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Sample records for attentional dwell time

  1. Modelling of Attentional Dwell Time

    DEFF Research Database (Denmark)

    Petersen, Anders; Kyllingsbæk, Søren; Bundesen, Claus

    2009-01-01

    Studies of the time course of visual attention have identified a temporary functional blindness to the second of two spatially separated targets: attending to one visual stimulus may lead to impairments in identifying a second stimulus presented between 200 to 500 ms after the first. This phenome......Studies of the time course of visual attention have identified a temporary functional blindness to the second of two spatially separated targets: attending to one visual stimulus may lead to impairments in identifying a second stimulus presented between 200 to 500 ms after the first....... This phenomenon is known as attentional dwell time (e.g. Duncan, Ward, Shapiro, 1994). All Previous studies of the attentional dwell time have looked at data averaged across subjects. In contrast, we have succeeded in running subjects for 3120 trials which has given us reliable data for modelling data from...... individual subjects. Our new model is based on the Theory of Visual Attention (TVA; Bundesen, 1990). TVA has previously been successful in explaining results from experiments where stimuli are presented simultaneously in the spatial domain (e.g. whole report and partial report) but has not yet been extended...

  2. Attentional dwell times for targets and masks.

    Science.gov (United States)

    Petersen, Anders; Kyllingsbæk, Søren; Bundesen, Claus

    2013-12-06

    Studies on the temporal dynamics of attention have shown that the report of a masked target (T2) is severely impaired when the target is presented with a delay (stimulus onset asynchrony) of less than 500 ms after a spatially separate masked target (T1). This is known as the attentional dwell time. Recently, we have proposed a computational model of this effect building on the idea that a stimulus retained in visual short-term memory (VSTM) takes up visual processing resources that otherwise could have been used to encode subsequent stimuli into VSTM. The resources are locked until the stimulus in VSTM has been recoded, which explains the long dwell time. Challenges for this model and others are findings by Moore, Egeth, Berglan, and Luck (1996) suggesting that the dwell time is substantially reduced when the mask of T1 is removed. Here we suggest that the mask of T1 modulates performance not by noticeably affecting the dwell time but instead by acting as a distractor drawing processing resources away from T2. This is consistent with our proposed model in which targets and masks compete for attentional resources and attention dwells on both. We tested the model by replicating the study by Moore et al., including a new condition in which T1 is omitted but the mask of T1 is retained. Results from this and the original study by Moore et al. are modeled with great precision.

  3. Measuring and modeling attentional dwell time.

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    Petersen, Anders; Kyllingsbæk, Søren; Bundesen, Claus

    2012-12-01

    Attentional dwell time (AD) defines our inability to perceive spatially separate events when they occur in rapid succession. In the standard AD paradigm, subjects should identify two target stimuli presented briefly at different peripheral locations with a varied stimulus onset asynchrony (SOA). The AD effect is seen as a long-lasting impediment in reporting the second target, culminating at SOAs of 200-500 ms. Here, we present the first quantitative computational model of the effect--a theory of temporal visual attention. The model is based on the neural theory of visual attention (Bundesen, Habekost, & Kyllingsbæk, Psychological Review, 112, 291-328 2005) and introduces the novel assumption that a stimulus retained in visual short-term memory takes up visual processing-resources used to encode stimuli into memory. Resources are thus locked and cannot process subsequent stimuli until the stimulus in memory has been recoded, which explains the long-lasting AD effect. The model is used to explain results from two experiments providing detailed individual data from both a standard AD paradigm and an extension with varied exposure duration of the target stimuli. Finally, we discuss new predictions by the model.

  4. The effect of masking in the attentional dwell time paradigm

    DEFF Research Database (Denmark)

    Petersen, Anders

    2009-01-01

    A temporary functional blindness to the second of two spatially separated targets has been identified in numerous studies of temporal visual attention. This effect is known as attentional dwell time and is maximal 200 to 500 ms after presentation of the first target (e.g. Duncan, Ward, Shapiro......, 1994). In most studies of attentional dwell time, two masked targets have been used. Moore et al. (1996) have criticised the masking of the first target when measuring the attentional dwell time, finding a shorter attentional dwell time when the first mask was omitted. In the presented work, the effect...... an impairment of the second target. Hence, the attentional dwell time may be a combined effect arising from attending to both the first target and its mask....

  5. Eye movements and practice effects in the attentional dwell time paradigm.

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    Petersen, Anders; Kyllingsbæk, Søren

    2013-01-01

    In the attentional dwell time paradigm by Duncan, Ward, and Shapiro (1994), two backward masked targets are presented at different spatial locations and separated by a varying time interval. Results show that report of the second target is severely impaired when the time interval is less than 500 ms which has been taken as a direct measure of attentional dwell time in human vision. However, we show that eye movements may have confounded the estimate of the dwell time and that the measure may not be robust as previously suggested. The latter is supported by evidence suggesting that intensive training strongly attenuates the dwell time because of habituation to the masks. Thus, this article points to eye movements and masking as two potential methodological pitfalls that should be considered when using the attentional dwell time paradigm to investigate the temporal dynamics of attention.

  6. An impaired attentional dwell time after parietal and frontal lesions related to impaired selective attention not unilateral neglect.

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    Correani, Alessia; Humphreys, Glyn W

    2011-07-01

    The attentional blink, a measure of the temporal dynamics of visual processing, has been documented to be more pronounced following brain lesions that are associated with visual neglect. This suggests that, in addition to their spatial bias in attention, neglect patients may have a prolonged dwell time for attention. Here the attentional dwell time was examined in patients with damage focused on either posterior parietal or frontal cortices. In three experiments, we show that there is an abnormally pronounced attentional dwell time, which does not differ in patients with posterior parietal and with frontal lobe lesions, and this is associated with a measure of selective attention but not with measures of spatial bias in selection. These data occurred both when we attempted to match patients and controls for overall differences in performance and when a single set stimulus exposure was used across participants. In Experiments 1 and 2, requiring report of colour-form conjunctions, there was evidence that the patients were also impaired at temporal binding, showing errors in feature combination across stimuli and in reporting in the correct temporal order. In Experiment 3, requiring only the report of features but introducing task switching led to similar results. The data suggest that damage to a frontoparietal network can compromise temporal selection of visual stimuli; however, this is not necessarily related to a deficit in hemispatial visual attention but it is to impaired target selection. We discuss the implications for understanding visual selection.

  7. Dwell-time switching

    NARCIS (Netherlands)

    Cao, Ming; Morse, A. Stephen

    Dwell-time switching is a logic for orchestrating the switching between controllers in a family of candidate controllers in order to control a process with a highly uncertain model. An analysis is given of dwell-time switching which is appropriate to a variety of control problems in which the class

  8. Practicing the attentional Dwell Away?

    DEFF Research Database (Denmark)

    Petersen, Anders; Kyllingsbæk, Søren; Bundesen, Claus Mogens

    2007-01-01

    Studies of the time course of visual attention have identified a temporary functional blindness to the second of two spatially separated targets: attending to one visual stimulus may lead to impairments in identifying a second stimulus presented about 200-500 ms later than the first. The phenomen...... the task....

  9. Factors affecting dwell times on digital displaying

    Science.gov (United States)

    Williams, A. J.; Harris, R. L., Sr.

    1985-01-01

    A series of exploratory tests were conducted to investigate the effects of advanced display formats and display media on pilot scanning behavior using Langley's oculometer, a desktop flight simulator, a conventional electro-mechanical meter, and various digital displays. The primary task was for the test subject to maintain level flight, on a specific course heading, during moderate turbulence. A secondary task of manually controlling the readout of a display was used to examine the effects of the display format on a subject's scan behavior. Secondary task scan parameters that were evaluated were average dwell time, dwell time histograms, and number of dwells per meter change. The round dial meter demonstrated shorter dwell times and fewer dwells per meter change than the digital displays. The following factors affected digital display scanning behavior: (1) the number of digits; (2) the update rate of the digits; (3) the display media; and (4) the character font. The size of the digits used in these tests (0.28 to 0.50 inches) did not affect scan behavior measures.

  10. Yet one more dwell time algorithm

    Science.gov (United States)

    Haberl, Alexander; Rascher, Rolf

    2017-06-01

    The current demand of even more powerful and efficient microprocessors, for e.g. deep learning, has led to an ongoing trend of reducing the feature size of the integrated circuits. These processors are patterned with EUV-lithography which enables 7 nm chips [1]. To produce mirrors which satisfy the needed requirements is a challenging task. Not only increasing requirements on the imaging properties, but also new lens shapes, such as aspheres or lenses with free-form surfaces, require innovative production processes. However, these lenses need new deterministic sub-aperture polishing methods that have been established in the past few years. These polishing methods are characterized, by an empirically determined TIF and local stock removal. Such a deterministic polishing method is ion-beam-figuring (IBF). The beam profile of an ion beam is adjusted to a nearly ideal Gaussian shape by various parameters. With the known removal function, a dwell time profile can be generated for each measured error profile. Such a profile is always generated pixel-accurately to the predetermined error profile, with the aim always of minimizing the existing surface structures up to the cut-off frequency of the tool used [2]. The processing success of a correction-polishing run depends decisively on the accuracy of the previously computed dwell-time profile. So the used algorithm to calculate the dwell time has to accurately reflect the reality. But furthermore the machine operator should have no influence on the dwell-time calculation. Conclusively there mustn't be any parameters which have an influence on the calculation result. And lastly it should take a minimum of machining time to get a minimum of remaining error structures. Unfortunately current dwell time algorithm calculations are divergent, user-dependent, tending to create high processing times and need several parameters to bet set. This paper describes an, realistic, convergent and user independent dwell time algorithm. The

  11. Cylindrical Optic Figuring and Dwell Time Optimization

    Science.gov (United States)

    Waluschka, Eugene

    2000-01-01

    Grazing incidence x-ray telescopes consist of surfaces which are nearly cylindrical in shape. The abrasive figuring of these surfaces is accomplished by moving a grinding tool along a helical path on this almost cylindrical surface. The measurement of the surface is, however, performed along "axial" scan lines which intercept this helical path. This approach to figuring and measuring permits a relatively simple scheme to be implemented for the determination of the optimal dwell times of the figuring tool. These optimal dwell times are determined by a deconvolution which approaches the problem in a linear programming context and uses the Simplex Method. The approach maximizes the amount of material removed at any point subject to inequality constraints. The effect of using these ''optimum" dwell times is to significantly improve the tools effectiveness at removing the higher spatial frequencies while staying (strictly) within the bounds and constraints imposed by the hardware. In addition, the ringing at the edges of the optic, frequently present in deconvolution problems, is completely eliminated.

  12. Cylindrical Optic Polishing Dwell Time Optimization

    Science.gov (United States)

    Waluschka, Eugene

    2000-01-01

    The Constellation-X x-ray telescope consists of replicated grazing incidence optics. The polishing of the "master' mandrel is accomplished by moving a polishing tool along a helical path on the surface of this almost cylindrical surface. The measurement of the surface is, however, performed along "axial" scan lines which intercept this helical path. This approach to polishing and measuring permits a relatively simple scheme to be implemented for the determination of the optimal dwell times of the polishing tool. These optimal dwell times are determined by a deconvolution which approaches the problem as a linear programming problem and uses the simplex method. This approach maximizes the amount of material removed at any point subject to inequality constraints. The effects of using these "optimum" dwell times is to significantly improve the "tools" effectiveness at removing the higher spatial frequencies while staying (strictly) within the bounds and constraints imposed by the hardware. In addition the "ringing" at the edges of the optic, frequently present in deconvolution problems, is completely eliminated.

  13. Optimizing peritoneal dialysis prescription for volume control: the importance of varying dwell time and dwell volume.

    Science.gov (United States)

    Fischbach, Michel; Zaloszyc, Ariane; Schaefer, Betti; Schmitt, Claus Peter

    2014-08-01

    Not only adequate uremic toxin removal but also volume control is essential in peritoneal dialysis (PD) to improve patient outcome. Modification of dwell time impacts on both ultrafiltration (UF) and purification. A short dwell favors UF but preferentially removes small solutes such as urea. A long dwell favors uremic toxin removal but also peritoneal fluid reabsorption due to the time-dependent loss of the crystalloid osmotic gradient. In particular, the long daytime dwell in automated PD may result in significant water and sodium reabsorption, and in such cases icodextrin should be considered. Increasing dwell volume favors the removal of solutes such as sodium due to the increased volume of diffusion and the recruitment of peritoneal surface area. A very large fill volume with too high an intraperitoneal pressure (IPP) may, however, result in back-filtration and thus reduced UF and sodium clearance. Based on these principles and the individual transport and pressure kinetics obtained from peritoneal equilibration tests and IPP measurements, we suggest combining short dwells with a low fill volume to favor UF with long dwells and a large fill volume to favor solute removal. Results from a recent randomized cross-over trial and earlier observational data in children support this concept: the absolute UF and UF relative to the administered glucose increased and solute removal and blood pressure improved.

  14. Train Dwell Time Models for Rail Passenger Service

    Directory of Open Access Journals (Sweden)

    San Hor Peay

    2016-01-01

    Full Text Available In recent years, more studies had been conducted about train dwell time as it is a key parameter of rail system performance and reliability. This paper draws an overview of train dwell time models for rail passenger service from various continents, namely Asia, North America, Europe and Australia. The factors affecting train dwell time are identified and analysed across some rail network operators. The dwell time models developed by various researches are also discussed and reviewed. Finally, the contributions from the outcomes of these models are briefly addressed. In conclusion, this paper suggests that there is a need to further study the factors with strong influence upon dwell time to improve the quality of the train services.

  15. Interpreting single turnover catalysis measurements with constrained mean dwell times.

    Science.gov (United States)

    Ochoa, Maicol A; Zhou, Xiaochun; Chen, Peng; Loring, Roger F

    2011-11-07

    Observation of a chemical transformation at the single-molecule level yields a detailed view of kinetic pathways contributing to the averaged results obtained in a bulk measurement. Studies of a fluorogenic reaction catalyzed by gold nanoparticles have revealed heterogeneous reaction dynamics for these catalysts. Measurements on single nanoparticles yield binary trajectories with stochastic transitions between a dark state in which no product molecules are adsorbed and a fluorescent state in which one product molecule is present. The mean dwell time in either state gives information corresponding to a bulk measurement. Quantifying fluctuations from mean kinetics requires identifying properties of the fluorescence trajectory that are selective in emphasizing certain dynamic processes according to their time scales. We propose the use of constrained mean dwell times, defined as the mean dwell time in a state with the constraint that the immediately preceding dwell time in the other state is, for example, less than a variable time. Calculations of constrained mean dwell times for a kinetic model with dynamic disorder demonstrate that these quantities reveal correlations among dynamic fluctuations at different active sites on a multisite catalyst. Constrained mean dwell times are determined from measurements of single nanoparticle catalysis. The results indicate that dynamical fluctuations at different active sites are correlated, and that especially rapid reaction events produce particularly slowly desorbing product molecules.

  16. Dwell time analysis of a single-molecule mechanochemical reaction.

    Science.gov (United States)

    Szoszkiewicz, Robert; Ainavarapu, Sri Rama Koti; Wiita, Arun P; Perez-Jimenez, Raul; Sanchez-Ruiz, Jose M; Fernandez, Julio M

    2008-02-19

    Force-clamp spectroscopy is a novel technique for studying mechanochemistry at the single-bond level. Single disulfide bond reduction events are accurately detected as stepwise increases in the length of polyproteins that contain disulfide bonds and that are stretched at a constant force with the cantilever of an atomic force microscope (AFM). The kinetics of this reaction has been measured from single-exponential fits to ensemble averages of the reduction events. However, exponential fits are notoriously ambiguous to use in cases of kinetic data showing multiple reaction pathways. Here we introduce a dwell time analysis technique, of widespread use in the single ion channel field, that we apply to the examination of the kinetics of reduction of disulfide bonds measured from single-molecule force-clamp spectroscopy traces. In this technique, exponentially distributed dwell time data is plotted as a histogram with a logarithmic time scale and a square root ordinate. The advantage of logarithmic histograms is that exponentially distributed dwell times appear as well-defined peaks in the distribution, greatly enhancing our ability to detect multiple kinetic pathways. We apply this technique to examine the distribution of dwell times of 4488 single disulfide bond reduction events measured in the presence of two very different kinds of reducing agents: tris-(2-carboxyethyl)phosphine hydrochloride (TCEP) and the enzyme thioredoxin (TRX). A different clamping force is used for each reducing agent to obtain distributions of dwell times on a similar time scale. In the case of TCEP, the logarithmic histogram of dwell times showed a single peak, corresponding to a single reaction mechanism. By contrast, similar experiments done with TRX showed two well-separated peaks, marking two distinct modes of chemical reduction operating simultaneously. These experiments demonstrate that dwell time analysis techniques are a powerful approach to studying chemical reactions at the single

  17. Dwell time modulation restrictions do not necessarily improve treatment plan quality for prostate HDR brachytherapy

    NARCIS (Netherlands)

    Balvert, M.; Gorissen, B.L.; den Hertog, D.; Hoffmann, A.L.

    Inverse planning algorithms for dwell time optimisation in interstitial high-dose-rate (HDR) brachytherapy may produce solutions with large dwell time variations within catheters, which may result in undesirable selective high-dose subvolumes. Extending the dwell time optimisation model with a dwell

  18. Nonlinear Switched Systems with State Dependent Dwell-Time

    NARCIS (Netherlands)

    Persis, Claudio De; Santis, Raffaella De; Morse, A. Stephen

    2002-01-01

    The asymptotic convergence of nonlinear switched systems in the presence of disturbances is studied in this paper. The system switches among a family of integral input-to-state stable systems. The time between two consecutive switchings is not less than a value τD. This dwell-time τD is allowed to

  19. Predictive modelling of running and dwell times in railway traffic

    NARCIS (Netherlands)

    Kecman, P.; Goverde, R.M.P.

    2015-01-01

    Accurate estimation of running and dwell times is important for all levels of planning and control of railway traffic. The availability of historical track occupation data with a high degree of granularity inspired a data-driven approach for estimating these process times. In this paper we present

  20. Switched nonlinear systems with state-dependent dwell-time

    NARCIS (Netherlands)

    De Persis, Claudio; De Santis, Raffaella; Morse, A. Stephen

    2003-01-01

    The asymptotic convergence of a switched nonlinear system in the presence of disturbances is studied. The system switches among a family of integral input-to-state stable systems. The time between two consecutive switchings is not less than a value τD. This dwell-time τD is allowed to take different

  1. A phantom for verification of dwell position and time of a high dose rate brachytherapy source.

    Science.gov (United States)

    Madebo, M; Pillainayagam, J; Kron, T; Franich, R

    2012-09-01

    Accuracy of dwell position and reproducibility of dwell time are critical in high dose rate (HDR) brachytherapy. A phantom was designed to verify dwell position and dwell time reproducibility for an Ir-192 HDR stepping source using Computed Radiography (CR). The central part of the phantom, incorporating thin alternating strips of lead and acrylic, was used to measure dwell positions. The outer part of the phantom features recesses containing different absorber materials (lead, aluminium, acrylic and polystyrene foam), and was used for determining reproducibility of dwell times. Dwell position errors of dwell time as low as 0.1 s, the minimum dwell time of the treatment unit, could be detected by choosing dwell times over the four materials that produce identical exposure at the CR detector.

  2. Variance of the Quantum Dwell Time for a Nonrelativistic Particle

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    Hahne, Gerhard

    2012-01-01

    Munoz, Seidel, and Muga [Phys. Rev. A 79, 012108 (2009)], following an earlier proposal by Pollak and Miller [Phys. Rev. Lett. 53, 115 (1984)] in the context of a theory of a collinear chemical reaction, showed that suitable moments of a two-flux correlation function could be manipulated to yield expressions for the mean quantum dwell time and mean square quantum dwell time for a structureless particle scattering from a time-independent potential energy field between two parallel lines in a two-dimensional spacetime. The present work proposes a generalization to a charged, nonrelativistic particle scattering from a transient, spatially confined electromagnetic vector potential in four-dimensional spacetime. The geometry of the spacetime domain is that of the slab between a pair of parallel planes, in particular those defined by constant values of the third (z) spatial coordinate. The mean Nth power, N = 1, 2, 3, . . ., of the quantum dwell time in the slab is given by an expression involving an N-flux-correlation function. All these means are shown to be nonnegative. The N = 1 formula reduces to an S-matrix result published previously [G. E. Hahne, J. Phys. A 36, 7149 (2003)]; an explicit formula for N = 2, and of the variance of the dwell time in terms of the S-matrix, is worked out. A formula representing an incommensurability principle between variances of the output-minus-input flux of a pair of dynamical variables (such as the particle s time flux and others) is derived.

  3. Dwell time distributions of the molecular motor myosin V.

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    Bierbaum, Veronika; Lipowsky, Reinhard

    2013-01-01

    The dwell times between two successive steps of the two-headed molecular motor myosin V are governed by non-exponential distributions. These distributions have been determined experimentally for various control parameters such as nucleotide concentrations and external load force. First, we use a simplified network representation to determine the dwell time distributions of myosin V, with the associated dynamics described by a Markov process on networks with absorbing boundaries. Our approach provides a direct relation between the motor's chemical kinetics and its stepping properties. In the absence of an external load, the theoretical distributions quantitatively agree with experimental findings for various nucleotide concentrations. Second, using a more complex branched network, which includes ADP release from the leading head, we are able to elucidate the motor's gating effect. This effect is caused by an asymmetry in the chemical properties of the leading and the trailing head of the motor molecule. In the case of an external load acting on the motor, the corresponding dwell time distributions reveal details about the motor's backsteps.

  4. A method for restricting intracatheter dwell time variance in high-dose-rate brachytherapy plan optimization.

    Science.gov (United States)

    Cunha, Adam; Siauw, Timmy; Hsu, I-Chow; Pouliot, Jean

    2016-01-01

    To present the algorithm of a modification to the inverse planning simulated annealing (IPSA) optimization engine that allows for restriction of the intracatheter dwell time variance. IPSA was modified to allow user control of dwell time variance within each catheter through a single parameter, the dwell time deviation constraint (DTDC). The minimum DTDC value (DTDC = 0) does not impose any restriction on dwell time variance, and the maximum value (DTDC = 1) restricts all dwell times within each catheter to take on the same value. The final optimization penalty function value was evaluated as a function of DTDC. The algorithm proposed fully preserves the inverse planning nature of the IPSA algorithm along with the penalty-based dose optimization workflow. Increasing DTDC creates less variance in dwell time between dwell positions in each catheter and may be used to induce a more smooth change in dwell time with dwell position in each catheter. Nonzero DTDC values always increased the optimization penalty function value. The DTDC was developed as an extension to IPSA to allow restriction of the difference in dwell time between adjacent dwell positions. This results in less variation between neighboring dwell positions which can be clinically desirable. However, the impact of this restriction needs to be considered for its clinical relevance on a case-by-case basis because considerable degradation in dose-volume histogram metrics can result for large DTDC values. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  5. Factors influencing bolus dwell times in healthy older adults assessed endoscopically.

    Science.gov (United States)

    Butler, Susan G; Maslan, Jonathan; Stuart, Andrew; Leng, Xiaoyan; Wilhelm, Erika; Lintzenich, Catherine Rees; Williamson, Jeff; Kritchevsky, Stephen B

    2011-12-01

    Scant data exist on normal bolus dwell time assessed during flexible endoscopic evaluation of swallowing (FEES). The purpose of this study was to examine bolus dwell time in healthy older adults. Because it has been previously reported that some healthy older adults aspirate, we also sought to determine if bolus dwell time varied as a function of aspiration status. Prospective. Seventy-six healthy volunteers from the seventh, eighth, and ninth decades of life participated. Dwell times were analyzed via FEES as a function of pharyngeal location, liquid type, delivery method, purée type, viscosity, age, and gender. Longer dwell times were evidenced with the eldest participants, straw delivery, and the smallest volume. Adults in the ninth decade were 4.8 (P = .01) and 3.8 (P = .02) times more likely to have longer dwell times at the vallecula and 7.1 (P = .002) and 3.8 (P = 0.02) at the pyriform sinus than those in the seventh and eighth decades, respectively. Longer dwell times at the vallecula and pyriform sinuses were 2 and 2.38 times (P times (P dwell times than larger volumes. Bolus dwell times did not significantly differ as a function of aspiration status. Advanced age, straw delivery, and small volumes yielded longer dwell times. These variables should be considered before diagnosing an abnormal bolus dwell time in elder patients. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

  6. Intravenous Infiltration Risk by Catheter Dwell Time Among Hospitalized Children.

    Science.gov (United States)

    Jeong, Ihn Sook; Jeon, Gey Rok; Lee, Man Seop; Shin, Bum Joo; Kim, Yong-Jin; Park, Soon Mi; Hyun, Sookyung

    This study was aimed to examine the cumulative risk for infiltration over IV catheter dwell time by general or catheterization-specific characteristics of pediatric patients with IV therapy. This secondary data analysis was done with the data of 1596 children who received peripheral IV therapy at least once during their hospital stay between August 1st and October 30th, 2011 and in June, 2013 in an academic medical center, Yangsan, Republic of Korea. The survival functions of infiltration were determined by using the Kaplan-Meier analysis. The cumulative risk for infiltration had rapidly increased from 1.5% after 24 hours of catheter dwell time to 17.3% after 96 hours. The survival functions were significantly different in the medical than in the surgical department (p=.005), lower extremities than upper ones (p=.001), and use of 10% dextrose (p=.001), ampicillin/sulbactam (pdwell times are similar, the cumulative risk for infiltration was higher in cases wherein the patient had a risk factor. The cumulative risk for infiltration has rapidly increased after 24 hours in patients who have 10% dextrose, high-concentration electrolytes, and phenytoin. The results suggest that nurses are required to assess the IV site every hour after 24 hours of catheter dwell time for the infusion of irritants for a safer practice of IV therapy. However, this monitoring time may be modified by the age of child, previous IV complications, and/or hemodynamic issues which may impact IV integrity. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Extending Short Peripheral Catheter Dwell Time: A Best Practice Discussion.

    Science.gov (United States)

    Ansel, Brenda; Boyce, Michelle; Embree, Jennifer L

    Complications involving short peripheral catheters (SPCs) can significantly affect health care costs, patient quality of life, morbidity, mortality, and treatment expense, especially when the hospital stay is lengthened. This article examines the relationship between SPC dwell time and the incidence of phlebitis and potential bacteremia. The literature is replete with most studies supporting SPCs remaining in situ until a clinical reason warrants catheter removal. Removing and not routinely restarting unneccessary intravenous catheters can help prevent catheter-related infections and other vascular complications and reduce cost.

  8. Dwell-time algorithm for polishing large optics.

    Science.gov (United States)

    Wang, Chunjin; Yang, Wei; Wang, Zhenzhong; Yang, Xu; Hu, Chenlin; Zhong, Bo; Guo, Yinbiao; Xu, Qiao

    2014-07-20

    The calculation of the dwell time plays a crucial role in polishing precision large optics. Although some studies have taken place, it remains a challenge to develop a calculation algorithm which is absolutely stable, together with a high convergence ratio and fast solution speed even for extremely large mirrors. For this aim, we introduced a self-adaptive iterative algorithm to calculate the dwell time in this paper. Simulations were conducted in bonnet polishing (BP) to test the performance of this method on a real 430  mm × 430  mm fused silica part with the initial surface error PV=1741.29  nm, RMS=433.204  nm. The final surface residual error in the clear aperture after two simulation steps turned out to be PV=11.7  nm, RMS=0.5  nm. The results confirm that this method is stable and has a high convergence ratio and fast solution speed even with an ordinary computer. It is notable that the solution time is usually just a few seconds even on a 1000  mm × 1000  mm part. Hence, we believe that this method is perfectly suitable for polishing large optics. And not only can it be applied to BP, but it can also be applied to other subaperture deterministic polishing processes.

  9. The effect of tubing dwell time on insulin adsorption during intravenous insulin infusions.

    Science.gov (United States)

    Thompson, Cecilia D; Vital-Carona, Jessica; Faustino, E Vincent S

    2012-10-01

    Insulin adsorbs to plastic tubing, which decreases the concentration of an insulin solution delivered from an intravenous infusion set. Dwelling insulin within tubing before starting the infusion decreases adsorption but delays treatment initiation and wastes time in infusion preparation. The lack of data on dwell time effects results in wide variability in practice. We aim to determine the effect of dwell time on insulin concentration from intravenous infusion tubing. In this in vitro study, we used insulin solutions with concentrations of 0.1 unit/mL, 1 unit/mL, and 10 units/mL. Each solution dwelled in intravenous infusion sets for 0, 15, 30, or 60 min. After the dwell, we measured insulin concentrations from the solution bags and tubing. We repeated each insulin concentration-dwell time combination five times. Comparisons were performed using analyses of variance. For each of the three insulin concentrations, the mean insulin concentrations from the tubing were not significantly different between dwell times. Duration of dwell time did not affect insulin adsorption in polypropylene intravenous infusion sets. We recommend that following a 20-mL flush, insulin infusions can be started without any dwell time. Removal of dwell times may improve clinical practice by minimizing preparation time and will allow faster initiation of insulin infusion therapy.

  10. Social anxiety is related to increased dwell time on socially threatening faces.

    Science.gov (United States)

    Lazarov, Amit; Abend, Rany; Bar-Haim, Yair

    2016-03-15

    Identification of reliable targets for therapeutic interventions is essential for developing evidence-based therapies. Threat-related attention bias has been implicated in the etiology and maintenance of social anxiety disorder. Extant response-time-based threat bias measures have demonstrated limited reliability and internal consistency. Here, we examined gaze patterns of socially anxious and nonanxious participants in relation to social threatening and neutral stimuli using an eye-tracking task, comprised of multiple threat and neutral stimuli, presented for an extended time-period. We tested the psychometric properties of this task with the hope to provide a solid stepping-stone for future treatment development. Eye gaze was tracked while participants freely viewed 60 different matrices comprised of eight disgusted and eight neutral facial expressions, presented for 6000ms each. Gaze patterns on threat and neutral areas of interest (AOIs) of participants with SAD, high socially anxious students and nonanxious students were compared. Internal consistency and test-retest reliability were evaluated. Participants did not differ on first-fixation variables. However, overall, socially anxious students and participants with SAD dwelled significantly longer on threat faces compared with nonanxious participants, with no difference between the anxious groups. Groups did not differ in overall dwell time on neutral faces. Internal consistency of total dwell time on threat and neutral AOIs was high and one-week test-retest reliability was acceptable. Only disgusted facial expressions were used. Relative small sample size. Social anxiety is associated with increased dwell time on socially threatening stimuli, presenting a potential target for therapeutic intervention. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Effects of Improvement on Selective Attention: Developing Appropriate Somatosensory Video Game Interventions for Institutional-Dwelling Elderly with Disabilities

    Science.gov (United States)

    Chen, Shang-Ti; Chiang, I-Tsun; Liu, Eric Zhi-Feng; Chang, Maiga

    2012-01-01

    The purpose of this study was to develop appropriate somatosensory video game interventions on enhancing selective attention of institutional-dwelling elderly with disabilities. Fifty-eight participants aged 65[approximately]92 were recruited and divided into four groups, 4-week and 8-week experimental and two control groups, for evaluating the…

  12. Modeling of switching regulator power stages with and without zero-inductor-current dwell time

    Science.gov (United States)

    Lee, F. C. Y.; Yu, Y.

    1979-01-01

    State-space techniques are employed to derive accurate models for the three basic switching converter power stages: buck, boost, and buck/boost operating with and without zero-inductor-current dwell time. A generalized procedure is developed which treats the continuous-inductor-current mode without dwell time as a special case of the discontinuous-current mode when the dwell time vanishes. Abrupt changes of system behavior, including a reduction of the system order when the dwell time appears, are shown both analytically and experimentally. Merits resulting from the present modeling technique in comparison with existing modeling techniques are illustrated.

  13. Determinants of dwell time in visual search: similarity or perceptual difficulty?

    Science.gov (United States)

    Becker, Stefanie I

    2011-03-08

    The present study examined the factors that determine the dwell times in a visual search task, that is, the duration the gaze remains fixated on an object. It has been suggested that an item's similarity to the search target should be an important determiner of dwell times, because dwell times are taken to reflect the time needed to reject the item as a distractor, and such discriminations are supposed to be harder the more similar an item is to the search target. In line with this similarity view, a previous study shows that, in search for a target ring of thin line-width, dwell times on thin linewidth Landolt C's distractors were longer than dwell times on Landolt C's with thick or medium linewidth. However, dwell times may have been longer on thin Landolt C's because the thin line-width made it harder to detect whether the stimuli had a gap or not. Thus, it is an open question whether dwell times on thin line-width distractors were longer because they were similar to the target or because the perceptual decision was more difficult. The present study de-coupled similarity from perceptual difficulty, by measuring dwell times on thin, medium and thick line-width distractors when the target had thin, medium or thick line-width. The results showed that dwell times were longer on target-similar than target-dissimilar stimuli across all target conditions and regardless of the line-width. It is concluded that prior findings of longer dwell times on thin linewidth-distractors can clearly be attributed to target similarity. As will be discussed towards the end, the finding of similarity effects on dwell times has important implications for current theories of visual search and eye movement control.

  14. Estimation of train dwell time at short stops based on track occupation event data

    NARCIS (Netherlands)

    Li, D.; Daamen, W.; Goverde, R.M.P.

    2015-01-01

    Train dwell time is one of the most unpredictable components of railway operations mainly due to the varying volumes of alighting and boarding passengers. For reliable estimations of train running times and route conflicts on main lines it is however necessary to obtain accurate estimations of dwell

  15. Dwell Time Modelling and Optimized Simulations for Crowded Rail Transit Lines Based on Train Capacity

    Directory of Open Access Journals (Sweden)

    Zhibin Jiang

    2015-04-01

    Full Text Available Understanding the nature of rail transit dwell time has potential benefits for both the users and the operators. Crowded passenger trains cause longer dwell times and may prevent some passengers from boarding the first available train that arrives. Actual dwell time and the process of passenger alighting and boarding are interdependent through the sequence of train stops and propagated delays. A comprehensive and feasible dwell time simulation model was developed and optimized to address the problems associated with scheduled timetables. The paper introduces the factors that affect dwell time in urban rail transit systems, including train headway, the process and number of passengers alighting and boarding the train, and the inability of train doors to properly close the first time because of overcrowded vehicles. Finally, based on a time-driven micro-simulation system, Shanghai rail transit Line 8 is used as an example to quantify the feasibility of scheduled dwell times for different stations, directions of travel and time periods, and a proposed dwell time during peak hours in several crowded stations is presented according to the simulation results.

  16. Dwell time and psychological screening outcomes among military service members with multiple combat deployments.

    Science.gov (United States)

    MacGregor, Andrew J; Heltemes, Kevin J; Clouser, Mary C; Han, Peggy P; Galarneau, Michael R

    2014-04-01

    Recent studies have found that longer dwell times, or the period of time between deployments, may be protective against combat-related psychological outcomes. The purpose of this study was to examine the association between dwell time and psychological morbidity, while accounting for combat exposure. U.S. Marines with two combat deployments between 2005 and 2008 were identified from electronic deployment records. Those who screened positive for post-traumatic stress disorder and depression, and who were referred for mental health services were identified from the Post-Deployment Health Assessment. For the final study sample of 3,512 Marines, dwell time was calculated as time between deployments, and was analyzed as a ratio over length of first deployment. After adjustment for all covariates, there was an interaction (p = 0.01) between dwell time and combat exposure on mental health referral outcome. For personnel with maximum reported combat exposure, longer dwell times were associated with a 49% to 92% reduced odds of mental health referral. Longer dwell times may be protective against combat-related psychological outcomes. Because multiple deployments are likely to be the norm in future military operations, regulating dwell time, particularly for those with greater risk of combat exposure, should continue to be explored. Reprint & Copyright © 2014 Association of Military Surgeons of the U.S.

