, based on the Danish Nurse Cohort.

    Science.gov (United States)

    Vesterlund, Gitte Kingo; Keller, Amélie Cléo; Heitmann, Berit Lilienthal

    2018-04-01

    Obesity as well as job strain is increasing, and job strain might contribute to weight gain. The objective of the current study was to examine associations between longitudinal alterations in the components of job strain and subsequent weight gain. The study was designed as a prospective cohort study with three questionnaire surveys enabling measurement of job-strain alterations over 6 years and subsequent measurements of weight gain after further 10 years of follow-up. ANCOVA and trend analyses were conducted. Job demands were measured as job busyness and speed, and control as amount of influence. Employed nurses in Denmark. We included a sub-sample of 6188 female nurses from the Danish Nurse Cohort, which consisted of the nurses who participated in surveys in 1993, 1999 and 2009. A linear trend in weight gain was seen in nurses who were often busy in 1999 between those who were rarely v. sometimes v. often busy in 1993 (P=0·03), with the largest weight gain in individuals with sustained high busyness in both years. Loss of influence between 1993 and 1999 was associated with larger subsequent weight gain than sustained high influence (P=0·003) or sustained low influence (P=0·02). For speed, no associations were found. Busyness, speed and influence differed in their relationship to subsequent weight gain. A decrease in job influence and a sustained burden of busyness were most strongly related to subsequent weight gain. Focus on job strain reduction and healthy diet is essential for public health.

  6. Replica symmetry breaking in short range spin glasses: A review of the theoretical foundations and of the numerical evidence

    International Nuclear Information System (INIS)

    Marinari, E.; Zuliani, F.; Parisi, G.; Ricci-Tersenghi, F.; Ruiz-Lorenzo, J.J.

    2000-04-01

    We discuss Replica Symmetry Breaking (RSB) in Spin Glasses. We present an update about the state of the matter, both from the analytical and from the numerical point of view. We put a particular attention in discussing the difficulties stressed by Newman and Stein concerning the problem of constructing pure states in spin glass systems. We mainly discuss about what happens in finite dimensional, realistic spin glasses. Together with a detailed review of some of most important features, facts, data, phenomena, we present some new theoretical ideas and numerical results. We discuss among others the basic idea of the RSB theory, correlation functions, interfaces, overlaps, pure states, random field and the dynamical approach. We present new numerical results for the behavior of coupled replicas and about the numerical verification of sum rules, and we review some of the available numerical results that we consider of larger importance (for example the determination of the phase transition point, the correlation functions, the window overlaps, the dynamical behavior of the system). (author)

  7. Measurements of the absolute neutron fluence spectrum emitted at 00 and 900 from the Little-Boy replica

    International Nuclear Information System (INIS)

    Roberts, J.H.; Gold, R.; Preston, C.C.

    1986-01-01

    Nuclear research emulsions (NRE) have been used to characterize the neutron spectrum emitted by the Little-Boy replica. NRE were irradiated at the Little-Boy surface, as well as approximately 2 m from the center of the Little-Boy replica, using polar angles of 0 0 , 30 0 , 60 0 , and 90 0 . For the NRE exposed at 2 m, neutron background was determined using shadow shields of borated polyethylene. Emulsion scanning to date has concentrated exclusively on the 2-m, 0 0 and 2-m, 90 0 locations. Approximately 5000 proton-recoil tracks have been measured in NRE irradiated at each of these locations. At the 2-m, 90 0 location, the NRE neutron spectrum extends from 0.37 MeV up to 8.2 MeV; whereas the NRE neutron spectrum at the 2-m, 0 0 location is much softer and extends only up to 2.7 MeV. NRE neutron spectrometry results at these two locations are compared with both liquid scintillator neutron spectrometry and Monte Carlo calculations. (author)

  8. Evaluating the Use of Synthetic Replicas for SEM Identification of Bloodstains (with Emphasis on Archaeological and Ethnographic Artifacts).

    Science.gov (United States)

    Hortolà, Policarp

    2015-12-01

    Some archaeological or ethnographic specimens are unavailable for direct examination using a scanning electron microscope (SEM) due to methodological obstacles or legal issues. In order to assess the feasibility of using SEM synthetic replicas for the identification of bloodstains (BSs) via morphology of red blood cells (RBCs), three fragments of different natural raw material (inorganic, stone; plant, wood; animal, shell) were smeared with peripheral human blood. Afterwards, molds and casts of the bloodstained areas were made using vinyl polysiloxane (VPS) silicone impression and polyurethane (PU) resin casting material, respectively. Then, the original samples and the resulting casts were coated with gold and examined in secondary-electron mode using a high-vacuum SEM. Results suggest that PU resin casts obtained from VPS silicone molds can preserve RBC morphology in BSs, and consequently that synthetic replicas are feasible for SEM identification of BSs on cultural heritage specimens made of natural raw materials. Although the focus of this study was on BSs, the method reported in this paper may be applicable to organic residues other than blood, as well as to the surface of other specimens when, for any reason, the original is unavailable for an SEM.

  9. Computer simulation study of in-zeolites templated carbon replicas: structural and adsorption properties for hydrogen storage application

    International Nuclear Information System (INIS)

    Roussel, T.

    2007-05-01

    Hydrogen storage is the key issue to envisage this gas for instance as an energy vector in the field of transportation. Porous carbons are materials that are considered as possible candidates. We have studied well-controlled microporous carbon nano-structures, carbonaceous replicas of meso-porous ordered silica materials and zeolites. We realized numerically (using Grand Canonical Monte Carlo Simulations, GCMC) the atomic nano-structures of the carbon replication of four zeolites: AlPO 4 -5, silicalite-1, and Faujasite (FAU and EMT). The faujasite replicas allow nano-casting of a new form of carbon crystalline solid made of tetrahedrally or hexagonally interconnected single wall nano-tubes. The pore size networks are nano-metric giving these materials optimized hydrogen molecular storage capacities (for pure carbon phases). However, we demonstrate that these new carbon forms are not interesting for room temperature efficient storage compared to the void space of a classical gas cylinder. We showed that doping with an alkaline element, such as lithium, one could store the same quantities at 350 bar compared to a classical tank at 700 bar. This result is a possible route to achieve interesting performances for on-board docking systems for instance. (author)

  10. Three-dimensional morphological characterization of the skin surface micro-topography using a skin replica and changes with age.

    Science.gov (United States)

    Masuda, Y; Oguri, M; Morinaga, T; Hirao, T

    2014-08-01

    Skin surface micro-topography (SSMT), consisting of pores, ridges and furrows, reflects the skin condition and is an important factor determining the aesthetics of the skin. Most previous studies evaluating SSMT have employed two-dimensional image analysis of magnified pictures captured by a video microscope. To improve the accuracy of SSMT analysis, we established a three-dimensional (3D) analysis method for SSMT and developed various parameters including the skin ridge number, and applied the method to study the age-dependent change in skin. Confocal laser scanning microscopy was used for 3D measurement of the surface morphology of silicon replicas taken from the cheek. We then used these data to calculate the parameters that reflect the nature of SSTM including the skin ridge number using originally developed software. Employing a superscription technique, we investigated the variation in SSMT with age for replicas taken from the cheeks of 103 Japanese females (5-85 years old). The skin surface area and roughness, the area of pores, the area, length, depth and width of skin furrows and the number of skin ridges were examined. The surface roughness, the area of pores and the depth of skin furrows increased with age. The area and length of skin furrows and the number of skin ridges decreased with age. The method proposed to analyse SSMT three dimensionally is an effective tool with which to characterize the condition of the skin. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Applied longitudinal analysis

    CERN Document Server

    Fitzmaurice, Garrett M; Ware, James H

    2012-01-01

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

  12. Axial displacement of abutments into implants and implant replicas, with the tapered cone-screw internal connection, as a function of tightening torque.

    Science.gov (United States)

    Dailey, Bruno; Jordan, Laurence; Blind, Olivier; Tavernier, Bruno

    2009-01-01

    The passive fit of a superstructure on implant abutments is essential to success. One source of error when using a tapered cone-screw internal connection may be the difference between the tightening torque level applied to the abutments by the laboratory technician compared to that applied by the treating clinician. The purpose of this study was to measure the axial displacement of tapered cone-screw abutments into implants and their replicas as a function of the tightening torque level. Twenty tapered cone-screw abutments were selected. Two groups were created: 10 abutments were secured into 10 implants, and 10 abutments were secured into 10 corresponding implant replicas. Each abutment was tightened in increasing increments of 5 Ncm, from 0 Ncm to 45 Ncm, with a torque controller. The length of each sample was measured repeatedly with an Electronic Digital Micrometer. The mean axial displacement for the implant group and the replica group was calculated. The data were analyzed by the Mann-Whitney and Spearman tests. For both groups, there was always an axial displacement of the abutment upon each incremental application of torque. The mean axial displacement values varied between 7 and 12 microm for the implant group and between 6 and 21 microm for the replica group at each 5-Ncm increment. From 0 to 45 Ncm, the total mean axial displacement values were 89 microm for the implant group and 122 microm for the replica group. There was a continuous axial displacement of the abutments into implants and implant replicas when the applied torque was raised from 0 to 45 Ncm. Torque applied above the level recommended by the manufacturer increased the difference in displacement between the two groups.

  13. Same-Sex Couples' Decisions and Experiences of Marriage in the Context of Minority Stress: Interviews From a Population-Based Longitudinal Study.

    Science.gov (United States)

    Rostosky, Sharon S; Riggle, Ellen D B; Rothblum, Esther D; Balsam, Kimberly F

    2016-08-01

    In the emerging context of marriage equality, it is important to explore the reasons for and experience of marriage for long-term same-sex couples, including the role of minority stress. In Wave 3 of the population-based, longitudinal CUPPLES Study we interviewed 21 long-term same-sex couples (14 female, 7 male) who resided in 12 different states and who were legally married. Couple members ranged in age from 37 to 84 and reported being together as a couple from 15 to 41 years. Seven couples lived in states that did not recognize their marriage at the time of the interview. Legal protection and social validation emerged as the two primary domains that captured couples' lived experiences of marriage. Minority stress experiences emerged in the narratives in the context of couples' long-term commitment, the availability of civil marriage, and couples' participation in activist efforts on behalf of marriage equality for themselves and others.

  14. Effects of self-reported hearing or vision impairment on depressive symptoms: a population-based longitudinal study.

    Science.gov (United States)

    Han, J H; Lee, H J; Jung, J; Park, E-C

    2018-02-08

    The aims of this study were to investigate the effects of either hearing, vision or dual sensory impairment on depressive symptoms and to identify subgroups that are vulnerable and significantly affected. Data from the 2006-2014 Korean Longitudinal Study of Aging (KLoSA) were used and a total of 5832 individuals were included in this study. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D10) scale. Sensory impairment was assessed according to the levels of self-reported hearing or vision, which were categorised as either good (excellent, very good or good) or poor (fair or poor). The changes in hearing or vision from records of previous survey were investigated. Changes from good to poor, which indicates new onset, were defined as hearing impairment or vision impairment. Interactions of changes in hearing and vision were considered in the analysis. Dual sensory impairment was indicated when hearing impairment and vision impairment both developed at the same time. Demographic, socioeconomic and health-related factors were considered as potential confounders and were adjusted for in the generalised estimating equation model. Individuals with hearing impairment demonstrated significantly more severe depressive symptoms [β = 0.434, standard errors (s.e.) = 0.097, p impairment also showed significantly elevated depressive symptoms (β = 0.253, s.e. = 0.058, p impairment showed significantly more severe depressive symptoms (β = 0.768, s.e. = 0.197, p impairment on depressive symptoms was significant in both sexes and across age groups, except for vision impairment in male participants. Hearing, vision and dual sensory impairment are significantly associated with depressive symptoms. Our results suggest that treatment or rehabilitation of either hearing or vision impairment would help prevent depression.

  15. The longitudinal relationship between mental health disorders and chronic disease for older adults: a population-based study.

    Science.gov (United States)

    Chen, Chun-Min; Lee, I-Chen; Su, Yung-Yu; Mullan, Judy; Chiu, Herng-Chia

    2017-09-01

    Although mental health disorders in older adults are common, their relationship with chronic disease and the influence of chronic disease on the development of mental health disorders over time is not well understood. This longitudinal study investigated the change in status of mental health disorders and chronic disease, as well as their interrelationships, over time. Participants included community-dwelling older adults living in Taiwan, aged 65 years or older, who completed six waves of survey interviews. Mental health disorders were scored using the Short Psychiatric Evaluation Schedule, and chronic disease(s) status was recorded during consecutive biennial data collection waves. The autoregressive latent trajectory model and parallel latent growth curve model were used for data analysis. The study findings suggest that in older people pre-existing mental health disorders and/or chronic disease(s) will predispose them to developing significantly more mental health disorders and/or chronic diseases respectively. The study findings also suggest that pre-existing mental health disorders can significantly contribute to the development of chronic disease over time, and that pre-existing chronic disease(s) significantly can contribute to the development of mental health disorders over time, indicating a reciprocal interrelationship. Our study findings suggest that it in addition to monitoring and treating chronic disease(s) in older people, it is also important to monitor and treat their mental health disorders. Doing so will result in overall better health outcomes and will facilitate a better quality of life as they age. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Longitudinal assessment of bone growth and development in a facility-based population of young adults with cerebral palsy.

    Science.gov (United States)

    Grossberg, Richard; Blackford, Martha G; Kecskemethy, Heidi H; Henderson, Richard; Reed, Michael D

    2015-11-01

    Osteoporosis is a significant clinical problem in persons with moderate to severe cerebral palsy (CP), causing fractures with minimal trauma. Over the past decade, most studies examining osteoporosis and CP have been cross-sectional in nature, focused exclusively on children and adolescents and only involving one evaluation of bone mineral density (BMD). The purpose of this study was to assess BMD in a group including adults with CP, and changes in each individual's BMD over a 5- to 6-year period. The study group included 40 residents of a long-term care facility aged 6 to 26 years at the time of their initial evaluation. Twenty-one patients (52.5%) were male, 35 (88%) were white, and 38 (95%) were in Gross Motor Function Classification System level V. BMD was assessed by dual-energy X-ray absorptiometry on the right and left distal femurs for three distinct regions of interest. Five residents had a fracture that occurred during the study period; this represented a fracture rate of 2.1% per year in the study group. Longitudinally, annualized change in the median BMD was 0.7% to 1.0% per year in the different regions of the distal femur, but ranged widely among the study group, with both increases and decreases in BMD. Increase in BMD over time was negatively correlated with age and positively correlated with change in weight. Changes in BMD over time in profoundly involved persons with CP can range widely, which is important to recognize when evaluating potential interventions to improve BMD. Age and changes in body weight appear the most relevant factors. © 2015 Mac Keith Press.

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

    Directory of Open Access Journals (Sweden)

    Rebecca Lubitz

    2015-12-01

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

  18. Número de replicações de inquéritos dietéticos para estimativa da ingestão de nutrientes em gestantes brasileiras

    Directory of Open Access Journals (Sweden)

    Daniela Saes Sartorelli

    2014-12-01

    Full Text Available Objetivos: determinar o número de replicações de inquéritos dietéticos necessários para estimar a ingestão usual de nutrientes e em categorias de consumo de gestantes no Brasil. Métodos: estudo prospectivo conduzido entre 82 gestantes, no qual as informações sobre energia e 18 nutrientes foram obtidas em três inquéritos recordatórios de 24 horas, sendo um em cada trimestre gestacional. Empregaram-se diferentes fórmulas para o cálculo do número de replicações do método necessárias para classificar as gestantes em categorias de ingestão, que considera a razão das variâncias intrapessoal/interpessoal, e para a estimativa da ingestão usual, baseado na variância intrapessoal. Resultados: para classificar as gestantes em categorias são necessárias entre 11 e 51 replicações do método, considerando-se coeficiente de correlação de 0,9. Admitindo coeficiente de correlação de 0,7, o número de replicações do método variou entre quatro e 19. Para a estimativa da ingestão usual são necessárias entre duas e 33 replicações, admitindo-se um erro de 10%. Considerando-se um erro de 20%, são necessárias entre uma e sete replicações de inquéritos dietéticos. Conclusões: é necessário um elevado número de replicações de inquéritos dietéticos na estimativa da ingestão de nutrientes na gestação e o emprego de um número reduzido de replicações poderá atenuar as associações entre a dieta e desfechos de saúde maternos e fetais.

  19. Construction of a web-based questionnaire for longitudinal investigation of work exposure, musculoskeletal pain and performance impairments in high-performance marine craft populations.

    Science.gov (United States)

    Lo Martire, Riccardo; de Alwis, Manudul Pahansen; Äng, Björn Olov; Garme, Karl

    2017-07-20

    High-performance marine craft personnel (HPMCP) are regularly exposed to vibration and repeated shock (VRS) levels exceeding maximum limitations stated by international legislation. Whereas such exposure reportedly is detrimental to health and performance, the epidemiological data necessary to link these adverse effects causally to VRS are not available in the scientific literature, and no suitable tools for acquiring such data exist. This study therefore constructed a questionnaire for longitudinal investigations in HPMCP. A consensus panel defined content domains, identified relevant items and outlined a questionnaire. The relevance and simplicity of the questionnaire's content were then systematically assessed by expert raters in three consecutive stages, each followed by revisions. An item-level content validity index (I-CVI) was computed as the proportion of experts rating an item as relevant and simple, and a scale-level content validity index (S-CVI/Ave) as the average I-CVI across items. The thresholds for acceptable content validity were 0.78 and 0.90, respectively. Finally, a dynamic web version of the questionnaire was constructed and pilot tested over a 1-month period during a marine exercise in a study population sample of eight subjects, while accelerometers simultaneously quantified VRS exposure. Content domains were defined as work exposure, musculoskeletal pain and human performance, and items were selected to reflect these constructs. Ratings from nine experts yielded S-CVI/Ave of 0.97 and 1.00 for relevance and simplicity, respectively, and the pilot test suggested that responses were sensitive to change in acceleration and that the questionnaire, following some adjustments, was feasible for its intended purpose. A dynamic web-based questionnaire for longitudinal survey of key variables in HPMCP was constructed. Expert ratings supported that the questionnaire content is relevant, simple and sufficiently comprehensive, and the pilot test suggested

  20. Data-driven identification of intensity normalization region based on longitudinal coherency of 18F-FDG metabolism in the healthy brain.

    Science.gov (United States)

    Zhang, Huiwei; Wu, Ping; Ziegler, Sibylle I; Guan, Yihui; Wang, Yuetao; Ge, Jingjie; Schwaiger, Markus; Huang, Sung-Cheng; Zuo, Chuantao; Förster, Stefan; Shi, Kuangyu

    2017-02-01

    analysis strategies (subject-based and age-cohort averaging). In addition, the proposed new intensity normalization method using the paracentral lobule generates significantly higher differentiation from the age-associated changes than other intensity normalization methods. Proper intensity normalization can enhance the longitudinal coherency of normal brain glucose metabolism. The paracentral lobule followed by the cerebellar tonsil are shown to be the two most stable intensity normalization regions concerning age-dependent brain metabolism. This may provide the potential to better differentiate disease-related changes from age-related changes in brain metabolism, which is of relevance in the diagnosis of neurodegenerative disorders. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Impact of Cardiac Resynchronization Therapy on Left Ventricular Mechanics: Understanding the Response through a New Quantitative Approach Based on Longitudinal Strain Integrals.

    Science.gov (United States)

    Bernard, Anne; Donal, Erwan; Leclercq, Christophe; Schnell, Frédéric; Fournet, Maxime; Reynaud, Amélie; Thebault, Christophe; Mabo, Philippe; Daubert, J-Claude; Hernandez, Alfredo

    2015-06-01

    The mechanisms of improvement of left ventricular (LV) function with cardiac resynchronization therapy (CRT) are not yet elucidated. The aim of this study was to describe a new tool based on automatic quantification of the integrals of regional longitudinal strain signals and evaluate changes in LV strain distribution after CRT. This was a retrospective observational study of 130 patients with heart failure before CRT device implantation and after 3 to 6 months of follow-up. Integrals of regional longitudinal strain signals (from the beginning of the cardiac cycle to strain peak [IL,peak] and to the instant of aortic valve closure [IL,avc]) were analyzed retrospectively with custom-made algorithms. Response to CRT was defined as a decrease in LV end-systolic volume of ≥15%. Responders (61%) and nonresponders (39%) showed similar baseline values of regional IL,peak and IL,avc. At follow-up, significant improvements of midlateral IL,peak and of midlateral IL,avc were noted only in responders. Midlateral IL,avc showed a relative increase of 151 ± 276% in responders, whereas a decrease of 33 ± 69% was observed in nonresponders. The difference between IL,avc and IL,peak (representing wasted energy of the LV myocardium) of the lateral wall showed a relative change of -59 ± 103% in responders between baseline and CRT, whereas in nonresponders, the relative change was 21 ± 113% (P = .009). Strain integrals revealed changes between baseline and CRT in the lateral wall, demonstrating the beneficial effects of CRT on LV mechanics with favorable myocardial reverse remodeling. Copyright © 2015 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

  2. Benefits of a Classroom Based Instrumental Music Program on Verbal Memory of Primary School Children: A Longitudinal Study

    Science.gov (United States)

    Rickard, Nikki S.; Vasquez, Jorge T.; Murphy, Fintan; Gill, Anneliese; Toukhsati, Samia R.

    2010-01-01

    Previous research has demonstrated a benefit of music training on a number of cognitive functions including verbal memory performance. The impact of school-based music programs on memory processes is however relatively unknown. The current study explored the effect of increasing frequency and intensity of classroom-based instrumental training…

  3. Is the naturalistic course of depression in older people related to received support over time? Results from a longitudinal population-based study

    NARCIS (Netherlands)

    Houtjes, W.; Deeg, D.J.H.; van de Ven, P.M.; van Meijel, B.; van Tilburg, T.G.; Beekman, A.T.F.

    Objectives: To test the interrelation of the naturalistic course of depression in older people with long-term support received. Design: Longitudinal cohort study. Methods: A sample of 277 adults age 55-85years participating in the Longitudinal Aging Study Amsterdam, with clinically relevant

  4. Longitudinal evaluation of a World Wide Web-based antimicrobial stewardship program: assessing factors associated with approval patterns and trends over time.

    Science.gov (United States)

    Venugopal, Vidya; Lehmann, Christoph U; Diener-West, Marie; Agwu, Allison L

    2014-02-01

    The Johns Hopkins Children's Medical and Surgery Center developed a Web-based Antimicrobial Stewardship Program (ASP) in 2005. The present study aimed to assess longitudinal antimicrobial request and approval patterns for this ASP. We analyzed a total of 16,229 antimicrobial requests for 3,542 patients between June 1, 2005, and June 30, 2009. Antimicrobial approval was the outcome of interest. We assessed gaming by studying trends in automatically approved requests. Nonparametric tests for trend were performed to detect changes in approval patterns. Multiple logistic regression was used to identify factors associated with approval. The vast majority (91.3%) of antimicrobial requests were approved, with an increase of 6.1% over time (P Web-based ASP allows management of a large number of antimicrobial requests, without apparent gaming. Observed differences in approval patterns based on patient, requestor, and antimicrobial factors may inform the development of ASPs and evaluation of provider education and training. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  5. Changes in Brain Activation Associated with Spontaneous Improvization and Figural Creativity After Design-Thinking-Based Training: A Longitudinal fMRI Study.

    Science.gov (United States)

    Saggar, Manish; Quintin, Eve-Marie; Bott, Nicholas T; Kienitz, Eliza; Chien, Yin-Hsuan; Hong, Daniel W-C; Liu, Ning; Royalty, Adam; Hawthorne, Grace; Reiss, Allan L

    2017-07-01

    Creativity is widely recognized as an essential skill for entrepreneurial success and adaptation to daily-life demands. However, we know little about the neural changes associated with creative capacity enhancement. For the first time, using a prospective, randomized control design, we examined longitudinal changes in brain activity associated with participating in a five-week design-thinking-based Creative Capacity Building Program (CCBP), when compared with Language Capacity Building Program (LCBP). Creativity, an elusive and multifaceted construct, is loosely defined as an ability to produce useful/appropriate and novel outcomes. Here, we focus on one of the facets of creative thinking-spontaneous improvization. Participants were assessed pre- and post-intervention for spontaneous improvization skills using a game-like figural Pictionary-based fMRI task. Whole-brain group-by-time interaction revealed reduced task-related activity in CCBP participants (compared with LCBP participants) after training in the right dorsolateral prefrontal cortex, anterior/paracingulate gyrus, supplementary motor area, and parietal regions. Further, greater cerebellar-cerebral connectivity was observed in CCBP participants at post-intervention when compared with LCBP participants. In sum, our results suggest that improvization-based creative capacity enhancement is associated with reduced engagement of executive functioning regions and increased involvement of spontaneous implicit processing. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  6. Measuring depths of sub-micron tracks in a CR-39 detector from replicas using Atomic Force Microscopy

    International Nuclear Information System (INIS)

    Yu, K.N.; Ng, F.M.F.; Nikezic, D.

    2005-01-01

    One of the challenging tasks in the application of solid-state nuclear track detectors (SSNTDs) is the measurement of the depth of the tracks, in particular, the shallow ones resulting from short etching periods. In the present work, a method is proposed to prepare replicas of tracks from α particles in the CR-39 SSNTDs and to measure their heights using atomic force microscopy (AFM). After irradiation, the detectors were etched in a 6.25N aqueous solution of NaOH maintained at 70 deg. C. The etched detectors were immersed into a beaker of the replicating fluid, which was placed in a water bath under ultrasonic vibration and maintained at room temperature to facilitate the filling of the etched tracks with the replicating fluid. As an example of application, these results have been used to derive a V function for the CR-39 detectors used in the present study (for the specified etching conditions)

  7. A replica exchange transition interface sampling method with multiple interface sets for investigating networks of rare events

    Science.gov (United States)

    Swenson, David W. H.; Bolhuis, Peter G.

    2014-07-01

    The multiple state transition interface sampling (TIS) framework in principle allows the simulation of a large network of complex rare event transitions, but in practice suffers from convergence problems. To improve convergence, we combine multiple state TIS [J. Rogal and P. G. Bolhuis, J. Chem. Phys. 129, 224107 (2008)] with replica exchange TIS [T. S. van Erp, Phys. Rev. Lett. 98, 268301 (2007)]. In addition, we introduce multiple interface sets, which allow more than one order parameter to be defined for each state. We illustrate the methodology on a model system of multiple independent dimers, each with two states. For reaction networks with up to 64 microstates, we determine the kinetics in the microcanonical ensemble, and discuss the convergence properties of the sampling scheme. For this model, we find that the kinetics depend on the instantaneous composition of the system. We explain this dependence in terms of the system's potential and kinetic energy.