  17. Observer design for switched recurrent neural networks: an average dwell time approach.

    Science.gov (United States)

    Lian, Jie; Feng, Zhi; Shi, Peng

    2011-10-01

    This paper is concerned with the problem of observer design for switched recurrent neural networks with time-varying delay. The attention is focused on designing the full-order observers that guarantee the global exponential stability of the error dynamic system. Based on the average dwell time approach and the free-weighting matrix technique, delay-dependent sufficient conditions are developed for the solvability of such problem and formulated as linear matrix inequalities. The error-state decay estimate is also given. Then, the stability analysis problem for the switched recurrent neural networks can be covered as a special case of our results. Finally, four illustrative examples are provided to demonstrate the effectiveness and the superiority of the proposed methods. © 2011 IEEE

  18. Dwell time modulation restrictions do not necessarily improve treatment plan quality for prostate HDR brachytherapy.

    Science.gov (United States)

    Balvert, Marleen; Gorissen, Bram L; den Hertog, Dick; Hoffmann, Aswin L

    2015-01-21

    Inverse planning algorithms for dwell time optimisation in interstitial high-dose-rate (HDR) brachytherapy may produce solutions with large dwell time variations within catheters, which may result in undesirable selective high-dose subvolumes. Extending the dwell time optimisation model with a dwell time modulation restriction (DTMR) that limits dwell time differences between neighboring dwell positions has been suggested to eliminate this problem. DTMRs may additionally reduce the sensitivity for uncertainties in dwell positions that inevitably result from catheter reconstruction errors and afterloader source positioning inaccuracies. This study quantifies the reduction of high-dose subvolumes and the robustness against these uncertainties by applying a DTMR to template-based prostate HDR brachytherapy implants. Three different DTMRs were consecutively applied to a linear dose-based penalty model (LD) and a dose-volume based model (LDV), both obtained from literature. The models were solved with DTMR levels ranging from no restriction to uniform dwell times within catheters in discrete steps. Uncertainties were simulated on clinical cases using in-house developed software, and dose-volume metrics were calculated in each simulation. For the assessment of high-dose subvolumes, the dose homogeneity index (DHI) and the contiguous dose volume histogram were analysed. Robustness was measured by the improvement of the lowest D90% of the planning target volume (PTV) observed in the simulations. For (LD), a DTMR yields an increase in DHI of approximately 30% and reduces the size of the largest high-dose volume by 2-5 cc. However, this comes at a cost of a reduction in D90% of the PTV of 10%, which often implies that it drops below the desired minimum of 100%. For (LDV), none of the DTMRs were able to improve high-dose volume measures. DTMRs were not capable of improving robustness of PTV D90% against uncertainty in dwell positions for both models.

  19. Dwell time modulation restrictions do not necessarily improve treatment plan quality for prostate HDR brachytherapy

    Science.gov (United States)

    Balvert, Marleen; Gorissen, Bram L.; den Hertog, Dick; Hoffmann, Aswin L.

    2015-01-01

    Inverse planning algorithms for dwell time optimisation in interstitial high-dose-rate (HDR) brachytherapy may produce solutions with large dwell time variations within catheters, which may result in undesirable selective high-dose subvolumes. Extending the dwell time optimisation model with a dwell time modulation restriction (DTMR) that limits dwell time differences between neighboring dwell positions has been suggested to eliminate this problem. DTMRs may additionally reduce the sensitivity for uncertainties in dwell positions that inevitably result from catheter reconstruction errors and afterloader source positioning inaccuracies. This study quantifies the reduction of high-dose subvolumes and the robustness against these uncertainties by applying a DTMR to template-based prostate HDR brachytherapy implants. Three different DTMRs were consecutively applied to a linear dose-based penalty model (LD) and a dose-volume based model (LDV), both obtained from literature. The models were solved with DTMR levels ranging from no restriction to uniform dwell times within catheters in discrete steps. Uncertainties were simulated on clinical cases using in-house developed software, and dose-volume metrics were calculated in each simulation. For the assessment of high-dose subvolumes, the dose homogeneity index (DHI) and the contiguous dose volume histogram were analysed. Robustness was measured by the improvement of the lowest D90% of the planning target volume (PTV) observed in the simulations. For (LD), a DTMR yields an increase in DHI of approximately 30% and reduces the size of the largest high-dose volume by 2-5 cc. However, this comes at a cost of a reduction in D90% of the PTV of 10%, which often implies that it drops below the desired minimum of 100%. For (LDV), none of the DTMRs were able to improve high-dose volume measures. DTMRs were not capable of improving robustness of PTV D90% against uncertainty in dwell positions for both models.

  20. Dwell time algorithm for multi-mode optimization in manufacturing large optical mirrors

    Science.gov (United States)

    Liu, Zhenyu

    2014-08-01

    CCOS (Computer Controlled Optical Surfacing) is one of the most important method to manufacture optical surface. By controlling the dwell time of a polishing tool on the mirror we can get the desired material removal. As the optical surface becoming larger, traditional CCOS method can't meet the demand that manufacturing the mirror in higher efficiency and precision. This paper presents a new method using multi-mode optimization. By calculate the dwell time map of different tool in one optimization cycle, the larger tool and the small one have complementary advantages and obtain a global optimization for multi tool and multi-processing cycles. To calculate the dwell time of different tool at the same time we use multi-mode dwell time algorithm that based on matrix calculation. With this algorithm we did simulation experiment, the result shows using multi-mode optimization algorithm can improve the efficiency maintaining good precision.

  1. Attention and Reaction Time in Shotokan Athletes

    OpenAIRE

    António VencesBrito; Carlos Silva; Luis Cid; Dora Ferreira; Ana Marques

    2012-01-01

    The aim of this study is to analyze the attention capacity and the reaction time in Portuguese karate Shotokan athletes. Participated 96 Shotokan athletes from the Portuguese Karate Association. We physically characterized the sample (weight, height, body mass index, and body fat mass percentage) and evaluated Simple Reaction Time (TRS), Choice Reaction Time (TRE), Decision Time (TD) and the Distributed Attention (AD). Data was analyzed according to athletes’ group age (15 to 19 yr, 20 to 35 ...

  2. Stability analysis of switched cellular neural networks: A mode-dependent average dwell time approach.

    Science.gov (United States)

    Huang, Chuangxia; Cao, Jie; Cao, Jinde

    2016-10-01

    This paper addresses the exponential stability of switched cellular neural networks by using the mode-dependent average dwell time (MDADT) approach. This method is quite different from the traditional average dwell time (ADT) method in permitting each subsystem to have its own average dwell time. Detailed investigations have been carried out for two cases. One is that all subsystems are stable and the other is that stable subsystems coexist with unstable subsystems. By employing Lyapunov functionals, linear matrix inequalities (LMIs), Jessen-type inequality, Wirtinger-based inequality, reciprocally convex approach, we derived some novel and less conservative conditions on exponential stability of the networks. Comparing to ADT, the proposed MDADT show that the minimal dwell time of each subsystem is smaller and the switched system stabilizes faster. The obtained results extend and improve some existing ones. Moreover, the validness and effectiveness of these results are demonstrated through numerical simulations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. A Fuzzy Logic-Based Approach for Estimation of Dwelling Times of Panama Metro Stations

    Directory of Open Access Journals (Sweden)

    Aranzazu Berbey Alvarez

    2015-04-01

    Full Text Available Passenger flow modeling and station dwelling time estimation are significant elements for railway mass transit planning, but system operators usually have limited information to model the passenger flow. In this paper, an artificial-intelligence technique known as fuzzy logic is applied for the estimation of the elements of the origin-destination matrix and the dwelling time of stations in a railway transport system. The fuzzy inference engine used in the algorithm is based in the principle of maximum entropy. The approach considers passengers’ preferences to assign a level of congestion in each car of the train in function of the properties of the station platforms. This approach is implemented to estimate the passenger flow and dwelling times of the recently opened Line 1 of the Panama Metro. The dwelling times obtained from the simulation are compared to real measurements to validate the approach.

  4. Retrieval of TRAPEASE and OPTEASE Inferior Vena Cava Filters with Extended Dwell Times.

    Science.gov (United States)

    Scher, Daniel; Venbrux, Anthony; Okapal, Kevin; Gabriel, Gaby; Dufour, Robert; Chun, Albert; Sarin, Shawn; Akman, Andrew

    2015-10-01

    To demonstrate that OPTEASE and TRAPEASE filters can be removed after dwell times greater than 60 days. A retrospective review was performed of patients who underwent an attempted removal of a TRAPEASE or OPTEASE filter with a greater than 60-day dwell time between 2009 and 2015 at a single institution. Eleven patients within that time span were identified, and 10 were included in the review. One patient was excluded from the study because the date of filter placement was unknown. All filters were successfully retrieved. The average dwell time for removed TRAPEASE filters was 1,273 days (range, 129-3,582 d), with a median of 492 days (n = 5). The average dwell time for OPTEASE filters was 977 days (range, 123-2,584 d), with a median of 661 days (n = 5). The average dwell time of all filters was 1,125 days (range, 123-3,582 d), with a median of 577 days (n = 10). All patients exhibited inferior vena cava (IVC) stenosis after filter retrieval. An IVC pseudoaneurysm was present following retrieval in one case and resolved. In one case, a fractured filter strut was left completely embedded in the caval wall. Two patients reported unilateral leg swelling on clinical follow-up, and the remainder reported no leg swelling or tightness. Initial experience suggests that TRAPEASE and OPTEASE filters can be removed after extended dwell times. Copyright © 2015 SIR. Published by Elsevier Inc. All rights reserved.

  5. Impact of Interlayer Dwell Time on Microstructure and Mechanical Properties of Nickel and Titanium Alloys

    Science.gov (United States)

    Foster, B. K.; Beese, A. M.; Keist, J. S.; McHale, E. T.; Palmer, T. A.

    2017-09-01

    Path planning in additive manufacturing (AM) processes has an impact on the thermal histories experienced at discrete locations in simple and complex AM structures. One component of path planning in directed energy deposition is the time required for the laser or heat source to return to a given location to add another layer of material. As structures become larger and more complex, the length of this interlayer dwell time can significantly impact the resulting thermal histories. The impact of varying dwell times between 0 and 40 seconds on the microstructural and mechanical properties of Inconel® 625 and Ti-6Al-4V builds has been characterized. Even though these materials display different microstructures and solid-state phase transformations, the addition of an interlayer dwell generally led to a finer microstructure in both materials that impacted the resulting mechanical properties. With the addition of interlayer dwell times up to 40 seconds in the Inconel® 625 builds, finer secondary dendrite arm spacing values, produced by changes in the thermal history, correspond to increased yield and tensile strengths. These mechanical properties did not appear to change significantly, however, for dwell times greater than 20 seconds in the Inconel® 625 builds, indicating that longer dwell times have a minimal impact. The addition of interlayer dwell times in Ti-6Al-4V builds resulted in a slight decrease in the measured alpha lath widths and a much more noticeable decrease in the width of prior beta grains. In addition, the yield and tensile values continued to increase, nearly reaching the values observed in the rolled plate substrate material with dwell times up to 40 seconds.

  6. Catheter dwell time and CLABSIs in neonates with PICCs: a multicenter cohort study.

    Science.gov (United States)

    Milstone, Aaron M; Reich, Nicholas G; Advani, Sonali; Yuan, Guoshu; Bryant, Kristina; Coffin, Susan E; Huskins, W Charles; Livingston, Robyn; Saiman, Lisa; Smith, P Brian; Song, Xiaoyan

    2013-12-01

    To determine whether the daily risk of central line-associated bloodstream infections (CLABSIs) increases over the dwell time of peripherally inserted central catheters (PICCs) in high-risk neonates. Multicenter retrospective cohort including NICU patients with a PICC inserted between January 2005 and June 2010. We calculated incidence rates and used Poisson regression models to assess the risk of developing CLABSI as a function of PICC dwell time. A total of 4797 PICCs placed in 3967 neonates were included; 149 CLABSIs occurred over 89,946 catheter-days (incidence rate 1.66 per 1000 catheter-days). In unadjusted analysis, PICCs with a dwell time of 8 to 13 days, 14 to 22 days, and ≥23 days each had an increased risk of infection compared with PICCs in place for ≤7 days (P dwell time of the catheter. There was an increased risk of CLABSIs in neonates with concurrent PICCs (adjusted incidence rate ratio 2.04, 1.12-3.71). The incidence of Gram-negative CLABSIs was greater in PICCs with dwell times >50 days (incidence rate ratio 5.26, 2.40-10.66). The risk of CLABSIs increased during the 2 weeks after PICC insertion and then remained elevated until PICC removal. Clinicians should review PICC necessity daily, optimize catheter maintenance practices, and investigate novel CLABSI prevention strategies in PICCs with prolonged dwell times.

  7. A Factorial Data Rate and Dwell Time Experiment in the National Transonic Facility

    Science.gov (United States)

    DeLoach, R.

    2000-01-01

    This report is an introductory tutorial on the application of formal experiment design methods to wind tunnel testing, for the benefit of aeronautical engineers with little formal experiment design training. It also describes the results of a Study to determine whether increases in the sample rate and dwell time of the National Transonic Facility data system Would result in significant changes in force and moment data. Increases in sample rate from 10 samples per second to 50 samples per second were examined, as were changes in dwell time from one second per data point to two seconds. These changes were examined for a representative aircraft model in a range of tunnel operating conditions defined by angles of attack from 0 deg to 3.8 degrees, total pressure from 15.0 psi to 24.1 psi, and Mach numbers from 0.52 to 0.82. No statistically significant effect was associated with the change in sample rate. The change in dwell time from one second to two seconds affected axial force measurements, and to a lesser degree normal force measurements. This dwell effect comprises a "rectification error" caused by incomplete cancellation of the positive and negative elements of certain low frequency dynamic components that are not rejected by the one-Hz low-pass filters of the data system. These low frequency effects may be due to tunnel circuit phenomena and other sources. The magnitude of the dwell effect depends on dynamic pressure, with angle of attack and Mach number influencing the strength of this dependence. An analysis is presented which suggests that the magnitude of the rectification error depends on the ratio of measurement dwell time to the period of the low-frequency dynamics, as well as the amplitude of the dynamics The essential conclusion of this analysis is that extending the dwell time (or, equivalently, replicating short-dwell data points) reduces the rectification error.

  8. Alert dwell time: introduction of a measure to evaluate interruptive clinical decision support alerts.

    Science.gov (United States)

    McDaniel, Robert B; Burlison, Jonathan D; Baker, Donald K; Hasan, Murad; Robertson, Jennifer; Hartford, Christine; Howard, Scott C; Sablauer, Andras; Hoffman, James M

    2016-04-01

    Metrics for evaluating interruptive prescribing alerts have many limitations. Additional methods are needed to identify opportunities to improve alerting systems and prevent alert fatigue. In this study, the authors determined whether alert dwell time-the time elapsed from when an interruptive alert is generated to when it is dismissed-could be calculated by using historical alert data from log files. Drug-drug interaction (DDI) alerts from 3 years of electronic health record data were queried. Alert dwell time was calculated for 25,965 alerts, including 777 unique DDIs. The median alert dwell time was 8 s (range, 1-4913 s). Resident physicians had longer median alert dwell times than other prescribers (P dwell times than alerts that only occurred once (P < 001). This metric can be used in future research to evaluate the effectiveness and efficiency of interruptive prescribing alerts. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Larmor precession and dwell time of a relativistic particle scattered by a rectangular quantum well

    CERN Document Server

    Li, Z J; Liang, J J; Liang, J Q

    2003-01-01

    The Larmor precession of a relativistic neutral spin particle in a uniform constant magnetic field confined to the region of a one-dimensional rectangular potential well is investigated. The spin precession serves as a clock to measure the time spent by a quantum particle dwelling at a potential well. With the help of a general spin coherent state it is explicitly shown that the spin precession time is equal to the dwell time in the first-order approximation of the infinitesimal field limit. The comparison of the time in a potential well with that in free space shows apparent superluminality.

  10. Effect of buccal dwell time on the pharmacokinetic profile of fentanyl buccal tablet.

    Science.gov (United States)

    Darwish, M; Kirby, M; Jiang, J G

    2007-09-01

    The time fentanyl buccal tablet (FBT) takes to completely dissolve after placement on the buccal mucosa (i.e., 'dwell time') could exceed the time to onset of analgesia. To examine the relationship between FBT dwell time and fentanyl pharmacokinetic parameters. This was a post hoc exploratory analysis of data from two randomized, open-label, crossover, pharmaco-kinetic studies that were designed to assess dose proportionality within the anticipated therapeutic dose range. Healthy adults received single FBT doses of 200-1080 microg in Study 1 (n = 28) and 270-1300 microg in Study 2 (n = 42). Assessments included buccal dwell time, defined as the duration of FBT presence in the oral cavity, and the following pharmacokinetic measures: maximum serum concentration (C(max)), time to C(max) (T(max)) and area under the concentration-time curve (AUC; exposure) from 0 minutes to median T(max) adjusted for the dose (T(max')) (AUC(0 T(max'))). Spontaneously reported adverse events were recorded. Mean buccal dwell time for FBT across the dose range varied from 14 to 25 minutes (range 3 - 62 minutes). There was no evidence of an association between FBT dwell time and values for T(max) (medians 45 - 60 minutes), dose-normalized C(max) (means 0.42-0.66 pg/ml/200 microg) or dose-normalized AUC(0 T(max')) (means 0.24-0.38 pg x h/ml/200 microg) over the range of FBT doses delivered. All adverse events reported were mild to moderate; none were unexpected or serious. The pharmacokinetic parameters of FBT did not appear to be related to its buccal dwell time.

  11. Attention and Reaction Time in Shotokan Athletes

    Directory of Open Access Journals (Sweden)

    António VencesBrito

    2012-07-01

    Full Text Available The aim of this study is to analyze the attention capacity and the reaction time in Portuguese karate Shotokan athletes. Participated 96 Shotokan athletes from the Portuguese Karate Association. We physically characterized the sample (weight, height, body mass index, and body fat mass percentage and evaluated Simple Reaction Time (TRS, Choice Reaction Time (TRE, Decision Time (TD and the Distributed Attention (AD. Data was analyzed according to athletes’ group age (15 to 19 yr, 20 to 35 yr and more than 35 yr, level of graduation (9th to 4th kyu, 3rd to 1st kyu, DAN and by gender (male and female. Male athletes present significant differences from female athletes in height, weight, years of practice and body fat mass. In relation to TRS all groups tend to a value near to 300 ms without significant differences among them, but the TRE and the TD are significantly higher in the Dan athletes and in the +35 yrs athletes than in the other groups. On the other hand the Dan and +35 yrs athletes tend to do less mistakes. Gender does not influence significantly the reaction time in the Shotokan karate athletes, but it seems that women tend to have smaller reaction times than men. Athletes with more years of practice and more graduation need more time to reply to the stimulus than the other athletes, but they tend to do fewer mistakes on their choices than other subjects. As for distributed attention, no significant differences were found in function of the athlete graduation, nor in function of gender. However, for distributed attention, we found statistical significant differences in function of the age, with the oldest athletes presenting lower levels of distributed attention. Our results seem to show that is necessary to do some modifications in the training process of Portuguese Shotokan karate athletes.

  12. Project HANDS: A Bundled Approach to Increase Short Peripheral Catheter Dwell Time.

    Science.gov (United States)

    Crowell, Judybeth; OʼNeil, Karen; Drager, Leslie

    Increasing short peripheral catheter (SPC) dwell time is becoming common practice. A number of variables lead to unscheduled restarts and significant complications with SPCs. Preventing complications is important to patient outcomes as dwell time increases. This quality improvement project compared the use of a manufactured securement device versus tape and transparent occlusive dressing while instituting a standardized insertion and care bundle with a 96-hour dwell time. Major findings included no statistically significant difference in restart rates in SPCs secured with a device compared with those secured with tape and transparent occlusive dressing (P = .06). These results differ from other published studies and may be due to the traditional nature of the hospital's infusion team and patients' average length of stay.

  13. An ELM-Based Approach for Estimating Train Dwell Time in Urban Rail Traffic

    Directory of Open Access Journals (Sweden)

    Wen-jun Chu

    2015-01-01

    Full Text Available Dwell time estimation plays an important role in the operation of urban rail system. On this specific problem, a range of models based on either polynomial regression or microsimulation have been proposed. However, the generalization performance of polynomial regression models is limited and the accuracy of existing microsimulation models is unstable. In this paper, a new dwell time estimation model based on extreme learning machine (ELM is proposed. The underlying factors that may affect urban rail dwell time are analyzed first. Then, the relationships among different factors are extracted and modeled by ELM neural networks, on basis of which an overall estimation model is proposed. At last, a set of observed data from Beijing subway is used to illustrate the proposed method and verify its overall performance.

  14. Role of step size and max dwell time in anatomy based inverse optimization for prostate implants.

    Science.gov (United States)

    Manikandan, Arjunan; Sarkar, Biplab; Rajendran, Vivek Thirupathur; King, Paul R; Sresty, N V Madhusudhana; Holla, Ragavendra; Kotur, Sachin; Nadendla, Sujatha

    2013-07-01

    In high dose rate (HDR) brachytherapy, the source dwell times and dwell positions are vital parameters in achieving a desirable implant dose distribution. Inverse treatment planning requires an optimal choice of these parameters to achieve the desired target coverage with the lowest achievable dose to the organs at risk (OAR). This study was designed to evaluate the optimum source step size and maximum source dwell time for prostate brachytherapy implants using an Ir-192 source. In total, one hundred inverse treatment plans were generated for the four patients included in this study. Twenty-five treatment plans were created for each patient by varying the step size and maximum source dwell time during anatomy-based, inverse-planned optimization. Other relevant treatment planning parameters were kept constant, including the dose constraints and source dwell positions. Each plan was evaluated for target coverage, urethral and rectal dose sparing, treatment time, relative target dose homogeneity, and nonuniformity ratio. The plans with 0.5 cm step size were seen to have clinically acceptable tumor coverage, minimal normal structure doses, and minimum treatment time as compared with the other step sizes. The target coverage for this step size is 87% of the prescription dose, while the urethral and maximum rectal doses were 107.3 and 68.7%, respectively. No appreciable difference in plan quality was observed with variation in maximum source dwell time. The step size plays a significant role in plan optimization for prostate implants. Our study supports use of a 0.5 cm step size for prostate implants.

  15. Asynchronous control of discrete-time impulsive switched systems with mode-dependent average dwell time.

    Science.gov (United States)

    Wang, Bo; Zhang, Hongbin; Wang, Gang; Dang, Chuangyin; Zhong, Sijun

    2014-03-01

    This paper mainly studies the asynchronous control problem for a class of discrete-time impulsive switched systems, where "asynchronous" means the switching of the controllers has a lag to the switching of system modes. By using multiple Lyapunov functions (MLFs), the much looser asymptotic stability result of closed-loop systems is derived with a mode-dependent average dwell time (MDADT) technique. Based on the stability result obtained, the problem of asynchronous control is solved under a proper switching law. Moreover, the stability and stabilization results are formulated in form of matrix inequalities that are numerically feasible. Finally, an illustrative numerical example is presented to show the effectiveness of the obtained stability results. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  16. Effect of dwell time on the mental health of US military personnel with multiple combat tours.

    Science.gov (United States)

    MacGregor, Andrew J; Han, Peggy P; Dougherty, Amber L; Galarneau, Michael R

    2012-03-01

    We investigated the association of the length of time spent at home between deployments, or dwell time, with posttraumatic stress disorder (PTSD) and other mental health disorders. We included US Marine Corps personnel identified from military deployment records who deployed to Operation Iraqi Freedom once (n = 49,328) or twice (n = 16,376). New-onset mental health diagnoses from military medical databases were included. We calculated the ratio of dwell-to-deployment time (DDR) as the length of time between deployments divided by the length of the first deployment. Marines with 2 deployments had higher rates of PTSD than did those with 1 deployment (2.1% versus 1.2%; P times at home relative to first deployment length was associated with reduced odds of PTSD (odds ratio [OR] = 0.47; 95% confidence interval [CI] = 0.32, 0.70), PTSD with other mental health disorder (OR = 0.56; 95% CI = 0.33, 0.94), and other mental health disorders (OR = 0.62; 95% CI = 0.51, 0.75). Longer dwell times may reduce postdeployment risk of PTSD and other mental health disorders. Future research should focus on the role of dwell time in adverse health outcomes.

  17. Ligand-specific endocytic dwell times control functional selectivity of the cannabinoid receptor 1.

    Science.gov (United States)

    Flores-Otero, Jacqueline; Ahn, Kwang H; Delgado-Peraza, Francheska; Mackie, Ken; Kendall, Debra A; Yudowski, Guillermo A

    2014-08-01

    G protein-coupled receptors (GPCRs) are the major transducers of external stimuli and key therapeutic targets in many pathological conditions. When activated by different ligands, one receptor can elicit multiple signalling cascades that are mediated by G proteins or β-arrestin, a process defined as functional selectivity or ligand bias. However, the dynamic mechanisms underlying β-arrestin signalling remain unknown. Here by studying the cannabinoid receptor 1 (CB1R), we identify ligand-specific endocytic dwell times, that is, the time during which receptors are clustered into clathrin pits together with β-arrestins before endocytosis, as the mechanism controlling β-arrestin signalling. Agonists inducing short endocytic dwell times produce little or no β-arrestin signalling, whereas those eliciting prolonged dwell times induce robust signalling. Remarkably, extending CB1R dwell times by preventing endocytosis substantially increased β-arrestin signalling. These studies reveal how receptor activation translates into β-arrestin signalling and identify a mechanism to control this pathway.

  18. Model and algorithm based on accurate realization of dwell time in magnetorheological finishing.

    Science.gov (United States)

    Song, Ci; Dai, Yifan; Peng, Xiaoqiang

    2010-07-01

    Classically, a dwell-time map is created with a method such as deconvolution or numerical optimization, with the input being a surface error map and influence function. This dwell-time map is the numerical optimum for minimizing residual form error, but it takes no account of machine dynamics limitations. The map is then reinterpreted as machine speeds and accelerations or decelerations in a separate operation. In this paper we consider combining the two methods in a single optimization by the use of a constrained nonlinear optimization model, which regards both the two-norm of the surface residual error and the dwell-time gradient as an objective function. This enables machine dynamic limitations to be properly considered within the scope of the optimization, reducing both residual surface error and polishing times. Further simulations are introduced to demonstrate the feasibility of the model, and the velocity map is reinterpreted from the dwell time, meeting the requirement of velocity and the limitations of accelerations or decelerations. Indeed, the model and algorithm can also apply to other computer-controlled subaperture methods.

  19. Inferior vena cava filter removal after prolonged dwell time of 2310 days.

    Science.gov (United States)

    Shah, Ankit H; Lichliter, Andrew; Cura, Marco

    2016-07-01

    Inferior vena cava filters are commonly placed for a variety of indications, often when anticoagulation is contraindicated. Although technical success is high and complication rates low, there are complications that are important to be aware of. We present the case of a 29-year-old woman with a prolonged filter dwell time resulting in complications.

  20. Analysis of Kinetic Intermediates in Single-Particle Dwell-Time Distributions

    NARCIS (Netherlands)

    Floyd, Daniel L.; Harrison, Stephen C.; Oijen, Antoine M. van

    2010-01-01

    Many biological and chemical processes proceed through one or more intermediate steps. Statistical analysis of dwell-time distributions from single molecule trajectories enables the study of intermediate steps that are not directly observable. Here, we discuss the application of the randomness

  1. Exponential stabilisation for time-varying delay system with actuator faults: an average dwell time method

    Science.gov (United States)

    Wang, Limin; Shao, Cheng

    2010-04-01

    The issue of exponential stabilisation for a class of special time-varying delay switched systems resulting from actuator faults is considered in this article. The time-varying delay is assumed to belong to an interval and can be a slow or fast time-varying function. A hybrid state feedback strategy is redesigned to guarantee the system stable since the original controller is unavailable for some actuators failures. A class of switching laws incorporating the average dwell time method is proposed so that the special switched system with interval time-varying delay is exponentially stable. New delay-range-dependent stabilisation conditions using state feedback controllers are formulated in terms of linear matrix inequalities (LMIs) by choosing appropriate Lyapunov-Krasovskii functional without neglecting some useful knowledge on system states. Parameterised characterisations of the controllers are given in terms of the feasibility solutions to the LMIs. Two numeral examples are given to demonstrate the applicability and the effectiveness of the proposed method.

  2. Evaluation of number concentration quantification by single-particle inductively coupled plasma mass spectrometry: microsecond vs. millisecond dwell times.

    Science.gov (United States)

    Abad-Álvaro, Isabel; Peña-Vázquez, Elena; Bolea, Eduardo; Bermejo-Barrera, Pilar; Castillo, Juan R; Laborda, Francisco

    2016-07-01

    The quality of the quantitative information in single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS) depends directly on the number concentration of the nanoparticles in the sample analyzed, which is proportional to the flux of nanoparticles through the plasma. Particle number concentrations must be selected in accordance with the data acquisition frequency, to control the precision from counting statistics and the bias, which is produced by the occurrence of multiple-particle events recorded as single-particle events. With quadrupole mass spectrometers, the frequency of data acquisition is directly controlled by the dwell time. The effect of dwell times from milli- to microseconds (10 ms, 5 ms, 100 μs, and 50 μs) on the quality of the quantitative data has been studied. Working with dwell times in the millisecond range, precision figures about 5 % were achieved, whereas using microsecond dwell times, the suitable fluxes of nanoparticles are higher and precision was reduced down to 1 %; this was independent of the dwell time selected. Moreover, due to the lower occurrence of multiple-nanoparticle events, linear ranges are wider when dwell times equal to or shorter than 100 μs are used. A calculation tool is provided to determine the optimal concentration for any instrument or experimental conditions selected. On the other hand, the use of dwell times in the microsecond range reduces significantly the contribution of the background and/or the presence of dissolved species, in comparison with the use of millisecond dwell times. Although the use of dwell times equal to or shorter than 100 μs offers improved performance working in single-particle mode, the use of conventional dwell times (3-10 ms) should not be discarded, once their limitations are known.

  3. Modified dwell time optimization model and its applications in subaperture polishing.

    Science.gov (United States)

    Dong, Zhichao; Cheng, Haobo; Tam, Hon-Yuen

    2014-05-20

    The optimization of dwell time is an important procedure in deterministic subaperture polishing. We present a modified optimization model of dwell time by iterative and numerical method, assisted by extended surface forms and tool paths for suppressing the edge effect. Compared with discrete convolution and linear equation models, the proposed model has essential compatibility with arbitrary tool paths, multiple tool influence functions (TIFs) in one optimization, and asymmetric TIFs. The emulational fabrication of a Φ200  mm workpiece by the proposed model yields a smooth, continuous, and non-negative dwell time map with a root-mean-square (RMS) convergence rate of 99.6%, and the optimization costs much less time. By the proposed model, influences of TIF size and path interval to convergence rate and polishing time are optimized, respectively, for typical low and middle spatial-frequency errors. Results show that (1) the TIF size is nonlinear inversely proportional to convergence rate and polishing time. A TIF size of ~1/7 workpiece size is preferred; (2) the polishing time is less sensitive to path interval, but increasing the interval markedly reduces the convergence rate. A path interval of ~1/8-1/10 of the TIF size is deemed to be appropriate. The proposed model is deployed on a JR-1800 and MRF-180 machine. Figuring results of Φ920  mm Zerodur paraboloid and Φ100  mm Zerodur plane by them yield RMS of 0.016λ and 0.013λ (λ=632.8  nm), respectively, and thereby validate the feasibility of proposed dwell time model used for subaperture polishing.

  4. Extending the absorbing boundary method to fit dwell-time distributions of molecular motors with complex kinetic pathways.

    Science.gov (United States)

    Liao, Jung-Chi; Spudich, James A; Parker, David; Delp, Scott L

    2007-02-27

    Dwell-time distributions, waiting-time distributions, and distributions of pause durations are widely reported for molecular motors based on single-molecule biophysical experiments. These distributions provide important information concerning the functional mechanisms of enzymes and their underlying kinetic and mechanical processes. We have extended the absorbing boundary method to simulate dwell-time distributions of complex kinetic schemes, which include cyclic, branching, and reverse transitions typically observed in molecular motors. This extended absorbing boundary method allows global fitting of dwell-time distributions for enzymes subject to different experimental conditions. We applied the extended absorbing boundary method to experimental dwell-time distributions of single-headed myosin V, and were able to use a single kinetic scheme to fit dwell-time distributions observed under different ligand concentrations and different directions of optical trap forces. The ability to use a single kinetic scheme to fit dwell-time distributions arising from a variety of experimental conditions is important for identifying a mechanochemical model of a molecular motor. This efficient method can be used to study dwell-time distributions for a broad class of molecular motors, including kinesin, RNA polymerase, helicase, F(1) ATPase, and to examine conformational dynamics of other enzymes such as ion channels.

  5. Adaptive Output-Feedback Neural Control of Switched Uncertain Nonlinear Systems With Average Dwell Time.

    Science.gov (United States)

    Long, Lijun; Zhao, Jun

    2015-07-01

    This paper investigates the problem of adaptive neural tracking control via output-feedback for a class of switched uncertain nonlinear systems without the measurements of the system states. The unknown control signals are approximated directly by neural networks. A novel adaptive neural control technique for the problem studied is set up by exploiting the average dwell time method and backstepping. A switched filter and different update laws are designed to reduce the conservativeness caused by adoption of a common observer and a common update law for all subsystems. The proposed controllers of subsystems guarantee that all closed-loop signals remain bounded under a class of switching signals with average dwell time, while the output tracking error converges to a small neighborhood of the origin. As an application of the proposed design method, adaptive output feedback neural tracking controllers for a mass-spring-damper system are constructed.

  6. T cell receptor dwell times control the kinase activity of Zap70.

    Science.gov (United States)

    Klammt, Christian; Novotná, Lucie; Li, Dongyang T; Wolf, Miriam; Blount, Amy; Zhang, Kai; Fitchett, Jonathan R; Lillemeier, Björn F

    2015-09-01

    Kinase recruitment to membrane receptors is essential for signal transduction. However, the underlying regulatory mechanisms are poorly understood. We investigated how conformational changes control T cell receptor (TCR) association and activity of the kinase Zap70. Structural analysis showed that TCR binding or phosphorylation of Zap70 triggers a transition from a closed, autoinhibited conformation to an open conformation. Using Zap70 mutants with defined conformations, we found that TCR dwell times controlled Zap70 activity. The closed conformation minimized TCR dwell times and thereby prevented activation by membrane-associated kinases. Parallel recruitment of coreceptor-associated Lck kinase to the TCR ensured Zap70 phosphorylation and stabilized Zap70 TCR binding. Our study suggests that the dynamics of cytosolic enzyme recruitment to the plasma membrane regulate the activity and function of receptors lacking intrinsic catalytic activity.

  7. Treating Fasciotomy Wounds with Negative Pressure Wound Therapy with Instillation and Dwell Time (NPWTi-d)

    OpenAIRE

    Lee, Priscilla

    2016-01-01

    Acute compartment syndrome (ACS) is a serious complication of lower-extremity trauma caused by accidents or post-procedure complications. ACS is characterized by increased pressure within the compartment, resulting in reduced blood flow, tissue hypoxia, and tissue necrosis. Fasciotomies to relieve pressure and debridement of necrotic tissue comprise primary treatment. My purpose is to present initial experience using negative pressure wound therapy with instillation and dwell time (NPWTi-d)* ...

  8. Ureteric stent dwelling time: a risk factor for post-ureteroscopy sepsis.

    Science.gov (United States)

    Nevo, Amihay; Mano, Roy; Baniel, Jack; Lifshitz, David A

    2017-07-01

    To evaluate the association between stent dwelling time and sepsis after ureteroscopy, and identify risk factors for sepsis in this setting. The prospectively collected database of a single institution was queried for all patients who underwent ureteroscopy for stone extraction between 2010 and 2016. Demographic, clinical, preoperative and operative data were collected. The primary study endpoint was sepsis within 48 h of ureteroscopy. Logistic regressions were performed to identify predictors of post-ureteroscopy sepsis in the ureteroscopy cohort and specifically in patients with prior stent insertion. Between October 2010 and April 2016, 1 256 patients underwent ureteroscopy for stone extraction. Risk factors for sepsis included prior stent placement, female gender and Charlson comorbidity index. A total of 601 patients had a ureteric stent inserted before the operation and were included in the study cohort, in which the median age was 56 years, 90 patients were women (30%), and 97 patients were treated for positive preoperative urine cultures (16.1%). Postoperative sepsis, Sepsis rates after stent dwelling times of 1, 2, 3 and >3 months were 1, 4.9, 5.5 and 9.2%, respectively. On multivariate analysis, stent dwelling time, stent insertion because of sepsis, and female gender were significantly associated with post-ureteroscopy sepsis in patients with prior stent placement. Patients who undergo ureteroscopy after ureteric stent insertion have a higher risk of postoperative sepsis. Prolonged stent dwelling time, sepsis as an indication for stent insertion, and female gender are independent risk factors. Stent placement should be considered cautiously, and if inserted, ureteroscopy should be performed within 1 month. © 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.