  8. An application of computer image-processing and filmy replica technique to the copper electroplating method of stress analysis

    Science.gov (United States)

    Sugiura, M.; Seika, M.

    1994-02-01

    In this study, a new technique to measure the density of slip-bands automatically is developed, namely, a TV image of the slip-bands observed through a microscope is directly processed by an image-processing system using a personal computer and an accurate value of the density of slip-bands is measured quickly. In the case of measuring the local stresses in machine parts of large size with the copper plating foil, the direct observation of slip-bands through an optical microscope is difficult. In this study, to facilitate a technique close to the direct microscopic observation of slip-bands in the foil attached to a large-sized specimen, the replica method using a platic film of acetyl cellulose is applied to replicate the slip-bands in the attached foil.

  9. The Membranes of the Basal Labyrinth in Kidney Cells of the Stickleback, Gasterosteus aculeatus, Studied in Ultrathin Sections and Freeze-Etch Replicas

    NARCIS (Netherlands)

    Wendelaar Bonga, S.E.; Veenhuis, M.

    1974-01-01

    The structure of the basal labyrinth in kidney cells of freshwater sticklebacks was studied in ultrathin sections (after fixation with permanganate, osmium tetroxide, and combinations of glutaraldehyde with osmium tetroxide) and in freeze-etch replicas (after pretreatment with glutaraldehyde and/or

  10. Autotransplantation of premolars with a 3-dimensional printed titanium replica of the donor tooth functioning as a surgical guide: proof of concept

    NARCIS (Netherlands)

    Verweij, J.P.; Moin, D.A.; Mensink, G.; Nijkamp, P.; Wismeijer, D.; van Merkesteyn, J.P.R.

    2016-01-01

    Purpose: Autotransplantation of premolars is a good treatment option for young patients who have missing teeth. This study evaluated the use of a preoperatively 3-dimensional (3D)-printed replica of the donor tooth that functions as a surgical guide during autotransplantation. Materials and Methods:

  11. Non-invasive Florentine Renaissance Panel Painting Replica Structures Investigation by Using Terahertz Time-Domain Imaging (THz-TDI) Technique

    DEFF Research Database (Denmark)

    Dandolo, Corinna Ludovica Koch; Picollo, Marcello; Cucci, Costanza

    2016-01-01

    The potentials of the Terahertz Time-Domain Imaging (THz-TDI) technique for a non-invasive inspection of panel paintings have been considered in detail. The THz-TD data acquired on a replica of a panel painting made in imitation of Italian Renaissance panel paintings were processed in order to pr...

  12. Computational and Genomic Analysis of Mycobacteriophage: A Longitudinal Study of Technology Engineered Biology Courses That Implemented an Inquiry Based Laboratory Practice Designed to Enhance, Encourage, and Empower Student Learning

    Science.gov (United States)

    Hollowell, Gail P.; Osler, James E.; Hester, April L.

    2015-01-01

    This paper provides an applied research rational for a longitudinal investigation that involved teaching a "Technology Engineered Science Education Course" via an Interactive Laboratory Based Genomics Curriculum. The Technology st Engineering [TE] methodology was first introduced at the SAPES: South Atlantic Philosophy of Education…

  13. Longitudinal evaluation of physician payment reform and team-based care for chronic disease management and prevention.

    Science.gov (United States)

    Kiran, Tara; Kopp, Alexander; Moineddin, Rahim; Glazier, Richard H

    2015-11-17

    We evaluated a large-scale transition of primary care physicians to blended capitation models and team-based care in Ontario, Canada, to understand the effect of each type of reform on the management and prevention of chronic disease. We used population-based administrative data to assess monitoring of diabetes mellitus and screening for cervical, breast and colorectal cancer among patients belonging to team-based capitation, non-team-based capitation or enhanced fee-for-service medical homes as of Mar. 31, 2011 (n = 10 675 480). We used Poisson regression models to examine these associations for 2011. We then used a fitted nonlinear model to compare changes in outcomes between 2001 and 2011 by type of medical home. In 2011, patients in a team-based capitation setting were more likely than those in an enhanced fee-for-service setting to receive diabetes monitoring (39.7% v. 31.6%, adjusted relative risk [RR] 1.22, 95% confidence interval [CI] 1.18 to 1.25), mammography (76.6% v. 71.5%, adjusted RR 1.06, 95% CI 1.06 to 1.07) and colorectal cancer screening (63.0% v. 60.9%, adjusted RR 1.03, 95% CI 1.02 to 1.04). Over time, patients in medical homes with team-based capitation experienced the greatest improvement in diabetes monitoring (absolute difference in improvement 10.6% [95% CI 7.9% to 13.2%] compared with enhanced fee for service; 6.4% [95% CI 3.8% to 9.1%] compared with non-team-based capitation) and cervical cancer screening (absolute difference in improvement 7.0% [95% CI 5.5% to 8.5%] compared with enhanced fee for service; 5.3% [95% CI 3.8% to 6.8%] compared with non-team-based capitation). For breast and colorectal cancer screening, there were no significant differences in change over time between different types of medical homes. The shift to capitation payment and the addition of team-based care in Ontario were associated with moderate improvements in processes related to diabetes care, but the effects on cancer screening were less clear. © 2015

  14. Role of a Semiotics-Based Curriculum in Empathy Enhancement: A Longitudinal Study in Three Dominican Medical Schools.

    Science.gov (United States)

    San-Martín, Montserrat; Delgado-Bolton, Roberto; Vivanco, Luis

    2017-01-01

    Background: Empathy in the context of patient care is defined as a predominantly cognitive attribute that involves an understanding of the patient's experiences, concerns, and perspectives, combined with a capacity to communicate this understanding and an intention to help. In medical education, it is recognized that empathy can be improved by interventional approaches. In this sense, a semiotic-based curriculum could be an important didactic tool for improving medical empathy. The main purpose of this study was to determine if in medical schools where a semiotic-based curriculum is offered, the empathetic orientation of medical students improves as a consequence of the acquisition and development of students' communication skills that are required in clinician-patient encounters. Design: This quasi-experimental study was conducted in three medical schools of the Dominican Republic that offer three different medical curricula: (i) a theoretical and practical semiotic-based curriculum; (ii) a theoretical semiotic-based curriculum; and (iii) a curriculum without semiotic courses. The Jefferson scale of empathy was administered in two different moments to students enrolled in pre-clinical cycles of those institutions. Data was subjected to comparative statistical analysis and logistic regression analysis. Results: The study included 165 students (55 male and 110 female). Comparison analysis showed statistically significant differences in the development of empathy among groups ( p semiotic-based curriculum contributed toward the enhancement of empathy. Conclusion: These findings demonstrate the importance of medical semiotics as a didactic teaching method for improving beginners' empathetic orientation in patients' care.

  15. Novel approach to the fabrication of an artificial small bone using a combination of sponge replica and electrospinning methods

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yang-Hee; Lee, Byong-Taek, E-mail: lbt@sch.ac.kr [Department of Biomedical Engineering and Materials, School of Medicine, Soonchunhyang University 366-1, Ssangyong-dong, Cheonan, Chungnam 330-090 (Korea, Republic of)

    2011-06-15

    In this study, a novel artificial small bone consisting of ZrO{sub 2}-biphasic calcium phosphate/polymethylmethacrylate-polycaprolactone-hydroxyapatite (ZrO{sub 2}-BCP/PMMA-PCL-HAp) was fabricated using a combination of sponge replica and electrospinning methods. To mimic the cancellous bone, the ZrO{sub 2}/BCP scaffold was composed of three layers, ZrO{sub 2}, ZrO{sub 2}/BCP and BCP, fabricated by the sponge replica method. The PMMA-PCL fibers loaded with HAp powder were wrapped around the ZrO{sub 2}/BCP scaffold using the electrospinning process. To imitate the Haversian canal region of the bone, HAp-loaded PMMA-PCL fibers were wrapped around a steel wire of 0.3 mm diameter. As a result, the bundles of fiber wrapped around the wires imitated the osteon structure of the cortical bone. Finally, the ZrO{sub 2}/BCP scaffold was surrounded by HAp-loaded PMMA-PCL composite bundles. After removal of the steel wires, the ZrO{sub 2}/BCP scaffold and bundles of HAp-loaded PMMA-PCL formed an interconnected structure resembling the human bone. Its diameter, compressive strength and porosity were approximately 12 mm, 5 MPa and 70%, respectively, and the viability of MG-63 osteoblast-like cells was determined to be over 90% by the MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay. This artificial bone shows excellent cytocompatibility and is a promising bone regeneration material.

  16. Restoration of longitudinal images.

    Science.gov (United States)

    Hu, Y; Frieden, B R

    1988-01-15

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

  17. Prevalence of Tourette Syndrome and Chronic Tics in the Population-Based Avon Longitudinal Study of Parents and Children Cohort

    Science.gov (United States)

    Scharf, Jeremiah M.; Miller, Laura L.; Mathews, Carol A.; Ben-Shlomo, Yoav

    2012-01-01

    Objective: Recent epidemiologic studies have demonstrated that Tourette syndrome (TS) and chronic tic disorder (CT) are more common than previously recognized. However, few population-based studies have examined the prevalence of co-occurring neuropsychiatric conditions such as obsessive-compulsive disorder (OCD) and…

  18. Validation and modification of dried blood spot-based glycosylated hemoglobin assay for the longitudinal aging study in India.

    Science.gov (United States)

    Hu, Peifeng; Edenfield, Michael; Potter, Alan; Kale, Varsha; Risbud, Arun; Williams, Sharon; Lee, Jinkook; Bloom, David E; Crimmins, Eileen; Seeman, Teresa

    2015-01-01

    This study aims to validate a modified dried blood spot (DBS)-based glycosylated hemoglobin (HbA1c) assay protocol, after a pretest in India showed poor correlation between the original DBS-based protocol and venous results. The original protocol was tested on different chemistry analyzers and then simplified at the University of Washington (UW). A second pretest was conducted in India to validate the modified assay protocol, using 44 quality control specimens. Data from UW indicated that, using the original protocol, the correlation coefficients between DBS and venous results were above 0.98 on both Bio-Rad and Olympus chemistry analyzers. The protocol worked equally well on filter paper, with or without pre-treatment, and when the recommended amount of blood spot material, or less, was used. A second pretest of the modified protocol confirmed that DBS-based levels from both Olympus and Roche chemistry analyzers were well correlated with DBS results from UW (correlation coefficients were above 0.96), as well as with venous values (correlation coefficients were above 0.94). The DBS-based HbA1c values are highly correlated with venous results. The pre-treatment of filter paper does not appear to be necessary. The poor results from the first pretest are probably due to factors unrelated to the protocol, such as problems with the chemistry analyzer or assay reagents. © 2015 Wiley Periodicals, Inc.

  19. Longitudinal monitoring of the safety of drugs by using a web-based system : the case of pregabalin

    NARCIS (Netherlands)

    Harmark, Linda; van Puijenbroek, Eugene; van Grootheest, Kees

    Purpose Information about the time course of adverse drug reactions (ADRs) is often lacking. If this information would be available, it could help increase patient's adherence to drugs when experiencing an ADR. The aim of this study was to demonstrate how a web-based intensive monitoring system

  20. Perceptions of community-based field workers on the effect of a longitudinal biomedical research project on their sustainable livelihoods

    Directory of Open Access Journals (Sweden)

    Christabelle S. Moyo

    2017-03-01

    Full Text Available Abstract Background Researchers involved in biomedical community-based projects rarely seek the perspectives of community fieldworkers, who are the ‘foot soldiers’ in such projects. Understanding the effect of biomedical research on community-based field workers could identify benefits and shortfalls that may be crucial to the success of community-based studies. The present study explored the perceptions of community-based field workers on the effect of the Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development Project" (MAL-ED South Africa on their tangible and intangible capital which together comprise sustainable livelihoods. Methods The study was conducted in Dzimauli community in Limpopo Province of South Africa between January-February 2016. The sustainable livelihoods framework was used to query community-based field workers’ perspectives of both tangible assets such as income and physical assets and intangible assets such as social capital, confidence, and skills. Data were collected through twenty one individual in-depth interviews and one focus group discussion. Data were analysed using the Thematic Content Analysis approach supported by ATLAS.ti, version 7.5.10 software. Results All the field workers indicated that they benefitted from the MAL-ED South Africa project. The benefits included intangible assets such as acquisition of knowledge and skills, stronger social capital and personal development. Additionally, all indicated that MAL-ED South Africa provided them with the tangible assets of increased income and physical assets. Observations obtained from the focus group discussion and the community-based leaders concurred with the findings from the in-depth interviews. Additionally, some field workers expressed the desire for training in public relations, communication, problem solving and confidence building. Conclusions The MAL-ED South Africa

  1. Constancy and Change in the Prevalence and Frequency of Offending When Based on Longitudinal Self-reports or Official Records: Comparisons by Gender, Race, and Crime Type

    Science.gov (United States)

    Farrington, David P.; Hipwell, Alison E.; Stepp, Stephanie D.; Pardini, Dustin; Ahonen, Lia

    2015-01-01

    Introduction The study examines age-crime prevalence and age-crime frequency curves based on longitudinal data from boys in the Pittsburgh Youth Study and girls in the Pittsburgh Girls Study. Results Results show that the prevalence of the age-crime curve for theft and violence (based on self-reports or police charges) followed the typical age-crime curve for males and slightly less distinctly for females, with the peak of offending occurring earlier for self-reports than for police charges. The decrease in police charges for violence and theft took place at an earlier age for females than males, but this was not distinct when self-reported delinquency was the criterion. The mean frequency of self-reported theft and violence followed the age-crime curve for males but not for females, who showed a mean frequency of offending which was more constant. In contrast, the mean frequency of police charges increased with age for males and females. Comparing African-American and Caucasian males and females shows a higher prevalence but not a higher mean frequency of self-reported offending. Conclusions The results are reviewed in the light of other studies, and the policy implications of the findings are discussed. PMID:27610337

  2. Stress and premenstrual symptoms among Korean women studying in the U.S. and South Korea: A longitudinal web-based study.