  9. Catheter dwell time and diameter affect the recurrence rates after internal urethrotomy.

    Science.gov (United States)

    Yürük, Emrah; Yentur, Serhat; Çakır, Ömer Onur; Ertaş, Kasım; Şerefoğlu, Ege Can; Semerciöz, Atilla

    2016-09-01

    Cold-knife direct vision internal urethrotomy (DVIU) is frequently used as the first-line treatment for urethral stricture disease. Although the steps of the procedure are defined in detail, the duration of catheterization and the diameter of the catheter to be used after the operation are not clearly defined. The aim of this study is to evaluate the effects of catheter dwell time and diameter on recurrence rates of urethral stricture disease after DVIU. Data of 193 consecutive treatment naïve bulbar urethral stricture patients who underwent DVIU between January 2009 and June 2013 were retrospectively analyzed. Patient demographics and stricture characteristics were noted. Catheter dwell times were grouped as dwell times, and diameter were evaluated with Tukey's test and Pearson's correlation test, respectively. Overall 193 patients with a mean age of 64.51±12.99 (range: 17 to 85) years were enrolled in the study. Urethral stricture disease recurred in 45 (23.31%) patients within the first year after DVIU. Mean duration of catheterization was 7.47±4.03 and 4.79±1.94 days in patients with and without recurrences, respectively (p=0.0001). Catheter dwell times for ≥5 days were also associated with increased recurrence (p=0.0001). Of the patients with recurrent strictures, 16, 18 and 22Fr catheters were placed in 22.22%, 20% and 57.78% of the patients, respectively. Increased catheter diameter was also associated with higher recurrence rates (p=0.004). Shortening the postoperative duration of catheterization and decreasing the catheter size may result in improved recurrence rates after DVIU. Further prospective randomized trials are necessary to confirm these findings.

  10. Effect of Catheter Dwell Time on Risk of Central Line-Associated Bloodstream Infection in Infants.

    Science.gov (United States)

    Greenberg, Rachel G; Cochran, Keith M; Smith, P Brian; Edson, Barbara S; Schulman, Joseph; Lee, Henry C; Govindaswami, Balaji; Pantoja, Alfonso; Hardy, Doug; Curran, John; Lin, Della; Kuo, Sheree; Noguchi, Akihiko; Ittmann, Patricia; Duncan, Scott; Gupta, Munish; Picarillo, Alan; Karna, Padmani; Cohen, Morris; Giuliano, Michael; Carroll, Sheri; Page, Brandi; Guzman-Cottrill, Judith; Walker, M Whit; Garland, Jeff; Ancona, Janice K; Ellsbury, Dan L; Laughon, Matthew M; McCaffrey, Martin J

    2015-12-01

    Central venous catheters in the NICU are associated with significant morbidity and mortality because of the risk of central line-associated bloodstream infections (CLABSIs). The purpose of this study was to determine the effect of catheter dwell time on risk of CLABSI. Retrospective cohort study of 13,327 infants with 15,567 catheters (93% peripherally inserted central catheters [PICCs], 7% tunneled catheters) and 256,088 catheter days cared for in 141 NICUs. CLABSI was defined using National Health Surveillance Network criteria. We defined dwell time as the number of days from line insertion until either line removal or day of CLABSI. We generated survival curves for each week of dwell time and estimated hazard ratios for CLABSI at each week by using a Cox proportional hazards frailty model. We controlled for postmenstrual age and year, included facility as a random effect, and generated separate models by line type. Median postmenstrual age was 29 weeks (interquartile range 26-33). The overall incidence of CLABSI was 0.93 per 1000 catheter days. Increased dwell time was not associated with increased risk of CLABSI for PICCs. For tunneled catheters, infection incidence was significantly higher in weeks 7 and 9 compared with week 1. Clinicians should not routinely replace uninfected PICCs for fear of infection but should consider removing tunneled catheters before week 7 if no longer needed. Additional studies are needed to determine what daily maintenance practices may be associated with decreased risk of infection, especially for tunneled catheters. Copyright © 2015 by the American Academy of Pediatrics.

  11. Effect of Catheter Dwell Time on Risk of Central Line–Associated Bloodstream Infection in Infants

    Science.gov (United States)

    Greenberg, Rachel G.; Cochran, Keith M.; Smith, P. Brian; Edson, Barbara S.; Schulman, Joseph; Lee, Henry C.; Govindaswami, Balaji; Pantoja, Alfonso; Hardy, Doug; Curran, John; Lin, Della; Kuo, Sheree; Noguchi, Akihiko; Ittmann, Patricia; Duncan, Scott; Gupta, Munish; Picarillo, Alan; Karna, Padmani; Cohen, Morris; Giuliano, Michael; Carroll, Sheri; Page, Brandi; Guzman-Cottrill, Judith; Walker, M. Whit; Garland, Jeff; Ancona, Janice K.; Ellsbury, Dan L.; Laughon, Matthew M.

    2015-01-01

    BACKGROUND AND OBJECTIVE: Central venous catheters in the NICU are associated with significant morbidity and mortality because of the risk of central line–associated bloodstream infections (CLABSIs). The purpose of this study was to determine the effect of catheter dwell time on risk of CLABSI. METHODS: Retrospective cohort study of 13 327 infants with 15 567 catheters (93% peripherally inserted central catheters [PICCs], 7% tunneled catheters) and 256 088 catheter days cared for in 141 NICUs. CLABSI was defined using National Health Surveillance Network criteria. We defined dwell time as the number of days from line insertion until either line removal or day of CLABSI. We generated survival curves for each week of dwell time and estimated hazard ratios for CLABSI at each week by using a Cox proportional hazards frailty model. We controlled for postmenstrual age and year, included facility as a random effect, and generated separate models by line type. RESULTS: Median postmenstrual age was 29 weeks (interquartile range 26–33). The overall incidence of CLABSI was 0.93 per 1000 catheter days. Increased dwell time was not associated with increased risk of CLABSI for PICCs. For tunneled catheters, infection incidence was significantly higher in weeks 7 and 9 compared with week 1. CONCLUSIONS: Clinicians should not routinely replace uninfected PICCs for fear of infection but should consider removing tunneled catheters before week 7 if no longer needed. Additional studies are needed to determine what daily maintenance practices may be associated with decreased risk of infection, especially for tunneled catheters. PMID:26574587

  12. Infinite dwell time and group delay in resonant electron tunneling through double complex potential barrier

    Science.gov (United States)

    Opacak, Nikola; Milanović, Vitomir; Radovanović, Jelena

    2017-12-01

    Tunneling times in complex potentials are investigated. Analytical expressions for dwell time, self-interference time and group delay are obtained for the case of complex double delta potentials. It is shown that we can always find a set of parameters of the potential so that the tunneling times achieve very large values and even approach infinity for the case of resonance. The phenomenon of infinite tunneling times occurs for only one particular positive value of the imaginary part of the potential, if all other parameters are given.

  13. Optimal dosage and dwell time of ethanol lock therapy on catheters infected with Candida species.

    Science.gov (United States)

    Öncü, Serkan

    2014-04-01

    Anti-infective lock therapy is a treatment strategy in conjunction with systemic antifungal agents for the treatment of intravascular catheter infections caused by fungi. In this study, the optimal dosage and dwell time of ethanol lock solution (ELS) effective against catheters infected by Candida species were assessed. Biofilm forming isolates of Candida albicans, Candida parapsilosis and Candida tropicalis was used as the study isolates. Infected catheters were exposed to ELS at 20%, 30%, 40%, 60% and 80% strength for a variety dwell times (15 min, 30 min, 1 h, 2 h, 4 h, 8 h, 12 h and 24 h). Fungal eradication was evaluated by the quantitative culture techniques. ELS's with 40% and greater strength sterilized the catheters within 30 min. Lower strength of ELS's (20% and 30%) sterilized the catheters in 24 h and 2 h, respectively. According to the study, lock therapy with ≥40% ethanol for 30 min appear to be the optimal schedule in sterilizing Candida infected catheters. Ethanol lock therapy with such concentrations and dwell time may be a useful adjunct to systemic anti-fungal antibiotics in sterilizing (and cleaning) and eradicating fungal catheter related infections in the hope of preserving crucial central venous access. Copyright © 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  14. Is an increased dwell time of a peripherally inserted catheter associated with an increased risk of bloodstream infection in infants?

    Science.gov (United States)

    Smith, P Brian; Benjamin, Daniel K; Cotten, C Michael; Schultz, Eric; Guo, Rose; Nowell, Lisa; Smithwick, Mary Laura; Thornburg, Courtney D

    2008-08-01

    To estimate the risk of bloodstream infection associated with catheter dwell time in infants. Retrospective study. Duke University Medical Center neonatal intensive care unit, an academic, level 3 nursery in Durham, North Carolina. A case of catheter-associated bloodstream infection was defined as one that occurred in an infant whose culture-positive blood sample was collected more than 24 hours after catheter insertion or within 72 hours after catheter removal. We used multivariable logistic regression to control for the catheter's position and dwell time as well as the infant's sex, gestational age, age at time of catheter insertion, birth weight, and weight at time of catheter insertion. We identified 135 cases of catheter-associated bloodstream infection. The mean catheter dwell time was 12.2 days (range, 0-113 days), and the mean time to bloodstream infection was 10.8 days (range, 1-57 days). An increase in catheter dwell time was associated with a lower risk of bloodstream infection (odds ratio, 0.975 [95% confidence interval, 0.954-0.996]; P = .02). No increased risk of catheter-associated bloodstream infection was observed with increased catheter dwell time. This may have been due to the infant's improved nutrition, decreased need for other invasive devices, and maturing skin and immune system as catheter dwell time increased.

  15. Intravesical bacillus Calmette-Guèrin therapy: experience with a reduced dwell-time in patients with pronounced side-effects.

    Science.gov (United States)

    Andius, Patrik; Fehrling, Marianne; Holmäng, Sten

    2005-12-01

    To report the side-effects after a reduction in the dwell-time in patients who had pronounced symptoms after intravesical bacillus Calmette-Guèrin (BCG) treatment, as side-effects such as fever, haematuria, and frequency are common and sometimes severe after BCG treatment in patients with bladder cancer. The dwell-time was reduced to dwell-time, fever, chills, dysuria and the overall time-to-recovery were significantly reduced but frequency and haematuria were not influenced. Patients with carcinoma in situ had significantly less dysuria than patients with papillary tumours. There was no difference in the treatment results between patients who had a normal dwell-time and a reduced dwell-time, determined at the first and second follow-up cystoscopy. Reducing the BCG dwell-time to dwell-time and after dose reduction has not been studied and warrants further investigation.

  16. Asymmetric dwell-time statistics of polarization chaos from free-running VCSEL.

    Science.gov (United States)

    Virte, Martin; Mirisola, Elodie; Sciamanna, Marc; Panajotov, Krassimir

    2015-04-15

    We experimentally report on asymmetric dwell-time statistics of polarization chaos dynamics generated from free-running vertical-cavity surface-emitting lasers (VCSELs). Theoretically, we explain this behavior by introducing a misalignment between the phase and amplitude anisotropy within the spin-flip model for VCSELs. It induces an asymmetry in the VCSEL polarization behavior which is then responsible for significant changes in the statistics of the chaotic mode-hopping with an increase in the average residence time and an inversion of the dominant mode.

  17. Increasing dwell time of mitomycin C in the upper tract with a reverse thermosensitive polymer.

    Science.gov (United States)

    Wang, Agnes J; Goldsmith, Zachariah G; Neisius, Andreas; Astroza, Gaston M; Oredein-McCoy, Olugbemisola; Iqbal, Muhammad W; Simmons, W Neal; Madden, John F; Preminger, Glenn M; Inman, Brant A; Lipkin, Michael E; Ferrandino, Michael N

    2013-03-01

    Abstract Background and Purpose: Topical chemotherapy for urothelial cancer is dependent on adequate contact time of the chemotherapeutic agent with the urothelium. To date, there has not been a reliable method of maintaining this contact for renal or ureteral urothelial carcinoma. We evaluated the safety and feasibility of using a reverse thermosensitive polymer to improve dwell times of mitomycin C (MMC) in the upper tract. Using a porcine model, four animals were treated ureteroscopically with both upper urinary tracts receiving MMC mixed with iodinated contrast. One additional animal received MMC percutaneously. The treatment side had ureteral outflow blocked with a reverse thermosensitive polymer plug. MMC dwell time was monitored fluoroscopically and intrarenal pressures measured. Two animals were euthanized immediately, and three animals were euthanized 5 days afterward. In control kidneys, drainage occurred at a mean of 5.3±0.58 minutes. Intrarenal pressures stayed fairly stable: 9.7±14.0 cm H20. In treatment kidneys, dwell time was extended to 60 minutes, when the polymer was washed out. Intrarenal pressures in the treatment kidneys peaked at 75.0±14.7 cm H20 and reached steady state at 60 cm H20. Pressures normalized after washout of the polymer with cool saline. Average washout time was 11.8±9.6 minutes. No histopathologic differences were seen between the control and treatment kidneys, or with immediate compared with delayed euthanasia. A reverse thermosensitive polymer can retain MMC in the upper urinary tract and appears to be safe from our examination of intrarenal pressures and histopathology. This technique may improve the efficacy of topical chemotherapy in the management of upper tract urothelial carcinoma.

  18. Treating Fasciotomy Wounds with Negative Pressure Wound Therapy with Instillation and Dwell Time (NPWTi-d).

    Science.gov (United States)

    Lee, Priscilla

    2016-10-28

    Acute compartment syndrome (ACS) is a serious complication of lower-extremity trauma caused by accidents or post-procedure complications. ACS is characterized by increased pressure within the compartment, resulting in reduced blood flow, tissue hypoxia, and tissue necrosis. Fasciotomies to relieve pressure and debridement of necrotic tissue comprise primary treatment. My purpose is to present initial experience using negative pressure wound therapy with instillation and dwell time (NPWTi-d)* to treat fasciotomy wounds in two patients. NPWTi-d provides automated, volumetric control of instilled topical wound solutions with a dwell time in combination with negative pressure wound therapy (NPWT). Patient 1, a 33-year-old male injured in a motorcycle accident, developed ACS within 24 hours of hospitalization. Prior treatments included wet-to-dry dressings and NPWT†. In the latter course of treatment, NPWTi-d was applied; 40 ml of normal saline (NS) were instilled with a ten-minute dwell time, followed by four hours of NPWT at ‑125 mmHg. After five days of NPWTi‑d, granulation tissue covered the bone. Four days later, the patient was discharged home. The wound continued to improve and, at the last recorded visit, was completely closed. Patient 2, a 44-year-old male, developed right lower extremity ACS due to complications post cardiac surgery. NPWT was initiated in the hospital and continued post-discharge to a nursing home. The patient was readmitted to the hospital with a right leg wound infection that was surgically debrided. NPWTi-d was then applied; 60 ml of NS were instilled with a ten-minute dwell time, followed by 3.5 hours of NPWT at -125 mmHg. After ten days of NPWTi-d, granulation tissue covered the bone. In Patient 2, NPWTi-d improved the likelihood of healing in a malnourished patient who had been critically ill by promoting granulation tissue over exposed bone. The use of NPWTi-d with NS contributed to positive outcomes for both patients. *V

  19. Exponential sum-fitting of dwell-time distributions without specifying starting parameters.

    Science.gov (United States)

    Landowne, David; Yuan, Bin; Magleby, Karl L

    2013-06-04

    Fitting dwell-time distributions with sums of exponentials is widely used to characterize histograms of open- and closed-interval durations recorded from single ion channels, as well as for other physical phenomena. However, it can be difficult to identify the contributing exponential components. Here we extend previous methods of exponential sum-fitting to present a maximum-likelihood approach that consistently detects all significant exponentials without the need for user-specified starting parameters. Instead of searching for exponentials, the fitting starts with a very large number of initial exponentials with logarithmically spaced time constants, so that none are missed. Maximum-likelihood fitting then determines the areas of all the initial exponentials keeping the time constants fixed. In an iterative manner, with refitting after each step, the analysis then removes exponentials with negligible area and combines closely spaced adjacent exponentials, until only those exponentials that make significant contributions to the dwell-time distribution remain. There is no limit on the number of significant exponentials and no starting parameters need be specified. We demonstrate fully automated detection for both experimental and simulated data, as well as for classical exponential-sum-fitting problems. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  20. Observer-based stabilization for switched positive system with mode-dependent average dwell time.

    Science.gov (United States)

    Ren, Yu; Sun, Guanghui; Feng, Zhiguang

    2017-09-01

    This paper concerns the exponential stabilization problem for a class of switched positive systems. The switching signal satisfies mode-dependent average dwell time (MDADT) and the state variables are partially unmeasurable. A further explanation of mode-dependent average dwell time is included. By employing a set of quasi-time variables, which is first proposed for switched systems with MDADT, new stability results are obtained for the switched nonlinear systems and the underlying linear systems. Observer-based stabilization controllers, both for single-input case and multi-input case, are designed such that the closed-loop system converges exponentially. The designed observers and controllers are both mode-dependent and quasi-time-dependent, which is proved to be less conservative than the ones only mode-dependent. A simplified design strategy is provided to reduce the computation burden. Illustrative examples are provided to demonstrate the effectiveness of the results. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  1. Single-Molecule Analysis beyond Dwell Times: Demonstration and Assessment in and out of Equilibrium.

    Science.gov (United States)

    Schmid, Sonja; Götz, Markus; Hugel, Thorsten

    2016-10-04

    We present a simple and robust technique for extracting kinetic rate models and thermodynamic quantities from single-molecule time traces. Single-molecule analysis of complex kinetic sequences (SMACKS) is a maximum-likelihood approach that resolves all statistically relevant rates and also their uncertainties. This is achieved by optimizing one global kinetic model based on the complete data set while allowing for experimental variations between individual trajectories. In contrast to dwell-time analysis, which is the current standard method, SMACKS includes every experimental data point, not only dwell times. As a result, it works as well for long trajectories as for an equivalent set of short ones. In addition, the previous systematic overestimation of fast over slow rates is solved. We demonstrate the power of SMACKS on the kinetics of the multidomain protein Hsp90 measured by single-molecule Förster resonance energy transfer. Experiments in and out of equilibrium are analyzed and compared to simulations, shedding new light on the role of Hsp90's ATPase function. SMACKS resolves accurate rate models even if states cause indistinguishable signals. Thereby, it pushes the boundaries of single-molecule kinetics beyond those of current methods. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  2. The influence of the dwell time deviation constraint (DTDC) parameter on dosimetry with IPSA optimisation for HDR prostate brachytherapy.

    Science.gov (United States)

    Smith, Ryan L; Panettieri, Vanessa; Lancaster, Craig; Mason, Natasha; Franich, Rick D; Millar, Jeremy L

    2015-03-01

    To investigate how the dwell time deviation constraint (DTDC) parameter, applied to inverse planning by simulated annealing (IPSA) optimisation limits large dwell times from occurring in each catheter and to characterise the effect on the resulting dosimetry for prostate high dose rate (HDR) brachytherapy treatment plans. An unconstrained IPSA optimised treatment plan, using the Oncentra Brachytherapy treatment planning system (version 4.3, Nucletron an Elekta company, Elekta AB, Stockholm, Sweden), was generated for 20 consecutive HDR prostate brachytherapy patients, with the DTDC set to zero. Successive constrained optimisation plans were also created for each patient by increasing the DTDC parameter by 0.2, up to a maximum value of 1.0. We defined a "plan modulation index", to characterise the change of dwell time modulation as the DTDC parameter was increased. We calculated the dose volume histogram indices for the PTV (D90, V100, V150, V200%) and urethra (D10%) to characterise the effect on the resulting dosimetry. The average PTV D90% decreases as the DTDC is applied, on average by only 1.5 %, for a DTDC = 0.4. The measures of high dose regions in the PTV, V150 and V200%, increase on average by less than 5 and 2 % respectively. The net effect of DTDC on the modulation of dwell times has been characterised by the introduction of the plan modulation index. DTDC applied during IPSA optimisation of HDR prostate brachytherapy plans reduce the occurrence of large isolated dwell times within individual catheters. The mechanism by which DTDC works has been described and its effect on the modulation of dwell times has been characterised. The authors recommend using a DTDC parameter no greater than 0.4 to obtain a plan with dwell time modulation comparable to a geometric optimised plan. This yielded on average a 1.5 % decrease in PTV coverage and an acceptable increase in V150%, without compromising the urethral dose.

  3. Distribution of dwell times of a ribosome: effects of infidelity, kinetic proofreading and ribosome crowding

    Science.gov (United States)

    Sharma, Ajeet K.; Chowdhury, Debashish

    2011-04-01

    Ribosome is a molecular machine that polymerizes a protein where the sequence of the amino acid residues, the monomers of the protein, is dictated by the sequence of codons (triplets of nucleotides) on a messenger RNA (mRNA) that serves as the template. The ribosome is a molecular motor that utilizes the template mRNA strand also as the track. Thus, in each step the ribosome moves forward by one codon and, simultaneously, elongates the protein by one amino acid. We present a theoretical model that captures most of the main steps in the mechanochemical cycle of a ribosome. The stochastic movement of the ribosome consists of an alternating sequence of pause and translocation; the sum of the durations of a pause and the following translocation is the time of dwell of the ribosome at the corresponding codon. We derive the analytical expression for the distribution of the dwell times of a ribosome in our model. Wherever experimental data are available, our theoretical predictions are consistent with those results. We suggest appropriate experiments to test the new predictions of our model, particularly the effects of the quality control mechanism of the ribosome and that of their crowding on the mRNA track.

  4. Changes in free water fraction and aquaporin function with dwell time during continuous ambulatory peritoneal dialysis.

    Science.gov (United States)

    Stachowska-Pietka, Joanna; Waniewski, Jacek; Vonesh, Edward; Lindholm, Bengt

    2010-12-01

    Diffusive (K(BD), A₀/Δx(t)) transport parameters and sieving coefficients (S) for small solutes and free water fraction (FWF), that is, the fraction of total water flow that is transported through aquaporins, were assessed as functions of dwell time t for 35 continuous ambulatory peritoneal dialysis patients using glucose 3.86% dialysis fluid.The individual values of the unrestricted pore area over diffusion distance, A₀/Δx(t), were estimated using the mixed effects nonlinear regression and applied for evaluation of S(t) for sodium and FWF(t). FWF decreased on average from the initial 51% of the total transcapillary water flow to 36% at 120 min, whereas the small pore water fraction and sodium sieving coefficient increased. Our results were consistent with the three-pore model if the contribution of the transcellular pores (α(TP)) at the beginning of dwell study was doubled and later decreased to the standard value of 0.02.We conclude that transport characteristics of fluid and small solutes should be considered as time-dependent variables during the peritoneal dialysis.

  5. Fission yeast mtr1p regulates interphase microtubule cortical dwell-time.

    Science.gov (United States)

    Carlier-Grynkorn, Frédérique; Ji, Liang; Fraisier, Vincent; Lombard, Berangère; Dingli, Florent; Loew, Damarys; Paoletti, Anne; Ronot, Xavier; Tran, Phong T

    2014-06-13

    The microtubule cytoskeleton plays important roles in cell polarity, motility and division. Microtubules inherently undergo dynamic instability, stochastically switching between phases of growth and shrinkage. In cells, some microtubule-associated proteins (MAPs) and molecular motors can further modulate microtubule dynamics. We present here the fission yeast mtr1(+), a new regulator of microtubule dynamics that appears to be not a MAP or a motor. mtr1-deletion (mtr1Δ) primarily results in longer microtubule dwell-time at the cell tip cortex, suggesting that mtr1p acts directly or indirectly as a destabilizer of microtubules. mtr1p is antagonistic to mal3p, the ortholog of mammalian EB1, which stabilizes microtubules. mal3Δ results in short microtubules, but can be partially rescued by mtr1Δ, as the double mutant mal3Δ mtr1Δ exhibits longer microtubules than mal3Δ single mutant. By sequence homology, mtr1p is predicted to be a component of the ribosomal quality control complex. Intriguingly, deletion of a predicted ribosomal gene, rps1801, also resulted in longer microtubule dwell-time similar to mtr1Δ. The double-mutant mal3Δ rps1801Δ also exhibits longer microtubules than mal3Δ single mutant alone. Our study suggests a possible involvement of mtr1p and the ribosome complex in modulating microtubule dynamics. © 2014. Published by The Company of Biologists Ltd.

  6. Robust linear equation dwell time model compatible with large scale discrete surface error matrix.

    Science.gov (United States)

    Dong, Zhichao; Cheng, Haobo; Tam, Hon-Yuen

    2015-04-01

    The linear equation dwell time model can translate the 2D convolution process of material removal during subaperture polishing into a more intuitional expression, and may provide relatively fast and reliable results. However, the accurate solution of this ill-posed equation is not so easy, and its practicability for a large scale surface error matrix is still limited. This study first solves this ill-posed equation by Tikhonov regularization and the least square QR decomposition (LSQR) method, and automatically determines an optional interval and a typical value for the damped factor of regularization, which are dependent on the peak removal rate of tool influence functions. Then, a constrained LSQR method is presented to increase the robustness of the damped factor, which can provide more consistent dwell time maps than traditional LSQR. Finally, a matrix segmentation and stitching method is used to cope with large scale surface error matrices. Using these proposed methods, the linear equation model becomes more reliable and efficient in practical engineering.

  7. The Application of Gas Dwell Time Control for Rapid Single Wall Carbon Nanotube Forest Synthesis to Acetylene Feedstock.

    Science.gov (United States)

    Matsumoto, Naoyuki; Oshima, Azusa; Sakurai, Shunsuke; Yamada, Takeo; Yumura, Motoo; Hata, Kenji; Futaba, Don N

    2015-07-17

    One aspect of carbon nanotube (CNT) synthesis that remains an obstacle to realize industrial mass production is the growth efficiency. Many approaches have been reported to improve the efficiency, either by lengthening the catalyst lifetime or by increasing the growth rate. We investigated the applicability of dwell time and carbon flux control to optimize yield, growth rate, and catalyst lifetime of water-assisted chemical vapor deposition of single-walled carbon nanotube (SWCNT) forests using acetylene as a carbon feedstock. Our results show that although acetylene is a precursor to CNT synthesis and possesses a high reactivity, the SWCNT forest growth efficiency is highly sensitive to dwell time and carbon flux similar to ethylene. Through a systematic study spanning a wide range of dwell time and carbon flux levels, the relationship of the height, growth rate, and catalyst lifetime is found. Further, for the optimum conditions for 10 min growth, SWCNT forests with ~2500 μm height, ~350 μm/min initial growth rates and extended lifetimes could be achieved by increasing the dwell time to ~5 s, demonstrating the generality of dwell time control to highly reactive gases.

  8. The Application of Gas Dwell Time Control for Rapid Single Wall Carbon Nanotube Forest Synthesis to Acetylene Feedstock

    Directory of Open Access Journals (Sweden)

    Naoyuki Matsumoto

    2015-07-01

    Full Text Available One aspect of carbon nanotube (CNT synthesis that remains an obstacle to realize industrial mass production is the growth efficiency. Many approaches have been reported to improve the efficiency, either by lengthening the catalyst lifetime or by increasing the growth rate. We investigated the applicability of dwell time and carbon flux control to optimize yield, growth rate, and catalyst lifetime of water-assisted chemical vapor deposition of single-walled carbon nanotube (SWCNT forests using acetylene as a carbon feedstock. Our results show that although acetylene is a precursor to CNT synthesis and possesses a high reactivity, the SWCNT forest growth efficiency is highly sensitive to dwell time and carbon flux similar to ethylene. Through a systematic study spanning a wide range of dwell time and carbon flux levels, the relationship of the height, growth rate, and catalyst lifetime is found. Further, for the optimum conditions for 10 min growth, SWCNT forests with ~2500 μm height, ~350 μm/min initial growth rates and extended lifetimes could be achieved by increasing the dwell time to ~5 s, demonstrating the generality of dwell time control to highly reactive gases.

  9. The time course of attention: It's better than we thought.

    NARCIS (Netherlands)

    Olivers, C.N.L.

    2007-01-01

    What is the time course of attention? Research using rapid-stimulus streams has suggested that it is rather slow: Attention takes half a second to recover from processing one thing before it can process the next. This period is referred to as the attentional blink, and it is thought to reflect a

  10. Sustained attention in adult ADHD : time-on-task effects of various measures of attention

    NARCIS (Netherlands)

    Tucha, Lara; Fuermaier, Anselm B.M.; Koerts, Janneke; Buggenthin, Rieka; Aschenbrenner, Steffen; Weisbrod, Matthias; Thome, Johannes; Lange, Klaus W.; Tucha, Oliver

    Neuropsychological research on adults with ADHD showed deficits in various aspects of attention. However, the majority of studies failed to explore the change of performance over time, so-called time-on-task effects. As a consequence, little is known about sustained attention performance of adults

  11. [Assertiveness and peripheral intravenous catheters dwell time with ultrasonography-guided insertion in children and adolescents].

    Science.gov (United States)

    Avelar, Ariane Ferreira Machado; Peterlini, Maria Angélica Sorgini; da Pedreira, Mavilde Luz Gonçalves

    2013-06-01

    Randomized controlled trial which aimed to verify whether the use of vascular ultrasound (VUS) increases assertiveness in the use of peripheral venous catheter in children, and the catheter dwell time, when compared to traditional puncture. Data were collected after approval of theethical merit. Children and adolescents undergoing VUS-guided peripheral intravenous (GVUS) or puncture guided by clinical assessment of the venous conditions(CG) were included in the study. Significance level was set at pdwell time presented a median of less than one day in both groups (p=0.121), showing nostatistically significant difference. VUS did not significantly influence the results of the dependent variables investigated. ClinicalTrials.govNCT00930254.

  12. Absolutely Exponential Stability and Temperature Control for Gas Chromatograph System Under Dwell Time Switching Techniques.

    Science.gov (United States)

    Sun, Xi-Ming; Wang, Xue-Fang; Tan, Ying; Wang, Xiao-Liang; Wang, Wei

    2016-06-01

    This paper provides a design strategy for temperature control of the gas chromatograph. Usually gas chromatograph is modeled by a simple first order system with a time-delay, and a proportion integration (PI) controller is widely used to regulate the output of the gas chromatograph to the desired temperature. As the characteristics of the gas chromatograph varies at the different temperature range, the single-model based PI controller cannot work well when output temperature varies from one range to another. Moreover, the presence of various disturbance will further deteriorate the performance. In order to improve the accuracy of the temperature control, multiple models are used at the different temperature ranges. With a PI controller designed for each model accordingly, a delay-dependent switching control scheme using the dwell time technique is proposed to ensure the absolute exponential stability of the closed loop. Experiment results demonstrate the effectiveness of the proposed switching technique.

  13. Comparison between variable and fixed dwell-time PN acquisition algorithms. [for synchronization in pseudonoise spread spectrum systems

    Science.gov (United States)

    Braun, W. R.

    1981-01-01

    Pseudo noise (PN) spread spectrum systems require a very accurate alignment between the PN code epochs at the transmitter and receiver. This synchronism is typically established through a two-step algorithm, including a coarse synchronization procedure and a fine synchronization procedure. A standard approach for the coarse synchronization is a sequential search over all code phases. The measurement of the power in the filtered signal is used to either accept or reject the code phase under test as the phase of the received PN code. This acquisition strategy, called a single dwell-time system, has been analyzed by Holmes and Chen (1977). A synopsis of the field of sequential analysis as it applies to the PN acquisition problem is provided. From this, the implementation of the variable dwell time algorithm as a sequential probability ratio test is developed. The performance of this algorithm is compared to the optimum detection algorithm and to the fixed dwell-time system.

  14. Dwell time and risk of central-line-associated bloodstream infection in neonates.

    Science.gov (United States)

    Sanderson, E; Yeo, K T; Wang, A Y; Callander, I; Bajuk, B; Bolisetty, S; Lui, K

    2017-11-01

    Umbilical venous catheters (UVCs) or peripherally inserted central catheters (PICCs), widely used in high-risk neonates, may have a threshold dwell time for subsequent increased risk of central-line-associated bloodstream infection (CLABSI). To evaluate the CLABSI risks in neonates having either UVC, PICC, or those having both sequentially. The study included 3985 infants who had UVC or PICC inserted between 2007 and 2009 cared for in 10 regional neonatal intensive care units: 1392 having UVC only (group 1), 1317 PICC only (group 2), and 1276 both UVC and PICC (group 3). There were 403 CLABSIs among 6000 venous catheters inserted, totalling 43,302 catheter-days. CLABSI rates were higher in group 3 infants who were of lowest gestation (16.9 per 1000 UVC-days and 12.5 per 1000 PICC-days; median: 28 weeks) when compared with group 1 (3.3 per 1000 UVC-days; 37 weeks) and group 2 (4.8 per 1000 PICC-days; 30 weeks). Life table and Kaplan-Meier hazard analysis showed that UVC CLABSI rate increased stepwise to 42 per 1000 UVC-days by day 10, with the highest rate in group 3 (85 per 1000 UVC-days). PICC CLABSI rates remained relatively stable at 12-20 per 1000 PICC-days. Compared to PICC, UVC had a higher adjusted CLABSI risk controlled for dwell time. Among group 3, replacing UVC electively before day 4 may have a trend of lower CLABSI risk than late replacement. There was no cut-off duration beyond which PICC should be removed electively. Early UVC removal and replacement by PICC before day 4 might be considered. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  15. On the time course of attentional focusing in older adults.

    Science.gov (United States)

    Jefferies, Lisa N; Roggeveen, Alexa B; Enns, James T; Bennett, Patrick J; Sekuler, Allison B; Di Lollo, Vincent

    2015-01-01

    Many sensory and cognitive changes accompany normal ageing, including changes to visual attention. Several studies have investigated age-related changes in the control of attention to specific locations (spatial orienting), but it is unknown whether control over the distribution or breadth of attention (spatial focus) also changes with age. In the present study, we employed a dual-stream attentional blink task and assessed changes to the spatial distribution of attention through the joint consequences of temporal lag and spatial separation on second-target accuracy. Experiment 1 compared the rate at which attention narrows in younger (mean age 22.6, SD 4.25) and older (mean age 66.8, SD 4.36) adults. The results showed that whereas young adults can narrow attention to one stream within 133 ms, older adults were unable to do the same within this time period. Experiment 2 showed that older adults can narrow their attention to one stream when given more time (266 ms). Experiment 3 confirmed that age-related changes in retinal illuminance did not account for delayed attentional narrowing in older adults. Considered together, these experiments demonstrate that older adults can narrow their attentional focus, but that they are delayed in initiating this process compared to younger adults. This finding adds to previously reported reductions in attentional dynamics, deficits in inhibitory processes, and reductions in posterior parietal cortex function that accompany normal ageing.

  16. Toward the complete practicability for the linear-equation dwell time model in subaperture polishing.

    Science.gov (United States)

    Dong, Zhichao; Cheng, Haobo

    2015-10-20

    This study intends to address several problems that are still obstructing the complete practicability of the linear equation dwell time model (LEDTM) used in deterministic subaperture polishing, including memory cost, time cost, arbitrary boundary, and arbitrary tool path. For a large-scale surface error matrix, the memory cost and time cost are two major problems of concern. Here, we present a method that uses the operation of a sparse matrix to build and store the coefficient matrix of the linear equation, which can reduce the memory cost and time cost tens to hundreds of times, thus making LEDTM readily deal with a large-scale surface error matrix on a common personal computer, with a time cost of ∼1-6  s for a surface error matrix with a scale of 300×300 to 600×600. The compatibility for an arbitrary surface error boundary and tool path is also addressed. Using the proposed method, we believe the LEDTM reaches a complete practicability in engineering.

  17. Stability analysis for discrete-time switched systems with unstable subsystems by a mode-dependent average dwell time approach.

    Science.gov (United States)

    Zhang, Hongbin; Xie, Dehua; Zhang, Hongyu; Wang, Gang

    2014-07-01

    This paper mainly intends to present new stability results of a discrete-time switched system with unstable subsystems. By adopting multiple Lyapunov functions׳ (MLFs׳) method, new and less conservative stability conditions are derived in terms of a set of numerical feasible linear matrix inequalities (LMIs) with mode-dependent average dwell time (MDADT) techniques. Different from previous literatures, unstable subsystems are considered under two situations in this paper. It is shown that the discrete-time switched system can achieve exponential stability under a slow switching scheme and even in the presence of fast switching of unstable subsystems. Finally a numerical example is given to demonstrate the effectiveness of the proposed method. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  18. Influence of the bulk diffusion of rubidium and sodium atoms in glass on their surface dwell time

    Science.gov (United States)

    Atutov, S. N.; Benimetskii, F. A.; Makarov, A. O.

    2017-05-01

    This paper presents the results of measurement of the surface potential and the dwell time of Rb and Na atoms on the surface of S-52 molybdenum glass. It is found that at temperatures below the glass transition temperature, the temperature dependence of the dwell time of Rb atoms is well described by the Arrhenius formula. The surface potentials for Rb and Na are measured to be 0.67 and 1.37 eV, respectively. At temperatures above the glass transition temperature, the dwell time of these atoms increases abnormally. The reason for this is that during impact of an atom on the surface of molten glass, it can penetrate into the volume of the window and then return by diffusion and desorb from the surface. In this case, the dwell time of the atom on the glass is determined by the diffusion time and can be very significant, despite the relatively low potential barrier at the surface and high temperature.