    Science.gov (United States)

    Lee, Yaelim; Im, Eun-Ok

    2017-07-01

    Premenstrual symptoms have been reported to be highly correlated with levels of perceived stress; however, the magnitude of the relationship remains unclear. The purpose of the study was to identify the relationships among perceived stress, acculturative stress, and premenstrual symptoms. The study used a 10-week longitudinal web-based design. A total of 98 female Korean international students studying in the U.S. and 89 Korean domestic students studying in South Korea were recruited using convenience sampling. Data collection was conducted between November 2014 and February 2015. The participants completed 10 weekly web-based surveys. Data were analyzed through descriptive analyses, linear multivariable mixed model regressions, t-tests, and hierarchical multiple regressions. The levels of both perceived stress and menstrual-related symptoms were higher during the premenstrual phase in Korean international students than in domestic students (p Korean international students, perceived stress (β = 0.30; p Korean domestic students, a history of sexual abuse was the strongest related factor (β = -0.28; p < .001). Because stress is a potentially modifiable factor, understanding its relationship to premenstrual symptoms can contribute to relieving these symptoms.

  3. Role of a Semiotics-Based Curriculum in Empathy Enhancement: A Longitudinal Study in Three Dominican Medical Schools

    Directory of Open Access Journals (Sweden)

    Montserrat San-Martín

    2017-11-01

    Full Text Available Background: Empathy in the context of patient care is defined as a predominantly cognitive attribute that involves an understanding of the patient’s experiences, concerns, and perspectives, combined with a capacity to communicate this understanding and an intention to help. In medical education, it is recognized that empathy can be improved by interventional approaches. In this sense, a semiotic-based curriculum could be an important didactic tool for improving medical empathy. The main purpose of this study was to determine if in medical schools where a semiotic-based curriculum is offered, the empathetic orientation of medical students improves as a consequence of the acquisition and development of students’ communication skills that are required in clinician–patient encounters.Design: This quasi-experimental study was conducted in three medical schools of the Dominican Republic that offer three different medical curricula: (i a theoretical and practical semiotic-based curriculum; (ii a theoretical semiotic-based curriculum; and (iii a curriculum without semiotic courses. The Jefferson scale of empathy was administered in two different moments to students enrolled in pre-clinical cycles of those institutions. Data was subjected to comparative statistical analysis and logistic regression analysis.Results: The study included 165 students (55 male and 110 female. Comparison analysis showed statistically significant differences in the development of empathy among groups (p < 0.001. Logistic regression confirmed that gender, age, and a semiotic-based curriculum contributed toward the enhancement of empathy.Conclusion: These findings demonstrate the importance of medical semiotics as a didactic teaching method for improving beginners’ empathetic orientation in patients’ care.

  4. A web-based simulation of a longitudinal clinic used in a 4-week ambulatory rotation: a cohort study

    Directory of Open Access Journals (Sweden)

    Lochnan Heather A

    2009-02-01

    Full Text Available Abstract Background Residency training takes place primarily on inpatient wards. In the absence of a resident continuity clinic, internal medicine residents rely on block rotations to learn about continuity of care. Alternate methods to introduce continuity of care are needed. Methods A web-based tool, Continuity of Care Online Simulations (COCOS, was designed for use in a one-month, postgraduate clinical rotation in endocrinology. It is an interactive tool that simulates the continuing care of any patient with a chronic endocrine disease. Twenty-three residents in internal medicine participated in a study to investigate the effects of using COCOS during a clinical rotation in endocrinology on pre-post knowledge test scores and self-assessment of confidence. Results Compared to residents who did the rotation alone, residents who used COCOS during the rotation had significantly higher improvements in test scores (% increase in pre-post test scores +21.6 [standard deviation, SD, 8.0] vs. +5.9 [SD 6.8]; p Conclusion A stand-alone web-based tool can be incorporated into an existing clinical rotation to help residents learn about continuity of care. It has the most potential to teach residents about topics that are less commonly seen during a clinical rotation. The adaptable, web-based format allows the creation of cases for most chronic medical conditions.

  5. Integrating an ecological approach into an Aboriginal community-based chronic disease prevention program: a longitudinal process evaluation

    Directory of Open Access Journals (Sweden)

    Maypilama Elaine

    2011-05-01

    Full Text Available Abstract Background Public health promotes an ecological approach to chronic disease prevention, however, little research has been conducted to assess the integration of an ecological approach in community-based prevention programs. This study sought to contribute to the evidence base by assessing the extent to which an ecological approach was integrated into an Aboriginal community-based cardiovascular disease (CVD and type 2 diabetes prevention program, across three-intervention years. Methods Activity implementation forms were completed by interview with implementers and participant observation across three intervention years. A standardised ecological coding procedure was applied to assess participant recruitment settings, intervention targets, intervention strategy types, extent of ecologicalness and organisational partnering. Inter-rater reliability for two coders was assessed at Kappa = 0.76 (p Results 215 activities were implemented across three intervention years by the health program (HP with some activities implemented in multiple years. Participants were recruited most frequently through organisational settings in years 1 and 2, and organisational and community settings in year 3. The most commonly utilised intervention targets were the individual (IND as a direct target, and interpersonal (INT and organisational (ORG environments as indirect targets; policy (POL, and community (COM were targeted least. Direct (HP→ IND and indirect intervention strategies (i.e., HP→ INT→ IND, HP→ POL → IND were used most often; networking strategies, which link at least two targets (i.e., HP→[ORG-ORG]→IND, were used the least. The program did not become more ecological over time. Conclusions The quantity of activities with IND, INT and ORG targets and the proportion of participants recruited through informal cultural networking demonstrate community commitment to prevention. Integration of an ecological approach would have been

  6. Big data in multiple sclerosis: development of a web-based longitudinal study viewer in an imaging informatics-based eFolder system for complex data analysis and management

    Science.gov (United States)

    Ma, Kevin; Wang, Ximing; Lerner, Alex; Shiroishi, Mark; Amezcua, Lilyana; Liu, Brent

    2015-03-01

    In the past, we have developed and displayed a multiple sclerosis eFolder system for patient data storage, image viewing, and automatic lesion quantification results stored in DICOM-SR format. The web-based system aims to be integrated in DICOM-compliant clinical and research environments to aid clinicians in patient treatments and disease tracking. This year, we have further developed the eFolder system to handle big data analysis and data mining in today's medical imaging field. The database has been updated to allow data mining and data look-up from DICOM-SR lesion analysis contents. Longitudinal studies are tracked, and any changes in lesion volumes and brain parenchyma volumes are calculated and shown on the webbased user interface as graphical representations. Longitudinal lesion characteristic changes are compared with patients' disease history, including treatments, symptom progressions, and any other changes in the disease profile. The image viewer is updated such that imaging studies can be viewed side-by-side to allow visual comparisons. We aim to use the web-based medical imaging informatics eFolder system to demonstrate big data analysis in medical imaging, and use the analysis results to predict MS disease trends and patterns in Hispanic and Caucasian populations in our pilot study. The discovery of disease patterns among the two ethnicities is a big data analysis result that will help lead to personalized patient care and treatment planning.

  7. A Longitudinal Study of State Strategies and Policies to Accelerate Evidence-Based Practices in the Context of Systems Transformation

    Science.gov (United States)

    Rieckmann, Traci; Abraham, Amanda; Zwick, Janet; Rasplica, Caitlin; McCarty, Dennis

    2015-01-01

    Objective To profile state agency efforts to promote implementation of three evidence-based practices (EBPs): screening and brief intervention (SBIRT), psychosocial interventions, and medication-assisted treatment (MAT). Data Sources/Study Setting Primary data collected from representatives of 50 states and the District of Columbia’s Single State Authorities from 2007 to 2009. Study Design/Data Collection The study used mixed methods, in-depth, semistructured interviews and quantitative surveys. Interviews assessed state and provider strategies to accelerate implementation of EBPs. Principal Findings Statewide implementation of psychosocial interventions and MAT increased significantly over 3 years. In the first two assessments, states that contracted directly with providers were more likely to link use of EBPs to reimbursement, and states with indirect contract, through counties and other entities, increased recommendations, and some requirements for provision of specific EBPs. The number of states using legislation as a policy lever to promote EBPs was unchanged. Conclusions Health care reform and implementation of parity in coverage increases access to treatment for alcohol and drug use. Science-based substance abuse treatment will become even more crucial as payers seek consistent quality of care. This study provides baseline data on service delivery, contracting, and financing as state agencies and treatment providers prepare for implementation of the Affordable Care Act. PMID:25532616

  8. Assemblies of amyloid-β30-36 hexamer and its G33V/L34T mutants by replica-exchange molecular dynamics simulation.

    Directory of Open Access Journals (Sweden)

    Zhenyu Qian

    Full Text Available The aggregation of amyloid-β peptides is associated with the pathogenesis of Alzheimer's disease, in which the 30-36 fragments play an important part as a fiber-forming hydrophobic region. The fibrillar structure of Aβ30-36 has been detected by means of X-ray diffraction, but its oligomeric structural determination, biophysical characterization, and pathological mechanism remain elusive. In this study, we have investigated the structures of Aβ30-36 hexamer as well as its G33V and L34T mutants in explicit water environment using replica-exchange molecular dynamics (REMD simulations. Our results show that the wild-type (WT Aβ30-36 hexamer has a preference to form β-barrel and bilayer β-sheet conformations, while the G33V or L34T mutation disrupts the β-barrel structures: the G33V mutant is homogenized to adopt β-sheet-rich bilayers, and the structures of L34T mutant on the contrary get more diverse. The hydrophobic interaction plays a critical role in the formation and stability of oligomeric assemblies among all the three systems. In addition, the substitution of G33 by V reduces the β-sheet content in the most populated conformations of Aβ30-36 oligomers through a steric effect. The L34T mutation disturbs the interpeptide hydrogen bonding network, and results in the increased coil content and morphological diversity. Our REMD runs provide structural details of WT and G33V/L34T mutant Aβ30-36 oligomers, and molecular insight into the aggregation mechanism, which will be helpful for designing novel inhibitors or amyloid-based materials.

  9. Jendl-3.1 iron validation on the PCA-REPLICA (H{sub 2}O/Fe) shielding benchmark experiment

    Energy Technology Data Exchange (ETDEWEB)

    Pescarini, M.; Borgia, M. G. [ENEA, Centro Ricerche ``Ezio Clementel``, Bologna (Italy). Dipt. Energia

    1997-03-01

    The PCA-REPLICA (H{sub 2}O/Fe) neutron shielding benchmarks experiment is analysed using the SN 2-D DOT 3.5-E code and the 3-D-equivalent flux synthesis method. This engineering benchmark reproduces the ex-core radial geometry of a PWR, including a mild steel reactor pressure vessel (RPV) simulator, and is designed to test the accuracy of the calculation of the in-vessel neutron exposure parameters. This accuracy is strongly dependent on the quality of the iron neutron cross sections used to describe the nuclear reactions within the RPV simulator. In particular, in this report, the cross sections based on the JENDL-3.1 iron data files are tested, through a comparison of the calculated integral and spectral results with the corresponding experimental data. In addition, the present results are compared, on the same benchmark experiment, with those of a preceding ENEA-Bologna validation of the ENDF/B VI iron cross sections. The integral result comparison indicates that, for all the threshold detectors considered (Rh-103 (n, n`) Rh-103m, In-115 (n, n`) In-115m and S-32 (n, p) P-32), the JENDL-3.1 natural iron data produce satisfactory results similar to those obtained with the ENDF/B VI iron data. On the contrary, when the JENDL/3.1 Fe-56 data file is used, strongly underestimated results are obtained for the lower energy threshold detectors, Rh-103 and In-115. This fact, in particular, becomes more evident with increasing the neutron penetration depth in the RPV simulator.