  19. Optimization of Solar Water Heating System under Time and Spatial Partition Heating in Rural Dwellings

    Directory of Open Access Journals (Sweden)

    Yanfeng Liu

    2017-10-01

    Full Text Available This paper proposes the application of time and spatial partition heating to a solar water heating system. The heating effect and system performance were analyzed under the continuous and whole space heating and time and spatial partition heating using TRNSYS. The results were validated by comparing with the test results of the demonstration building. Compared to continuous and whole space heating, the use of time and spatial partition heating increases the solar fraction by 16.5%, reduces the auxiliary heating by 7390 MJ, and reduces the annual operation cost by 2010 RMB. Under time and spatial partition heating, optimization analyses were conducted for the two system capacity parameters of the solar collector area and tank volume and the one operation parameter of auxiliary heater setting outlet temperature. The results showed that a reasonable choice of the solar collector area can reduce the dynamic annual cost, the increased tank volume is advantageous to heat storage, and the auxiliary heater setting outlet temperature have greater influence on the indoor heating effect. The advanced opening of solar water heating system and the normal opening of passive air vents are recommended. Based on the comparison of the two modes, the time and spatial partition heating technology is a better choice for rural dwellings.

  20. Defining Prolonged Dwell Time: When Are Advanced Inferior Vena Cava Filter Retrieval Techniques Necessary? An Analysis in 762 Procedures.

    Science.gov (United States)

    Desai, Kush R; Laws, James L; Salem, Riad; Mouli, Samdeep K; Errea, Martin F; Karp, Jennifer K; Yang, Yihe; Ryu, Robert K; Lewandowski, Robert J

    2017-06-01

    Despite growth in placement of retrievable inferior vena cava filters, retrieval rates remain low. Filters with extended implantation times present a challenge to retrieval, where standard techniques often fail. The development of advanced retrieval techniques has positively impacted retrieval of retrievable inferior vena cava filters with prolonged dwell times; however, there is no precise definition of the time point when advanced techniques become necessary. We aim to define prolonged retrievable inferior vena cava filters dwell time by determining the inflection point when the risk of standard retrieval technique failure increases significantly, necessitating advanced retrieval techniques to maintain overall technical success of retrieval. From January 2009 to April 2015, 762 retrieval procedures were identified from a prospectively acquired database. We assessed patient age/sex, filter dwell time, procedural technical success, the use of advanced techniques, and procedure-related adverse events. Overall retrieval success rate was 98% (n=745). When standard retrieval techniques failed, advanced techniques were used; this was necessary 18% of the time (n=138). Logistic regression identified that dwell time was the only risk factor for failure of standard retrieval technique (odds ratio, 1.08; 95% confidence interval, 1.05-1.10; P technique failure was 40.9%. Adverse events occurred at a rate of 2% (n=18; 15 minor and 3 major). The necessity of advanced techniques to maintain technical success of retrieval increases with dwell time. Patients with retrievable inferior vena cava filters in place beyond 7 months may benefit from referral to centers with expertise in advanced filter retrieval. © 2017 American Heart Association, Inc.

  1. Time-course of attention biases in social phobia.

    Science.gov (United States)

    Schofield, Casey A; Inhoff, Albrecht W; Coles, Meredith E

    2013-10-01

    Theoretical models of social phobia implicate preferential attention to social threat in the maintenance of anxiety symptoms, though there has been limited work characterizing the nature of these biases over time. The current study utilized eye-movement data to examine the time-course of visual attention over 1500ms trials of a probe detection task. Nineteen participants with a primary diagnosis of social phobia based on DSM-IV criteria and 20 non-clinical controls completed this task with angry, fearful, and happy face trials. Overt visual attention to the emotional and neutral faces was measured in 50ms segments across the trial. Over time, participants with social phobia attend less to emotional faces and specifically less to happy faces compared to controls. Further, attention to emotional relative to neutral expressions did not vary notably by emotion for participants with social phobia, but control participants showed a pattern after 1000ms in which over time they preferentially attended to happy expressions and avoided negative expressions. Findings highlight the importance of considering attention biases to positive stimuli as well as the pattern of attention between groups. These results suggest that attention "bias" in social phobia may be driven by a relative lack of the biases seen in non-anxious participants. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Does help structures play a role in reducing the variation of dwell time in IPSA planning for gynaecological brachytherapy application?

    Science.gov (United States)

    Jamema, Swamidas; Mahantshetty, Umesh; Deshpande, Dd; Sharma, Smriti; Shrivastava, Sk

    2011-09-01

    To report our experience of dosimetric comparison of IPSA and manual plans, with a focus on the use of help structures (HS) during optimization. 33 patients who underwent MR image-based HDR intracavitary-brachytherapy for cervix cancer based on GYN-ESTRO recommendations were selected for evaluation. Tandem/ovoid (T/O) and Vienna applicators were used. HS of diameter of 5 mm were drawn around the tandem/needles/ovoid and ring. Three plans were generated: manual optimized plan (MOPT), IPSA without help structures (IPSA_woHS) and IPSA with help structures (IPSA_wHS). Dose-volume parameters and the loading pattern were evaluated. For T/O, the use of HS did not make significant impact in the dose-volume parameters and in the loading of tandem and ovoids, however steep variation was found in the individual dwell time. In case of Vienna applicator, inclusion of HS in the optimization made a significant impact in loading of needles. The percentage ratio of total time of needles to the tandem (T(N/T%)) was found to be 14±2.5, 53±9, 22±6 for MOPT, IPSA_woHS and IPSA_wHS, respectively, which implies that in IPSA_woHS the dwell time in needles were half of the dwell time in the tandem, while in MOPT the needles were loaded only in 14%, and in IPSA_wHS it was 22% of the dwell time of tandem. Inclusion of HS in the optimization has reduced the contribution of dwell time of needle in IPSA_wHS. The individual variation of dwell time was also reduced in IPSA_wHS, however drawing of HS is a time consuming procedure and may not be practical for a routine practice. The role of HS was evaluated for IPSA for T/O and Vienna-applicator, the use of HS may be beneficial in case of combined intracavitary - interstitial approach.

  3. Cooperative action of KIF1A Brownian motors with finite dwell time.

    Science.gov (United States)

    Oriola, David; Casademunt, Jaume

    2014-03-01

    We study in detail the cooperative action of small groups of KIF1A motors in its monomeric (single-headed) form within an arrangement relevant to vesicle traffic or membrane tube extraction. It has been recently shown that under these circumstances, the presence of a finite dwell time in the motor cycle contributes to remarkably enhance collective force generation [D. Oriola and J. Casademunt, Phys. Rev. Lett. 111, 048103 (2013)]. We analyze this mechanism in detail by means of a two-state noise-driven ratchet model with hard-core repulsive interactions. We obtain staircase-shaped velocity-force curves and show that motors self-organize in clusters with a nontrivial force distribution that conveys a large part of the load to the central motors. Under heavy loads, large clusters adopt a synchronic mode of totally asymmetric steps. We also find a dramatic increase of the collective efficiency with the number of motors. Finally, we complete the study by addressing different interactions that impose spatial constraints such as rigid coupling and raft-induced confinement. Our results reinforce the hypothesis that the specificity of KIF1A to axonal vesicular transport may be deeply related to its high cooperativity.

  4. Developmental trajectories of regulating attentional selection over time

    Directory of Open Access Journals (Sweden)

    Sabine eHeim

    2012-08-01

    Full Text Available Adaptive behavior in learning environments requires both the maintenance of an attentional focus on a task-set and suppression of distracting stimuli. This may be especially difficult when the competing information is more appealing than the target event. The aptitude to pay attention and resist distraction has often been noted as an important prerequisite of successful acquisition of intellectual abilities in children. This focused review draws on research that highlights interindividual differences in the temporal dynamics of attentional engagement and disengagement under competition, and their relation with age and cognitive/academic skills. Although basic strategies of attention control are present in very young children, the more refined ability to manage attentional resources over time in an economic and adaptive fashion appears during early school years, dramatically improves until the early teen years, and continues to develop into late adolescence. Across studies, parameters of attention control over time predict specific aspects of academic performance, rather than general intellectual ability. We conclude that the ability to strategically regulate the dynamic allocation of attention at rapid rates may represent an important element of cognitive and academic development.

  5. Meditation-induced states predict attentional control over time.

    Science.gov (United States)

    Colzato, Lorenza S; Sellaro, Roberta; Samara, Iliana; Baas, Matthijs; Hommel, Bernhard

    2015-12-01

    Meditation is becoming an increasingly popular topic for scientific research and various effects of extensive meditation practice (ranging from weeks to several years) on cognitive processes have been demonstrated. Here we show that extensive practice may not be necessary to achieve those effects. Healthy adult non-meditators underwent a brief single session of either focused attention meditation (FAM), which is assumed to increase top-down control, or open monitoring meditation (OMM), which is assumed to weaken top-down control, before performing an Attentional Blink (AB) task - which assesses the efficiency of allocating attention over time. The size of the AB was considerably smaller after OMM than after FAM, which suggests that engaging in meditation immediately creates a cognitive-control state that has a specific impact on how people allocate their attention over time. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Effect of increased dwell times for solvent evaporation on the bond strength and degree of conversion of an ethanol-based adhesive system.

    Science.gov (United States)

    Argolo, Saryta; Oliveira, Denise C; Fontes, Céres M; Lima, Adriano F; de Freitas, Anderson P; Cavalcanti, Andrea N

    2012-01-01

    This study evaluated the influence of the prolonged setting time of an ethanol-based adhesive system on the dentin bond strength and degree of conversion. Labial and lingual surfaces of fifteen human third molars were flattened until the dentin was exposed and randomly allocated to 3 groups (n = 10), according to the dwell time between the application of two consecutive layers of the adhesive system (Adper Single Bond Plus, 3M ESPE) and light activation: G1--control (no extra dwell time); G2 and G3--dwell time of 30 seconds and 60 seconds, respectively. After light curing, two cylinders (1.4 x 1 mm) of composite resin (Filtek Flow, 3M ESPE) were bonded to each surface and submitted to micro-shear testing, 24 hours after light curing. A similar adhesive procedure was used for the degree of conversion evaluation using Fourier transform infrared spectroscopy (FTIR). Significant differences between bond strength values (p = 0.0003) and degrees of conversion (p = 0.0004) were detected. The bond strength of G3 (60-second dwell time) was statistically higher than that of other groups. G1 (control) and G2 (30-second dwell time) presented similar results. Values of degree of conversion indicated that both the 30-second and 60-second dwell times resulted in similar and greater percentages of conversion. The use of a longer dwell time (60 seconds) might provide better solvent volatilization and monomer infiltration; bringing benefits to dentin bonding using simplified etch & rinse adhesive systems.

  7. Musical Meter Modulates the Allocation of Attention across Time.

    Science.gov (United States)

    Fitzroy, Ahren B; Sanders, Lisa D

    2015-12-01

    Dynamic attending theory predicts that attention is allocated hierarchically across time during processing of hierarchical rhythmic structures such as musical meter. ERP research demonstrates that attention to a moment in time modulates early auditory processing as evidenced by the amplitude of the first negative peak (N1) approximately 100 msec after sound onset. ERPs elicited by tones presented at times of high and low metric strength in short melodies were compared to test the hypothesis that hierarchically structured rhythms direct attention in a manner that modulates early perceptual processing. A more negative N1 was observed for metrically strong beats compared with metrically weak beats; this result provides electrophysiological evidence that hierarchical rhythms direct attention to metrically strong times during engaged listening. The N1 effect was observed only on fast tempo trials, suggesting that listeners more consistently invoke selective processing based on hierarchical rhythms when sounds are presented rapidly. The N1 effect was not modulated by musical expertise, indicating that the allocation of attention to metrically strong times is not dependent on extensive training. Additionally, changes in P2 amplitude and a late negativity were associated with metric strength under some conditions, indicating that multiple cognitive processes are associated with metric perception.

  8. Gas dwell time control for rapid and long lifetime growth of single-walled carbon nanotube forests.

    Science.gov (United States)

    Yasuda, Satoshi; Futaba, Don N; Yamada, Takeo; Yumura, Motoo; Hata, Kenji

    2011-09-14

    The heat history (i.e., "dwell time") of the carbon source gas was demonstrated as a vital parameter for very rapid single-walled carbon nanotube (SWNT) forest growth with long lifetime. When the dwell time was raised to 7 s from the 4 s used for standard growth, the growth rate increased to 620 μm/min: a benchmark for SWNT forest growth on substrates. Importantly, the increase in growth rate was achieved without decreasing either the growth lifetime or the quality of the SWNTs. We interpret that the conversion rate of the carbon feedstock into CNTs was selectively increased (versus catalyst deactivation) by delivering a thermally decomposed carbon source with the optimum thermal history to the catalyst site.

  9. Dwell Time and Surface Parameter Effects on Removal of Silicone Oil From D6ac Steel Using TCA

    Science.gov (United States)

    Boothe, R. E.

    2003-01-01

    This study was conducted to evaluate the impact of dwell time, surface roughness, and the surface activation state on 1,1,1-trichloroethane's (TCA's) effectiveness for removing silicone oil from D6ac steel. Silicone-contaminated test articles were washed with TCA solvent, and then the surfaces were analyzed for residue, using Fourier transform infrared spectroscopy. The predominant factor affecting the ability to remove the silicone oil was surface roughness.

  10. The dwell time and survival rates of PICC placement after balloon angioplasty in patient with unexpected central venous obstruction.

    Science.gov (United States)

    Kim, Ki Hyun; Park, Sang Woo; Chang, Il Soo; Yim, Younghee

    2016-09-21

    To evaluate the dwell time and actual survival rates of peripherally inserted central catheter (PICC) placements after balloon angioplasty in patients with unexpected central venous obstructions. Data were obtained on all PICC insertions performed in a tertiary care hospital from August 2008 to December 2013. Thirty-five PICCs attempted after balloon angioplasty in 25 patients (15 male and 10 female patients; mean age, 63 years). Fisher's exact test was used to test for differences in reasons for catheter removal between the groups of patients with stenosis or obstructions. Survival curves for PICC dwell time of all patients, stenosis group, and obstruction group were generated separately using Kaplan-Meier survival analysis and compared with log-rank tests. There were a total 21 obstructions and 14 stenoses. The overall technical success rate of PICC placement after balloon angioplasty was 94% (33 of 35 procedures). The PICC dwell time was determined for 27 PICCs and ranged from 4 to 165 days (mean, 39.6 days). Among all PICCs, 16 were removed early, resulting in an actual survival rate of 40.7% (11 of 27 PICCs). There were no significant differences in reasons for catheter removal between the stenosis and obstruction groups (p = 0.24). The dwell times for both groups were not significantly different by Kaplan-Meier analysis (p = 0.54). PICC placement after balloon angioplasty is a good treatment option for patients with unexpected central venous lesions, and offers high technical success rates. The actual survival rate was relatively lower (40.7%) than that from previous studies.

  11. Fast rebinding increases dwell time of Src homology 2 (SH2)-containing proteins near the plasma membrane.

    Science.gov (United States)

    Oh, Dongmyung; Ogiue-Ikeda, Mari; Jadwin, Joshua A; Machida, Kazuya; Mayer, Bruce J; Yu, Ji

    2012-08-28

    Receptor tyrosine kinases (RTKs) control a host of biological functions by phosphorylating tyrosine residues of intracellular proteins upon extracellular ligand binding. The phosphotyrosines (p-Tyr) then recruit a subset of ∼100 Src homology 2 (SH2) domain-containing proteins to the cell membrane. The in vivo kinetics of this process are not well understood. Here we use total internal reflection (TIR) microscopy and single-molecule imaging to monitor interactions between SH2 modules and p-Tyr sites near the cell membrane. We found that the dwell time of SH2 modules within the TIR illumination field is significantly longer than predictions based on chemical dissociation rate constants, suggesting that SH2 modules quickly rebind to nearby p-Tyr sites after dissociation. We also found that, consistent with the rebinding model, the effective diffusion constant is negatively correlated with the respective dwell time for different SH2 domains and the dwell time is positively correlated with the local density of RTK phosphorylation. These results suggest a mechanism whereby signal output can be regulated through the spatial organization of multiple binding sites, which will prompt reevaluation of many aspects of RTK signaling, such as signaling specificity, mechanisms of spatial control, and noise suppression.

  12. The time course of attention modulation elicited by spatial uncertainty.

    Science.gov (United States)

    Huang, Dan; Liang, Huilou; Xue, Linyan; Wang, Meijian; Hu, Qiyi; Chen, Yao

    2017-09-01

    Uncertainty regarding the target location is an influential factor for spatial attention. Modulation in spatial uncertainty can lead to adjustments in attention scope and variations in attention effects. Hence, investigating spatial uncertainty modulation is important for understanding the underlying mechanism of spatial attention. However, the temporal dynamics of this modulation remains unclear. To evaluate the time course of spatial uncertainty modulation, we adopted a Posner-like attention orienting paradigm with central or peripheral cues. Different numbers of cues were used to indicate the potential locations of the target and thereby manipulate the spatial uncertainty level. The time interval between the onsets of the cue and the target (stimulus onset asynchrony, SOA) varied from 50 to 2000ms. We found that under central cueing, the effect of spatial uncertainty modulation could be detected from 200 to 2000ms after the presence of the cues. Under peripheral cueing, the effect of spatial uncertainty modulation was observed from 50 to 2000ms after cueing. Our results demonstrate that spatial uncertainty modulation produces robust and sustained effects on target detection speed. The time course of this modulation is influenced by the cueing method, which suggests that discrepant processing procedures are involved under different cueing conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Dose error from deviation of dwell time and source position for high dose-rate 192Ir in remote afterloading system.

    Science.gov (United States)

    Okamoto, Hiroyuki; Aikawa, Ako; Wakita, Akihisa; Yoshio, Kotaro; Murakami, Naoya; Nakamura, Satoshi; Hamada, Minoru; Abe, Yoshihisa; Itami, Jun

    2014-07-01

    The influence of deviations in dwell times and source positions for (192)Ir HDR-RALS was investigated. The potential dose errors for various kinds of brachytherapy procedures were evaluated. The deviations of dwell time ΔT of a (192)Ir HDR source for the various dwell times were measured with a well-type ionization chamber. The deviations of source position ΔP were measured with two methods. One is to measure actual source position using a check ruler device. The other is to analyze peak distances from radiographic film irradiated with 20 mm gap between the dwell positions. The composite dose errors were calculated using Gaussian distribution with ΔT and ΔP as 1σ of the measurements. Dose errors depend on dwell time and distance from the point of interest to the dwell position. To evaluate the dose error in clinical practice, dwell times and point of interest distances were obtained from actual treatment plans involving cylinder, tandem-ovoid, tandem-ovoid with interstitial needles, multiple interstitial needles, and surface-mold applicators. The ΔT and ΔP were 32 ms (maximum for various dwell times) and 0.12 mm (ruler), 0.11 mm (radiographic film). The multiple interstitial needles represent the highest dose error of 2%, while the others represent less than approximately 1%. Potential dose error due to dwell time and source position deviation can depend on kinds of brachytherapy techniques. In all cases, the multiple interstitial needles is most susceptible. © The Author 2014. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  14. Isochronous sequential presentation helps children orient their attention in time.

    Directory of Open Access Journals (Sweden)

    Katherine A Johnson

    2016-09-01

    Full Text Available Knowing when an event is likely to occur allows attentional resources to be oriented towards that moment in time, enhancing processing of the event. We previously found that children (mean age 11 years are unable to use endogenous temporal cues (line length to orient attention in time, despite being able to use endogenous spatial cues (arrows to orient attention in space. Arrow cues, however, may have proved beneficial by engaging exogenous (automatic, as well as endogenous (voluntary, orienting mechanisms. We therefore conducted two studies in which the exogenous properties of visual temporal cues were increased, to examine whether this helped children orient their attention in time. In the first study, the location of an imperative target was predicted by the direction of a left or right spatial arrow cue while its onset was predicted by the relative duration of a short or long temporal cue. To minimise the influence of rhythmic entrainment in the temporal condition, target onset time (500ms/1100ms was deliberately chosen so as not to precisely match the duration of the temporal cue (100ms/400ms. Targets appeared either at cued locations/onset times (valid trials or at unexpected locations/onset times (invalid trials. Adults’ response times were significantly slower for invalid versus valid trials, in both spatial and temporal domains. Despite being slowed by invalid spatial cues, children (mean age 10.7 years were unperturbed by invalid temporal cues, suggesting that these duration-based temporal cues did not help them orient attention in time. In the second study, we enhanced the exogenous properties of temporal cues further, by presenting multiple temporal cues in an isochronous (rhythmic sequence. Again, to minimise automatic entrainment, target onset did not match the isochronous interval. Children (mean age 11.4 years, as well as adults, were now significantly slowed by invalid cues in both the temporal and spatial dimension. The

  15. Auditory attention: time of day and type of school

    Directory of Open Access Journals (Sweden)

    Picolini, Mirela Machado

    2010-06-01

    Full Text Available Introduction: The sustained auditory attention is crucial for the development of some communication skills and learning. Objective: To evaluate the effect of time of day and type of school attended by children in their ability to sustained auditory attention. Method: We performed a prospective study of 50 volunteer children of both sexes, aged 7 years, with normal hearing, no learning or behavioral problems and no complaints of attention. These participants underwent Ability Test of Sustained Auditory Attention (SAAAT. The performance was evaluated by total score and the decrease of vigilance. Statistical analysis was used to analysis of variance (ANOVA with significance level of 5% (p<0.05. Results: The result set by the normative test for the age group evaluated showed a statistically significant difference for the errors of inattention (p=0.041, p=0.027 and total error score (p=0.033, p=0.024, in different periods assessment and school types, respectively. Conclusion: Children evaluated in the afternoon and the children studying in public schools had a poorer performance on auditory attention sustained.

  16. The physical capabilities underlying timed "Up and Go" test are time-dependent in community-dwelling older women.

    Science.gov (United States)

    Coelho-Junior, Hélio José; Rodrigues, Bruno; Gonçalves, Ivan de Oliveira; Asano, Ricardo Yukio; Uchida, Marco Carlos; Marzetti, Emanuele

    2018-02-02

    Timed 'Up and Go' (TUG) has been widely used in research and clinical practice to evaluate physical function and mobility in older adults. However, the physical capabilities underlying TUG performance are not well elucidated. Therefore, the present study aimed at investigating a selection of physical capacities underlying TUG performance in community-dwelling older women. Four hundred and sixty-eight apparently healthy older women independent to perform the activities of daily living (mean age: 65.8 ± 6.0 years) were recruited from two specialized healthcare centers for older adults to participate in the study. Volunteers had their medical books reviewed and underwent evaluations of anthropometric data as well as physical and functional capacities. Pearson's correlation results indicate that TUG performance was significantly associated with upper (i.e., handgrip strength) and lower (i.e., sit-to-stand) limb muscle strength, balance (i.e., one-leg stand), lower limb muscle power (i.e., countermovement jump), aerobic capacity (i.e., 6-minute walk test), and mobility (i.e., usual and maximal walking speeds). When the analyses were performed based on TUG quartiles, a larger number of physical capabilities were associated with TUG >75% in comparison with TUG performance was determined. As a whole, our findings indicate that the contribution of physical capabilities to TUG performance is altered according to the time taken to perform the test, so that older women in the lower quartiles - indicating a higher performance - have an important contribution of lower limb muscle strength, while volunteers in the highest quartile demonstrate a decreased dependence on lower limb muscle strength and an increased contribution of other physical capabilities, such as lower limb muscle power and balance. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Effects of substituting a portion of standard physiotherapy time with virtual reality games among community-dwelling stroke survivors.

    Science.gov (United States)

    Singh, Devinder Kaur Ajit; Mohd Nordin, Nor Azlin; Abd Aziz, Noor Azah; Lim, Beng Kooi; Soh, Li Ching

    2013-12-13

    Evidence indicates that the continuation of therapy among community-dwelling stroke survivors improves physical function. Community rehabilitation programmes often face limitations in terms of resources. It is imperative to include new motivational interventions to encourage some level of non-clinician management. The aim of this study was to determine whether there were any changes in physical function and activities of daily living when substituting a portion of the standard physiotherapy time with virtual reality games among community-dwelling stroke survivors. In this controlled trial, the experimental group received 30 minutes of virtual reality balance games in addition to 90 minutes of standard physiotherapy. The control group continued with their two hours of routine standard physiotherapy. Both groups received 12 therapy sessions: two-hour sessions twice per week for six continuous weeks. Changes in physical function, activities of daily living and balance ability were assessed using the Timed Up and Go test, 30-second Sit to Stand test, Timed Ten-Metre Walk test, Six-Minute Walk test and the Barthel Index, and static balance was assessed using a probalance board. Twenty-eight participants completed post-intervention assessments. The results showed a significant within-subject effect on the Timed Up and Go test: F (1, 26) = 5.83, p = 0.02; and the 30-second Sit to Stand test; F (1, 26) = 13.50, p = 0.001. The between-subject effect was not significant (p > 0.05) for any of the outcome measurements. Substituting a portion of the standard physiotherapy time with virtual reality games was equally effective in maintaining physical function outcomes and activities of daily living among community-dwelling stroke survivors. Australia and New Zealand Clinical Trials Register, ACTRN12613000478718.

  18. Influence of the preceding dwell time on the peritoneal equilibration test with 3.86% glucose solution in automated peritoneal dialysis.

    Science.gov (United States)

    Cnossen, Trijntje; Beerenhout, Charles; Smit, Watske; Konings, Constantijn; Kooman, Jeroen; Leunissen, Karel; Krediet, Raymond T

    2010-01-01

    The peritoneal equilibration test (PET) using 3.86% glucose solution is preceded by a long dwell with 3.86% glucose solution. A point of concern in patients treated with automated peritoneal dialysis (APD) is the influence of the preceding short nightly dwells on the results of a standardized PET. The aim of the study was to compare net ultrafiltration, small solute transport, sodium sieving, and solute transport type between a PET preceded by a long night dwell and one preceded by short (APD) dwells. 13 stable APD patients (mean age 60 +/- 15 years; mean duration of peritoneal dialysis 31 +/- 15 months) underwent 2 PETs: 1 preceded by short nightly dwells (PET A) and 1 preceded by a long night dwell (PET B). Both PETs were performed within a mean period of 8 (range 5 - 11) days. Mean total ultrafiltration of PET A was 626 +/- 218 mL and PET B was 644 +/- 223 mL (NS). The 4-hour results of both tests for dialysate-to-plasma (D/P) ratios of creatinine and urea, D(t)/D(0) ratios of glucose, and the dip in D/P sodium (sodium sieving) were similar. Classification of transport categories was identical for 10 of 13 patients. In APD, the preceding dwell time of a 3.86% glucose PET does not influence fluid transport, solute transport, or transport type.

  19. Long dwell-time passage of DNA through nanometer-scale pores: kinetics and sequence dependence of motion.

    Science.gov (United States)

    Jetha, Nahid N; Feehan, Christopher; Wiggin, Matthew; Tabard-Cossa, Vincent; Marziali, Andre

    2011-06-22

    A detailed understanding of the kinetics of DNA motion though nanometer-scale pores is important for the successful development of many of the proposed next-generation rapid DNA sequencing and analysis methods. Many of these approaches require DNA motion through nanopores to be slowed by several orders of magnitude from its native translocation velocity so that the translocation times for individual nucleotides fall within practical timescales for detection. With the increased dwell time of DNA in the pore, DNA-pore interactions begin to play an increasingly important role in translocation kinetics. In previous work, we and others observed that when the DNA dwell time in the pore is substantial (>1 ms), DNA motion in α-hemolysin (α-HL) pores leads to nonexponential kinetics in the escape of DNA out of the pore. Here we show that a three-state model for DNA escape, involving stochastic binding interactions of DNA with the pore, accurately reproduces the experimental data. In addition, we investigate the sequence dependence of the DNA escape process and show that the interaction strength of adenine with α-HL is substantially lower relative to cytosine. Our results indicate a difference in the process by which DNA moves through an α-HL nanopore when the motion is fast (microsecond timescale) as compared with when it is slow (millisecond timescale) and strongly influenced by DNA-pore interactions of the kind reported here. We also show the ability of wild-type α-HL to detect and distinguish between 5-methylcytosine and cytosine based on differences in the absolute ionic current through the pore in the presence of these two nucleotides. The results we present here regarding sequence-dependent (and dwell-time-dependent) DNA-pore interaction kinetics will have important implications for the design of methods for DNA analysis through reduced-velocity motion in nanopores. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  20. Children can implicitly, but not voluntarily, direct attention in time.

    Directory of Open Access Journals (Sweden)

    Katherine A Johnson

    Full Text Available Children are able to use spatial cues to orient their attention to discrete locations in space from around 4 years of age. In contrast, no research has yet investigated the ability of children to use informative cues to voluntarily predict when an event will occur in time. The spatial and temporal attention task was used to determine whether children were able to voluntarily orient their attention in time, as well as in space: symbolic spatial and temporal cues predicted where or when an imperative target would appear. Thirty typically developing children (average age 11 yrs and 32 adults (average age 27 yrs took part. Confirming previous findings, adults made use of both spatial and temporal cues to optimise behaviour, and were significantly slower to respond to invalidly cued targets in either space or time. Children were also significantly slowed by invalid spatial cues, demonstrating their use of spatial cues to guide expectations. In contrast, children's responses were not slowed by invalid temporal cues, suggesting that they were not using the temporal cue to voluntarily orient attention through time. Children, as well as adults, did however demonstrate signs of more implicit forms of temporal expectation: RTs were faster for long versus short cue-target intervals (the variable foreperiod effect and slower when the preceding trial's cue-target interval was longer than that on the current trial (sequential effects. Overall, our results suggest that although children implicitly made use of the temporally predictive information carried by the length of the current and previous trial's cue-target interval, they could not deliberately use symbolic temporal cues to speed responses. The developmental trajectory of the ability to voluntarily use symbolic temporal cues is therefore delayed, relative both to the use of symbolic (arrow spatial cues, and to the use of implicit temporal information.

  1. Effects of dwell time of excitation waveform on meniscus movements for a tubular piezoelectric print-head: experiments and model

    Science.gov (United States)

    Chang, Jiaqing; Liu, Yaxin; Huang, Bo

    2017-07-01

    In inkjet applications, it is normal to search for an optimal drive waveform when dispensing a fresh fluid or adjusting a newly fabricated print-head. To test trial waveforms with different dwell times, a camera and a strobe light were used to image the protruding or retracting liquid tongues without ejecting any droplets. An edge detection method was used to calculate the lengths of the liquid tongues to draw the meniscus movement curves. The meniscus movement is determined by the time-domain response of the acoustic pressure at the nozzle of the print-head. Starting at the inverse piezoelectric effect, a mathematical model which considers the liquid viscosity in acoustic propagation is constructed to study the acoustic pressure response at the nozzle of the print-head. The liquid viscosity retards the propagation speed and dampens the harmonic amplitude. The pressure response, which is the combined effect of the acoustic pressures generated during the rising time and the falling time and after their propagations and reflections, explains the meniscus movements well. Finally, the optimal dwell time for droplet ejections is discussed.

  2. Effect heating dwell time has on the retention of heavy metals in the structure of lightweight aggregates manufactured from wastes.

    Science.gov (United States)

    González-Corrochano, Beatriz; Alonso-Azcárate, Jacinto; Rodríguez, Luis; Pérez Lorenzo, Agripino; Fernández Torío, María; Tejado Ramos, Juan José; Corvinos, María Dolores; Muro, Carlos

    2017-08-10

    The main objective of this paper was to study how effective thermal treatment is in the retention of different heavy metals (HMs) within the structure of artificial lightweight aggregates (LWAs). These LWAs were manufactured by washing aggregate sludge and sewage sludge. The consequence of increasing the heating dwell time whilst manufacturing these LWAs was also determined. Partitioning of the HMs (Cr, Ni, Cu, Zn, Cd and Pb) was studied by means of the optimized BCR sequential extraction procedure. Then, the leaching ratio (LRx,y) was calculated. Thermal treatment was totally effective for immobilizing most of the elements studied except for a part of the non-residual Zn and Cd fraction which could volatilize, and the fractions of Pb which were water- and acid-soluble, weakly adsorbed, exchangeable, and oxidable. These were more highly concentrated in the LWAs than in the initial waste mixture. The effect of increasing heating dwell time on the retention of heavy metals in the LWAs depended on both the chemical element studied and the heating dwell time. This study is very important since certain rises in the heating dwell time caused a decrease in retention of some specific heavy metals in the LWAs. BCR-SEP: optimized BCR sequential extraction procedure; b.d.l: below the detection limit; F1: weakly adsorbed, exchangeable and water- and acid- soluble fraction; F2: reducible fraction; F3: oxidable fraction; F4: residual fraction; HM: heavy metal; ICP-MS: inductively coupled plasma-mass spectroscopy; LOI: loss on ignition; LWA: lightweight aggregate; LWA-5: lightweight aggregate sintered for 5 min; LWA-10: lightweight aggregate sintered for 10 min; LWA-20: lightweight aggregate sintered for 20 min; LWA-30: lightweight aggregate sintered for 30 min; LRx,y: leaching ratio of the element x in the fraction y; n.e: not established; S: compressive strength; SS: sewage sludge; WA24h: water absorption after 24 hours; WAS: washing aggregate sludge; W75S25: mixture of

  3. Beyond time and space: The effect of a lateralized sustained attention task and brain stimulation on spatial and selective attention.

    Science.gov (United States)

    Shalev, Nir; De Wandel, Linde; Dockree, Paul; Demeyere, Nele; Chechlacz, Magdalena

    2017-10-03

    The Theory of Visual Attention (TVA) provides a mathematical formalisation of the "biased competition" account of visual attention. Applying this model to individual performance in a free recall task allows the estimation of 5 independent attentional parameters: visual short-term memory (VSTM) capacity, speed of information processing, perceptual threshold of visual detection; attentional weights representing spatial distribution of attention (spatial bias), and the top-down selectivity index. While the TVA focuses on selection in space, complementary accounts of attention describe how attention is maintained over time, and how temporal processes interact with selection. A growing body of evidence indicates that different facets of attention interact and share common neural substrates. The aim of the current study was to modulate a spatial attentional bias via transfer effects, based on a mechanistic understanding of the interplay between spatial, selective and temporal aspects of attention. Specifically, we examined here: (i) whether a single administration of a lateralized sustained attention task could prime spatial orienting and lead to transferable changes in attentional weights (assigned to the left vs right hemi-field) and/or other attentional parameters assessed within the framework of TVA (Experiment 1); (ii) whether the effects of such spatial-priming on TVA parameters could be further enhanced by bi-parietal high frequency transcranial random noise stimulation (tRNS) (Experiment 2). Our results demonstrate that spatial attentional bias, as assessed within the TVA framework, was primed by sustaining attention towards the right hemi-field, but this spatial-priming effect did not occur when sustaining attention towards the left. Furthermore, we show that bi-parietal high-frequency tRNS combined with the rightward spatial-priming resulted in an increased attentional selectivity. To conclude, we present a novel, theory-driven method for attentional modulation

  4. Radiobiological evaluation of the influence of dwell time modulation restriction in HIPO optimized HDR prostate brachytherapy implants.