  10. Longitudinal Control for Mengshi Autonomous Vehicle via Cloud Model

    Science.gov (United States)

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

    2018-03-01

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

  11. In vivo x-ray phase contrast analyzer-based imaging for longitudinal osteoarthritis studies in guinea pigs

    Energy Technology Data Exchange (ETDEWEB)

    Coan, Paola [Faculty of Medicine and Institute of Clinical Radiology, Ludwig-Maximilians University, Munich (Germany); Wagner, Andreas; Mollenhauer, Juergen [Department of Orthopaedics of the University of Jena, Rudolf-Elle-Hospital Eisenberg (Germany); Bravin, Alberto; Diemoz, Paul C; Keyrilaeinen, Jani, E-mail: Paola.Coan@physik.uni-muenchen.d [European Synchrotron Radiation Facility (ESRF), Grenoble (France)

    2010-12-21

    Over the last two decades phase contrast x-ray imaging techniques have been extensively studied for applications in the biomedical field. Published results demonstrate the high capability of these imaging modalities of improving the image contrast of biological samples with respect to standard absorption-based radiography and routinely used clinical imaging techniques. A clear depiction of the anatomic structures and a more accurate disease diagnosis may be provided by using radiation doses comparable to or lower than those used in current clinical methods. In the literature many works show images of phantoms and excised biological samples proving the high sensitivity of the phase contrast imaging methods for in vitro investigations. In this scenario, the applications of the so-called analyzer-based x-ray imaging (ABI) phase contrast technique are particularly noteworthy. The objective of this work is to demonstrate the feasibility of in vivo x-ray ABI phase contrast imaging for biomedical applications and in particular with respect to joint anatomic depiction and osteoarthritis detection. ABI in planar and tomographic modes was performed in vivo on articular joints of guinea pigs in order to investigate the animals with respect to osteoarthritis by using highly monochromatic x-rays of 52 keV and a low noise detector with a pixel size of 47 x 47 {mu}m{sup 2}. Images give strong evidence of the ability of ABI in depicting both anatomic structures in complex systems as living organisms and all known signs of osteoarthritis with high contrast, high spatial resolution and with an acceptable radiation dose. This paper presents the first proof of principle study of in vivo application of ABI. The technical challenges encountered when imaging an animal in vivo are discussed. This experimental study is an important step toward the study of clinical applications of phase contrast x-ray imaging techniques.

  12. Geographic Distribution of Radiologists and Utilization of Teleradiology in Japan: A Longitudinal Analysis Based on National Census Data.

    Science.gov (United States)

    Matsumoto, Masatoshi; Koike, Soichi; Kashima, Saori; Awai, Kazuo

    2015-01-01

    Japan has the most CT and MRI scanners per unit population in the world, and as these technologies spread, their geographic distribution is becoming equalized. In contrast, the number of radiologists per unit population in Japan is the lowest among OECD countries and their geographic distribution is unknown. Likewise, little is known about the use of teleradiology, which can compensate for the uneven distribution of radiologists. Based on the Survey of Physicians, Dentists and Pharmacists and the Static Survey of Medical Institutions by the Ministry of Health, Labour and Welfare, a dataset of radiologists and CT and MRI utilizations in each of Japan's 1811 municipalities was created. The inter-municipality equity of the number of radiologists was evaluated using Gini coefficient. Logistic regression analysis, based on Static Survey data, was performed to evaluate the association between hospital location and teleradiology use. Between 2006 and 2012 the number of radiologists increased by 21.7%, but the Gini coefficient remained unchanged. The number of radiologists per 1,000 CT (MRI) utilizations decreased by 17.9% (1.0%); the number was highest in metropolis and lowest in town/village and the disparity has widened from 1.9 to 2.2 (1.6 to 2.0) times. The number of hospitals and clinics using teleradiology has increased (by 69.6% and 18.1%, respectively). Hospitals located in towns/villages (odds ratio 1.61; 95% confidence interval 1.26-2.07) were more likely to use teleradiology than those in metropolises. Contrary to the CT and MRI distributions, radiologist distribution has not been evened out by the increase in their number; in other words, the distribution of radiologists was not affected by market-derived spatial competition force. As a consequence, the gap of the radiologist shortage between urban and rural areas is increasing. Teleradiology, which is one way to ameliorate this gap, should be encouraged.

  13. Health-related quality of life and chronic obstructive pulmonary disease in early stages - longitudinal results from the population-based KORA cohort in a working age population.

    Science.gov (United States)

    Wacker, Margarethe E; Hunger, Matthias; Karrasch, Stefan; Heinrich, Joachim; Peters, Annette; Schulz, Holger; Holle, Rolf

    2014-08-09

    It is widely recognized that health-related quality of life (HRQL) is impaired in patients with Chronic Obstructive Pulmonary Disease (COPD), but there is a lack of research on longitudinal associations of COPD and HRQL. This study examined the effects of COPD in early stages of disease on HRQL over ten years in a working-age general population setting in Southern Germany while considering the influence of common comorbidities. In the population-based KORA F4 study (2006-08) 1,321 participants aged 41-61 years performed spirometry and reported information on HRQL (measured by the generic SF-12) and comorbidities. For the same participants, HRQL information was available seven years before and three years after the lung function test from the previous S4 (1999-2001) and the F4L follow-up study (2010). Using linear mixed models, the physical and mental component summary scores (PCS-12 / MCS-12) of the SF-12 were compared over time between COPD groups. 7.8% of participants were classified as having COPD (according to the LLN definition and the Global Lungs Initiative), 59.4% of them in grade 1. Regression models showed a negative cross-sectional association of COPD grade 2+ with PCS-12 which persisted when comorbidities were considered. Adjusted mean PCS-12 scores for the COPD grade 2+ group were reduced (-3.5 (p=0.008) in F4, -3.3 (p=0.014) in S4 and -4.7 (p=0.003) in F4L) compared to the group without airflow limitation. The size of the COPD effect in grade 2+ was similar to the effect of myocardial infarction and cancer. Over ten years, a small decline in PCS-12 was observed in all groups. This decline was larger in participants with COPD grade 2+, but insignificant. Regarding MCS-12, no significant cross-sectional or longitudinal associations with COPD were found. Despite small HRQL differences between COPD patients in early disease stages and controls and small changes over ten years, our results indicate that it is important to prevent subjects with airflow

  14. Predictors of Cigarette Smoking Progression Among a School-Based Sample of Adolescents in Irbid, Jordan: A Longitudinal Study (2008-2011).

    Science.gov (United States)

    Jaber, Rana; Mzayek, Fawaz; Madhivanan, Purnima; Khader, Yousuf; Maziak, Wasim

    2016-04-01

    Little evidence regarding longitudinal predictors of cigarette smoking progression is available from developing countries. This study aimed to identify gender-specific individual and social predictors of cigarette smoking progression among a school-based sample of adolescents in Irbid, Jordan. A total of 1781 seventh graders (participation rate 95%) were enrolled and completed an annual self-administered questionnaire from 2008 through 2011. Students who reported "ever-smoking a cigarette" at baseline or in the subsequent follow-up but not being "heavy daily smokers" (>10 cigarettes per day) were eligible for this analysis (N = 669). Grouped-time survival analyses were used to identify predictors of cigarette smoking progression in boys and girls. Among the study sample, 38.3% of students increased the frequency and /or amount of cigarette smoking during the 3 years of follow-up. Among individual factors, the urge to smoke in the morning predicted smoking progression for boys and girls. The independent predictors of cigarette smoking progression were friends' smoking and attending public schools in boys, and siblings' smoking in girls. Discussing the dangers of smoking with family members was protective for girls. Boys and girls progressed similarly in cigarette smoking once they initiated the habit. Progression among girls was solely family-related, while it was peer-related for boys. © The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Predictors of Cigarette Smoking Progression Among a School-Based Sample of Adolescents in Irbid, Jordan: A Longitudinal Study (2008–2011)

    Science.gov (United States)

    Mzayek, Fawaz; Madhivanan, Purnima; Khader, Yousuf; Maziak, Wasim

    2016-01-01

    Introduction: Little evidence regarding longitudinal predictors of cigarette smoking progression is available from developing countries. This study aimed to identify gender-specific individual and social predictors of cigarette smoking progression among a school-based sample of adolescents in Irbid, Jordan. Methods: A total of 1781 seventh graders (participation rate 95%) were enrolled and completed an annual self-administered questionnaire from 2008 through 2011. Students who reported “ever-smoking a cigarette” at baseline or in the subsequent follow-up but not being “heavy daily smokers” (>10 cigarettes per day) were eligible for this analysis (N = 669). Grouped-time survival analyses were used to identify predictors of cigarette smoking progression in boys and girls. Results: Among the study sample, 38.3% of students increased the frequency and /or amount of cigarette smoking during the 3 years of follow-up. Among individual factors, the urge to smoke in the morning predicted smoking progression for boys and girls. The independent predictors of cigarette smoking progression were friends’ smoking and attending public schools in boys, and siblings’ smoking in girls. Discussing the dangers of smoking with family members was protective for girls. Conclusion: Boys and girls progressed similarly in cigarette smoking once they initiated the habit. Progression among girls was solely family-related, while it was peer-related for boys. PMID:25957340

  16. Progression of brain atrophy in the early stages of Parkinson's disease: a longitudinal tensor-based morphometry study in de novo patients without cognitive impairment.

    Science.gov (United States)

    Tessa, Carlo; Lucetti, Claudio; Giannelli, Marco; Diciotti, Stefano; Poletti, Michele; Danti, Sabrina; Baldacci, Filippo; Vignali, Claudio; Bonuccelli, Ubaldo; Mascalchi, Mario; Toschi, Nicola

    2014-08-01

    The presence of brain atrophy and its progression in early Parkinson's disease (PD) are still a matter of debate, particularly in patients without cognitive impairment. The aim of this longitudinal study was to assess whether PD patients who remain cognitively intact develop progressive atrophic changes in the early stages of the disease. For this purpose, we employed high-resolution T1-weighted MR imaging to compare 22 drug-naïve de novo PD patients without cognitive impairment to 17 age-matched control subjects, both at baseline and at three-year follow-up. We used tensor-based morphometry to explore the presence of atrophic changes at baseline and to compute yearly atrophy rates, after which we performed voxel-wise group comparisons using threshold-free cluster enhancement. At baseline, we did not observe significant differences in regional atrophy in PD patients with respect to control subjects. In contrast, PD patients showed significantly higher yearly atrophy rates in the prefrontal cortex, anterior cingulum, caudate nucleus, and thalamus when compared to control subjects. Our results indicate that even cognitively preserved PD patients show progressive cortical and subcortical atrophic changes in regions related to cognitive functions and that these changes are already detectable in the early stages of the disease. Copyright © 2014 Wiley Periodicals, Inc.

  17. A population-based longitudinal study of recent stressful life events as risk factors for suicidal behavior in major depressive disorder.

    Science.gov (United States)

    Wang, Yunqiao; Sareen, Jitender; Afifi, Tracie O; Bolton, Shay-Lee; Johnson, Edward A; Bolton, James M

    2015-01-01

    The purpose of this study is to investigate whether the type and number of stressful life events (SLEs) will be associated with suicidal behavior in a 3-year follow-up period in persons with major depressive disorder (MDD). Data came from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a nationally representative longitudinal survey of mental health in non-institutionalized adults in the United States. The survey consisted of two waves: Wave 1 (2001--2002) and Wave 2 (2004-2005), n = 34,653. Twelve past-year SLEs were assessed at baseline. These SLEs were categorized into the following groups based on previous research: Loss or victimization; Relationship, friendship, or interpersonal stress; Financial stress; and Legal problems. Only respondents with MDD at Wave 1 were included (n = 6,004). Several SLEs were strongly associated with suicide attempts, among which, "serious problems with neighbor, friend, or relative" (adjusted odds ratio [AOR] = 2.21; 95% confidence interval [95% CI]: 1.41, 3.45) and "major financial crisis, bankruptcy, or unable to pay bills" (AOR = 2.31; 95% CI: 1.45, 3.66) were the most robust predictors of suicide attempts even after adjusting for sociodemographic variables and any anxiety, substance use, or personality disorder. People with MDD who had been exposed to certain SLEs are at elevated risk for future suicide attempts, even after accounting for the demographic factors and psychiatric comorbidity.

  18. Haplotype-based association analysis of general cognitive ability in Generation Scotland, the English Longitudinal Study of Ageing, and UK Biobank [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    David M. Howard

    2017-08-01

    Full Text Available Background: Cognitive ability is a heritable trait with a polygenic architecture, for which several associated variants have been identified using genotype-based and candidate gene approaches. Haplotype-based analyses are a complementary technique that take phased genotype data into account, and potentially provide greater statistical power to detect lower frequency variants. Methods: In the present analysis, three cohort studies (ntotal = 48,002 were utilised: Generation Scotland: Scottish Family Health Study (GS:SFHS, the English Longitudinal Study of Ageing (ELSA, and the UK Biobank. A genome-wide haplotype-based meta-analysis of cognitive ability was performed, as well as a targeted meta-analysis of several gene coding regions. Results: None of the assessed haplotypes provided evidence of a statistically significant association with cognitive ability in either the individual cohorts or the meta-analysis. Within the meta-analysis, the haplotype with the lowest observed P-value overlapped with the D-amino acid oxidase activator (DAOA gene coding region. This coding region has previously been associated with bipolar disorder, schizophrenia and Alzheimer’s disease, which have all been shown to impact upon cognitive ability. Another potentially interesting region highlighted within the current genome-wide association analysis (GS:SFHS: P = 4.09 x 10-7, was the butyrylcholinesterase (BCHE gene coding region. The protein encoded by BCHE has been shown to influence the progression of Alzheimer’s disease and its role in cognitive ability merits further investigation. Conclusions: Although no evidence was found for any haplotypes with a statistically significant association with cognitive ability, our results did provide further evidence that the genetic variants contributing to the variance of cognitive ability are likely to be of small effect.