    Science.gov (United States)

    Mavroidis, Panayiotis; Katsilieri, Zaira; Kefala, Vasiliki; Milickovic, Natasa; Papanikolaou, Nikos; Karabis, Andreas; Zamboglou, Nikolaos; Baltas, Dimos

    2010-09-01

    One of the issues that a planner is often facing in HDR brachytherapy is the selective existence of high dose volumes around some few dominating dwell positions. If there is no information available about its necessity (e.g. location of a GTV), then it is reasonable to investigate whether this can be avoided. This effect can be eliminated by limiting the free modulation of the dwell times. HIPO, an inverse treatment plan optimization algorithm, offers this option. In treatment plan optimization there are various methods that try to regularize the variation of dose non-uniformity using purely dosimetric measures. However, although these methods can help in finding a good dose distribution they do not provide any information regarding the expected treatment outcome as described by radiobiology based indices. The quality of 12 clinical HDR brachytherapy implants for prostate utilizing HIPO and modulation restriction (MR) has been compared to alternative plans with HIPO and free modulation (without MR). All common dose-volume indices for the prostate and the organs at risk have been considered together with radiobiological measures. The clinical effectiveness of the different dose distributions was investigated by calculating the response probabilities of the tumors and organs-at-risk (OARs) involved in these prostate cancer cases. The radiobiological models used are the Poisson and the relative seriality models. Furthermore, the complication-free tumor control probability, P+ and the biologically effective uniform dose ([Formula: see text]) were used for treatment plan evaluation and comparison. Our results demonstrate that HIPO with a modulation restriction value of 0.1-0.2 delivers high quality plans which are practically equivalent to those achieved with free modulation regarding the clinically used dosimetric indices. In the comparison, many of the dosimetric and radiobiological indices showed significantly different results. The modulation restricted clinical

  5. Radiobiological evaluation of the influence of dwell time modulation restriction in HIPO optimized HDR prostate brachytherapy implants

    Directory of Open Access Journals (Sweden)

    Dimos Baltas

    2010-10-01

    Full Text Available Purpose: One of the issues that a planner is often facing in HDR brachytherapy is the selective existence of high dose volumes around some few dominating dwell positions. If there is no information available about its necessity (e.g. location of a GTV, then it is reasonable to investigate whether this can be avoided. This effect can be eliminated by limiting the free modulation of the dwell times. HIPO, an inverse treatment plan optimization algorithm, offers this option.In treatment plan optimization there are various methods that try to regularize the variation of dose non-uniformity using purely dosimetric measures. However, although these methods can help in finding a good dose distribution they do not provide any information regarding the expected treatment outcome as described by radiobiology based indices.Material and methods: The quality of 12 clinical HDR brachytherapy implants for prostate utilizing HIPO and modulation restriction (MR has been compared to alternative plans with HIPO and free modulation (without MR.All common dose-volume indices for the prostate and the organs at risk have been considered together with radiobiological measures. The clinical effectiveness of the different dose distributions was investigated by calculating the response probabilities of the tumors and organs-at-risk (OARs involved in these prostate cancer cases. The radiobiological models used are the Poisson and the relative seriality models. Furthermore, the complication-free tumor control probability, P+ and the biologically effective uniform dose (D = were used for treatment plan evaluation and comparison.Results: Our results demonstrate that HIPO with a modulation restriction value of 0.1-0.2 delivers high quality plans which are practically equivalent to those achieved with free modulation regarding the clinically used dosimetric indices.In the comparison, many of the dosimetric and radiobiological indices showed significantly different results. The

  6. Tandem-ring dwell time ratio in Nigeria: dose comparisons of two loading patterns in standard high-dose-rate brachytherapy planning for cervical cancer.

    Science.gov (United States)

    Ibhade, Obed Rachel; Oyeyemi, Oyekunle Emmanuel; Idayat, Akinlade Bidemi; Atara I, Ntekim

    2015-04-01

    In high-dose-rate (HDR) brachytherapy (BT), the source dwell times and dwell positions are essential treatment planning parameters. An optimal choice of these factors is fundamental to obtain the desired target coverage with the lowest achievable dose to the organs at risk (OARs). This study evaluates relevant dose parameters in cervix brachytherapy in order to assess existing tandem-ring dwell time ratio used at the first HDR BT center in Nigeria, and compare it with an alternative source loading pattern. At the Radiotherapy Department, University College Hospital (UCH), Ibadan, Nigeria, a total of 370 standard treatment plans in two alternative sets were generated with HDR basic 2.6 software for one hundred and eighty five cervical cancer patients. The initial 185 individual plans were created for clinical treatment using the tandem-ring dwell time ratio of 1 : 1. Modifying the initial applicator loading ratio, the second set of plans with related dose data were also obtained for study purposes only. Total reference air kerma (TRAK), total time index (TTI), ICRU volume, treatment time, point B dose, ICRU bladder dose, and rectal points dose were evaluated for both sets of plans. The means of all evaluated dose parameters decreased when the existing tandem-ring dwell time ratio (1 : 1) was modified to other dwell weightings (1 : 1 - 3 : 1). These reductions were 13.43% (ICRU volume), 9.83% (rectal dose), 6.68% (point B dose), 6.08% (treatment time), 5.90% (TRAK), 5.88% (TTI), and 1.08% (bladder dose). Correspondingly, coefficients of variation changed by -7.98%, -5.02%, -5.23%, -4.20%, -3.93%, 8.65%, and 3.96% from the existing pattern to the alternative one. Tandem-ring dwell time ratio has significant influence on dosimetric parameters. This study has indicated the need to modify the existing planning approach at UCH.

  7. Leisure-Time Physical Inactivity Associated with Vascular Depression or Apathy in Community-Dwelling Elderly Subjects: The Sefuri Study.

    Science.gov (United States)

    Yao, Hiroshi; Takashima, Yuki; Araki, Yuko; Uchino, Akira; Yuzuriha, Takefumi; Hashimoto, Manabu

    2015-11-01

    Although physical inactivity is a major public health problem, the causative factors for physical inactivity per se are poorly understood. To address this issue, we investigated the relationship between deep white matter lesions (DWMLs) on magnetic resonance imaging, apathy, and physical activities using structural equation modeling (SEM). We examined 317 community-dwelling elderly subjects (137 men and 180 women with a mean age of 64.5 years) without dementia or clinically apparent depression. Physical activity was assessed with a questionnaire consisting of 3 components (leisure-time, work, and sport activities). The mean score from the apathy scale (a visual analogue version of Starkstein's apathy scale) of the Grades 2-3 DWML group was 420 (95% confidence interval [CI] 379-461), which was lower (more apathetic) than the Grade 0 DWML group score of 478 (95% CI 463-492) after adjustment for education as a covariate. SEM showed that the direct paths from DWMLs or education to apathy were significant, and the direct path from apathy to leisure-time activity was highly significant (β = .25, P effects on leisure-time physical activity in community-dwelling elderly subjects. Even a minor level of apathy without major depression would have a significant impact on activities of daily living and quality of life. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  8. Negative Pressure Wound Therapy With Instillation and Dwell Time Used to Treat Infected Orthopedic Implants: A 4-patient Case Series.

    Science.gov (United States)

    Dettmers, Robert; Brekelmans, Wouter; Leijnen, Michiel; van der Burg, Boudewijn; Ritchie, Ewan

    2016-09-01

    Infection following orthopedic implants for bone fixation or joint replacement is always serious and may require removal of the osteosynthetic material. Negative pressure wound therapy with instillation and dwell time (NPWTi-d) is an emerging therapy for the treatment of complex wounds, including infected wounds with osteosynthetic material. The purpose of this case study was to evaluate the outcomes of 4 patients (1 man, 3 women; age range 49 to 71 years) with a postoperative wound infection (POWI) following fracture repair and internal fixation. All patients were at high risk for surgical complications, including infections. Standard infection treatments (antibiotics) had been unsuccessful. Based on the available literature, a NPWTi-d protocol was developed. Following surgical debridement, wounds were instilled with polyhexanide biguanide with a set dwell time of 15 minutes, followed by continuous NPWTi-d of -125 mm Hg for 4 hours. The system was changed every 3 to 4 days until sufficient granulation tissue was evident and negative pressure without instillation could be used. Systemic antibiotics were continued in all patients. Granulation tissue was found to be sufficient in 12 to 35 days in the 4 cases, no recurrence of infection was noted, and the osteosynthesis material remained in place. No adverse events were observed. Research is needed to compare the safety and effectiveness of this adjunct treatment in the management of challenging wounds to other patient and wound management approaches.

  9. Dwell-Time Distribution, Long Pausing and Arrest of Single-Ribosome Translation through the mRNA Duplex.

    Science.gov (United States)

    Xie, Ping

    2015-10-09

    Proteins in the cell are synthesized by a ribosome translating the genetic information encoded on the single-stranded messenger RNA (mRNA). It has been shown that the ribosome can also translate through the duplex region of the mRNA by unwinding the duplex. Here, based on our proposed model of the ribosome translation through the mRNA duplex we study theoretically the distribution of dwell times of the ribosome translation through the mRNA duplex under the effect of a pulling force externally applied to the ends of the mRNA to unzip the duplex. We provide quantitative explanations of the available single molecule experimental data on the distribution of dwell times with both short and long durations, on rescuing of the long paused ribosomes by raising the pulling force to unzip the duplex, on translational arrests induced by the mRNA duplex and Shine-Dalgarno(SD)-like sequence in the mRNA. The functional consequences of the pauses or arrests caused by the mRNA duplex and the SD sequence are discussed and compared with those obtained from other types of pausing, such as those induced by "hungry" codons or interactions of specific sequences in the nascent chain with the ribosomal exit tunnel.

  10. Temporal cognition: Connecting subjective time to perception, attention, and memory.

    Science.gov (United States)

    Matthews, William J; Meck, Warren H

    2016-08-01

    Time is a universal psychological dimension, but time perception has often been studied and discussed in relative isolation. Increasingly, researchers are searching for unifying principles and integrated models that link time perception to other domains. In this review, we survey the links between temporal cognition and other psychological processes. Specifically, we describe how subjective duration is affected by nontemporal stimulus properties (perception), the allocation of processing resources (attention), and past experience with the stimulus (memory). We show that many of these connections instantiate a "processing principle," according to which perceived time is positively related to perceptual vividity and the ease of extracting information from the stimulus. This empirical generalization generates testable predictions and provides a starting-point for integrated theoretical frameworks. By outlining some of the links between temporal cognition and other domains, and by providing a unifying principle for understanding these effects, we hope to encourage time-perception researchers to situate their work within broader theoretical frameworks, and that researchers from other fields will be inspired to apply their insights, techniques, and theorizing to improve our understanding of the representation and judgment of time. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  11. Attention Inhibition Training Can Reduce Betel-Nut Chewing Time

    Directory of Open Access Journals (Sweden)

    Ming-Chou Ho

    2011-05-01

    Full Text Available Betel nut (or areca is the fourth most commonly used drug worldwide after tobacco, alcohol, and caffeine. Many chemical ingredients of betel nut are carcinogenic. We examined whether the manipulation of attentional inhibition toward the areca-related stimuli could affect betel-nut chewing time. Three matched groups of habitual chewers were recruited: inhibit-areca, inhibit-non-areca, and control. This study consisted of a Go/No-Go task for inhibition training, followed by a taste test for observing chewing behavior. The Go/No-Go task constituted three phases (pretest, training and posttest. In the taste test, the habitual chewers were asked to rate the flavors of one betel nut and one gum. The purpose (blind to the chewers of this taste test was to observe whether their picking order and chewing time were affected by experimental manipulation. Results from the Go/No-Go task showed successful training. Further, the training groups (the inhibit-areca and inhibit-non-areca groups showed a significant reduction in betel nut chewing time, in comparison to the control group. Since both training groups showed reduced chewing time, the inhibition training may affect general control ability, in regardless of the stimulus (areca or not to be inhibited. Reduced chewing time is important for reducing areca-related diseases.

  12. Multi-Train Energy Saving for Maximum Usage of Regenerative Energy by Dwell Time Optimization in Urban Rail Transit Using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Fei Lin

    2016-03-01

    Full Text Available With its large capacity, the total urban rail transit energy consumption is very high; thus, energy saving operations are quite meaningful. The effective use of regenerative braking energy is the mainstream method for improving the efficiency of energy saving. This paper examines the optimization of train dwell time and builds a multiple train operation model for energy conservation of a power supply system. By changing the dwell time, the braking energy can be absorbed and utilized by other traction trains as efficiently as possible. The application of genetic algorithms is proposed for the optimization, based on the current schedule. Next, to validate the correctness and effectiveness of the optimization, a real case is studied. Actual data from the Beijing subway Yizhuang Line are employed to perform the simulation, and the results indicate that the optimization method of the dwell time is effective.

  13. Repeated and time-correlated morphological convergence in cave-dwelling harvestmen (Opiliones, Laniatores from Montane Western North America.

    Directory of Open Access Journals (Sweden)

    Shahan Derkarabetian

    Full Text Available BACKGROUND: Many cave-dwelling animal species display similar morphologies (troglomorphism that have evolved convergent within and among lineages under the similar selective pressures imposed by cave habitats. Here we study such ecomorphological evolution in cave-dwelling Sclerobuninae harvestmen (Opiliones from the western United States, providing general insights into morphological homoplasy, rates of morphological change, and the temporal context of cave evolution. METHODOLOGY/PRINCIPAL FINDINGS: We gathered DNA sequence data from three independent gene regions, and combined these data with Bayesian hypothesis testing, morphometrics analysis, study of penis morphology, and relaxed molecular clock analyses. Using multivariate morphometric analysis, we find that phylogenetically unrelated taxa have convergently evolved troglomorphism; alternative phylogenetic hypotheses involving less morphological convergence are not supported by Bayesian hypothesis testing. In one instance, this morphology is found in specimens from a high-elevation stony debris habitat, suggesting that troglomorphism can evolve in non-cave habitats. We discovered a strong positive relationship between troglomorphy index and relative divergence time, making it possible to predict taxon age from morphology. Most of our time estimates for the origin of highly-troglomorphic cave forms predate the Pleistocene. CONCLUSIONS/SIGNIFICANCE: While several regions in the eastern and central United States are well-known hotspots for cave evolution, few modern phylogenetic studies have addressed the evolution of cave-obligate species in the western United States. Our integrative studies reveal the recurrent evolution of troglomorphism in a perhaps unexpected geographic region, at surprisingly deep time depths, and in sometimes surprising habitats. Because some newly discovered troglomorphic populations represent undescribed species, our findings stress the need for further biological

  14. Stabilization for a Class of Switched Nonlinear Systems With Novel Average Dwell Time Switching by T-S Fuzzy Modeling.

    Science.gov (United States)

    Zhao, Xudong; Yin, Yunfei; Niu, Ben; Zheng, Xiaolong

    2016-08-01

    In this paper, the problem of switching stabilization for a class of switched nonlinear systems is studied by using average dwell time (ADT) switching, where the subsystems are possibly all unstable. First, a new concept of ADT is given, which is different from the traditional definition of ADT. Based on the new proposed switching signals, a sufficient condition of stabilization for switched nonlinear systems with unstable subsystems is derived. Then, the T-S fuzzy modeling approach is applied to represent the underlying nonlinear system to make the obtained condition easily verified. A novel multiple quadratic Lyapunov function approach is also proposed, by which some conditions are provided in terms of a set of linear matrix inequalities to guarantee the derived T-S fuzzy system to be asymptotically stable. Finally, a numerical example is given to demonstrate the effectiveness of our developed results.

  15. Fine tuning of dwelling time in friction stir welding for preventing material overheating, weld tensile strength increase and weld nugget size decrease

    Directory of Open Access Journals (Sweden)

    Mijajlović Miroslav M.

    2016-01-01

    Full Text Available After successful welding, destructive testing into test samples from Al 2024-T351 friction stir butt welds showed that tensile strength of the weld improve along the joint line, while dimensions of the weld nugget decrease. For those welds, both the base material and the welding tool constantly cool down during the welding phase. Obviously, the base material became overheated during the long dwelling phase what made conditions for creation of joints with the reduced mechanical properties. Preserving all process parameters but varying the dwelling time from 5-27 seconds a new set of welding is done to reach maximal achievable tensile strength. An analytical-numerical-experimental model is used for optimising the duration of the dwelling time while searching for the maximal tensile strength of the welds

  16. Dwell times and risk of non-elective removal of 1-French peripherally inserted central catheters according to catheter tip position in very preterm infants.

    Science.gov (United States)

    Erhard, Daniela M; Nguyen, Sarah; Guy, Katelyn J; Casalaz, Dan M; König, Kai

    2017-03-01

    We investigated dwell times and risk of non-elective removal of 975 single-lumen 1-French peripherally inserted central catheters (1FR-PICC) according to tip position in a cohort of very preterm infants with a mean (SD) gestational age of 27 +6 (2 +1 ) weeks and a mean (SD) birth weight of 988 (294) g over an eight-year period. Infants with a 1FR-PICC inserted for continuous infusion of intravenous fluids within the first 30 days of life were eligible. Dwell times of PICC with elective versus non-elective removal, risk of non-elective removal of PICC according to tip position, and differences between upper versus lower limb catheter insertion were analysed. 33.8% PICC were removed non-electively. Median (IQR) dwell time was 193 (142-287) versus 154 (102-260) h for elective versus non-elective removal (p positioned in the axillary, cephalic, external iliac, and femoral veins had a higher risk of non-elective removal. What is Known: •Peripherally inserted central catheters (PICC) are widely used in neonatal intensive care. •Previous studies focused on 2-French PICC and newborns of all gestational ages. What is New: •Dwell times of 1-French PICC removed non-electively were similar to 2-French PICC. •1-French PICC tips positioned more peripherally had a higher risk of non-elective removal.

  17. Attentional cartography: mapping the distribution of attention across time and space.

    Science.gov (United States)

    Taylor, J Eric T; Chan, David; Bennett, Patrick J; Pratt, Jay

    2015-10-01

    Decades of research have shown that the orienting of attention follows a reliable pattern of facilitation and then inhibition following a peripheral cue. However, the literature lacks a high-resolution spatiotemporal map of this pattern. Moreover, the use of visual placeholders to highlight potential stimulus locations is inconsistent. This is puzzling, given attention's well-known predilection for objects. In this article, we remedy these outstanding issues with a large-scale investigation charting the spatiotemporal distribution of attention. Participants detected targets presented at 121 possible locations 100, 200, 400, or 800 ms following an uninformative peripheral cue. The cued locations were presented with or without placeholders. With placeholders, the classic pattern of early facilitation and late inhibition was observed for targets appearing within the placeholders, and the spread of inhibition was severely limited to within the placeholders. Without placeholders, we observed inhibition shortly after cue presentation, upsetting the famously reliable effect of facilitation following a cue. Moreover, inhibition spread from the cued location, unlike when placeholders were present. This investigation has produced an eminently detailed spatiotemporal map of attentional orienting and illustrated the consequences of placeholder stimuli, with surprising results.

  18. Dwelling Designers

    Science.gov (United States)

    Szekely, George

    2012-01-01

    Children's inventions go far beyond track housing or Ethan Allen furniture; they foreshadow the most innovative ideas in building forms and interior designs. Children improvise with containers and find places in a home that suggest enticing dwellings. A drawer left open becomes a balcony, soap trays become cots, and the space between twin beds…

  19. Fast microbubble dwell-time based ultrasonic molecular imaging approach for quantification and monitoring of angiogenesis in cancer.

    Science.gov (United States)

    Pysz, Marybeth A; Guracar, Ismayil; Tian, Lu; Willmann, Jürgen K

    2012-06-01

    PURPOSE: To develop and test a fast ultrasonic molecular imaging technique for quantification and monitoring of angiogenesis in cancer. MATERIALS AND METHODS: A new software algorithm measuring the dwell time of contrast microbubbles in near real-time (henceforth, fast method) was developed and integrated in a clinical ultrasound system. In vivo quantification and monitoring of tumor angiogenesis during anti-VEGF antibody therapy was performed in human colon cancer xenografts in mice (n=20) using the new fast method following administration of vascular endothelial growth factor receptor 2 (VEGFR2)-targeted contrast microbubbles. Imaging results were compared with a traditional destruction/replenishment approach (henceforth, traditional method) in an intra-animal comparison. RESULTS: There was excellent correlation (R(2)=0.93; Pdwell time microbubble signal measurements correlates well with the traditional measurement method, and allows reliable in vivo monitoring of anti-angiogenic therapy in human colon cancer xenografts. The improved work-flow afforded by the new quantification approach may facilitate clinical translation of ultrasonic molecular imaging.

  20. The Influence of Dwell Time on Low Cycle Fatigue Behavior of Ni-base Superalloy IC10

    Science.gov (United States)

    Wang, Anqiang; Liu, Lu; Wen, Zhixun; Li, Zhenwei; Yue, Zhufeng

    2017-09-01

    Low cycle fatigue and creep-fatigue experiments of IC10 Ni-base superalloy plate specimens with multiple holes were performed below 1,000 °C. The average fatigue life is 105.4 cycles, while the creep-fatigue life is 103.4 cycles, which shows that the life of creep-fatigue is reduced 1-2 times compared with low cycle fatigue life. After tests, the detailed fracture and microscopic structure evolution were observed by scanning electron microscopy (SEM); meanwhile, the constitutive model based on crystal plasticity theory was established and the fracture mechanism was analyzed. Three conclusions have been obtained: First, the load during dwell time leads to the damage accumulation caused by deformation and the interaction of fatigue and creep shortens the service life of materials seriously. Second, in order to maintain the macroscopic deformation, a new slip plane starts to makes the dislocation slide in reverse direction, which leads to fatigue damage and initial cracks. Third, the inner free surface creates opportunities for escape of the dislocation line, which is caused by the cavity. What's more, the cure dislocation generated by cyclic loading contributes to the formation and growth of cavities.

  1. Effects of equivalence ratio and dwell time on exhaust emissions from an experimental premixing prevaporizing burner

    Science.gov (United States)

    Anderson, D.

    1975-01-01

    A flame-tube study was performed to determine the effects of equivalence ratio and residence time on exhaust emissions with premixed, prevaporized propane fuel. Nitrogen oxides emissions as low as 0.3 g NO2/kg fuel were measured with greater than 99 percent combustion efficiency at 800 K inlet temperature and an equivalence ratio of 0.4. For a constant combustion efficiency, lower nitrogen oxides emissions were obtained by burning very lean with relatively long residence times than by using somewhat higher equivalence ratios with shorter times.

  2. Cognitive tasks in information analysis: Use of event dwell time to characterize component activities

    Energy Technology Data Exchange (ETDEWEB)

    Sanquist, Thomas F.; Greitzer, Frank L.; Slavich, Antoinette L.; Littlefield, Rik J.; Littlefield, Janis S.; Cowley, Paula J.

    2004-09-28

    Technology-based enhancement of information analysis requires a detailed understanding of the cognitive tasks involved in the process. The information search and report production tasks of the information analysis process were investigated through evaluation of time-stamped workstation data gathered with custom software. Model tasks simulated the search and production activities, and a sample of actual analyst data were also evaluated. Task event durations were calculated on the basis of millisecond-level time stamps, and distributions were plotted for analysis. The data indicate that task event time shows a cyclic pattern of variation, with shorter event durations (< 2 sec) reflecting information search and filtering, and longer event durations (> 10 sec) reflecting information evaluation. Application of cognitive principles to the interpretation of task event time data provides a basis for developing “cognitive signatures” of complex activities, and can facilitate the development of technology aids for information intensive tasks.

  3. Masking T1 Difficulty: Processing Time and the Attentional Blink

    Science.gov (United States)

    Visser, Troy A. W.

    2007-01-01

    When observers are presented with 2 targets in rapid succession, identification of the 1st is highly accurate, whereas identification of the 2nd is impaired at brief intertarget intervals (i.e., 200-500 ms). This 2nd-target deficit is known as the attentional blink (AB). According to bottleneck models, the AB arises because attending to the 1st…

  4. It's time to pay attention to the endometrium.

    Science.gov (United States)

    Casper, Robert F

    2011-09-01

    The physiologic importance of the endometrium in assisted reproductive technology is now receiving much research attention. The historical importance of ultrasound for determination of endometrial pattern, thickness and contractility is reviewed and speculation provided for a possible mechanism of the adverse effect of thin endometrium on implantation. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  5. Drug Burden Index and change in cognition over time in community-dwelling older men: the CHAMP study.

    Science.gov (United States)

    Jamsen, Kris M; Gnjidic, Danijela; Hilmer, Sarah N; Ilomäki, Jenni; Le Couteur, David G; Blyth, Fiona M; Handelsman, David J; Naganathan, Vasi; Waite, Louise M; Cumming, Robert G; Bell, J Simon

    2017-03-01

    Anticholinergic and sedative medications are associated with acute cognitive impairment, but the long-term impact on change in cognition is unclear. This study investigated the effect of anticholinergic and sedative medications, quantified using the Drug Burden Index (DBI), on change in cognition over time in community-dwelling older men. This was a prospective cohort study of men aged ≥70 years in Sydney, Australia. DBI was assessed at baseline, 2, and 5 years. Cognitive performance was assessed using the Mini-Mental State Exam (MMSE) at each wave. Logistic quantile mixed-effects modelling was used to assess the adjusted effect of DBI on the median MMSE-time profile. Analyses were restricted to men with English-speaking backgrounds (n = 1059, 862, and 611 at baseline, 2, and 5 years). Overall, 292 (27.7%), 258 (29.9%), and 189 (31.3%) men used anticholinergic or sedative medications at baseline, 2, and 5 years. There was a concave relationship between MMSE and time, where higher DBI corresponded to lower MMSE scores (coefficient: -0.161; 95% CI: -0.250 to -0.071) but not acceleration of declining MMSE over time. Exposure to anticholinergic and sedative medications is associated with a small impairment in cognitive performance but not decline in cognition over time. KEY MESSAGES Exposure to anticholinergic and sedative medications, quantified using the Drug Burden Index, is associated with small cross-sectional impairments in cognitive performance. There was no evidence that exposure to anticholinergic and sedative medications is associated with accelerating decline in cognitive performance over a 5-year follow-up. Older people taking anticholinergic and sedative medications may derive immediate but small benefits in cognitive performance from clinical medication reviews to minimize or cease prescribing of these medications.

  6. Estradiol modulates the efficacy of synaptic inhibition by decreasing the dwell time of GABAA receptors at inhibitory synapses.

    Science.gov (United States)

    Mukherjee, Jayanta; Cardarelli, Ross A; Cantaut-Belarif, Yasmine; Deeb, Tarek Z; Srivastava, Deepak P; Tyagarajan, Shiva K; Pangalos, Menelas N; Triller, Antoine; Maguire, Jamie; Brandon, Nicholas J; Moss, Stephen J

    2017-10-31

    Estrogen plays a critical role in many physiological processes and exerts profound effects on behavior by regulating neuronal excitability. While estrogen has been established to exert effects on dendritic morphology and excitatory neurotransmission its role in regulating neuronal inhibition is poorly understood. Fast synaptic inhibition in the adult brain is mediated by specialized populations of γ-c aA receptors (GABAARs) that are selectively enriched at synapses, a process dependent upon their interaction with the inhibitory scaffold protein gephyrin. Here we have assessed the role that estradiol (E2) plays in regulating the dynamics of GABAARs and stability of inhibitory synapses. Treatment of cultured cortical neurons with E2 reduced the accumulation of GABAARs and gephyrin at inhibitory synapses. However, E2 exposure did not modify the expression of either the total or the plasma membrane GABAARs or gephyrin. Mechanistically, single-particle tracking revealed that E2 treatment selectively reduced the dwell time and thereby decreased the confinement of GABAARs at inhibitory synapses. Consistent with our cell biology measurements, we observed a significant reduction in amplitude of inhibitory synaptic currents in both cultured neurons and hippocampal slices exposed to E2, while their frequency was unaffected. Collectively, our results suggest that acute exposure of neurons to E2 leads to destabilization of GABAARs and gephyrin at inhibitory synapses, leading to reductions in the efficacy of GABAergic inhibition via a postsynaptic mechanism. Published under the PNAS license.

  7. The Simultaneous Vehicle Scheduling and Passenger Service Problem with Flexible Dwell Times

    DEFF Research Database (Denmark)

    Fonseca, Joao Filipe Paiva; Larsen, Allan; van der Hurk, Evelien

    times at important transfer points based on expected passenger ows. We introduce a compact mixed integer linear formulation of the SVSPSP-FDT able to address small instances. We also present a meta-heuristic approach to solve medium/large instances of the problem. The e ectiveness of the proposed...

  8. Dwell Time Of Stentriever Influences Complete Revascularisation And First Pass Tici3 Revascularisation In Acute Large Vessel Occlusive Stroke.

    Science.gov (United States)

    Kannath, Santhosh Kumar; Rajan, Jayadevan Enakshy; N, Sylaja Padmavathy; P, Sankara Sarma; Sukumaran, Sajith; Sreedharan, Sapna Erat; Kapilamoorthy, Tirur Raman

    2017-11-04

    In acute ischemic stroke with large vessel occlusion, the interaction between the clot retriever and the stent is critical for achieving successful recanalization. The ideal time of stent deployment (dwell time, DT) to improve revascularization is currently unknown., We systematically analysed the effect of different DT on final angiographic and clinical outcome of of patients who underwent mechanical thrombectomy. The DT was progressively increased from 3 minutes to 5 minutes and later, 8 minutes during the study period. The effect of DT on recanalization attempts, successful angiographic outcome (TICI 2B or 3), total revascularisation time, immediate and 3 month clinical outcomes were evaluated. The DT of 3 minutes and 5 minutes (DT3-5) was compared against DT of 8 minutes(DT8). A total of 40 patients were included in the analysis. The good angiographic outcome was observed in 94.1% of patients in DT8 cohort with an average attempt of 1.2 compared to 78.3% with average attempts of 2.0 in other group. Single pass good recanalization (TICI 2b or 3) and single pass complete revascularisation (TICI3) was significantly higher in DT group compared to DT3-5 group (82.4% vs 43.5%, P=0.013 and 42.9% vs 8.7%, P=0.003 respectively). A favourable trend towards a reduced overall procedural time (34.59 vs 55.59 minutes) was observed, but was not statistically significant (p value 0.15) CONCLUSION: Mild prolongation of DT to 8 minutes improves revascularisation outcome with fewer attempts, possibly due to better clot-stent interaction. Copyright © 2017. Published by Elsevier Inc.

  9. Automated peritoneal dialysis prescriptions for enhancing sodium and fluid removal: a predictive analysis of optimized, patient-specific dwell times for the day period.

    Science.gov (United States)

    Akonur, Alp; Guest, Steven; Sloand, James A; Leypoldt, John K

    2013-01-01

    Remaining edema-free is a challenge for many automated peritoneal dialysis (APD) patients, especially those with fast ("high") transport characteristics. Although increased use of peritoneal dialysis (PD) solutions with high glucose concentrations may improve volume control, frequent use of such solutions is undesirable. We used the 3-pore kinetic model to evaluate 4 alternative therapy prescriptions for the APD day exchange in anuric patients with high, high-average, and low-average transport characteristics. Four prescriptions were modeled: Therapy 1: Optimal, individualized dwell times with a dry period. Therapy 2: Use of a midday exchange. Therapy 3: Use of an icodextrin-containing dialysate during a 14-hour dwell. Therapy 4: Use of optimal, individualized dwell times, followed by an icodextrin dwell to complete the daytime period. The alternative therapies were compared with a reference standard therapy using glucose solution during a 14-hour dwell. The nighttime prescription was identical in all cases (10 L over 10 hours), and all glucose solutions contained 2.27% glucose. Net ultrafiltration (UF), sodium removal (NaR), total carbohydrate (CHO) absorption, and weekly urea Kt/V for a 24-hour period were computed and compared. The UF and NaR were substantially higher with therapy 1 than with standard therapy (1034 mL vs 621 mL and 96 mmol vs 51 mmol respectively), without significant changes in CHO absorption or urea Kt/V. However, therapy 1 resulted in reduced β2-microglobulin clearance (0.74 mL/min vs 0.89 mL/min with standard therapy). Compared with therapy 1, therapy 2 improved UF and NaR (1062 mL vs 1034 mL and 99 mmol vs 96 mmol); however, that improvement is likely not clinically significant. Therapy 2 also resulted in a higher Kt/V (2.07 vs 1.72), but at the expense of higher glucose absorption (difference: 42 g). The UF and NaR were highest with a long icodextrin-containing daytime dwell either preceded by a short optimized dwell (1426 mL and 155 mmol

  10. Using mid infrared technology as new method for the determination of the dwell time of salivary substitutes on three dimensional gingiva models.

    Science.gov (United States)

    Engelhart, Karin; Popescu, Alice; Bernhardt, Jürgen

    2016-01-01

    Many people suffer from dry mouth (xerostomia) due to radiotherapy treatment of head and neck cancer, diseases like Sjogren's syndrome or as adverse effects to prescribed medications. Salivary substitute products like gels or sprays are often used for treatment. Efficacy of those oral care products are regularly assessed by validated or even not validated questionnaires. To determine the adhesion effect over time more objectively a new and sensitive method was established. The following study was designed to assess the dwell time of different oral care products in vitro. Two different types of surfaces were covered with oral care products and washed using a definite protocol with artificial saliva salt solution. First, oral care gels or oral care sprays were spread to a polystyrene surface of 2.25 cm(2), then onto cell based three-dimensional gingiva models. The surfaces were washed ten times with artificial saliva salt solution. The resulting washing solutions were examined using mid infrared spectroscopy in order to detect ingredients of the oral care products. All assessed oral care gels or oral care sprays and their components were detected very sensitive. Even traces of the products were detected in the eluent and thus enabled to differentiate the dwell times of the different products. In general, the dwell time of oral care gels on polystyrene or gingiva models was longer than that of oral care sprays. The use of gingiva models improved the differentiation between different products. MIR spectroscopy turned out to be a sensitive method to detect salivary substitutes. Differences between single components and different products can be detected. The described method is a simple, reliable and easy process to evaluate the dwell time of oral care products in vitro and thus a useful tool to design optimised salivary substitute products. This is an in vitro study. No ethics or consent was required for this study.

  11. Virtual Realities: How Remote Dwelling Populations Become More Remote Over Time despite Technological Improvements

    Directory of Open Access Journals (Sweden)

    Dean Carson

    2010-05-01

    Full Text Available For those who have access to them, technologies of various sorts play a key role in maintaining connections between small and geographically dispersed settlements and to the wider World. For technologies to work in remote areas, there must be a framework of adaptability which ensures that users can adapt their practices to suit the new technology, technologies can be customised for local conditions, and an institutional infrastructure (including a regulatory environment allows these adaptations to occur. In recent times, remote Australia’s “power to persuade” government to consider its needs when designing regulatory environments has diminished as a result of the changing nature of remote economies. This paper uses two case examples—that of air transport technology and that of communications technology—to demonstrate how a poor regulatory environment in effect increases the isolation of remote settlements. In the case of air transport, over regulation has made the cost of adoption and access too high for many remote dwellers. In the case of communications technology, de-regulation has made it difficult for remote dwellers to demand equity of access to infrastructure. We conclude by suggesting that regulatory systems need to be more aware of the unique conditions facing remote populations. Research into the persistently low rates of technology adoption in remote areas needs to be more cognizant of the regulatory adaptability aspect.

  12. Closed-loop training of attention with real-time brain imaging.

    Science.gov (United States)

    deBettencourt, Megan T; Cohen, Jonathan D; Lee, Ray F; Norman, Kenneth A; Turk-Browne, Nicholas B

    2015-03-01

    Lapses of attention can have negative consequences, including accidents and lost productivity. Here we used closed-loop neurofeedback to improve sustained attention abilities and reduce the frequency of lapses. During a sustained attention task, the focus of attention was monitored in real time with multivariate pattern analysis of whole-brain neuroimaging data. When indicators of an attentional lapse were detected in the brain, we gave human participants feedback by making the task more difficult. Behavioral performance improved after one training session, relative to control participants who received feedback from other participants' brains. This improvement was largest when feedback carried information from a frontoparietal attention network. A neural consequence of training was that the basal ganglia and ventral temporal cortex came to represent attentional states more distinctively. These findings suggest that attentional failures do not reflect an upper limit on cognitive potential and that attention can be trained with appropriate feedback about neural signals.

  13. Improved resolution of single channel dwell times reveals mechanisms of binding, priming, and gating in muscle AChR

    Science.gov (United States)

    Mukhtasimova, Nuriya; daCosta, Corrie J.B.

    2016-01-01

    The acetylcholine receptor (AChR) from vertebrate skeletal muscle initiates voluntary movement, and its kinetics of activation are crucial for maintaining the safety margin for neuromuscular transmission. Furthermore, the kinetic mechanism of the muscle AChR serves as an archetype for understanding activation mechanisms of related receptors from the Cys-loop superfamily. Here we record currents through single muscle AChR channels with improved temporal resolution approaching half an order of magnitude over our previous best. A range of concentrations of full and partial agonists are used to elicit currents from human wild-type and gain-of-function mutant AChRs. For each agonist–receptor combination, rate constants are estimated from maximum likelihood analysis using a kinetic scheme comprised of agonist binding, priming, and channel gating steps. The kinetic scheme and rate constants are tested by stochastic simulation, followed by incorporation of the experimental step response, sampling rate, background noise, and filter bandwidth. Analyses of the simulated data confirm all rate constants except those for channel gating, which are overestimated because of the established effect of noise on the briefest dwell times. Estimates of the gating rate constants were obtained through iterative simulation followed by kinetic fitting. The results reveal that the agonist association rate constants are independent of agonist occupancy but depend on receptor state, whereas those for agonist dissociation depend on occupancy but not on state. The priming rate and equilibrium constants increase with successive agonist occupancy, and for a full agonist, the forward rate constant increases more than the equilibrium constant; for a partial agonist, the forward rate and equilibrium constants increase equally. The gating rate and equilibrium constants also increase with successive agonist occupancy, but unlike priming, the equilibrium constants increase more than the forward rate

  14. Theory of Visual Attention (TVA) applied to mice in the 5-choice serial reaction time task

    DEFF Research Database (Denmark)

    Fitzpatrick, C. M.; Caballero-Puntiverio, M.; Gether, U.