  19. Office-Based Screening for Dementia in Parkinson Disease: The Montreal Parkinson Risk of Dementia Scale in 4 Longitudinal Cohorts.

    Science.gov (United States)

    Dawson, Benjamin K; Fereshtehnejad, Seyed-Mohammad; Anang, Julius B M; Nomura, Takashi; Rios-Romenets, Silvia; Nakashima, Kenji; Gagnon, Jean-François; Postuma, Ronald B

    2018-06-01

    Parkinson disease dementia dramatically increases mortality rates, patient expenditures, hospitalization risk, and caregiver burden. Currently, predicting Parkinson disease dementia risk is difficult, particularly in an office-based setting, without extensive biomarker testing. To appraise the predictive validity of the Montreal Parkinson Risk of Dementia Scale, an office-based screening tool consisting of 8 items that are simply assessed. This multicenter study (Montreal, Canada; Tottori, Japan; and Parkinson Progression Markers Initiative sites) used 4 diverse Parkinson disease cohorts with a prospective 4.4-year follow-up. A total of 717 patients with Parkinson disease were recruited between May 2005 and June 2016. Of these, 607 were dementia-free at baseline and followed-up for 1 year or more and so were included. The association of individual baseline scale variables with eventual dementia risk was calculated. Participants were then randomly split into cohorts to investigate weighting and determine the scale's optimal cutoff point. Receiver operating characteristic curves were calculated and correlations with selected biomarkers were investigated. Dementia, as defined by Movement Disorder Society level I criteria. Of the 607 patients (mean [SD] age, 63.4 [10.1]; 376 men [62%]), 70 (11.5%) converted to dementia. All 8 items of the Montreal Parkinson Risk of Dementia Scale independently predicted dementia development at the 5% significance level. The annual conversion rate to dementia in the high-risk group (score, >5) was 14.9% compared with 5.8% in the intermediate group (score, 4-5) and 0.6% in the low-risk group (score, 0-3). The weighting procedure conferred no significant advantage. Overall predictive validity by the area under the receiver operating characteristic curve was 0.877 (95% CI, 0.829-0.924) across all cohorts. A cutoff of 4 or greater yielded a sensitivity of 77.1% (95% CI, 65.6-86.3) and a specificity of 87.2% (95% CI, 84.1-89.9), with a

  20. On Longitudinal Spectral Coherence

    DEFF Research Database (Denmark)

    Kristensen, Leif

    1979-01-01

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

  1. School experiences may be important determinants of mental health problems in middle childhood - a Swedish longitudinal population-based study.

    Science.gov (United States)

    Waenerlund, Anna-Karin; Stenmark, Helena; Bergström, Erik; Hägglöf, Bruno; Öhman, Ann; Petersen, Solveig

    2016-04-01

    Little is known about the association between school experiences and mental health in young schoolchildren. This study explored the cross-sectional and prospective associations between children's school experiences and mental health in middle childhood. We gathered comprehensive population-based data on the school experiences and mental health of 592 schoolchildren attending grades three and six in Sweden (ages approximately nine and 12 years). The KIDSCREEN questionnaire was used to measure school experiences in both age groups while the Child Behavior Checklist and the Strengths and Difficulties Questionnaire measured mental health in grades three and six, respectively. Children with problematic school experiences in grade three had an approximately two times higher odds for concurrent total, internalised, externalised, attention-hyperactivity and social problems. They also had a 1.5-2.5 higher odds for these mental health problems three years later. Likewise, there was an association between problematic school experiences in grade three and lower levels of prosocial behaviour three years later. These associations were shown in both boys and girls, but were particularly pronounced in girls. This study indicated that school experiences in young schoolchildren may be important determinants of concurrent and later mental health problems. ©2016 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  2. Ventral Striatum Functional Connectivity as a Predictor of Adolescent Depressive Disorder in a Longitudinal Community-Based Sample.

    Science.gov (United States)

    Pan, Pedro Mario; Sato, João R; Salum, Giovanni A; Rohde, Luis A; Gadelha, Ary; Zugman, Andre; Mari, Jair; Jackowski, Andrea; Picon, Felipe; Miguel, Eurípedes C; Pine, Daniel S; Leibenluft, Ellen; Bressan, Rodrigo A; Stringaris, Argyris

    2017-11-01

    Previous studies have implicated aberrant reward processing in the pathogenesis of adolescent depression. However, no study has used functional connectivity within a distributed reward network, assessed using resting-state functional MRI (fMRI), to predict the onset of depression in adolescents. This study used reward network-based functional connectivity at baseline to predict depressive disorder at follow-up in a community sample of adolescents. A total of 637 children 6-12 years old underwent resting-state fMRI. Discovery and replication analyses tested intrinsic functional connectivity (iFC) among nodes of a putative reward network. Logistic regression tested whether striatal node strength, a measure of reward-related iFC, predicted onset of a depressive disorder at 3-year follow-up. Further analyses investigated the specificity of this prediction. Increased left ventral striatum node strength predicted increased risk for future depressive disorder (odds ratio=1.54, 95% CI=1.09-2.18), even after excluding participants who had depressive disorders at baseline (odds ratio=1.52, 95% CI=1.05-2.20). Among 11 reward-network nodes, only the left ventral striatum significantly predicted depression. Striatal node strength did not predict other common adolescent psychopathology, such as anxiety, attention deficit hyperactivity disorder, and substance use. Aberrant ventral striatum functional connectivity specifically predicts future risk for depressive disorder. This finding further emphasizes the need to understand how brain reward networks contribute to youth depression.

  3. Effects on alcohol use of a Swedish school-based prevention program for early adolescents: a longitudinal study

    Directory of Open Access Journals (Sweden)

    Linda Beckman

    2017-01-01

    Full Text Available Abstract Background The aim of the study was to address the lack of evaluations of school-based substance use prevention programs and to conduct a quasi-experimental evaluation of the alcohol use part of the Triad intervention. Methods Eleven Swedish intervention schools (285 pupils and three control schools (159 pupils participated in the evaluation. Baseline measurements were conducted in 2011 before the alcohol part in the prevention program was implemented in the intervention schools (school year 6, ages 12–13. We estimated an Intention-To-Treat (ITT Difference-in-Difference (DD model to analyze the effectiveness of the intervention on subsequent alcohol use measured in grades 7, 8 and 9. Results The main results show no effect on the likelihood of drinking alcohol or drinking to intoxication. Conclusions The lack of positive effects highlights the need for policy-makers and public health officials need to carefully consider and evaluate prevention programs in order to ensure that they are worthwhile from school, health, and societal perspectives.

  4. Geographic Distribution of CT, MRI and PET Devices in Japan: A Longitudinal Analysis Based on National Census Data.

    Science.gov (United States)

    Matsumoto, Masatoshi; Koike, Soichi; Kashima, Saori; Awai, Kazuo

    2015-01-01

    Japan has the most CT and MRI scanners per unit population in the world; however, the geographic distribution of these technologies is currently unknown. Moreover, nothing is known of the cause-effect relationship between the number of diagnostic imaging devices and their geographic distribution. Data on the number of CT, MRI and PET devices and that of their utilizations in all 1829 municipalities of Japan was generated, based on the Static Survey of Medical Institutions conducted by the government. The inter-municipality equity of the number of devices or utilizations was evaluated with Gini coefficient. Between 2005 and 2011, the number of CT, MRI and PET devices in Japan increased by 47% (8789 to 12945), 19% (5034 to 5990) and 70% (274 to 466), respectively. Gini coefficient of the number of devices was largest for PET and smallest for CT (p for PET-MRI difference geographic distribution of the diagnostic imaging technology in Japan appears to be affected by spatial competition derived from a market force.

  5. Trends in Addressing Social Needs: A Longitudinal Study of Congregation-Based Service Provision and Political Participation

    Directory of Open Access Journals (Sweden)

    Brad R. Fulton

    2016-05-01

    Full Text Available When congregations seek to address social needs, they often pursue this goal through acts of service and political engagement. Over the past three decades, a tremendous amount of research has been dedicated to analyzing congregation-based service provision and political participation. However, little is known about how congregations’ involvement in these arenas has changed during this period. To help fill this gap, this study analyzes three waves of data from a national survey of congregations to assess how congregations’ participation patterns in service-related and political activities have been changing since the 1990s. It also examines trends among subpopulations of congregations grouped by their religious tradition, ethnoracial composition, and ideological orientation. Overall, this study finds that among most types of congregations, the percentage participating in service-related activities is substantial and increasing, while the percentage participating in political activities is less substantial and decreasing. This decline in political participation has implications for the role congregations play in addressing social needs. Relieving immediate needs through service provision without also pursuing long-term solutions through political participation can limit congregations’ ability to comprehensively address social needs. Among the few types of congregations that have high and/or increasing participation rates in both service-related and political activities are Catholic, predominantly Hispanic, and politically liberal congregations.

  6. A population-based longitudinal study of Clostridium difficile infection-related hospitalization in mid-age and older Australians.

    Science.gov (United States)

    Chen, Y; Glass, K; Liu, B; Riley, T V; Korda, R; Kirk, M D

    2017-02-01

    Clostridium difficile is the principal cause of infectious diarrhoea in hospitalized patients. We investigated the incidence and risk factors for hospitalization due to C. difficile infection (CDI) in older Australians. We linked data from a population-based prospective cohort study (the 45 and Up Study) of 266 922 adults aged ⩾45 years recruited in New South Wales, Australia to hospitalization and death records for 2006-2012. We estimated the incidence of CDI hospitalization and calculated days in hospital and costs per hospitalization. We also estimated hazard ratios (HR) for CDI hospitalization using Cox regression with age as the underlying time variable. Over a total follow-up of 1 126 708 person-years, 187 adults had an incident CDI hospitalization. The crude incidence of CDI hospitalization was 16·6/100 000 person-years, with a median hospital stay of 6 days, and a median cost of AUD 6102 per admission. Incidence increased with age and year of follow-up, with a threefold increase for 2009-2012. After adjustment, CDI hospitalization rates were significantly lower in males than females (adjusted HR 0·6, 95% confidence interval 0·4-0·7). CDI hospitalization rates increased significantly over 2009-2012. There is a need to better understand the increasing risk of CDI hospitalization in women.

  7. Are Biodegradable Osteosyntheses Still an Option for Midface Trauma? Longitudinal Evaluation of Three Different PLA-Based Materials

    Directory of Open Access Journals (Sweden)

    Andreas Kolk

    2015-01-01

    Full Text Available The aim was to evaluate three different biodegradable polylactic acid- (PLA- based osteosynthesis materials (OM. These OM (BioSorb, LactoSorb, and Delta were used in 64 patients of whom 55 (85.9% had fractures of the zygoma, five (7.8% in the LeFort II level, two of the frontal bone (3.1%, and two of the maxillary sinus wall (3.1%. In addition to routine follow-up (FU at 3, 6, and 12 months (m (T1, T2, and T3 all patients were finally evaluated at a mean FU after 14.1 m for minor (e.g., nerve disturbances, swelling, and pain and major (e.g., infections and occlusal disturbances complications. Out of all 64 patients 38 presented with complications; of these 28 were minor (43.8% and 10 major (15.6% resulting in an overall rate of 59.4%. Differences in minor complications regarding sensibility disturbance at T1 and T3 were statistically significant (P=0.04. Differences between the OM were not statistically significant. Apart from sufficient mechanical stability for clinical use of all tested OM complications mostly involved pain and swelling probably mainly related to the initial bulk reaction attributable to the drop of pH value during the degradation process. This paper includes a review of the current aspects of biodegradable OM.

  8. Long term sickness absence and diabetes: a Danish register-based longitudinal study with up to 17 years of followup

    DEFF Research Database (Denmark)

    Nexø, Mette Andersen; Carlsen, Kathrine; Pedersen, Jacob

    Background and aims: The number of individuals with diabetes mellitus within the working age range is expected to rise. Type 1 and type 2 diabetes mellitus (diabetes) can have work related consequences such as decreased productivity, increased risks of sickness absence and early retirement...... year of diagnosis and in subsequent years. Materials and methods: The study was based on registers with up to 17 years of follow-up. In a working population (n=102.746) individuals with the diagnoses of type 1 or type 2 diabetes (n=3.325: women, n=1.987, men=1338) and individuals without diabetes (n=99.......421: women, n=73.332, men=26.089) were identified by Danish national registries of diagnosis (ICD-10 codes: E10.0-10.9, E11.0-E11.9, E12-E14) and prescribed medicine (ATC codes: A10A, A10B, A10BA02), in the period 1994 to 2011. We estimated the hazard ratios of transitions from work to LTSA (>3 consecutive...