    2017-01-01

    Rationale The 5-choice serial reaction time task (5-CSRTT) is widely used to measure rodent attentional functions. In humans, many attention studies in healthy and clinical populations have used testing based on Bundesen’s Theory of Visual Attention (TVA) to estimate visual processing speeds...... thresholds and motor response baselines. Conclusions This study shows for the first time how 5-CSRTT performance in mice can be mathematically modelled to yield estimates of attentional capacity that are directly comparable to estimates from human studies....

  15. Play, attention, and learning: how do play and timing shape the development of attention and influence classroom learning?

    Science.gov (United States)

    Hedges, James H; Adolph, Karen E; Amso, Dima; Bavelier, Daphne; Fiez, Julie A; Krubitzer, Leah; McAuley, J Devin; Newcombe, Nora S; Fitzpatrick, Susan M; Ghajar, Jamshid

    2013-07-01

    The behavioral and neurobiological connections between play and the development of critical cognitive functions, such as attention, remain largely unknown. We do not yet know how these connections relate to the formation of specific abilities, such as spatial ability, and to learning in formal environments, such as in the classroom. Insights into these issues would be beneficial not only for understanding play, attention, and learning individually, but also for the development of more efficacious systems for learning and for the treatment of neurodevelopmental disorders. Different operational definitions of play can incorporate or exclude varying types of behavior, emphasize varying developmental time points, and motivate different research questions. Relevant questions to be explored in this area include, How do particular kinds of play relate to the development of particular kinds of abilities later in life? How does play vary across societies and species in the context of evolution? Does play facilitate a shift from reactive to predictive timing, and is its connection to timing unique or particularly significant? This report will outline important research steps that need to be taken in order to address these and other questions about play, human activity, and cognitive functions. © 2013 The Authors. Annals of the New York Academy of Sciences published by Wiley Periodicals Inc. on behalf of The New York Academy of Sciences.

  16. Finger tapping and pre-attentive sensorimotor timing in adults with ADHD.

    Science.gov (United States)

    Hove, Michael J; Gravel, Nickolas; Spencer, Rebecca M C; Valera, Eve M

    2017-12-01

    Sensorimotor timing deficits are considered central to attention-deficit/hyperactivity disorder (ADHD). However, the tasks establishing timing impairments often involve interconnected processes, including low-level sensorimotor timing and higher level executive processes such as attention. Thus, the source of timing deficits in ADHD remains unclear. Low-level sensorimotor timing can be isolated from higher level processes in a finger-tapping task that examines the motor response to unexpected shifts of metronome onsets. In this study, adults with ADHD and ADHD-like symptoms (n = 25) and controls (n = 26) performed two finger-tapping tasks. The first assessed tapping variability in a standard tapping task (metronome-paced and unpaced). In the other task, participants tapped along with a metronome that contained unexpected shifts (±15, 50 ms); the timing adjustment on the tap following the shift captures pre-attentive sensorimotor timing (i.e., phase correction) and thus should be free of potential higher order confounds (e.g., attention). In the standard tapping task, as expected, the ADHD group had higher timing variability in both paced and unpaced tappings. However, in the pre-attentive task, performance did not differ between the ADHD and control groups. Together, results suggest that low-level sensorimotor timing and phase correction are largely preserved in ADHD and that some timing impairments observed in ADHD may stem from higher level factors (such as sustained attention).

  17. Influences of Visual Attention and Reading Time on Children and Adults

    Science.gov (United States)

    Wei, Chun-Chun; Ma, Min-Yuan

    2017-01-01

    This study investigates the relationship between visual attention and reading time using a mobile electroencephalography device. The mobile electroencephalography device uses a single channel dry sensor, which easily measures participants' attention in the real-world reading environment. The results reveal that age significantly influences visual…

  18. The role of time on task performance in modifying the effects of gum chewing on attention

    NARCIS (Netherlands)

    Tucha, Lara; Simpson, William

    Recent research examined the effects of chewing gum on attention and reported a significant interaction of gum chewing with time. Using a crossover within-subject design, the present study examined the effect of gum chewing on sustained attention in healthy adults over a period of 30 min. The

  19. SU-E-T-16: A Comparison of Expected Dwell Times and Dose Variations for NAMD Patients Treated with An Episcleral Brachytherapy Device

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, R [Univ Arizona, Tucson, AZ (United States); Patel, P; Balaggan, K; Restori, M; Ilginis, T [Moorfields Eye Hospital, London (United Kingdom); Drew, M; McGovern, M; Vitali, J; Marsteller, L [Salutaris Medical Devices, Inc., Tucson, AZ (United States)

    2015-06-15

    Purpose: To evaluate the variations in dwell times and doses expected when using an episcleral brachytherapy device for treatment of neovascular agerelated macular degeneration (n-AMD) based on accurate imaging modalities Methods: Data from 40 eyes from 40 subjects with known n- AMD acquired through the Distance of Choroid Study (DOCS) conducted at Moorfields Eye Hospital was used to determine the target depth; the distance from the outer scleral surface of the eye, through the choroid, to the apex of the choroidal neovascularization (CNV). Each subject underwent, in triplicate, enhanced-depth Spectral Domain Optical Coherence Tomography (SD-OCT), Swept Source Optical Coherence Tomography, (SS-OCT) and Ocular Ultrasound (O-US). These data are the most comprehensive and accurate measurements of the dimensions of the CNV and adjacent layers of the eye for this cohort of patients. During treatment of n-AMD, patients receive a dose of 24Gy to the apex at the target depth. Using the percentage depth dose for a Sr-90 episcleral brachytherapy device, dwell times and doses to the apex were computed to determine the expected variations. Results: The mean target depth and the 95% confidence interval (CI) determined by combining O-US with SD-OCT were 1326 (956,1696)µm and with SS-OCT were 1332 (970,1693)µm. The calculated corresponding mean dwell times and 95% (CI) were 334 (223,445)s and 335 (226,445)s for SD-OCT and SS-OCT determined depths, respectively. The corresponding mean apex dose and 95% (CI) were 24 (35.9,18.0)Gy (SD-OCT) and 24 (35.6,18.1)Gy (SS-OCT). Conclusion: For episcleral brachytherapy treatment of n-AMD, using a patient population average target depth for treatment planning is inadequate, resulting in dose variations of a factor of approximately two over the 95% CI and larger variations for a nontrivial segment of the population. Each patient should have individualized imaging studies to determine the target depth for use in the dwell time calculation

  20. Relating lab to life: Decrements in attention over time predict math productivity among children with ADHD.

    Science.gov (United States)

    Fosco, Whitney D; Hawk, Larry W

    2017-02-01

    A child's ability to sustain attention over time (AOT) is critical in attention-deficit/hyperactivity disorder (ADHD), yet no prior work has examined the extent to which a child's decrement in AOT on laboratory tasks relates to clinically-relevant behavior. The goal of this study is to provide initial evidence for the criterion validity of laboratory assessments of AOT. A total of 20 children with ADHD (7-12 years of age) who were enrolled in a summer treatment program completed two lab attention tasks (a continuous performance task and a self-paced choice discrimination task) and math seatwork. Analyses focused on relations between attention task parameters and math productivity. Individual differences in overall attention (OA) measures (averaged across time) accounted for 23% of the variance in math productivity, supporting the criterion validity of lab measures of attention. The criterion validity was enhanced by consideration of changes in AOT. Performance on all laboratory attention measures deteriorated as time-on-task increased, and individual differences in the decrement in AOT accounted for 40% of the variance in math productivity. The only variable to uniquely predict math productivity was from the self-paced choice discrimination task. This study suggests that attention tasks in the lab do predict a clinically-relevant target behavior in children with ADHD, supporting their use as a means to study attention processes in a controlled environment. Furthermore, this prediction is improved when attention is examined as a function of time-on-task and when the attentional demands are consistent between lab and life contexts.

  1. Attentional bias for emotional information in older adults: the role of emotion and future time perspective.

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    Ineke Demeyer

    Full Text Available OBJECTIVES: Research suggests that older adults display a positivity bias at the level of information processing. However, because studies investigating attentional bias for emotional information in older adults have produced mixed findings, research identifying inter-individual differences that may explain these inconsistent results is necessary. Therefore, we investigated whether mood, symptoms of depression, symptoms of anxiety and future time perspective are related to attentional bias in older adults. METHOD: Thirty-seven healthy older adults and 25 healthy middle-aged adults completed questionnaires to assess mood, symptoms of depression, symptoms of anxiety and future time perspective. Attentional bias towards happy, sad and neutral information was measured using a modified exogenous cueing paradigm with long cue presentations, to measure maintained attention versus avoidance of emotional stimuli. RESULTS: Older adults showed attentional avoidance for all emotional faces, whereas no attentional biases were found in the middle-aged group. Moreover, in the older adult group, avoidance for negative information was related to anxiety. Future time perspective was unrelated to attentional bias. DISCUSSION: These findings suggest that anxiety may lead to inter-individual differences in attentional bias in older adults, and that avoidance from negative information may be an emotion regulation strategy.

  2. Attentional bias for emotional information in older adults: the role of emotion and future time perspective.

    Science.gov (United States)

    Demeyer, Ineke; De Raedt, Rudi

    2013-01-01

    Research suggests that older adults display a positivity bias at the level of information processing. However, because studies investigating attentional bias for emotional information in older adults have produced mixed findings, research identifying inter-individual differences that may explain these inconsistent results is necessary. Therefore, we investigated whether mood, symptoms of depression, symptoms of anxiety and future time perspective are related to attentional bias in older adults. Thirty-seven healthy older adults and 25 healthy middle-aged adults completed questionnaires to assess mood, symptoms of depression, symptoms of anxiety and future time perspective. Attentional bias towards happy, sad and neutral information was measured using a modified exogenous cueing paradigm with long cue presentations, to measure maintained attention versus avoidance of emotional stimuli. Older adults showed attentional avoidance for all emotional faces, whereas no attentional biases were found in the middle-aged group. Moreover, in the older adult group, avoidance for negative information was related to anxiety. Future time perspective was unrelated to attentional bias. These findings suggest that anxiety may lead to inter-individual differences in attentional bias in older adults, and that avoidance from negative information may be an emotion regulation strategy.

  3. Everyday Attention and Lecture Retention: The Effects of Time, Fidgeting, and Mind Wandering

    Directory of Open Access Journals (Sweden)

    James eFarley

    2013-09-01

    Full Text Available We have all had our thoughts wander from the immediate task at hand. The emerging embodied cognition literature emphasizes the role that the body plays in human thought, and raises the possibility that changes in attentional focus may be associated with changes in body behaviour. Recent research has found that when individuals view a lecture, mind wandering increases as a function of time. In the present study we asked whether this decline in attention during lecture viewing was associated with fidgeting. Participants were filmed while they watched a 40-minute lecture video, and at regular 5 minute intervals provided ratings of their attentiveness. Following the lecture, participant's memory for the material was assessed. Fidgeting behaviour was coded from video recordings of each session. Results indicated that attention to, and retention of, lecture material declined as a function of time on task. Critically, and as predicted, fidgeting also increased with time on task. We also found that the relation between fidgeting and retention was significant even when the role of attention was factored into the equation, suggesting that fidgeting makes a unique contribution to retention of lecture material over and above that contributed by an individual’s attention. We propose a novel non-attentional stress-based account of fidgeting and how this impacts retention for lecture material over and above changes in levels in mind wandering vis-a-vis changes in attention.

  4. Time-course of attention to negative stimuli: negative affectivity, anxiety, or dysphoria?

    Science.gov (United States)

    Oehlberg, Katherine A; Revelle, William; Mineka, Susan

    2012-10-01

    Although biased attention to emotional stimuli is considered a vulnerability factor for anxiety and dysphoria, research has infrequently related such attentional biases to dimensional models of vulnerability for anxiety and mood disorders. In two studies (Study 1, n = 64; Study 2, n = 168), we evaluate the differential associations of general negative affectivity, anxiety, and dysphoria with biases in selective attention among nonclinical participants selected to vary in both anxiety and dysphoria. Across both studies, preferential processing of angry faces at a 300-ms exposure duration was associated with a general tendency to experience a range of negative affect, rather than being specific to symptoms of either anxiety or dysphoria. In the second study, we found evidence of a suppressor relationship between anxiety and dysphoria in the prediction of delayed attentional biases (1,000 ms) for sad faces. In particular, dysphoria was specifically associated with biased attention toward sad cues, but only after statistically accounting for anxiety; by contrast, anxiety was specifically associated with attentional avoidance of sad cues, but only after statistically accounting for dysphoria. These results suggest that the specificity of relationships between components of negative affectivity and attention to emotional stimuli varies as a function of the time course at which attentional biases are assessed, highlighting the importance of evaluating both anxiety and dysphoria in research on attentional processing of emotional stimuli.

  5. Psychometric comparisons of the timed up and go, one-leg stand, functional reach, and Tinetti balance measures in community-dwelling older people.

    Science.gov (United States)

    Lin, Mau-Roung; Hwang, Hei-Fen; Hu, Ming-Hsia; Wu, Hong-Dar Isaac; Wang, Yi-Wei; Huang, Fu-Chao

    2004-08-01

    To compare the practicality, reliability, validity, and responsiveness of the timed up and go (TUG), one-leg stand (OLS), functional reach (FR), and Tinetti balance (TB) performance measures in people aged 65 and older. A prospective study. Shin-Sher Township of Taichung County, west-central Taiwan. Twelve hundred community-dwelling older people. During an initial assessment at their residences, participants were interviewed for demographics, cognition, fall history, use of a walking aid, and activities of daily living (ADLs), in addition to completing the four balance tests. Falls were ascertained by telephone every 3 months for a 1-year follow-up; the four balance measures and ADLs were also reassessed at the end of the follow-up year. Of the four balance measures, the OLS had the lowest participation rate, and participation of people who were cognitively impaired had fallen in the previous year, used a walking aid, or suffered from an ADL disability was lower than for their counterparts. The time to complete the tests ranged from 58 seconds for OLS, to 160 seconds for the TB. All four balance measures exhibited excellent test-retest reliability and discriminant validity but poor responsiveness to fall status. The TB showed better discriminant, convergent, and predictive validities and responsiveness to ADL changes than the other three tests. According to psychometric properties, the most suitable performance measure for evaluating balance in community-dwelling older people was the TB, followed by the TUG.

  6. Compression Effects on the Phase Behaviour of Miconazole-Poly (1-Vinylpyrrolidone-Co-Vinyl Acetate) Solid Dispersions-Role of Pressure, Dwell Time, and Preparation Method.

    Science.gov (United States)

    Singh, Abhishek; De Bisschop, Cathérine; Schut, Henk; Van Humbeeck, Jan; Van Den Mooter, Guy

    2015-10-01

    Compression of miconazole-poly (1-vinylpyrrolidone-co-vinyl acetate) (PVPVA64) solid dispersions prepared by spray drying and hot-melt extrusion was performed to gain insights into effect of compression pressure, dwell time, and preparation method on compression-dependent phase behavior. The solid dispersions prepared by spray drying were initially phase-separated showing two glass transition temperature (Tg), whereas the extruded samples showed one single Tg indicating better mixing. Compression caused mixing of spray-dried solid dispersions at high compression pressures and especially high dwell times. The extruded systems showed no statistically significant differences. However, physical mixtures made up from extruded samples containing 20% and 40% of active pharmaceutical ingredient underwent mixing upon compression. Coincidence Doppler measurements were performed to quantify the free volume of PVPVA64 which is a major contributor to the free volume in the solid dispersion matrix. A small but significant difference was found between the open free volume of the pure polymer subjected to varied manufacturing processes. Compression-induced plastic deformation and plastic flow enhances molecular mobility leading to mixing of different domains in solid dispersions. Different manufacturing methods may result in products with similar free volume, thereby showing similar molecular mobility. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  7. Effect of intraurethral dwell time of local anesthetic jelly on pain perception in men undergoing outpatient rigid cystoscopy: a randomized prospective study.

    Science.gov (United States)

    Vasudeva, Pawan; Kumar, Anup; Kumar, Niraj; Jha, Sanjeev Kumar; Kumar, Rohit; Mohanty, Avijit; Nanda, Biswajit; Singh, Harbinder

    2014-07-01

    To determine optimum duration of intraurethral 2% lidocaine jelly for pain relief during outpatient rigid cystoscopy. This prospective randomized study was conducted between June 2012 and November 2013. Four hundred consecutive adult males requiring diagnostic rigid cystoscopy were randomized into four groups depending on intraurethral 2% lidocaine jelly dwell time before rigid cystoscopy: jelly was instilled 5, 10, 15, and 20 minutes before start of the procedure in group A, B, C, and D patients, respectively. The patients' age, patient-reported preoperative anxiety score, patient-reported intraoperative pain score, the surgeon-reported patient's pain score, and the duration of rigid cystoscopy were recorded and analyzed. The mean age, patient-reported preoperative anxiety score, and duration of rigid cystoscopy were similar between the four groups with no significant difference noted between them. The least and highest mean patient-reported and surgeon-reported intraoperative pain scores were reported in group C (1.49±0.82 and 1.58±0.67) patients and group A (4.86±1.24 and 4.04±1.11) patients, respectively, while no significant difference was found in these scores between group C and D patients. For male patients undergoing diagnostic rigid cystoscopy, an intraurethral dwell time of 15 minutes (of 20 mL 2% lidocaine jelly) provided optimum pain relief.

  8. Effect of Dwell Time on Joint Interface Microstructure and Strength of Dissimilar Friction Stir Spot-Welded Al-5083 and St-12 Alloy Sheets

    Science.gov (United States)

    Fereiduni, Eskandar; Movahedi, Mojtaba; Kokabi, Amir Hossein; Najafi, Hossein

    2017-04-01

    Joining of Al-5083 alloy sheet to St-12 steel sheet was performed using a new friction stir spot welding (FSSW) technique in which the tool pin tip did not enter lower steel sheet. Effect of dwell time on the microstructure and mechanical properties of the joints was studied by various methods including microhardness measurements, shear test, stereo and light microscopy as well as scanning and transmission electron microscopy (SEM and TEM). Results indicated that compared to the conventional FSSW process, stronger joints can be achieved by this FSSW technique. Cross-sectional observation of the failed specimens indicated the occurrence of final fracture from the circumference of the tool pin where the Al sheet thickness was decreased as a result of the tool pin penetration. However, microhardness measurements introduced these fracture locations as the hardest regions of the Al part of welds. In addition to the Al3Fe and Al5Fe2 intermetallic compounds reported in the literature to form at the interface of dissimilar Al/steel joints, a third layer of AlFe intermetallic compound was also identified adjacent to the steel side of welds. Enhancement of the dwell time from 5 to 15 seconds increased the intermetallic layer thickness from 1.7 to 3 µm and resulted in the formation of harder stirred zone. This consequently increased the strength of the weld.

  9. Identifying the dwelling time problems faced by users of seaport services on import activities: study on freight forwarders in East Java, Indonesia

    Directory of Open Access Journals (Sweden)

    Supriono

    2017-08-01

    Full Text Available Freight Forwarders as an intermediary between exporters and importers are also affected by dwelling time performance. This study aims to identify the problems faced by Freight Forwarders in East Java in the application of dwelling time at the port. The research method is qualitative with descriptive analysis, with in-depth interviews on some Freight Forwarders and Association on Logistics and Forwarder of Indonesia (ALFI. Respondents are chosen through purposive sampling. Here are the results of the study. The problems faced by the forwarders are the delay of NOA (Notice of Arrival and DO (Delivery Order bills from the shipping parties. Overlapping regulations related to the process of export and import documents due to differences of perception among ministries in charge. The next problem is the lack of knowledge of exporters and importers on export and import regulations. There are also problems related to interruption on INSW (Indonesia National Single Window server and CEISA (Customs Excise Information System and Automation. The random system on imported goods after inspection at CEISA, limited importer warehouse, and no needs over imported goods are also the obstacles faced. The other problem is that importers tend to keep stockpile in containers in the depots because security assurance in the depots is much better than in the importer warehouse.

  10. The beneficial influence on the effectiveness of automated peritoneal dialysis of varying the dwell time (short/long) and fill volume (small/large): a randomized controlled trial.

    Science.gov (United States)

    Fischbach, Michel; Issad, Belkacem; Dubois, Vincent; Taamma, Redouane

    2011-01-01

    It is well known that the efficiency of peritoneal dialysis (PD) varies with the duration of the dwell and with the prescribed fill volume. Automated PD (APD) is classically given as a series of recurrent exchanges, each having the same dwell time and fill volume-that is, conventional APD (APD-C). We propose a new way of giving PD, using a modified version of APD-C. This method first uses a short dwell time with a small fill volume to promote ultrafiltration (UF) and subsequently uses a longer dwell time and a larger fill volume to promote removal of uremic toxins from the blood. We use the term "adapted APD" (APD-A) to describe this modified form of PD. We designed a multicenter prospective randomized crossover trial to assess the impact of APD-A in comparison with APD-C on the efficacy of dialysis. The parameters investigated were overnight UF; weekly peritoneal Kt/V(urea); weekly peritoneal creatinine clearance corrected to 1.73 m(2) body surface area (K(creat)); and phosphate (PDR) and sodium dialytic removal (SDR) in millimoles per session, corrected for glucose absorption, which provides an estimate of metabolic cost. Blood pressure was also regularly monitored. Initially, 25 patients were identified for inclusion in the study. There were 6 withdrawals in total: 2 at enrolment, 1 at day 75 (transplantation), 2 at day 30 (catheter dysfunction), and 1 for drainage alarms. All patients received the same duration of overnight APD, using the same total volume of dialysate, with the same 1.5% glucose, lactate-buffered dialysate (Balance: Fresenius Medical Care, Bad Homburg, Germany). Tolerance was good. Compared with APD-C, APD-A resulted in a significant enhancement of Kt/V(urea), K(creat), and PDR. The metabolic cost, in terms of glucose absorption, required to achieve dialytic capacity for urea, creatinine, and phosphate blood purification was significantly lower for APD-A than for APD-C, and UF increased during APD-A. With APD-A, each gram of glucose absorbed

  11. Delaying school starting time by one hour: some effects on attention levels in adolescents.

    Science.gov (United States)

    Lufi, Dubi; Tzischinsky, Orna; Hadar, Stav

    2011-04-15

    The purpose of the study was to assess the attention level of middle-school students by providing a group of students with the opportunity for an additional one hour of sleep in the morning by delaying school starting time by one hour, as compared to another group received no additional sleep. For the first week of the study, the school starting time was delayed 1 h for the experimental group (N = 26). In the second week, these students returned to their regular school schedule. A control group (N = 21) remained on their regular schedule for these 2 weeks. Both groups were tested at the end of each week with 2 measures to assess their attention. The results showed that in the first week the experimental group slept an average of 55 minutes longer each night, for 5 nights (total 275 minutes). Students who slept longer performed better in measures of attention as assessed by the "Mathematics Continuous Performance Test" and the "d2 Test of Attention," indicating better performance in attention level, impulsivity, and the rate of performance. The study strongly recommends that middle schools should consider delaying the school starting time by at least one hour. Such a change could enhance students' cognitive performance by improving their attention level, increasing rate of performance, as well as reducing their mistakes and impulsivity.

  12. Attentional cues affect accuracy and reaction time via different cognitive and neural processes.

    Science.gov (United States)

    van Ede, Freek; de Lange, Floris P; Maris, Eric

    2012-07-25

    We investigated whether symbolic endogenous attentional cues affect perceptual accuracy and reaction time (RT) via different cognitive and neural processes. We recorded magnetoencephalography in 19 humans while they performed a cued somatosensory discrimination task in which the cue-target interval was varied between 0 and 1000 ms. Comparing behavioral and neural measures, we show that (1) attentional cueing affects accuracy and RT with different time courses and (2) the time course of our neural measure (anticipatory suppression of neuronal oscillations in stimulus-receiving sensory cortex) only accounts for the accuracy time course. A model is proposed in which the effect on accuracy is explained by a single process (preparatory excitability increase in sensory cortex), whereas the effect on RT is explained by an additional process that is sensitive to cue-target compatibility (post-target comparison between expected and actual stimulus location). These data provide new insights into the mechanisms underlying behavioral consequences of attentional cueing.

  13. Dynamic attentional modulation of vision across space and time after right hemisphere stroke and in ageing

    Science.gov (United States)

    Russell, Charlotte; Malhotra, Paresh; Deidda, Cristiana; Husain, Masud

    2013-01-01

    Introduction Attention modulates the availability of sensory information to conscious perception. In particular, there is evidence of pathological, spatial constriction of the effective field of vision in patients with right hemisphere damage when a central task exhausts available attentional capacity. In the current study we first examined whether this constriction might be modulated across both space and time in right hemisphere stroke patients without neglect. Then we tested healthy elderly people to determine whether non-pathological ageing also leads to spatiotemporal impairments of vision under conditions of high attention load. Methods Right hemisphere stroke patients completed a task at fixation while attempting to discriminate letters appearing in the periphery. Attentional load of the central task was modulated by increasing task difficulty. Peripheral letters appeared simultaneously with the central task or at different times (stimulus onset asynchronies, SOAs) after it. In a second study healthy elderly volunteers were tested with a modified version of this paradigm. Results Under conditions of high attention load right hemisphere stroke patients have a reduced effective visual field, over a significantly extended ‘attentional blink’, worse for items presented to their left. In the second study, older participants were unable to discriminate otherwise salient items across the visual field (left or right) when their attention capacity was loaded on the central task. This deficit extended temporally, with peripheral discrimination ability not returning to normal for up to 450 msec. Conclusions Dynamically tying up attention resources on a task at fixation can have profound effects in patient populations and in normal ageing. These results demonstrate that items can escape conscious detection across space and time, and can thereby impact significantly on visual perception in these groups. PMID:23245427

  14. An integrated theory of prospective time interval estimation : The role of cognition, attention, and learning

    NARCIS (Netherlands)

    Taatgen, Niels A.; van Rijn, Hedderik; Anderson, John

    A theory of prospective time perception is introduced and incorporated as a module in an integrated theory of cognition, thereby extending existing theories and allowing predictions about attention and learning. First, a time perception module is established by fitting existing datasets (interval

  15. Timing deficits in attention-deficit/hyperactivity disorder (ADHD) : Evidence from neurocognitive and neuroimaging studies

    NARCIS (Netherlands)

    Noreika, Valdas; Falter, Christine M.; Rubia, Katya

    Relatively recently, neurocognitive and neuroimaging studies have indicated that individuals with attention-deficit/hyperactivity disorder (ADHD) may have deficits in a range of timing functions and their underlying neural networks. Despite this evidence, timing deficits in ADHD are still somewhat

  16. Late endovascular removal of Günther-Tulip inferior vena cava filter and stent reconstruction of chronic post-thrombotic iliocaval obstruction after 4753 days of filter dwell time: a case report with review of literature.

    Science.gov (United States)

    Doshi, Mehul Harshad; Narayanan, Govindarajan

    2016-12-01

    Chronic post-thrombotic obstruction of the inferior vena cava (IVC) or iliocaval junction is an uncommon complication of long indwelling IVC filter. When such an obstruction is symptomatic, endovascular treatment options include stent placement with or without filter retrieval. Filter retrieval becomes increasingly difficult with longer dwell times. We present a case of symptomatic post-thrombotic obstruction of the iliocaval junction related to Günther-Tulip IVC filter (Cook Medical Inc, Bloomington, IN) with dwell time of 4753 days, treated successfully with endovascular filter removal and stent reconstruction. Filter retrieval and stent reconstruction may be a treatment option in symptomatic patients with filter-related chronic IVC or iliocaval junction obstruction, even after prolonged dwell time.

  17. Effects of load on the time course of attentional engagement, disengagement, and orienting in reading.

    Science.gov (United States)

    Ghahghaei, Saeideh; Linnell, Karina J; Fischer, Martin H; Dubey, Amit; Davis, Robert

    2013-01-01

    We examined how the frequency of the fixated word influences the spatiotemporal distribution of covert attention during reading. Participants discriminated gaze-contingent probes that occurred with different spatial and temporal offsets from randomly chosen fixation points during reading. We found that attention was initially focused at fixation and that subsequent defocusing was slower when the fixated word was lower in frequency. Later in a fixation, attention oriented more towards the next saccadic target for high- than for low-frequency words. These results constitute the first report of the time course of the effect of load on attentional engagement and orienting in reading. They are discussed in the context of serial and parallel models of reading.

  18. Attention dependency in implicit learning of repeated search context.

    Science.gov (United States)

    Rausei, Valeria; Makovski, Tal; Jiang, Yuhong V

    2007-10-01

    How much attention is needed to produce implicit learning? Previous studies have found inconsistent results, with some implicit learning tasks requiring virtually no attention while others rely on attention. In this study we examine the degree of attentional dependency in implicit learning of repeated visual search context. Observers searched for a target among distractors that were either highly similar to the target or dissimilar to the target. We found that the size of contextual cueing was comparable from repetition of the two types of distractors, even though attention dwelled much longer on distractors highly similar to the target. We suggest that beyond a minimal amount, further increase in attentional dwell time does not contribute significantly to implicit learning of repeated search context.

  19. Sequential sampling model for multiattribute choice alternatives with random attention time and processing order.

    Science.gov (United States)

    Diederich, Adele; Oswald, Peter

    2014-01-01

    A sequential sampling model for multiattribute binary choice options, called multiattribute attention switching (MAAS) model, assumes a separate sampling process for each attribute. During the deliberation process attention switches from one attribute consideration to the next. The order in which attributes are considered as well for how long each attribute is considered-the attention time-influences the predicted choice probabilities and choice response times. Several probability distributions for the attention time with different variances are investigated. Depending on the time and order schedule the model predicts a rich choice probability/choice response time pattern including preference reversals and fast errors. Furthermore, the difference between finite and infinite decision horizons for the attribute considered last is investigated. For the former case the model predicts a probability p 0 > 0 of not deciding within the available time. The underlying stochastic process for each attribute is an Ornstein-Uhlenbeck process approximated by a discrete birth-death process. All predictions are also true for the widely applied Wiener process.

  20. Sequential sampling model for multiattribute choice alternatives with random attention time and processing order

    Directory of Open Access Journals (Sweden)

    Adele eDiederich

    2014-09-01

    Full Text Available A sequential sampling model for multiattribute binary choice options, called Multiattribute attention switching (MAAS model, assumes a separate sampling process for each attribute. During the deliberation process attention switches from one attribute consideration to the next. The order in which attributes are considered as well for how long each attribute is considered - the attention time - influences the predicted choice probabilities and choice response times. Several probability distributions for the attention time including deterministic, Poisson, binomial, geometric, and uniform with different variances are investigated. Depending on the time and order schedule the model predicts a rich choice probability/choice response time pattern including preference reversals and fast errors. Furthermore, the difference between a finite and infinite decision horizons for the attribute considered last is investigated. For the former case the model predicts a probability $p_0> 0$ of not deciding within the available time. The underlying stochastic process for each attribute is an Ornstein-Uhlenbeck process approximated by a discrete birth-death process. All predictions are also true for the widely applied Wiener process.

  1. Time-dependent effects of cortisol on selective attention and emotional interference: a functional MRI study

    Directory of Open Access Journals (Sweden)

    Marloes J.A.G. Henckens

    2012-08-01

    Full Text Available Acute stress is known to induce a state of hypervigilance, allowing optimal detection of threats. Although one may benefit from sensitive sensory processing, it comes at the cost of unselective attention and increased distraction by irrelevant information. Corticosteroids have been shown to profoundly influence brain function in a time-dependent manner, causing rapid non-genomic and slow genomic effects. Here, we investigated how these time-dependent effects influence the neural mechanisms underlying selective attention and the inhibition of emotional distracters in humans. Implementing a randomized, double-blind, placebo-controlled design, 65 young healthy men received 10 mg hydrocortisone either 60 min (rapid effects or 270 min (slow effects, or placebo prior to an emotional distraction task, consisting of color-naming of either neutral or aversive words. Overall, participants responded slower to aversive compared to neutral words, indicating emotional interference with selective attention. Importantly, the rapid effects of corticosteroids increased emotional interference, which was associated with reduced amygdala inhibition to aversive words. Moreover, they induced enhanced amygdala connectivity with frontoparietal brain regions, which may reflect increased influence of the amygdala on an executive network. The slow effects of corticosteroids acted on the neural correlates of sustained attention. They decreased overall activity in the cuneus, possibly indicating reduced bottom-up attentional processing, and disrupted amygdala connectivity to the insula, potentially reducing emotional interference. Altogether, these data suggest a time-specific corticosteroid modulation of attentive processing. Whereas high circulating corticosteroid levels acutely increase emotional interference, possibly facilitating the detection of threats, a history of elevation might promote sustained attention and thereby contribute to stress-recovery of cognitive

  2. Theory of Visual Attention (TVA) applied to mice in the 5-choice serial reaction time task.

    Science.gov (United States)

    Fitzpatrick, C M; Caballero-Puntiverio, M; Gether, U; Habekost, T; Bundesen, C; Vangkilde, S; Woldbye, D P D; Andreasen, J T; Petersen, A

    2017-03-01

    The 5-choice serial reaction time task (5-CSRTT) is widely used to measure rodent attentional functions. In humans, many attention studies in healthy and clinical populations have used testing based on Bundesen's Theory of Visual Attention (TVA) to estimate visual processing speeds and other parameters of attentional capacity. We aimed to bridge these research fields by modifying the 5-CSRTT's design and by mathematically modelling data to derive attentional parameters analogous to human TVA-based measures. C57BL/6 mice were tested in two 1-h sessions on consecutive days with a version of the 5-CSRTT where stimulus duration (SD) probe length was varied based on information from previous TVA studies. Thereafter, a scopolamine hydrobromide (HBr; 0.125 or 0.25 mg/kg) pharmacological challenge was undertaken, using a Latin square design. Mean score values were modelled using a new three-parameter version of TVA to obtain estimates of visual processing speeds, visual thresholds and motor response baselines in each mouse. The parameter estimates for each animal were reliable across sessions, showing that the data were stable enough to support analysis on an individual level. Scopolamine HBr dose-dependently reduced 5-CSRTT attentional performance while also increasing reward collection latency at the highest dose. Upon TVA modelling, scopolamine HBr significantly reduced visual processing speed at both doses, while having less pronounced effects on visual thresholds and motor response baselines. This study shows for the first time how 5-CSRTT performance in mice can be mathematically modelled to yield estimates of attentional capacity that are directly comparable to estimates from human studies.

  3. Reaction Times to Consecutive Automation Failures: A Function of Working Memory and Sustained Attention.

    Science.gov (United States)

    Jipp, Meike

    2016-12-01

    This study explored whether working memory and sustained attention influence cognitive lock-up, which is a delay in the response to consecutive automation failures. Previous research has demonstrated that the information that automation provides about failures and the time pressure that is associated with a task influence cognitive lock-up. Previous research has also demonstrated considerable variability in cognitive lock-up between participants. This is why individual differences might influence cognitive lock-up. The present study tested whether working memory-including flexibility in executive functioning-and sustained attention might be crucial in this regard. Eighty-five participants were asked to monitor automated aircraft functions. The experimental manipulation consisted of whether or not an initial automation failure was followed by a consecutive failure. Reaction times to the failures were recorded. Participants' working-memory and sustained-attention abilities were assessed with standardized tests. As expected, participants' reactions to consecutive failures were slower than their reactions to initial failures. In addition, working-memory and sustained-attention abilities enhanced the speed with which participants reacted to failures, more so with regard to consecutive than to initial failures. The findings highlight that operators with better working memory and sustained attention have small advantages when initial failures occur, but their advantages increase across consecutive failures. The results stress the need to consider personnel selection strategies to mitigate cognitive lock-up in general and training procedures to enhance the performance of low ability operators. © 2016, Human Factors and Ergonomics Society.