  9. Divorce and the Onset of Alcohol Use Disorders: A Swedish Population-Based Longitudinal Cohort and Co-Relative Study

    Science.gov (United States)

    Kendler, Kenneth S.; Larsson Lönn, Sara; Salvatore, Jessica; Sundquist, Jan; Sundquist, Kristina

    2017-01-01

    Objective To clarify the magnitude and nature of the relationship between divorce and risk for alcohol use disorder (AUD). Method In a population-based Swedish sample of married individuals (n=942,366), we examined the association between divorce or widowhood and risk for first registration for AUD. AUD was assessed using medical, criminal and pharmacy registries. Results Divorce was strongly associated with risk for first AUD onset in both men (HR=5.98, 95% CI, 5.65–6.33) and women (HR=7.29, 6.72–7.91). We estimated the HR for AUD onset given divorce in discordant monozygotic twins to equal 3.45 and 3.62 in men and women, respectively. Divorce was also associated with an AUD recurrence in those with AUD registrations before marriage. Furthermore, widowhood increased risk for AUD in men (HR=3.85, 2.81–5.28) and women (HR=4.10, 2.98–5.64). Among divorced individuals, remarriage was associated with a large decline in AUD in both sexes: males 0.56, 0.62–0.64 and females 0.61, 0.55–0.69. Divorce produced a greater increase in first AUD onset in those with a family history of AUD or with prior externalizing behaviors. Conclusions Spousal loss through divorce or bereavement is associated with a large enduring increased AUD risk. This association likely reflects both causal and non-causal processes. That the AUD status of the spouse alters this association highlights the importance of spouse characteristics for the behavioral health consequences of spousal loss. The pronounced elevation in AUD risk following divorce or widowhood, and the protective effect of remarriage against subsequent AUD, speaks to the profound impact of marriage on problematic alcohol use. PMID:28103713

  10. Divorce and the Onset of Alcohol Use Disorder: A Swedish Population-Based Longitudinal Cohort and Co-Relative Study.

    Science.gov (United States)

    Kendler, Kenneth S; Lönn, Sara Larsson; Salvatore, Jessica; Sundquist, Jan; Sundquist, Kristina

    2017-05-01

    The purpose of this study was to clarify the magnitude and nature of the relationship between divorce and risk for alcohol use disorder (AUD). In a population-based Swedish sample of married individuals (N=942,366), the authors examined the association between divorce or widowhood and risk for first registration for AUD. AUD was assessed using medical, criminal, and pharmacy registries. Divorce was strongly associated with risk for first AUD onset in both men (hazard ratio=5.98, 95% CI=5.65-6.33) and women (hazard ratio=7.29, 95% CI=6.72-7.91). The hazard ratio was estimated for AUD onset given divorce among discordant monozygotic twins to equal 3.45 and 3.62 in men and women, respectively. Divorce was also associated with an AUD recurrence in those with AUD registrations before marriage. Furthermore, widowhood increased risk for AUD in men (hazard ratio=3.85, 95% CI=2.81-5.28) and women (hazard ratio=4.10, 95% CI=2.98-5.64). Among divorced individuals, remarriage was associated with a large decline in AUD in both sexes (men: hazard ratio=0.56, 95% CI=0.52-0.64; women: hazard ratio=0.61, 95% CI=0.55-0.69). Divorce produced a greater increase in first AUD onset in those with a family history of AUD or with prior externalizing behaviors. Spousal loss through divorce or bereavement is associated with a large enduring increased AUD risk. This association likely reflects both causal and noncausal processes. That the AUD status of the spouse alters this association highlights the importance of spouse characteristics for the behavioral health consequences of spousal loss. The pronounced elevation in AUD risk following divorce or widowhood, and the protective effect of remarriage against subsequent AUD, speaks to the profound impact of marriage on problematic alcohol use.

  11. The relationship between social functioning and subjective memory complaints in older persons: a population-based longitudinal cohort study.

    Science.gov (United States)

    Kuiper, Jisca S; Oude Voshaar, Richard C; Zuidema, Sytse U; Stolk, Ronald P; Zuidersma, Marij; Smidt, Nynke

    2017-10-01

    Poor social functioning is associated with cognitive decline in older adults. It is unclear whether social functioning is also associated with subjective memory complaints (SMC). We investigated the association between social functioning and incident SMC and SMC recovery. A population-based sample of 8762 older adults (aged ≥65 years) with good objective cognitive functioning at baseline (MMSE ≥26) from the LifeLines Cohort Study were followed for 1.5 years. Self-reported SMC were measured at baseline and after 1.5 years follow-up. Aspects of social functioning included marital status, household composition, social network size, social activity, quality of social relationships, social support, affection, behavioral confirmation, and status. Thirteen percent (513/3963) developed SMC during follow-up (incident SMC). Multivariate logistic regression analyses (adjusted for age, gender, education level, physical activity, alcohol use, smoking status, depression, arrhythmia, myocardial infarction, heart failure, stroke) showed that participants with better feelings of affection, behavioral confirmation and stable good social support had a lower risk of incident SMC. Thirty-four percent (1632/4799) reported recovery. Participants with good social functioning at baseline on all determinants reported more SMC recovery. People who remained stable in a relationship, stable in good quality of social relationships or increased in quality of social relationships more often report SMC recovery. Good social functioning is associated with less incident SMC and more SMC recovery over a follow-up period of 1.5 years. Albeit future confirmative studies are needed, we argue for targeting also social functioning when designing multidomain interventions to prevent or slow down cognitive decline. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  12. Empirically Based Composite Fracture Prediction Model From the Global Longitudinal Study of Osteoporosis in Postmenopausal Women (GLOW)

    Science.gov (United States)

    Compston, Juliet E.; Chapurlat, Roland D.; Pfeilschifter, Johannes; Cooper, Cyrus; Hosmer, David W.; Adachi, Jonathan D.; Anderson, Frederick A.; Díez-Pérez, Adolfo; Greenspan, Susan L.; Netelenbos, J. Coen; Nieves, Jeri W.; Rossini, Maurizio; Watts, Nelson B.; Hooven, Frederick H.; LaCroix, Andrea Z.; March, Lyn; Roux, Christian; Saag, Kenneth G.; Siris, Ethel S.; Silverman, Stuart; Gehlbach, Stephen H.

    2014-01-01

    Context: Several fracture prediction models that combine fractures at different sites into a composite outcome are in current use. However, to the extent individual fracture sites have differing risk factor profiles, model discrimination is impaired. Objective: The objective of the study was to improve model discrimination by developing a 5-year composite fracture prediction model for fracture sites that display similar risk profiles. Design: This was a prospective, observational cohort study. Setting: The study was conducted at primary care practices in 10 countries. Patients: Women aged 55 years or older participated in the study. Intervention: Self-administered questionnaires collected data on patient characteristics, fracture risk factors, and previous fractures. Main Outcome Measure: The main outcome is time to first clinical fracture of hip, pelvis, upper leg, clavicle, or spine, each of which exhibits a strong association with advanced age. Results: Of four composite fracture models considered, model discrimination (c index) is highest for an age-related fracture model (c index of 0.75, 47 066 women), and lowest for Fracture Risk Assessment Tool (FRAX) major fracture and a 10-site model (c indices of 0.67 and 0.65). The unadjusted increase in fracture risk for an additional 10 years of age ranges from 80% to 180% for the individual bones in the age-associated model. Five other fracture sites not considered for the age-associated model (upper arm/shoulder, rib, wrist, lower leg, and ankle) have age associations for an additional 10 years of age from a 10% decrease to a 60% increase. Conclusions: After examining results for 10 different bone fracture sites, advanced age appeared the single best possibility for uniting several different sites, resulting in an empirically based composite fracture risk model. PMID:24423345

  13. Co-occurring development of early childhood communication and motor skills: results from a population-based longitudinal study.

    Science.gov (United States)

    Wang, M V; Lekhal, R; Aarø, L E; Schjølberg, S

    2014-01-01

    Communicative and motor development is frequently found to be associated. In the current study we investigate to what extent communication and motor skills at 1½ years predict skills in the same domains at 3 years of age. This study is based on the Norwegian Mother and Child Cohort Study (MoBa) conducted by the Norwegian Institute of Public Heath. Data stem from 62,944 children and their mothers. Mothers completed questionnaires on their child's communication and motor skills at ages 1½ and 3. Associations between communication and motor skills were estimated in a cross-lagged model with latent variables. Early communication skills were correlated with early motor skills (0.72). Stability was high (0.81) across time points for motor skills and somewhat lower (0.40) for communication skills. Early motor skills predicted later communication skills (0.38) whereas early communication skills negatively predicted later motor skills (-0.14). Our findings provide support for the hypothesis that these two difficulties are not symptoms of separate disorders, but might rather be different manifestations of a common underlying neurodevelopmental weakness. However, there also seem to be specific developmental pathways for each domain. Besides theoretical interest, more knowledge about the relationship between these early skills might shed light upon early intervention strategies and preventive efforts commonly used with children with problems in these areas. Our findings suggest that the relationship between language and motor skills is not likely to be simple and directional but rather to be complex and multifaceted. © 2012 John Wiley & Sons Ltd.

  14. The effects of caregiver and household HIV on child development: a community-based longitudinal study of young children.

    Science.gov (United States)

    Sherr, L; Skeen, S; Hensels, I S; Tomlinson, M; Macedo, A

    2016-11-01

    Many studies that document child outcomes in the context of parental HIV - which has been established as a risk factor for child development - focus on older children/adolescents. Studies also concentrate on the status of the primary caregiver, not other household members who might be infected. This study examined the effects of caregiver and household HIV on child development (4-13 years) in South Africa and Malawi (2011-2014). Data were gathered from 989 children and their primary caregivers at baseline and repeated at 12-15 months follow-up (86.5% follow-up rate). Only caregivers of a single child and caregiver/child dyads without missing data were included, providing a sample of 808 dyads for analysis. Children were divided into three groups according to caregiver-reported HIV burden: having an HIV-positive primary caregiver (19.8%), having HIV in the household (14.2%) or no HIV (66%). The HIV burden was positively associated with an array of negative child outcomes, often mediated by caregiver depression levels. Family HIV burden at baseline affected child behavioural problems at follow-up indirectly through carer depression (B = 0.02; CI = 0.003, 0.06). Internalizing (B = 0.02; CI = 0.002, 0.05) and externalizing problems at follow-up (B = 0.01; CI = 0.0002, 0.03) were also indirectly affected by family HIV burden through caregiver depression. The data suggest that family HIV can affect child development, emphasizing the important role of depression in the pathway to such an effect. Community-based interventions directed at alleviating parental depression in the presence of HIV may help to interrupt the cycle of family HIV and adverse child outcomes. © 2016 The Authors. Child: Care, Health and Development Published by John Wiley & Sons Ltd.

  15. Social and geographical inequalities in suicide in Japan from 1975 through 2005: a census-based longitudinal analysis.

    Directory of Open Access Journals (Sweden)

    Etsuji Suzuki

    Full Text Available Despite advances in our understanding of the countercyclical association between economic contraction and suicide, less is known about the levels of and changes in inequalities in suicide. The authors examined social and geographical inequalities in suicide in Japan from 1975 through 2005.Based on quinquennial vital statistics and census data, the authors analyzed the entire population aged 25-64 years. The total number of suicides was 75,840 men and 30,487 women. For each sex, the authors estimated odds ratios (ORs and 95% credible intervals (CIs for suicide using multilevel logistic regression models with "cells" (cross-tabulated by age and occupation at level 1, seven different years at level 2, and 47 prefectures at level 3. Prefecture-level variance was used as an estimate of geographical inequalities in suicide.Adjusting for age and time-trends, the lowest odds for suicide was observed among production process and related workers (the reference group in both sexes. The highest OR for men was 2.52 (95% CI: 2.43, 2.61 among service workers, whereas the highest OR for women was 9.24 (95% CI: 7.03, 12.13 among security workers. The degree of occupational inequalities increased among men with a striking change in the pattern. Among women, we observed a steady decline in suicide risk across all occupations, except for administrative and managerial workers and transport and communication workers. After adjusting for individual age, occupation, and time-trends, prefecture-specific ORs ranged from 0.76 (Nara Prefecture to 1.36 (Akita Prefecture for men and from 0.79 (Kanagawa Prefecture to 1.22 (Akita Prefecture for women. Geographical inequalities have increased primarily among men since 1995.The present findings demonstrate a striking temporal change in the pattern of social inequalities in suicide among men. Further, geographical inequalities in suicide have considerably increased across 47 prefectures, primarily among men, since 1995.

  16. Quality of life among elderly patients undergoing transcatheter or surgical aortic valve replacement- a model-based longitudinal data analysis.

    Science.gov (United States)

    Kaier, Klaus; Gutmann, Anja; Baumbach, Hardy; von Zur Mühlen, Constantin; Hehn, Philip; Vach, Werner; Beyersdorf, Friedhelm; Zehender, Manfred; Bode, Christoph; Reinöhl, Jochen

    2016-07-26

    Quality of life (QoL) measurements reported in observational studies are often biased, since patients who failed to improve are more likely to be unable to respond due to death or impairment. In order to observe the development of QoL in patients close to death, we analyzed a set of monthly QoL measurements for a cohort of elderly patients treated for aortic valve stenosis (AS) with special consideration of the effect of distance to death. QoL in 169 elderly patients (age ≥ 75 years), treated either with transcatheter aortic valve replacement (TAVR; n = 92), surgical aortic-valve replacement (n = 70), or drug-based therapy (n = 7), was evaluated using the standardized EQ-5D questionnaire. Over a two-year period, patients were consulted using monthly telephone interviews or outpatient visits, leading to a total of 2463 time points at which QoL values, New York Heart Association (NYHA) Functional Classification and their status of assistance were assessed. Furthermore, post-procedural clinical events and complications were monitored. Linear and ordered logistic regression analyses with random intercept were carried out, taking into account overall trends and distance to death. QoL measures decreased slightly over time, were temporarily impaired at month 1 after the initial episode of hospitalization and decreased substantially at the end of life with a measurable effect starting at the sixth from last follow-up (month) before death. Many clinical complications (bleeding complications, stroke, acute kidney injury) showed an impairment of QoL measurements, but the inclusion of lagged variables demonstrated medium term (three months) QoL impairments for access site bleeding only. All other complications are associated with event-related impairments that decreased dramatically at the second and third follow-up interviews (month) after event. Distance to death shows clear effects on QoL and should be taken into account when analyzing QoL measures in the

  17. Natural history of chronic HBV infection in West Africa: a longitudinal population-based study from The Gambia.

    Science.gov (United States)

    Shimakawa, Yusuke; Lemoine, Maud; Njai, Harr Freeya; Bottomley, Christian; Ndow, Gibril; Goldin, Robert D; Jatta, Abdoulie; Jeng-Barry, Adam; Wegmuller, Rita; Moore, Sophie E; Baldeh, Ignatius; Taal, Makie; D'Alessandro, Umberto; Whittle, Hilton; Njie, Ramou; Thursz, Mark; Mendy, Maimuna

    2016-12-01

    The natural history of chronic HBV infection in sub-Saharan Africa is unknown. Data are required to inform WHO guidelines that are currently based on studies in Europe and Asia. Between 1974 and 2008, serosurveys were repeated in two Gambian villages, and an open cohort of treatment-naive chronic HBV carriers was recruited. Participants were followed to estimate the rates of hepatitis B e (HBeAg) and surface antigen (HBsAg) clearance and incidence of hepatocellular carcinoma (HCC). In 2012-2013, a comprehensive liver assessment was conducted to estimate the prevalence of severe liver disease. 405 chronic carriers (95% genotype E), recruited at a median age of 10.8 years, were followed for a median length of 28.4 years. Annually, 7.4% (95% CI 6.3% to 8.8%) cleared HBeAg and 1.0% (0.8% to 1.2%) cleared HBsAg. The incidence of HCC was 55.5/100 000 carrier-years (95% CI 24.9 to 123.5). In the 2012-2013 survey (n=301), 5.5% (95% CI 3.4% to 9.0%) had significant liver fibrosis. HBV genotype A (versus E), chronic aflatoxin B1 exposure and an HBsAg-positive mother, a proxy for mother-to-infant transmission, were risk factors for liver fibrosis. A small proportion (16.0%) of chronic carriers were infected via mother-to-infant transmission; however, this population represented a large proportion (63.0%) of the cases requiring antiviral therapy. The incidence of HCC among chronic HBV carriers in West Africa was higher than that in Europe but lower than rates in East Asia. High risk of severe liver disease among the few who are infected by their mothers underlines the importance of interrupting perinatal transmission in sub-Saharan Africa. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

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

    Science.gov (United States)

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

    2016-07-26

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

  19. HHEX_23 AA Genotype Exacerbates Effect of Diabetes on Dementia and Alzheimer Disease: A Population-Based Longitudinal Study.

    Directory of Open Access Journals (Sweden)

    Wei-Li Xu

    2015-07-01

    Full Text Available Research has suggested that variations within the IDE/HHEX gene region may underlie the association of type 2 diabetes with Alzheimer disease (AD. We sought to explore whether IDE genes play a role in the association of diabetes with dementia, AD, and structural brain changes using data from two community-based cohorts of older adults and a subsample with structural MRI.The first cohort, which included dementia-free adults aged ≥75 y (n = 970 at baseline, was followed for 9 y to detect incident dementia (n = 358 and AD (n = 271 cases. The second cohort (for replication, which included 2,060 dementia-free participants aged ≥60 y at baseline, was followed for 6 y to identify incident dementia (n = 166 and AD (n = 121 cases. A subsample (n = 338 of dementia-free participants from the second cohort underwent MRI. HHEX_23 and IDE_9 were genotyped, and diabetes (here including type 2 diabetes and prediabetes was assessed. In the first cohort, diabetes led to an adjusted hazard ratio (HR of 1.73 (95% CI 1.19-2.32 and 1.66 (95% CI 1.06-2.40 for dementia and AD, respectively, among all participants. Compared to people carrying the GG genotype without diabetes, AA genotype carriers with diabetes had an adjusted HR of 5.54 (95% CI 2.40-7.18 and 4.81 (95% CI 1.88-8.50 for dementia and AD, respectively. There was a significant interaction between HHEX_23-AA and diabetes on dementia (HR 4.79, 95% CI 1.63-8.90, p = 0.013 and AD (HR 3.55, 95% CI 1.45-9.91, p = 0.025 compared to the GG genotype without diabetes. In the second cohort, the HRs were 1.68 (95% CI 1.04-2.99 and 1.64 (1.02-2.33 for the diabetes-AD and dementia-AD associations, respectively, and 4.06 (95% CI 1.06-7.58, p = 0.039 and 3.29 (95% CI 1.02-8.33, p = 0.044 for the interactions, respectively. MRI data showed that HHEX_23-AA carriers with diabetes had significant structural brain changes compared to HHEX_23-GG carriers without diabetes. No joint effects of IDE_9 and diabetes on dementia

  20. Longitudinal course and outcome of chronic insomnia in Hong Kong Chinese children: a 5-year follow-up study of a community-based cohort.

    Science.gov (United States)

    Zhang, Jihui; Lam, Siu Ping; Li, Shirley Xin; Li, Albert Martin; Lai, Kelly Y C; Wing, Yun-Kwok

    2011-10-01

    There are limited data on the long-term outcome of childhood insomnia. We explored the longitudinal course, predictors, and impact of childhood insomnia in a community-based cohort. 5-year prospective follow-up. Community-based. 611 children (49% boys) aged 9.0 ± 1.8 years at baseline; 13.7 ± 1.8 years at follow-up. NA. Chronic insomnia was defined as difficulty initiating sleep, difficulty maintaining sleep and/or early morning awakening ≥ 3 times/week in the past 12 months. General health, upper airway inflammatory diseases, and behavioral problems in recent one year were assessed at both time points, while mental health and lifestyle practice were assessed at follow-up study. The questionnaires at baseline and follow-up were reported by parents/caretakers and adolescents themselves, respectively. The prevalence of chronic insomnia was 4.2% and 6.6% for baseline and follow-up, respectively. The incidence and persistence rates of chronic insomnia were 6.2% and 14.9%, respectively. New incidence of insomnia was associated with lower paternal education level, baseline factors of frequent temper outbursts and daytime fatigue as well as alcohol use and poor mental health at follow-up. Baseline chronic medical disorders, frequent temper outbursts, and poor mental health at follow-up were associated with the persistence of insomnia in adolescents. Baseline insomnia was associated with frequent episodes of laryngopharyngitis and lifestyle practice (coffee and smoking) at follow-up. Chronic insomnia is a common problem with moderate persistent rate in children. The associations of adverse physical and mental health consequences with maladaptive lifestyle coping (smoking and alcohol) argue for rigorous intervention of childhood insomnia.

  1. Changes in the lifetime prevalence of suicidal feelings and thoughts among Norwegian doctors from 2000 to 2010: a longitudinal study based on national samples.

    Science.gov (United States)

    Rosta, Judith; Aasland, Olaf G

    2013-11-28

    Thinking about suicide is an indicator of suicide risk. Suicide rates are higher among doctors than in the population. The main aims of this study are to describe the changes in the lifetime prevalence of suicidal feelings from 2000 to 2010 and the possible predictors of serious suicidal thoughts in 2010 among Norwegian doctors. Differences in lifetime prevalence of suicidal feelings between Norwegian doctors in 2010 and German doctors in 2006 will be also described. Longitudinal and cross-sectional study based on questionnaire data from 2000 and 2010, including approximately 1,600 Norwegian doctors. In Germany, cross-sectional study based on questionnaire data from 2006 among a sample of 3,295 doctors. The main outcome measures were the lifetime prevalence of suicidal feelings (felt life was not worth living, wished own death, had thoughts of taking own life). The prevalences in 2000 and 2010 of ever had feelings of life not worth living were 48 (44 to 52) % and 45 (41 to 49) %, of ever wished own death 27 (23 to 30) % and 23 (20 to 26) %, and of ever had thoughts of taking own life 29 (16 to 33) % and 24 (21 to 27) %. Paired t-tests among those who responded both in 2000 and 2010 show significant reductions for felt life not worth living (t = -3.4; p = 0.001), wished own death (t = -3.1; p = 0.002) and had thoughts of taking own life (t = -3.5; p feelings. Suicidal feelings among Norwegian doctors decreased from 2000 to 2010. Individual and work-related factors may to certain explain these findings. Compared with other professionals in Norway and doctors in Germany, Norwegian doctors showed no higher risk of suicidal thoughts.

  2. Obtain ceramic porous alumina-zirconia by replica method calcium phosphate coated; Oobtencao de ceramicas porosas de alumina-zirconia pelo metodo da replica recobertas com fosfato de calcio

    Energy Technology Data Exchange (ETDEWEB)

    Silva, A.D.R.; Rigoli, W.R.; Osiro, Denise; Pallone, E.M.J.A., E-mail: adinizrs@yahoo.com.br [Universidade de Sao Paulo (FZEA/USP), Pirassununga, SP (Brazil). Faculdade de Zootecnia e Engenharia de Alimentos; Lobo, A.O. [Universidade do Vale do Paraiba (UNIVAP), Sao Jose dos Campos, SP (Brazil)

    2016-07-01

    Biomaterials used in bone replacement, including porous bioceramics, are often used as support structure for bone formation and repair. The porous bioceramics are used because present features as biocompatibility, high porosity and pore morphology that confer adequate mechanical strength and induce bone growth. In this work were obtained porous specimens of alumina containing 5% by inclusion of volume of zirconia produced by the replica method. The porous specimens had its surface chemically treated with phosphoric acid and were coated with calcium phosphate. The coating was performed using the biomimetic method during 14 days and an initial pH of 6.1. The porous specimens were characterized using the follow techniques: porosity, axial compression tests, microtomography, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and pH measurements SBF solution. The results showed specimens with suitable pore morphology for application as biomaterial, and even a reduced time of incubation favored the calcium phosphate phases formation on the material surfaces. (author)

  3. Are Mental Health Effects of Internet Use Attributable to the Web-Based Content or Perceived Consequences of Usage? A Longitudinal Study of European Adolescents.

    Science.gov (United States)

    Hökby, Sebastian; Hadlaczky, Gergö; Westerlund, Joakim; Wasserman, Danuta; Balazs, Judit; Germanavicius, Arunas; Machín, Núria; Meszaros, Gergely; Sarchiapone, Marco; Värnik, Airi; Varnik, Peeter; Westerlund, Michael; Carli, Vladimir

    2016-07-13

    Adolescents and young adults are among the most frequent Internet users, and accumulating evidence suggests that their Internet behaviors might affect their mental health. Internet use may impact mental health because certain Web-based content could be distressing. It is also possible that excessive use, regardless of content, produces negative consequences, such as neglect of protective offline activities. The objective of this study was to assess how mental health is associated with (1) the time spent on the Internet, (2) the time spent on different Web-based activities (social media use, gaming, gambling, pornography use, school work, newsreading, and targeted information searches), and (3) the perceived consequences of engaging in those activities. A random sample of 2286 adolescents was recruited from state schools in Estonia, Hungary, Italy, Lithuania, Spain, Sweden, and the United Kingdom. Questionnaire data comprising Internet behaviors and mental health variables were collected and analyzed cross-sectionally and were followed up after 4 months. Cross-sectionally, both the time spent on the Internet and the relative time spent on various activities predicted mental health (Pengaging in those activities were more important predictors, explaining 11.1% variance. Only Web-based gaming, gambling, and targeted searches had mental health effects that were not fully accounted for by perceived consequences. The longitudinal analyses showed that sleep loss due to Internet use (ß=.12, 95% CI=0.05-0.19, P=.001) and withdrawal (negative mood) when Internet could not be accessed (ß=.09, 95% CI=0.03-0.16, Peffect on mental health in the long term. Perceived positive consequences of Internet use did not seem to be associated with mental health at all. The magnitude of Internet use is negatively associated with mental health in general, but specific Web-based activities differ in how consistently, how much, and in what direction they affect mental health. Consequences of

  4. Joint model-based clustering of nonlinear longitudinal trajectories and associated time-to-event data analysis, linked by latent class membership: with application to AIDS clinical studies.

    Science.gov (United States)

    Huang, Yangxin; Lu, Xiaosun; Chen, Jiaqing; Liang, Juan; Zangmeister, Miriam

    2017-10-27

    Longitudinal and time-to-event data are often observed together. Finite mixture models are currently used to analyze nonlinear heterogeneous longitudinal data, which, by releasing the homogeneity restriction of nonlinear mixed-effects (NLME) models, can cluster individuals into one of the pre-specified classes with class membership probabilities. This clustering may have clinical significance, and be associated with clinically important time-to-event data. This article develops a joint modeling approach to a finite mixture of NLME models for longitudinal data and proportional hazard Cox model for time-to-event data, linked by individual latent class indicators, under a Bayesian framework. The proposed joint models and method are applied to a real AIDS clinical trial data set, followed by simulation studies to assess the performance of the proposed joint model and a naive two-step model, in which finite mixture model and Cox model are fitted separately.

  5. Association between rates of caesarean section and maternal and neonatal mortality in the 21st century: a worldwide population-based ecological study with longitudinal data.

    Science.gov (United States)

    Ye, J; Zhang, J; Mikolajczyk, R; Torloni, M R; Gülmezoglu, A M; Betran, A P

    2016-04-01