  4. Attention, temporal predictability, and the time course of context effects in naming performance

    NARCIS (Netherlands)

    Roelofs, Ardi

    2010-01-01

    Models of attention and context effects in naming performance should be able to account for the time course of color-word Stroop interference revealed by manipulations of the stimulus onset asynchrony (SOA) between color and word. Prominent models of Stroop task performance (Cohen, Dunbar, &

  5. Reaction time, processing speed and sustained attention in schizophrenia: impact on social functioning.

    Science.gov (United States)

    Lahera, Guillermo; Ruiz, Alicia; Brañas, Antía; Vicens, María; Orozco, Arantxa

    Previous studies have linked processing speed with social cognition and functioning of patients with schizophrenia. A discriminant analysis is needed to determine the different components of this neuropsychological construct. This paper analyzes the impact of processing speed, reaction time and sustained attention on social functioning. 98 outpatients between 18 and 65 with DSM-5 diagnosis of schizophrenia, with a period of 3 months of clinical stability, were recruited. Sociodemographic and clinical data were collected, and the following variables were measured: processing speed (Trail Making Test [TMT], symbol coding [BACS], verbal fluency), simple and elective reaction time, sustained attention, recognition of facial emotions and global functioning. Processing speed (measured only through the BACS), sustained attention (CPT) and elective reaction time (but not simple) were associated with functioning. Recognizing facial emotions (FEIT) correlated significantly with scores on measures of processing speed (BACS, Animals, TMT), sustained attention (CPT) and reaction time. The linear regression model showed a significant relationship between functioning, emotion recognition (P=.015) and processing speed (P=.029). A deficit in processing speed and facial emotion recognition are associated with worse global functioning in patients with schizophrenia. Copyright © 2017 SEP y SEPB. Publicado por Elsevier España, S.L.U. All rights reserved.

  6. Attention and time constraints in perceptual-motor learning and performance: Instruction, analogy, and skill level

    NARCIS (Netherlands)

    Koedijker, J.M.; Poolton, J.M.; Maxwell, J.P.; Oudejans, R.R.D.; Beek, P.J.; Masters, R.S.W.

    2011-01-01

    We sought to gain more insight into the effects of attention focus and time constraints on skill learning and performance in novices and experts by means of two complementary experiments using a table tennis paradigm. Experiment 1 showed that skill-focus conditions and slowed ball frequency

  7. The time course of working memory effects on visual attention differs depending on memory type

    NARCIS (Netherlands)

    Dombrowe, I.; Olivers, C.N.L.; Donk, M.

    2010-01-01

    Previous work has generated inconsistent results with regard to what extent working memory (WM) content guides visual attention. Some studies found effects of easy to verbalize stimuli, whereas others only found an influence of visual memory content. To resolve this, we compared the time courses of

  8. Carbon monoxide poisoning in Nigeria - it is time to pay attention ...

    African Journals Online (AJOL)

    Methods: Information was drawn from local media reports and relevant literature. A literature search was done using Medline and Embase. Result: CO poisoning is underestimated in Nigeria. Conclusion: CO poisoning, although silent, is a major public health problem in Nigeria. It is indeed time to pay attention. Keywords: ...

  9. Attention, spatial integration, and the tail of response time distributions in Stroop task performance

    NARCIS (Netherlands)

    Roelofs, A.P.A.

    2012-01-01

    A few studies have examined selective attention in Stroop task performance through ex-Gaussian analyses of response time (RT) distributions. It has remained unclear whether the tail of the RT distribution in vocal responding reflects spatial integration of relevant and irrelevant attributes, as

  10. Features of perceived neighborhood environment associated with daily walking time or habitual exercise: differences across gender, age, and employment status in a community-dwelling population of Japan.

    Science.gov (United States)

    Chen, Tzu-an; Lee, Jung Su; Kawakubo, Kiyoshi; Watanabe, Etsuko; Mori, Katsumi; Kitaike, Tadashi; Akabayashi, Akira

    2013-09-01

    Perceived neighborhood environment (NE) is considered a determinant of daily physical activity (PA). However, evidence concerning differences among types of PA, gender, and age is limited. The study purpose was to clarify the association between NE and walking time (WT) or habitual exercise (HE) across gender, age, and employment status in a community-dwelling population of Japan. A questionnaire mail survey with a stratified random 7,515 sampling was conducted in a northeast city in January 2007. Multiple logistic analysis was conducted to examine the associations between seven NE indices and WT or HE across gender, age, and employment status: 20-39 (young-employed), 40-59 (middle-employed), and 60-79 (old-employed or old-unemployed) after adjustment for age and means of transportation. A total of 3,806 residents (52.4 % females) completed the survey. Traffic and crime safety in old-unemployed males and proximity to service facilities and traffic and crime safety in middle-employed females were significantly associated with a low risk of insufficient WT. Proximity to service facilities in old-employed males, number of service facilities, places for walking, and good view in middle-employed females, and density of dwelling and proximity to service facilities in old-unemployed females were significantly associated with a low risk of non-HE. The association between NE and WT or HE differed across type of PA, gender, age, and employment status, and was observed mainly in middle- and old-aged females. The middle- and old-aged female residents' PA possibly were more influenced by their NE, and NE would contribute to promote active living.

  11. Attention focussing and anomaly detection in real-time systems monitoring

    Science.gov (United States)

    Doyle, Richard J.; Chien, Steve A.; Fayyad, Usama M.; Porta, Harry J.

    1993-01-01

    In real-time monitoring situations, more information is not necessarily better. When faced with complex emergency situations, operators can experience information overload and a compromising of their ability to react quickly and correctly. We describe an approach to focusing operator attention in real-time systems monitoring based on a set of empirical and model-based measures for determining the relative importance of sensor data.

  12. Measuring dwell time percentage from head-mounted eye-tracking data--comparison of a frame-by-frame and a fixation-by-fixation analysis.

    Science.gov (United States)

    Vansteenkiste, Pieter; Cardon, Greet; Philippaerts, Renaat; Lenoir, Matthieu

    2015-01-01

    Although analysing software for eye-tracking data has significantly improved in the past decades, the analysis of gaze behaviour recorded with head-mounted devices is still challenging and time-consuming. Therefore, new methods have to be tested to reduce the analysis workload while maintaining accuracy and reliability. In this article, dwell time percentages to six areas of interest (AOIs), of six participants cycling on four different roads, were analysed both frame-by-frame and in a 'fixation-by-fixation' manner. The fixation-based method is similar to the classic frame-by-frame method but instead of assigning frames, fixations are assigned to one of the AOIs. Although some considerable differences were found between the two methods, a Pearson correlation of 0.930 points out a good validity of the fixation-by-fixation method. For the analysis of gaze behaviour over an extended period of time, the fixation-based approach is a valuable and time-saving alternative for the classic frame-by-frame analysis.

  13. Joint Attention is Slowed in Older Adults.

    Science.gov (United States)

    Deroche, Thomas; Castanier, Carole; Perrot, Alexandra; Hartley, Alan

    2016-01-01

    The automatic propensity to orient to the location where other people are looking is the main way of establishing joint attention with others. Whereas joint attention has been mostly investigated with young adults, the present study examines age-related differences in the magnitude and time course of joint attention. Forty-three community-dwelling seniors and 43 younger adults performed a visuospatial task. The procedures closely follow those of gaze-cueing tasks commonly used to investigate joint attention. The findings revealed that a gaze-cueing effect occurs for both younger and older adults, with an equivalent average magnitude but with different time courses. The effect peaks later in older adults. Age-related differences in joint attention could be linked to a more general cognitive slowing rather than to poorer basic social skills. The present study adds to the growing interest in gerontological research regarding social attention.

  14. Inspection time and attention-deficit/hyperactivity disorder symptoms in children with cerebral palsy.

    Science.gov (United States)

    Shank, Laura K; Kaufman, Jacqueline; Leffard, Stacie; Warschausky, Seth

    2010-05-01

    To examine between-groups differences in the associations between aspects of processing speed assessed with an inspection time task and attention-deficit/hyperactivity disorder (ADHD) symptoms. Two groups comprising 34 children with cerebral palsy (CP) and 70 nonaffected peers (control), ages 8-16 years, participated in a prospective correlational study. Measures included a visual inspection time task and the Conners' Parent Rating Scale-Revised: Long Version. Children with CP exhibited significantly slower processing speed and more symptoms of inattention and hyperactivity than controls. Significant associations between inspection time and ADHD symptoms were found only in the control group. Findings have implications for clinical assessment and understanding of attentional risks associated with CP.

  15. Effect of a dual task on quantitative Timed Up and Go performance in community-dwelling older adults: A preliminary study.

    Science.gov (United States)

    Smith, Erin; Walsh, Lorcan; Doyle, Julie; Greene, Barry; Blake, Catherine

    2017-08-01

    The Timed Up and Go test (TUG) is used as a measure of functional ability in older adults; however, the method of measurement does not allow us to determine which aspects of the test deficits occur in. The aim of the present study was to examine the ability of the quantitative TUG (QTUG) to measure performance during the TUG test under three different conditions - single task, motor task and cognitive dual task - and to compare performance between fallers and non-fallers in high-functioning community-dwelling older adults. A total of 37 community-dwelling older adults, 16 with a self-reported falls history in the previous year, were recruited. Participants underwent a falls risk assessment with a physiotherapist including the QTUG under three conditions (single task, motor task, cognitive dual-task). A total of 10 clinical parameters were chosen for analysis using mancova and a series of ancova, with age, sex and body mass index included as covariates. The mancova analysis showed a significant difference across the three task conditions (Wilk's Lambda F20,186  = 3.37, P < 0.001. No overall significant difference between faller and non-faller groups (Wilk's Lambda F10,96  = 1.469, P = 0.163) or significant interaction between task and faller status (Wilk's Lambda F20,192  = 1.131, P = 0.321) was found. ancova results for each of the parameters showed overall differences between single, motor and cognitive tasks for all of the variables, except time in double support. When faller and non-faller differences were explored, cadence and stride velocity was greater, and stride time longer in those with a prior history of falls. In community-dwelling older adults, these preliminary results show that a cognitive dual-task significantly (P < 0.025) affects QTUG performance in almost all parameters, with a significant (P < 0.025) reduction in time-to-stand observed with a motor task. Although no statistical difference was found between fallers

  16. Associations between Perceived Neighborhood Walkability and Walking Time, Wellbeing, and Loneliness in Community-Dwelling Older Chinese People in Hong Kong.

    Science.gov (United States)

    Yu, Ruby; Cheung, Osbert; Lau, Kevin; Woo, Jean

    2017-10-09

    This study examined the cross-sectional associations between perceived neighborhood walkability and walking time, physical activity, wellbeing, and loneliness, and examined which components of walkability were most strongly associated with better wellbeing and less loneliness in older adults. Participants were community-dwelling Chinese adults aged 60+ (n = 181). Walkability was measured using nine items selected from the Chinese version of the abbreviated Neighborhood Environment Walkability Scales (NEWS) and NEWS for Chinese Seniors. Outcomes were walking time, physical activity, wellbeing (life satisfaction, happiness, sense of purpose and meaning in life), and loneliness. The mean age of the participants was 71.7 ± 7.8 years. Walkability was positively associated with walking time (p = 0.001, p for trend walkable had higher scores for life satisfaction (p = 0.002) and happiness (p = 0.002), and lower scores for loneliness (p = 0.019), compared with those who perceived their neighborhoods as less walkable. However, perceived neighborhood walkability was not associated with sense of purpose and meaning in life. Among components of walkability, land use mix-access, infrastructure and safety for walking, and traffic safety showed the strongest associations with the measures of wellbeing. The results of this study support the importance of neighborhood walkability for health behavior and wellbeing of older adults. The wellbeing of older adults may be enhanced through the improvement of land use mix-access, infrastructure for walking, and traffic safety.

  17. Thoron exposure in Dutch dwellings - An overview.

    NARCIS (Netherlands)

    de With, G; Smetsers, R C G M; Slaper, H; de Jong, P

    2018-01-01

    In the Netherlands considerable attention has been given to the exposure from thoron progeny in dwellings. For this purpose a nationwide survey on the thoron exhalation and thoron progeny concentration has been completed in 2015. Furthermore, extensive laboratory studies have been performed to

  18. Real-time decoding of the direction of covert visuospatial attention.

    Science.gov (United States)

    Andersson, Patrik; Ramsey, Nick F; Raemaekers, Mathijs; Viergever, Max A; Pluim, Josien P W

    2012-08-01

    Brain-computer interfaces (BCIs) make it possible to translate a person's intentions into actions without depending on the muscular system. Brain activity is measured and classified into commands, thereby creating a direct link between the mind and the environment, enabling, e.g., cursor control or navigation of a wheelchair or robot. Most BCI research is conducted with scalp EEG but recent developments move toward intracranial electrodes for paralyzed people. The vast majority of BCI studies focus on the motor system as the appropriate target for recording and decoding movement intentions. However, properties of the visual system may make the visual system an attractive and intuitive alternative. We report on a study investigating feasibility of decoding covert visuospatial attention in real time, exploiting the full potential of a 7 T MRI scanner to obtain the necessary signal quality, capitalizing on earlier fMRI studies indicating that covert visuospatial attention changes activity in the visual areas that respond to stimuli presented in the attended area of the visual field. Healthy volunteers were instructed to shift their attention from the center of the screen to one of four static targets in the periphery, without moving their eyes from the center. During the first part of the fMRI-run, the relevant brain regions were located using incremental statistical analysis. During the second part, the activity in these regions was extracted and classified, and the subject was given visual feedback of the result. Performance was assessed as the number of trials where the real-time classifier correctly identified the direction of attention. On average, 80% of trials were correctly classified (chance level <25%) based on a single image volume, indicating very high decoding performance. While we restricted the experiment to five attention target regions (four peripheral and one central), the number of directions can be higher provided the brain activity patterns can be

  19. The footprints of a wandering mind: Further examination of the time course of an attentional lapse.

    Science.gov (United States)

    Smallwood, Jonathan

    2011-06-01

    Recently, understanding the sequence of events that precedes an attentional lapse has become an important question in cognitive neuroscience. To examine the processes which lead to such errors, participants performed a simple go/no-go task used for measuring attentional failure. To study the role of internal distraction, the participants' tendency to daydreaming was assessed via a questionnaire. Principal components analysis (PCA) was used to decompose the response time (RT) course into the underlying components. Analysis identified three components that made up 54% of the data collected. One factor indicated the overall magnitude of the RT in a given block. This factor showed a significant negative weighting prior to an error. A second factor indicating that RT shifted from slow to fast was also identified. The parity of this factor was predictive of error for individuals high on daydreaming, indicating that errors in individuals with a rich, imaginative mental life showed a shift from slow to fast responding prior to an attentional lapse. This analysis provides further evidence that attentional lapses can result from events that took place many seconds before the mistake and that the elements of the default mode may be involved in these lapses.

  20. Introducing a Third Timed Up & Go Test Trial Improves Performances of Hospitalized and Community-Dwelling Older Individuals

    DEFF Research Database (Denmark)

    Bloch, Mette L; Jønsson, Line R; Kristensen, Morten T

    2017-01-01

    BACKGROUND AND PURPOSE: Originally, the Timed Up & Go (TUG) test was described as including a practice trial before a timed trial, but recent studies in individuals with hip fracture have reported that performance improved with a third trial and that high intertester reliability was achieved when...

  1. Self-reported hearing is associated with time spent out-of-home and withdrawal from leisure activities in older community-dwelling adults.

    Science.gov (United States)

    Mikkola, Tuija M; Polku, Hannele; Portegijs, Erja; Rantakokko, Merja; Tsai, Li-Tang; Rantanen, Taina; Viljanen, Anne

    2016-04-01

    Hearing difficulties are prevalent among older people and can lead to difficulties in social interaction. These difficulties may increase the tendency to remain at home and withdraw from leisure activities. To investigate whether self-reported hearing problems are associated with time spent out-of-home and withdrawal from a leisure activity among older persons. Cross-sectional and longitudinal data on 75- to 90-year-old community-dwelling men and women (n = 767) was used. Self-reports of hearing, diseases, and difficulty walking 2 km were obtained via home interviews at baseline, and withdrawal from a leisure activity via 1- and 2-year follow-up telephone interviews. Time spent out-of-home was obtained from a subsample (n = 532) via seven-day diaries at baseline. Hearing problems were associated with time spent out-of-home (p = 0.025) and withdrawal from a leisure activity (p = 0.025) among persons reporting no walking difficulty, but not among those reporting walking difficulty (p = 0.269 and 0.396, respectively). Among the former, persons with major hearing problems spent significantly less time out-of-home (estimated marginal mean 161 min, 95 % CI 122-212) than those with good hearing (242, 95 % CI 218-270). Persons with major hearing problems also had 3.0 times higher odds (95 % CI 1.3-7.1) for withdrawal from a leisure activity than persons with good hearing during the two-year follow-up. Among older adults without walking difficulty, hearing problems may reduce time spent out-of-home and increase the likelihood for withdrawal from a leisure activity. Decreased leisure and out-of-home activity may have negative effects on older persons' social, mental and physical functioning.

  2. Time course and cost of misdirecting auditory spatial attention in younger and older adults.

    Science.gov (United States)

    Singh, Gurjit; Pichora-Fuller, M Kathleen; Schneider, Bruce A

    2013-01-01

    The effects of directing, switching, and misdirecting auditory spatial attention in a complex listening situation were investigated in 8 younger and 8 older listeners with normal-hearing sensitivity below 4 kHz. In two companion experiments, a target sentence was presented from one spatial location and two competing sentences were presented simultaneously, one from each of two different locations. Pretrial, listeners were informed of the call-sign cue that identified which of the three sentences was the target and of the probability of the target sentence being presented from each of the three possible locations. Four different probability conditions varied in the likelihood of the target being presented at the left, center, and right locations. In Experiment 1, four timing conditions were tested: the original (unedited) sentences (which contained about 300 msec of filler speech between the call-sign cue and the onset of the target words), or modified (edited) sentences with silent pauses of 0, 150, or 300 msec replacing the filler speech. In Experiment 2, when the cued sentence was presented from an unlikely (side) listening location, for half of the trials the listener's task was to report target words from the cued sentence (cue condition); for the remaining trials, the listener's task was to report target words from the sentence presented from the opposite, unlikely (side) listening location (anticue condition). In Experiment 1, for targets presented from the likely (center) location, word identification was better for the unedited than for modified sentences. For targets presented from unlikely (side) locations, word identification was better when there was more time between the call-sign cue and target words. All listeners benefited similarly from the availability of more compared with less time and the presentation of continuous compared with interrupted speech. In Experiment 2, the key finding was that age-related performance deficits were observed in

  3. Situations of dwelling

    DEFF Research Database (Denmark)

    Welling, Helen; Duelund Mortensen, Peder; Wiell Nordberg, Lene

    2006-01-01

    values and needs in differnet situations, lifestyles and stages. The study is based on information from users in new housing schemes in and around Copenhagen - 'open building' dwellings that reveal a variety of approaches to these problems? The analysis of the dwellings show that the architecture...... of the 'open dwelling' is dependent on three basic conditions: the static condition, the suitable condition and the situational condition. Each condition has its own powerful way of articulation. Our aim is to translate the observations of the projects in concepts and models that are applicable in new projects....

  4. Associations between Perceived Neighborhood Walkability and Walking Time, Wellbeing, and Loneliness in Community-Dwelling Older Chinese People in Hong Kong

    Directory of Open Access Journals (Sweden)

    Ruby Yu

    2017-10-01

    Full Text Available This study examined the cross-sectional associations between perceived neighborhood walkability and walking time, physical activity, wellbeing, and loneliness, and examined which components of walkability were most strongly associated with better wellbeing and less loneliness in older adults. Participants were community-dwelling Chinese adults aged 60+ (n = 181. Walkability was measured using nine items selected from the Chinese version of the abbreviated Neighborhood Environment Walkability Scales (NEWS and NEWS for Chinese Seniors. Outcomes were walking time, physical activity, wellbeing (life satisfaction, happiness, sense of purpose and meaning in life, and loneliness. The mean age of the participants was 71.7 ± 7.8 years. Walkability was positively associated with walking time (p = 0.001, p for trend <0.001 but not with physical activity. After adjusting for socio-demographic characteristics, health conditions, lifestyle, and negative life events, those who perceived their neighborhoods as walkable had higher scores for life satisfaction (p = 0.002 and happiness (p = 0.002, and lower scores for loneliness (p = 0.019, compared with those who perceived their neighborhoods as less walkable. However, perceived neighborhood walkability was not associated with sense of purpose and meaning in life. Among components of walkability, land use mix-access, infrastructure and safety for walking, and traffic safety showed the strongest associations with the measures of wellbeing. The results of this study support the importance of neighborhood walkability for health behavior and wellbeing of older adults. The wellbeing of older adults may be enhanced through the improvement of land use mix-access, infrastructure for walking, and traffic safety.

  5. The neural time course of evaluating self-initiated joint attention bids.

    Science.gov (United States)

    Caruana, Nathan; de Lissa, Peter; McArthur, Genevieve

    2015-08-01

    During interactions with other people, we constantly evaluate the significance of our social partner's gaze shifts in order to coordinate our behaviour with their perspective. In this study, we used event-related potentials (ERPs) to investigate the neural time course of evaluating gaze shifts that signal the success of self-initiated joint attention bids. Nineteen participants were allocated to a "social" condition, in which they played a cooperative game with an anthropomorphic virtual character whom they believed was controlled by a human partner in a nearby laboratory. Participants were required to initiate joint attention towards a target. In response, the virtual partner shifted his gaze congruently towards the target-thus achieving joint attention--or incongruently towards a different location. Another 19 participants completed the same task in a non-social "control" condition, in which arrows, believed to be controlled by a computer program, pointed at a location that was either congruent or incongruent with the participant's target fixation. In the social condition, ERPs to the virtual partner's incongruent gaze shifts evoked significantly larger P350 and P500 peaks compared to congruent gaze shifts. This P350 and P500 morphology was absent in both the congruent and incongruent control conditions. These findings are consistent with previous claims that gaze shifts differing in their social significance modulate central-parietal ERPs 350 ms following the onset of the gaze shift. Our control data highlights the social specificity of the observed P350 effect, ruling out explanations pertaining to attention modulation or error detection. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Exploring the Effects of Working Memory on Time Perception in Attention Deficit Hyperactivity Disorder.

    Science.gov (United States)

    Lee, Hom-Yi; Yang, En-Lin

    2018-01-01

    Children with attention deficit hyperactivity disorder (ADHD) are often reported to have deficits of time perception. However, there is a strong relation between performance on tasks of working memory and time perception. Thus, it is possible that the poor performance of children with ADHD on time perception results from their deficit of working memory. In this study, the working memory of participants was separately assessed; therefore, we could explore the relationship between working memory and time perception of children with ADHD. Fifty-six children with ADHD and those of healthy controls completed tasks measuring working memory and time perception. The results showed that the time discrimination ability of children with ADHD was poorer than that of controls. However, there was a strong association between time perception and working memory. After controlling working memory and intelligence, the time discrimination ability of children with ADHD was not significantly poorer than that of controls. We suggest that there is an interdependent relationship between time perception and working memory for children with ADHD.

  7. Effects of spatial attention on mental time travel in patients with neglect.

    Science.gov (United States)

    Anelli, Filomena; Avanzi, Stefano; Arzy, Shahar; Mancuso, Mauro; Frassinetti, Francesca

    2018-02-02

    Numerous studies agree that time is represented in spatial terms in the brain. Here we investigate how a deficit in orienting attention in space influences the ability to mentally travel in time, that is to recall the past and anticipate the future. Right brain-damaged patients, with (RBD-N+) and without neglect (RBD-N-), and healthy controls (HC) were subjected to a Mental Time Travel (MTT) task. Participants were asked to project themselves in time to past, present or future (i.e., self-projection) and, for each self-projection, to judge whether events were located relatively in the past or the future (i.e., self-reference). The MTT-task was performed before and after a manipulation, through prismatic adaptation (PA), inducing a leftward shift of spatial attention. Before PA, RBD-N+ were slower for future than for past events, whereas RBD-N- and HC responded similarly to past and future events. A leftward shift of spatial attention by PA reduced the difference in past/future processing in RBD-N+ and fastened RBD-N- and HC's response to past events. Assuming that time concepts, such as past/future, are coded with a left-to-right order on a mental time line (MTL), a recursive search of future-events can explain neglect patients' performance. Improvement of the spatial deficit following PA reduces the recursive search of future events on the rightmost part of the MTL, facilitating exploration of past events on the leftmost part of the MTL, finally favoring the correct location of past and future events. In addition, the study of the anatomical correlates of the temporal deficit in mental time travel through voxel-based lesion-symptom mapping showed a correlation with a lesion located in the insula and in the thalamus. These findings provide new insights about the inter-relations of space and time, and can pave the way to a procedure to rehabilitate a deficit in these cognitive domains. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. An orthotopic xenograft model for high-risk non-muscle invasive bladder cancer in mice: influence of mouse strain, tumor cell count, dwell time and bladder pretreatment.

    Science.gov (United States)

    Huebner, Doreen; Rieger, Christiane; Bergmann, Ralf; Ullrich, Martin; Meister, Sebastian; Toma, Marieta; Wiedemuth, Ralf; Temme, Achim; Novotny, Vladimir; Wirth, Manfred P; Bachmann, Michael; Pietzsch, Jens; Fuessel, Susanne

    2017-11-23

    Novel theranostic options for high-risk non-muscle invasive bladder cancer are urgently needed. This requires a thorough evaluation of experimental approaches in animal models best possibly reflecting human disease before entering clinical studies. Although several bladder cancer xenograft models were used in the literature, the establishment of an orthotopic bladder cancer model in mice remains challenging. Luciferase-transduced UM-UC-3LUCK1 bladder cancer cells were instilled transurethrally via 24G permanent venous catheters into athymic NMRI and BALB/c nude mice as well as into SCID-beige mice. Besides the mouse strain, the pretreatment of the bladder wall (trypsin or poly-L-lysine), tumor cell count (0.5 × 106-5.0 × 106) and tumor cell dwell time in the murine bladder (30 min - 2 h) were varied. Tumors were morphologically and functionally visualized using bioluminescence imaging (BLI), magnetic resonance imaging (MRI), and positron emission tomography (PET). Immunodeficiency of the mouse strains was the most important factor influencing cancer cell engraftment, whereas modifying cell count and instillation time allowed fine-tuning of the BLI signal start and duration - both representing the possible treatment period for the evaluation of new therapeutics. Best orthotopic tumor growth was achieved by transurethral instillation of 1.0 × 106 UM-UC-3LUCK1 bladder cancer cells into SCID-beige mice for 2 h after bladder pretreatment with poly-L-lysine. A pilot PET experiment using 68Ga-cetuximab as transurethrally administered radiotracer revealed functional expression of epidermal growth factor receptor as representative molecular characteristic of engrafted cancer cells in the bladder. With the optimized protocol in SCID-beige mice an applicable and reliable model of high-risk non-muscle invasive bladder cancer for the development of novel theranostic approaches was established.

  9. Still feeling it: the time course of emotional recovery from an attentional perspective

    Science.gov (United States)

    Morriss, Jayne; Taylor, Alexander N. W.; Roesch, Etienne B.; van Reekum, Carien M.

    2013-01-01

    Emotional reactivity and the time taken to recover, particularly from negative, stressful, events, are inextricably linked, and both are crucial for maintaining well-being. It is unclear, however, to what extent emotional reactivity during stimulus onset predicts the time course of recovery after stimulus offset. To address this question, 25 participants viewed arousing (negative and positive) and neutral pictures from the International Affective Picture System (IAPS) followed by task-relevant face targets, which were to be gender categorized. Faces were presented early (400–1500 ms) or late (2400–3500 ms) after picture offset to capture the time course of recovery from emotional stimuli. Measures of reaction time (RT), as well as face-locked N170 and P3 components were taken as indicators of the impact of lingering emotion on attentional facilitation or interference. Electrophysiological effects revealed negative and positive images to facilitate face-target processing on the P3 component, regardless of temporal interval. At the individual level, increased reactivity to: (1) negative pictures, quantified as the IAPS picture-locked Late Positive Potential (LPP), predicted larger attentional interference on the face-locked P3 component to faces presented in the late time window after picture offset. (2) Positive pictures, denoted by the LPP, predicted larger facilitation on the face-locked P3 component to faces presented in the earlier time window after picture offset. These results suggest that subsequent processing is still impacted up to 3500 ms after the offset of negative pictures and 1500 ms after the offset of positive pictures for individuals reacting more strongly to these pictures, respectively. Such findings emphasize the importance of individual differences in reactivity when predicting the temporality of emotional recovery. The current experimental model provides a novel basis for future research aiming to identify profiles of adaptive and

  10. Still feeling it: The time course of emotional recovery from an attentional perspective

    Directory of Open Access Journals (Sweden)

    Jayne eMorriss

    2013-05-01

    Full Text Available Emotional reactivity and the time taken to recover, particularly from negative, stressful, events, are inextricably linked, and both are crucial for maintaining well-being. It is unclear, however, to what extent emotional reactivity during stimulus onset predicts the time course of recovery after stimulus offset. To address this question, 25 participants viewed arousing (negative and positive and neutral pictures from the International Affective Picture System (IAPS followed by task-relevant face targets, which were to be gender categorised. Faces were presented early (400–1500 ms or late (2400–3500 ms after picture offset to capture the time course of recovery from emotional stimuli. Measures of reaction time, as well as face-locked N170 and P3 components were taken as indicators of the impact of lingering emotion on attentional facilitation or interference. Electrophysiological effects revealed negative and positive images to facilitate face-target processing on the P3 component, regardless of temporal interval. At the individual level, increased reactivity to: (1 negative pictures, quantified as the IAPS picture-locked Late Positive Potential (LPP, predicted larger attentional interference on the face-locked P3 component to faces presented in the late time window after picture offset. (2 Positive pictures, denoted by the LPP, predicted larger facilitation on the face-locked P3 component to faces presented in the earlier time window after picture offset. These results suggest that subsequent processing is still impacted up to 3500 ms after the offset of negative pictures and 1500 ms after the offset of positive pictures for individuals reacting more strongly to these pictures respectively. Such findings emphasise the importance of individual differences in reactivity when predicting the temporality of emotional recovery.The current experimental model provides a novel basis for future research aiming to identify profiles of adaptive and

  11. Real-time decoding of brain responses to visuospatial attention using 7T fMRI.

    Directory of Open Access Journals (Sweden)

    Patrik Andersson

    Full Text Available Brain-Computer interface technologies mean to create new communication channels between our mind and our environment, independent of the motor system, by detecting and classifying self regulation of local brain activity. BCIs can provide patients with severe paralysis a means to communicate and to live more independent lives. There has been a growing interest in using invasive recordings for BCI to improve the signal quality. This also potentially gives access to new control strategies previously inaccessible by non-invasive methods. However, before surgery, the best implantation site needs to be determined. The blood-oxygen-level dependent signal changes measured with fMRI have been shown to agree well spatially with those found with invasive electrodes, and are the best option for pre-surgical localization. We show, using real-time fMRI at 7T, that eye movement-independent visuospatial attention can be used as a reliable control strategy for BCIs. At this field strength even subtle signal changes can be detected in single trials thanks to the high contrast-to-noise ratio. A group of healthy subjects were instructed to move their attention between three (two peripheral and one central spatial target regions while keeping their gaze fixated at the center. The activated regions were first located and thereafter the subjects were given real-time feedback based on the activity in these regions. All subjects managed to regulate local brain areas without training, which suggests that visuospatial attention is a promising new target for intracranial BCI. ECoG data recorded from one epilepsy patient showed that local changes in gamma-power can be used to separate the three classes.

  12. Effects of time of day, introversion and neuroticism on selectivity in memory and attention.

    Science.gov (United States)

    Smith, A P

    1992-06-01

    Two experiments examined the effects of time of day, introversion and neuroticism on selectivity in memory and attention. The first experiment showed that none of these factors interacted with task priority, which suggests that such variables do not produce the same changes in selectivity as do exogenous factors such as noise. In Exp. 2, colour names were read more quickly in the late afternoon than in the early morning, whereas patches of colour were named more quickly in the morning. Results from the Stroop interference condition showed that subjects classified as extraverts on the basis of Eysenck Personality Questionnaire scores were less susceptible to distraction than those scored as introverts, but the size of this effect was influenced both by time of day and by whether the subjects scored as stable or neurotic on the questionnaire.

  13. Self-Regulation of the Primary Auditory Cortex Attention Via Directed Attention Mediated By Real Time fMRI Neurofeedback

    Science.gov (United States)

    2017-05-05

    Researc 2:Ild EHDORaEMENT (IiD2 laOJJAC Ur;lI 0 33. D..-.TE RECEIVE E1::pi!rt ’ER BIG NATURE ARDED TO 59 M ’,." 32. DATE Apri. 26. 20.7...entered into our computer file. Please advise us (by phone or mail) that your presentation was given. At that time, we will need the date (month, day...PHONEJPAG ER N’_ 5ER !10-!9~-73_4 wsu WSU DHA,’HCE WSU WSU :20. DATE 19 Apr 17 cRDED TO 5D2 13 171]5 PROCESSI G OF PROFESSIONAL MEDICAL RESEARCHfTECH

  14. Navigation of a telepresence robot via covert visuospatial attention and real-time fMRI.

    Science.gov (United States)

    Andersson, Patrik; Pluim, Josien P W; Viergever, Max A; Ramsey, Nick F

    2013-01-01

    Brain-computer interfaces (BCIs) allow people with severe neurological impairment and without ability to control their muscles to regain some control over their environment. The BCI user performs a mental task to regulate brain activity, which is measured and translated into commands controlling some external device. We here show that healthy participants are capable of navigating a robot by covertly shifting their visuospatial attention. Covert Visuospatial Attention (COVISA) constitutes a very intuitive brain function for spatial navigation and does not depend on presented stimuli or on eye movements. Our robot is equipped with motors and a camera that sends visual feedback to the user who can navigate it from a remote location. We used an ultrahigh field MRI scanner (7 Tesla) to obtain fMRI signals that were decoded in real time using a support vector machine. Four healthy subjects with virtually no training succeeded in navigating the robot to at least three of four target locations. Our results thus show that with COVISA BCI, realtime robot navigation can be achieved. Since the magnitude of the fMRI signal has been shown to correlate well with the magnitude of spectral power changes in the gamma frequency band in signals measured by intracranial electrodes, the COVISA concept may in future translate to intracranial application in severely paralyzed people.

  15. Eye-movement evidence of the time-course of attentional bias for threatening pictures in test-anxious students

    NARCIS (Netherlands)

    Dong, Y.; De Beuckelaer, A.; Yu, L.; Zhou, R

    2017-01-01

    Protocols for measuring attentional bias to threat in test-anxiety, a special form of trait-anxiety, are rarely found in the literature. In our eye-tracking study, we introduced a new protocol, and studied the time-course of attention to test-related pictures with varying threat levels in 22 high

  16. The time course of semantic and associative priming effects is different in an attentional blink task.

    Science.gov (United States)

    Murphy, Karen; Hunt, Hayley

    2013-08-01

    When two targets are presented using rapid serial visual presentation (RSVP) and the interval between the targets is 200-500 ms, report of the second target is impaired, a phenomena known as the attentional blink (AB). This study examined the time course of semantic-only and associate-semantic priming effects during an AB task. Three RSVP experiments were conducted using targets that shared either a semantic-only or an associative-semantic relationship. The results of the three experiments demonstrated semantic-only priming effects at the shortest stimulus onset asynchronies (SOAs). Associative-semantic priming was evident at shorter and longer SOAs. This suggests that priming in an AB task is driven by conceptual overlap facilitating lexical access at short SOAs and with longer SOAs lexical access benefits from word associations links between targets.

  17. Sound insulation between dwellings

    DEFF Research Database (Denmark)

    Rasmussen, Birgit

    2011-01-01

    Regulatory sound insulation requirements for dwellings exist in more than 30 countries in Europe. In some countries, requirements have existed since the 1950s. Findings from comparative studies show that sound insulation descriptors and requirements represent a high degree of diversity...... and initiate – where needed – improvement of sound insulation of new and existing dwellings in Europe to the benefit of the inhabitants and the society. A European COST Action TU0901 "Integrating and Harmonizing Sound Insulation Aspects in Sustainable Urban Housing Constructions", has been established and runs...... 2009-2013. The main objectives of TU0901 are to prepare proposals for harmonized sound insulation descriptors and for a European sound classification scheme with a number of quality classes for dwellings. Findings from the studies provide input for the discussions in COST TU0901. Data collected from 24...

  18. Sound Insulation between Dwellings

    DEFF Research Database (Denmark)

    Rasmussen, Birgit

    2011-01-01

    Regulatory sound insulation requirements for dwellings exist in more than 30 countries in Europe. In some countries, requirements have existed since the 1950s. Findings from comparative studies show that sound insulation descriptors and requirements represent a high degree of diversity...... and initiate – where needed – improvement of sound insulation of new and existing dwellings in Europe to the benefit of the inhabitants and the society. A European COST Action TU0901 "Integrating and Harmonizing Sound Insulation Aspects in Sustainable Urban Housing Constructions", has been established and runs...... 2009-2013. The main objectives of TU0901 are to prepare proposals for harmonized sound insulation descriptors and for a European sound classification scheme with a number of quality classes for dwellings. Findings from the studies provide input for the discussions in COST TU0901. Data collected from 24...

  19. Sustained attention is associated with error processing impairment: evidence from mental fatigue study in four-choice reaction time task

    National Research Council Canada - National Science Library

    Xiao, Yi; Ma, Feng; Lv, Yixuan; Cai, Gui; Teng, Peng; Xu, FengGang; Chen, Shanguang

    2015-01-01

    .... In this study, we examined how error-related negativity (ERN) of a four-choice reaction time task was reduced in the mental fatigue condition and investigated the role of sustained attention in error processing...

  20. Improvement of attention span and reaction time with hyperbaric oxygen treatment in patients with toxic injury due to mold exposure.

    Science.gov (United States)

    Ezra, N; Dang, K; Heuser, G

    2011-01-01

    It is, by now, well established that mold toxins (mycotoxins) can cause significant adverse health effects. In this study, 15 subjects who developed an attention deficit disorder (ADD) and slowing of reaction time at the time of exposure to mold toxins were identified. Deficits in attention span and reaction time were documented not only by taking a careful history, but also by performing a Test of Variables of Attention (TOVA). The TOVA test provides an objective measure of these two variables. It was found that mold-exposed subjects show statistically significant decreases in attention span and significant increases in reaction time to stimuli compared to controls. After ten sessions of hyperbaric oxygen treatment (HBOT), a statistically significant improvement was seen in both measures. This preliminary study suggests promising outcomes in treating mold-exposed patients with hyperbaric oxygen.

  1. Sleep restriction may lead to disruption in physiological attention and reaction time

    Directory of Open Access Journals (Sweden)

    Arbind Kumar Choudhary

    2016-07-01

    Full Text Available Sleepiness is the condition where for some reason fails to go into a sleep state and will have difficulty in remaining awake even while carrying out activities. Sleep restriction occurs when an individual fails to get enough sleep due to high work demands. The mechanism between sleep restriction and underlying brain physiology deficits is not well assumed. The objective of the present study was to investigate the mental attention (P300 and reaction time [visual (VRT and auditory (ART] among night watchmen, at subsequent; first (1st day, fourth (4th day and seventh (7th day of restricted sleep period. After exclusion and inclusion criteria, the study was performed among 50 watchmen (age=18–35 years (n=50 after providing written informed consent and divided into two group. Group I-(Normal sleep (n=28 working in day time and used to have normal sleep in night (≥8 h; Group II-(Restricted sleep (n=22 - working in night time and used to have less sleep in night (≤3 h. Statistical significance between the different groups was determined by the independent student ʻtʼ test and the significance level was fixed at p≤0.05. We observed that among all normal and restricted sleep watchmen there was not any significant variation in Karolinska Sleepiness Scale (KSS score, VRT and ART, along with latency and amplitude of P300 on 1st day of restricted sleep. However at subsequent on 4th day and 7th day of restricted sleep, there was significant increase in (KSSscore, and prolongation of VRT and ART as well as alteration in latency and amplitude of P300 wave in restricted sleep watchmen when compare to normal sleep watchmen. The present finding concludes that loss of sleep has major impact in dynamic change in mental attention and reaction time among watchmen employed in night shift. Professional regulations and work schedules should integrate sleep schedules before and during the work period as an essential dimension for their healthy life.

  2. Time Sharing Between Robotics and Process Control: Validating a Model of Attention Switching.

    Science.gov (United States)

    Wickens, Christopher Dow; Gutzwiller, Robert S; Vieane, Alex; Clegg, Benjamin A; Sebok, Angelia; Janes, Jess

    2016-03-01

    The aim of this study was to validate the strategic task overload management (STOM) model that predicts task switching when concurrence is impossible. The STOM model predicts that in overload, tasks will be switched to, to the extent that they are attractive on task attributes of high priority, interest, and salience and low difficulty. But more-difficult tasks are less likely to be switched away from once they are being performed. In Experiment 1, participants performed four tasks of the Multi-Attribute Task Battery and provided task-switching data to inform the role of difficulty and priority. In Experiment 2, participants concurrently performed an environmental control task and a robotic arm simulation. Workload was varied by automation of arm movement and both the phases of environmental control and existence of decision support for fault management. Attention to the two tasks was measured using a head tracker. Experiment 1 revealed the lack of influence of task priority and confirmed the differing roles of task difficulty. In Experiment 2, the percentage attention allocation across the eight conditions was predicted by the STOM model when participants rated the four attributes. Model predictions were compared against empirical data and accounted for over 95% of variance in task allocation. More-difficult tasks were performed longer than easier tasks. Task priority does not influence allocation. The multiattribute decision model provided a good fit to the data. The STOM model is useful for predicting cognitive tunneling given that human-in-the-loop simulation is time-consuming and expensive. © 2016, Human Factors and Ergonomics Society.

  3. Focused attention vs. crossmodal signals paradigm: Deriving predictions from the time-window-of-integration model

    Directory of Open Access Journals (Sweden)

    Hans eColonius

    2012-08-01

    Full Text Available In the crossmodal signals paradigm (CSP participants are instructed to respond to a set of stimuli from different modalities, presented more or less simultaneously, as soon as a stimulus from any modality has been detected. In the focused attention paradigm (FAP, on the other hand, responses should only be made to a stimulus from a pre-defined target modality and stimuli from non-target modalities should be ignored. Whichever paradigm is being applied, a typical result is that responses tend to be faster to crossmodal stimuli than to unimodal stimuli, a phenomenon often referred to as 'crossmodal interaction'. Here we investigate predictions of the time-window-of-integration (TWIN modeling framework previously proposed by the authors. It is shown that TWIN makes specific qualitative and quantitative predictions on how the two paradigms differ with respect to the probability of multisensory integration and the amount of response enhancement, including the effect of stimulus intensity ('inverse effectiveness'. Introducing a decision-theoretic framework for TWIN further allows comparing the two paradigms with respect to the predicted optimal time window size and its dependence on the prior probability that the crossmodal stimulus information refers to the same event. In order to test these predictions, experimental studies that systematically compare crossmodal effects under stimulus conditions that are identical except for the CSP-FAP instruction should be performed in the future.

  4. Front-of-pack nutrition labels. Their effect on attention and choices when consumers have varying goals and time constraints.

    Science.gov (United States)

    van Herpen, Erica; Trijp, Hans C M van

    2011-08-01

    Although front-of-pack nutrition labeling can help consumers make healthier food choices, lack of attention to these labels limits their effectiveness. This study examines consumer attention to and use of three different nutrition labeling schemes (logo, multiple traffic-light label, and nutrition table) when they face different goals and resource constraints. To understand attention and processing of labels, various measures are used including self-reported use, recognition, and eye-tracking measures. Results of two experiments in different countries show that although consumers evaluate the nutrition table most positively, it receives little attention and does not stimulate healthy choices. Traffic-light labels and especially logos enhance healthy product choice, even when consumers are put under time pressure. Additionally, health goals of consumers increase attention to and use of nutrition labels, especially when these health goals concern specific nutrients. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Time Course of Attention and Decision Making during a Volleyball Set

    Science.gov (United States)

    Sibley, Benjamin A.; Etnier, Jennifer L.

    2004-01-01

    Attention is a term that has been used to describe a broad range of topics in the sport and exercise literature (Nougier, Stein, & Bonnel, 1991). Research focusing on attention has included studies on selectivity, concentration, mental set, visual search, arousal, and information processing (Abernethy, 2001), and a variety of techniques (e.g.,…

  6. Feature Migration in Time: Reflection of Selective Attention on Speech Errors

    Science.gov (United States)

    Nozari, Nazbanou; Dell, Gary S.

    2012-01-01

    This article describes an initial study of the effect of focused attention on phonological speech errors. In 3 experiments, participants recited 4-word tongue twisters and focused attention on 1 (or none) of the words. The attended word was singled out differently in each experiment; participants were under instructions to avoid errors on the…

  7. The cognitive and hedonic costs of dwelling on achievement-related negative experiences: implications for enduring happiness and unhappiness.

    Science.gov (United States)

    Lyubomirsky, Sonja; Boehm, Julia K; Kasri, Fazilet; Zehm, Keri

    2011-10-01

    Increasing evidence suggests that multiple cognitive and motivational processes underlie individual differences in happiness (Lyubomirsky, 2001, 2008). One behavior that is associated with (un)happiness is self-reflection or dwelling. We hypothesized that unhappy individuals would be inclined to dwell about themselves, and that this behavior would have a variety of adverse consequences. Three studies tested the prediction that, unlike their happier peers, unhappy participants would be sensitive to unfavorable achievement feedback, likely to dwell about its implications and, hence, show impaired attention during important academic tasks. The results of Studies 1 and 2 showed that unhappy participants who had "failed" relative to peers subsequently displayed increased interfering thoughts; spent the most time performing a portion of the graduate record examination; and later demonstrated impaired reading comprehension. Study 3 experimentally induced versus inhibiting dwelling and found that the manipulation only impacted unhappy students. Implications of our results for the consequences of dwelling for work and social functioning, as well as for detracting from enduring happiness, are discussed.

  8. "Gaze Leading": Initiating Simulated Joint Attention Influences Eye Movements and Choice Behavior

    Science.gov (United States)

    Bayliss, Andrew P.; Murphy, Emily; Naughtin, Claire K.; Kritikos, Ada; Schilbach, Leonhard; Becker, Stefanie I.

    2013-01-01

    Recent research in adults has made great use of the gaze cuing paradigm to understand the behavior of the follower in joint attention episodes. We implemented a gaze leading task to investigate the initiator--the other person in these triadic interactions. In a series of gaze-contingent eye-tracking studies, we show that fixation dwell time upon…

  9. Child attention to pain and pain tolerance are dependent upon anxiety and attention control: An eye-tracking study.

    Science.gov (United States)

    Heathcote, L C; Lau, J Y F; Mueller, S C; Eccleston, C; Fox, E; Bosmans, M; Vervoort, T

    2017-02-01

    Pain is common and can be debilitating in childhood. Theoretical models propose that attention to pain plays a key role in pain outcomes, however, very little research has investigated this in youth. This study examined how anxiety-related variables and attention control interacted to predict children's attention to pain cues using eye-tracking methodology, and their pain tolerance on the cold pressor test (CPT). Children aged 8-17 years had their eye-gaze tracked whilst they viewed photographs of other children displaying painful facial expressions during the CPT, before completing the CPT themselves. Children also completed self-report measures of anxiety and attention control. Findings indicated that anxiety and attention control did not impact children's initial fixations on pain or neutral faces, but did impact how long they dwelled on pain versus neutral faces. For children reporting low levels of attention control, higher anxiety was associated with less dwell time on pain faces as opposed to neutral faces, and the opposite pattern was observed for children with high attention control. Anxiety and attention control also interacted to predict pain outcomes. For children with low attention control, increasing anxiety was associated with anticipating more pain and tolerating pain for less time. This is the first study to examine children's attention to pain cues using eye-tracking technology in the context of a salient painful experience. Data suggest that attention control is an important moderator of anxiety on multiple outcomes relevant to young people's pain experiences. This study uses eye tracking to study attention to pain cues in children. Attention control is an important moderator of anxiety on attention bias to pain and tolerance of cold pressor pain in youth. © 2016 European Pain Federation - EFIC®.

  10. Development of new punch shape to replicate scale-up issues in laboratory tablet press II: a new design of punch head to emulate consolidation and dwell times in commercial tablet press.

    Science.gov (United States)

    Aoki, Shigeru; Uchiyama, Jumpei; Ito, Manabu

    2014-06-01

    Differences between laboratory and commercial tablet presses are frequently observed during scale-up of tableting process. These scale-up issues result from the differences in total compression time that is the sum of consolidation and dwell times. When a lubricated blend is compressed into tablets, the tablet thickness produced by the commercial tablet press is often thicker than that by a laboratory tablet press. A new punch shape design, designated as shape adjusted for scale-up (SAS), was developed and used to demonstrate the ability to replicate scale-up issues in commercial-scale tableting processes. It was found that the consolidation time can be slightly shortened by changing the vertical curvature of the conventional punch head rim. However, this approach is not enough to replicate the consolidation time. A secondary two-stage SAS punch design and an embossed punch head was designed to replicate the consolidation and dwell times on a laboratory tablet press to match those of a commercial tablet press. The resulting tablet thickness using this second SAS punch on a laboratory tablet press was thicker than when using a conventional punch in the same laboratory tablet press. The secondary SAS punches are more useful tools for replicating and understanding potential scale-up issues. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  11. Timed up and go test combined with self-rated multifactorial questionnaire on falls risk and sociodemographic factors predicts falls among community-dwelling older adults better than the timed up and go test on its own

    Directory of Open Access Journals (Sweden)

    Ibrahim A

    2017-10-01

    Full Text Available Azianah Ibrahim,1,2 Devinder Kaur Ajit Singh,1 Suzana Shahar,3 Mohd Azahadi Omar4 1Physiotherapy Programme, School of Rehabilitation Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, 2Pantai Integrated Rehab Services Sendirian Berhad, Pandan Indah, 3Community Rehabilitation and Ageing Research Centre, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, 4Institute for Public Health, Ministry of Health, Kuala Lumpur, Malaysia Background: Early detection of falls risk among older adults using simple tools may assist in fall prevention strategies. The aim of this study was to identify the best parameters associated with previous falls, either the timed up and go (TUG test combined with sociodemographic factors and a self-rated multifactorial questionnaire (SRMQ on falls risk or the TUG on its own. Falls risk was determined based on parameters associated with previous falls.Design: This was a retrospective cohort study. Setting: The study was conducted in a community setting. Participants: The participants were 1,086 community-dwelling older adults, with mean age of 69.6±5.6 years. Participants were categorized into fallers and nonfallers based on their history of falls in the past 12 months. Method: Participants’ sociodemographic data was taken, and SRMQ consisting of five falls-related questions was administered. Participants performed the TUG test twice, and the mean was taken as the result. Results: A total of 161 participants were categorized as fallers (14.8%. Multivariate logistic regression analysis showed that the model (χ2(6=61.0, p<0.001, Nagelkerke R2=0.10 consisting of the TUG test, sociodemographic factors (gender, cataract/glaucoma and joint pain, as well as the SRMQ items “previous falls history” (Q1 and “worried of falls” (Q5, was more robust in terms of falls risk association compared to that with TUG on its own (χ2(1=10.3, p<0.001, Nagelkerke R2=0.02. Conclusion: Combination of

  12. Long-Term Retention in 3.5-Month-Olds: Familiarization Time and Individual Differences in Attentional Style.

    Science.gov (United States)

    Courage, Mary L.; Howe, Mark L.

    2001-01-01

    Examined effect of familiarization on 3.5-month-olds' retention of visual stimuli with varying delay times. Found support for retention models in which direction of attentional preferences (novel, familiar, or null) depends on memory accessibility. Short lookers showed better retention over time than long lookers, indicating that much of the…

  13. Time Reproduction in Finger Tapping Tasks by Children with Attention-Deficit Hyperactivity Disorder and/or Dyslexia

    Science.gov (United States)

    Tiffin-Richards, Margaret C.; Hasselhorn, Marcus; Richards, Michael L.; Banaschewski, Tobias; Rothenberger, Aribert

    2004-01-01

    Aim: Deficits in timing and sequencing behaviour in children with dyslexia and with attention-deficit hyperactivity disorder have already been identified. However many studies have not controlled for comorbidity between dyslexia and ADHD. This study investigated timing performance of children with either dyslexia or ADHD, or ADHD + dyslexia or…

  14. Attention-Deficit/Hyperactivity Disorder (ADHD) and Motor Timing in Adolescents and Their Parents : Familial Characteristics of Reaction Time Variability Vary With Age

    NARCIS (Netherlands)

    Thissen, Andrieke J. A. M.; Luman, Marjolein; Hartman, Catharina; Hoekstra, Pieter; van Lieshout, Marloes; Franke, Barbara; Oosterlaan, Jaap; Rommelse, Nanda N. J.; Buitelaar, Jan K.

    Objective: There is consistent evidence that attention-deficit/hyperactivity disorder (ADHD) is strongly related to impaired motor timing as reflected in decreased accuracy and increased reaction time variability (RTV). It is not known whether motor timing impairments are present in adolescents and

  15. Sound classification of dwellings

    DEFF Research Database (Denmark)

    Rasmussen, Birgit

    2012-01-01

    National schemes for sound classification of dwellings exist in more than ten countries in Europe, typically published as national standards. The schemes define quality classes reflecting different levels of acoustical comfort. Main criteria concern airborne and impact sound insulation between...... dwellings, facade sound insulation and installation noise. The schemes have been developed, implemented and revised gradually since the early 1990s. However, due to lack of coordination between countries, there are significant discrepancies, and new standards and revisions continue to increase the diversity...... is needed, and a European COST Action TU0901 "Integrating and Harmonizing Sound Insulation Aspects in Sustainable Urban Housing Constructions", has been established and runs 2009-2013, one of the main objectives being to prepare a proposal for a European sound classification scheme with a number of quality...

  16. Testing possible mechanisms of deficient supra-second time estimation in adults with attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    Pollak, Y; Kroyzer, N; Yakir, A; Friedler, M

    2009-09-01

    Numerous studies indicate deficient time estimation in individuals with attention-deficit/hyperactivity disorder (ADHD). Several hypotheses have been raised to explain this deficit including delay aversion, vulnerability to nontemporal distractions, deficient working memory, as well as pure deficit in temporal processing. To test the different hypotheses, adults with or without ADHD performed a prospective time-estimation task under different conditions: with or without nontemporal distraction; and with or without increased load of working memory. Such design was used to rule out the effect of motor control and to manipulate the hypothesized mechanisms of working memory and attention to nontemporal stimuli. The authors report that compared with the control group, adults with ADHD showed greater and more variable deviation in time estimation. In addition, the magnitude of time estimation was affected by allocation of attention to nontemporal stimuli and by load of working memory. The intraindividual variability of time estimation was only partially accounted for by load of working memory. These findings suggest that the ADHD-associated deficit in prospective time estimation is not attributable to special attention to nontemporal stimuli or compromised working memory.

  17. Health anxiety and attentional bias: the time course of vigilance and avoidance in light of pictorial illness information.

    Science.gov (United States)

    Jasper, Fabian; Witthöft, Michael

    2011-12-01

    Cognitive-behavioral models of health anxiety stress the importance of selective attention not only towards internal but also towards external health threat related stimuli. Yet, little is known about the time course of this attentional bias. The current study investigates threat related attentional bias in participants with varying degrees of health anxiety. Attentional bias was assessed using a visual dot-probe task with health-threat and neutral pictures at two exposure durations, 175ms and 500ms. A baseline condition was added to the dot-probe task to dissociate indices of vigilance towards threat and difficulties to disengage from threat. Substantial positive correlations of health anxiety, anxiety sensitivity, and absorption with difficulties to disengage from threat were detected at 500ms exposure time. At an early stage (i.e., at 175ms exposure time), we found significant positive correlations of health anxiety and absorption with orientation towards threat. Results suggest a vigilance avoidance pattern of selective attention associated with pictorial illness related stimuli in health anxiety. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Lessons learned from 118,970 multidetector computed tomographic intravenous contrast material administrations: impact of catheter dwell time and gauge, catheter location, rate of contrast material administration, and patient age and sex on volume of extravasate.

    Science.gov (United States)

    Moreno, Courtney Coursey; Pinho, Daniella; Nelson, Rendon C; Sahani, Dushyant V; Jenkins, Melissa; Zabrycki, MaryAnne; Chaudhry, Humaira; Kang, Jian; Chen, Zhengjia

    2013-01-01

    The aim of this study was to determine the impact of catheter dwell time and gauge, catheter location, rate of contrast material administration, and patient age and sex on volume of extravasate at intravenous contrast-enhanced multidetector computed tomography. Incident reports were reviewed for all extravasation events that occurred in adult patients between March 2006 and December 2009 at 2 institutions. Patient age and sex; catheter dwell time, gauge, and location; rate of contrast material administration; and estimated volume of extravasated contrast material were recorded. Three hundred thirty extravasation events were recorded for the 118,970 contrast material administrations (0.3%). Mean volume of extravasated contrast material was statistically significantly less for catheters newly placed in the radiology department, for higher flow rates, for smaller gauge catheters, and for catheters placed in the hand. Mean volume of extravasated contrast material did not vary significantly based on patient age or sex. The volume of extravasate was likely to be smaller for smaller-gauge catheters in the hand with higher flow rates and for catheters newly placed in the radiology department.

  19. Investigating the time course of tactile reflexive attention using a non-spatial discrimination task.

    Science.gov (United States)

    Miles, Eleanor; Poliakoff, Ellen; Brown, Richard J

    2008-06-01

    Peripheral cues are thought to facilitate responses to stimuli presented at the same location because they lead to exogenous attention shifts. Facilitation has been observed in numerous studies of visual and auditory attention, but there have been only four demonstrations of tactile facilitation, all in studies with potential confounds. Three studies used a spatial (finger versus thumb) discrimination task, where the cue could have provided a spatial framework that might have assisted the discrimination of subsequent targets presented on the same side as the cue. The final study circumvented this problem by using a non-spatial discrimination; however, the cues were informative and interspersed with visual cues which may have affected the attentional effects observed. In the current study, therefore, we used a non-spatial tactile frequency discrimination task following a non-informative tactile white noise cue. When the target was presented 150 ms after the cue, we observed faster discrimination responses to targets presented on the same side compared to the opposite side as the cue; by 1000 ms, responses were significantly faster to targets presented on the opposite side to the cue. Thus, we demonstrated that tactile attentional facilitation can be observed in a non-spatial discrimination task, under unimodal conditions and with entirely non-predictive cues. Furthermore, we provide the first demonstration of significant tactile facilitation and tactile inhibition of return within a single experiment.

  20. Perception of Temporal Order Is Impaired during the Time Course of the Attentional Blink

    Science.gov (United States)

    Spalek, Thomas M.; Lagroix, Hayley E. P.; Yanko, Matthew R.; Di Lollo, Vincent

    2012-01-01

    Identification accuracy for the second of two target (T2) is impaired when presented shortly after the first (T1). Does this attentional blink (AB) also impair the perception of the order of presentation? In four experiments, three letter targets (T1, T2, T3) were inserted in a stream of digit distractors displayed in rapid serial visual…

  1. Time-dependent effects of cortisol on selective attention and emotional interference: a functional MRI study

    NARCIS (Netherlands)

    Henckens, M.J.; Wingen, G.A. van; Joels, M.; Fernandez, G.S.E.

    2012-01-01

    Acute stress is known to induce a state of hypervigilance, allowing optimal detection of threats. Although one may benefit from sensitive sensory processing, it comes at the cost of unselective attention and increased distraction by irrelevant information. Corticosteroids, released in response to

  2. Time to see the bigger picture : Individual differences in the attentional blink

    NARCIS (Netherlands)

    Willems, Charlotte; Martens, Sander

    2016-01-01

    If two to-be-identified targets are presented in close temporal succession, identification for the second target is typically impaired. This attentional blink (AB) phenomenon has long been considered as a robust, universal cognitive limitation. However, more recent studies have demonstrated that AB

  3. When the Chips Are down: Taking Time to Pay Attention to Real Issues

    Science.gov (United States)

    Model, David

    2011-01-01

    Global warming, deforestation, destruction of the oceans, hunger, poverty, human rights abuses and war crimes will, at best, be redressed by empty words and token gestures unless the public imbibes massive doses of caffeine. Unfortunately the public's attention seems to be focused elsewhere. Blackberries, cell phones, social networks on the…

  4. Nicotine-induced enhancement of attention in the five-choice serial reaction time task: the influence of task demands.

    Science.gov (United States)

    Hahn, B; Shoaib, M; Stolerman, I P

    2002-07-01

    Beneficial effects of nicotine on cognitive processes including attention have potential therapeutic uses and have been proposed as incentives for tobacco smoking. To establish task conditions under which the effects of nicotine on attention are obtained reliably and to characterise such effects further. Rats were trained in a modified version of the five-choice serial reaction time task (5-CSRTT) to detect 1-s light stimuli with greater than 70% accuracy and fewer than 20% omission errors. Nicotine was tested under different task requirements by varying signal event rate, stimulus duration and stimulus predictability, and by introducing white-noise distractors. Nicotine (0.05-0.2 mg/kg, s.c.) repeatedly improved accuracy and reduced omission errors and reaction times, leading to increases in numbers of reinforcers earned. Anticipatory responding was increased. Parametric modifications intended to increase demands on sustained attention did not affect performance in a manner suggesting that this subtype of attention was being taxed, and the effects of nicotine were not more marked under such conditions. Shorter stimulus durations impaired performance, but this manipulation weakened the effect of nicotine on accuracy. In contrast, the presence of noise distractors facilitated the effects of nicotine to the extent that distractor-induced impairments were abolished by the drug. The 5-CSRTT can provide a sensitive rodent model for the attention-enhancing effects of nicotine. Changes made to the procedure may have increased its sensitivity to nicotine, particularly with respect to accuracy. There were indications that the effects of nicotine were largest on processes of selective attention or on disengaging attention from irrelevant events and shifting it to behaviourally significant stimuli.

  5. Effects of amphetamine and methylphenidate on attentional performance and impulsivity in the mouse 5-Choice Serial Reaction Time Task

    DEFF Research Database (Denmark)

    Caballero Puntiverio, Maitane; Fitzpatrick, Ciarán Martin; Woldbye, David Paul Drucker

    2017-01-01

    Background: Few studies have investigated the effects of conventional attention deficit-hyperactivity disorder (ADHD) medication in the mouse 5-choice serial reaction time task (5-CSRTT), and rat studies have yielded inconsistent results. Objective: We aimed to examine the effects of acute...

  6. Accuracy of Timed Up and Go Test for screening risk of falls among community-dwelling elderly Acurácia do Timed Up and Go Test para rastrear risco de quedas em idosos da comunidade

    Directory of Open Access Journals (Sweden)

    Tiago S. Alexandre

    2012-10-01

    Full Text Available OBJECTIVE: To determine the accuracy of the Timed Up and Go Test (TUGT for screening the risk of falls among community-dwelling elderly individuals. METHOD: This is a prospective cohort study with a randomly by lots without reposition sample stratified by proportional partition in relation to gender involving 63 community-dwelling elderly individuals. Elderly individuals who reported having Parkinson's disease, a history of transitory ischemic attack, stroke and with a Mini Mental State Exam lower than the expected for the education level, were on a wheelchair and that reported a single fall in the previous six months were excluded. The TUGT, a mobility test, was the measure of interested and the occurrence of falls was the outcome. The performance of basic activities of daily living (ADL and instrumental activities of daily living (IADL was determined through the Older American Resources and Services, and the socio-demographic and clinical data were determined through the use of additional questionnaires. Receiver Operating Characteristic Curves were used to analyze the sensitivity and specificity of the TUGT. RESULTS: Elderly individuals who fell had greater difficulties in ADL and IADL (pOBJETIVO: Determinar a acurácia do Timed Up and Go Test (TUGT para rastrear risco de quedas em idosos da comunidade. MÉTODO: Trata-se de um estudo de coorte prospectivo com amostra sorteada aleatoriamente, sem reposição e estratificada por partilha proporcional em relação ao sexo de 63 idosos da comunidade. Excluíram-se idosos com doença de Parkinson, ataque isquêmico transitório, acidente vascular encefálico, Miniexame do Estado Mental inferior ao considerado normal de acordo com a escolaridade, movimentação exclusiva por cadeira de rodas e relato de uma queda nos seis meses anteriores à primeira entrevista. O TUGT, um teste de mobilidade, foi a medida testada, e o desfecho, a ocorrência de queda. Mensuraram-se atividades básicas (ABVD e

  7. Time-resolved neuroimaging of visual short term memory consolidation by post-perceptual attention shifts.

    Science.gov (United States)

    Hecht, Marcus; Thiemann, Ulf; Freitag, Christine M; Bender, Stephan

    2016-01-15

    Post-perceptual cues can enhance visual short term memory encoding even after the offset of the visual stimulus. However, both the mechanisms by which the sensory stimulus characteristics are buffered as well as the mechanisms by which post-perceptual selective attention enhances short term memory encoding remain unclear. We analyzed late post-perceptual event-related potentials (ERPs) in visual change detection tasks (100ms stimulus duration) by high-resolution ERP analysis to elucidate these mechanisms. The effects of early and late auditory post-cues (300ms or 850ms after visual stimulus onset) as well as the effects of a visual interference stimulus were examined in 27 healthy right-handed adults. Focusing attention with post-perceptual cues at both latencies significantly improved memory performance, i.e. sensory stimulus characteristics were available for up to 850ms after stimulus presentation. Passive watching of the visual stimuli without auditory cue presentation evoked a slow negative wave (N700) over occipito-temporal visual areas. N700 was strongly reduced by a visual interference stimulus which impeded memory maintenance. In contrast, contralateral delay activity (CDA) still developed in this condition after the application of auditory post-cues and was thereby dissociated from N700. CDA and N700 seem to represent two different processes involved in short term memory encoding. While N700 could reflect visual post processing by automatic attention attraction, CDA may reflect the top-down process of searching selectively for the required information through post-perceptual attention. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Acoustic classification of dwellings

    DEFF Research Database (Denmark)

    Berardi, Umberto; Rasmussen, Birgit

    2014-01-01

    insulation performance, national schemes for sound classification of dwellings have been developed in several European countries. These schemes define acoustic classes according to different levels of sound insulation. Due to the lack of coordination among countries, a significant diversity in terms...... of descriptors, number of classes, and class intervals occurred between national schemes. However, a proposal “acoustic classification scheme for dwellings” has been developed recently in the European COST Action TU0901 with 32 member countries. This proposal has been accepted as an ISO work item. This paper...

  9. Time to see the bigger picture: Individual differences in the attentional blink.

    Science.gov (United States)

    Willems, Charlotte; Martens, Sander

    2016-10-01

    If two to-be-identified targets are presented in close temporal succession, identification for the second target is typically impaired. This attentional blink (AB) phenomenon has long been considered as a robust, universal cognitive limitation. However, more recent studies have demonstrated that AB task performance greatly differs between individuals, with some individuals even showing no AB in certain paradigms. Several studies have focused on these individual differences in an attempt to reveal the mechanism underlying the AB, but an overview of this approach is currently missing. Here, by reviewing studies regarding individual differences in AB task performance, we investigate how individual differences have contributed to our understanding of the AB. We show that the individual differences AB literature provides reliable indications that the AB is a multifaceted phenomenon that presumably arises from a combination of factors; individuals with higher levels of executive working memory (WM) functioning and broad attentional focus perform better in the AB paradigm than individuals with lower executive functioning of WM and narrow attentional focus. As it turns out, seeing the bigger picture certainly seems helpful for AB task performance.

  10. The acute effects of caffeinated versus non-caffeinated alcoholic beverage on driving performance and attention/reaction time.

    Science.gov (United States)

    Howland, Jonathan; Rohsenow, Damaris J; Arnedt, J Todd; Bliss, Caleb A; Hunt, Sarah K; Calise, Tamara Vehige; Heeren, Timothy; Winter, Michael; Littlefield, Caroline; Gottlieb, Daniel J

    2011-02-01

    Marketing that promotes mixing caffeinated 'energy' drinks with alcoholic beverages (e.g. Red Bull with vodka) targets young drinkers and conveys the expectation that caffeine will offset the sedating effects of alcohol and enhance alertness. Such beliefs could result in unwarranted risk taking (e.g. driving while intoxicated). The aim of this study was to assess the acute effects of caffeinated versus non-caffeinated alcoholic beverages on a simulated driving task and attention/reaction time. We conducted a 2 × 2 between-groups randomized trial in which participants were randomized to one of four conditions: beer and non-alcoholic beer, with and without caffeine added. Caffeine was added in the same proportion as found in a commercially available caffeinated beer (69 mg/12 oz of beer at 4.8% alc. by vol). Participants were 127 non-dependent, heavy episodic, young adult drinkers (age 21-30) who were college students or recent graduates. The target breath alcohol level was 0.12 g%. Driving performance was assessed with a driving simulator; sustained attention/reaction with the Psychomotor Vigilance Task (PVT). Across the driving and attention/reaction time we found main effects for alcohol, with alcohol significantly impairing driving and sustained attention/reaction time, with mainly large statistical effects; however, the addition of caffeine had no main or interaction effects on performance. The addition of caffeine to alcohol does not appear to enhance driving or sustained attention/reaction time performance relative to alcohol alone. © 2010 The Authors, Addiction © 2010 Society for the Study of Addiction.

  11. ASSESSMENT OF ATTENTION THRESHOLD IN RATS BY TITRATION OF VISUAL CUE DURATION DURING THE FIVE CHOICE SERIAL REACTION TIME TASK

    Science.gov (United States)

    Martin, Thomas J.; Grigg, Amanda; Kim, Susy A.; Ririe, Douglas G.; Eisenach, James C.

    2014-01-01

    Background The 5 choice serial reaction time task (5CSRTT) is commonly used to assess attention in rodents. We sought to develop a variant of the 5CSRTT that would speed training to objective success criteria, and to test whether this variant could determine attention capability in each subject. New Method Fisher 344 rats were trained to perform a variant of the 5CSRTT in which the duration of visual cue presentation (cue duration) was titrated between trials based upon performance. The cue duration was decreased when the subject made a correct response, or increased with incorrect responses or omissions. Additionally, test day challenges were provided consisting of lengthening the intertrial interval and inclusion of a visual distracting stimulus. Results Rats readily titrated the cue duration to less than 1 sec in 25 training sessions or less (mean ± SEM, 22.9 ± 0.7), and the median cue duration (MCD) was calculated as a measure of attention threshold. Increasing the intertrial interval increased premature responses, decreased the number of trials completed, and increased the MCD. Decreasing the intertrial interval and time allotted for consuming the food reward demonstrated that a minimum of 3.5 sec is required for rats to consume two food pellets and successfully attend to the next trial. Visual distraction in the form of a 3 Hz flashing light increased the MCD and both premature and time out responses. Comparison with existing method The titration variant of the 5CSRTT is a useful method that dynamically measures attention threshold across a wide range of subject performance, and significantly decreases the time required for training. Task challenges produce similar effects in the titration method as reported for the classical procedure. Conclusions The titration 5CSRTT method is an efficient training procedure for assessing attention and can be utilized to assess the limit in performance ability across subjects and various schedule manipulations. PMID

  12. Low-frequency fluctuation in continuous real-time feedback of finger force: a new paradigm for sustained attention.

    Science.gov (United States)

    Dong, Zhang-Ye; Liu, Dong-Qiang; Wang, Jue; Qing, Zhao; Zang, Zhen-Xiang; Yan, Chao-Gan; Zang, Yu-Feng

    2012-08-01

    Behavioral studies have suggested a low-frequency (0.05 Hz) fluctuation of sustained attention on the basis of the intra-individual variability of reaction-time. Conventional task designs for functional magnetic resonance imaging (fMRI) studies are not appropriate for frequency analysis. The present study aimed to propose a new paradigm, real-time finger force feedback (RT-FFF), to study the brain mechanisms of sustained attention and neurofeedback. We compared the low-frequency fluctuations in both behavioral and fMRI data from 38 healthy adults (19 males; mean age, 22.3 years). Two fMRI sessions, in RT-FFF and sham finger force feedback (S-FFF) states, were acquired (TR 2 s, Siemens Trio 3-Tesla scanner, 8 min each, counter-balanced). Behavioral data of finger force were obtained simultaneously at a sampling rate of 250 Hz. Frequency analysis of the behavioral data showed lower amplitude in the low-frequency band (0.004-0.104 Hz) but higher amplitude in the high-frequency band (27.02-125 Hz) in the RT-FFF than the S-FFF states. The mean finger force was not significantly different between the two states. fMRI data analysis showed higher fractional amplitude of low-frequency fluctuation (fALFF) in the S-FFF than in the RT-FFF state in the visual cortex, but higher fALFF in RT-FFF than S-FFF in the middle frontal gyrus, the superior frontal gyrus, and the default mode network. The behavioral results suggest that the proposed paradigm may provide a new approach to studies of sustained attention. The fMRI results suggest that a distributed network including visual, motor, attentional, and default mode networks may be involved in sustained attention and/or real-time feedback. This paradigm may be helpful for future studies on deficits of attention, such as attention deficit hyperactivity disorder and mild traumatic brain injury.

  13. Measuring attention in rodents: comparison of a modified signal detection task and the 5-choice serial reaction time task

    Directory of Open Access Journals (Sweden)

    Karly Maree Turner

    2016-01-01

    Full Text Available Neuropsychiatric research has utilised cognitive testing in rodents to improve our understanding of cognitive deficits and for preclinical drug development. However, more sophisticated cognitive tasks have not been as widely exploited due to low throughput and the extensive training time required. We developed a modified signal detection task (SDT based on the growing body of literature aimed at improving cognitive testing in rodents. This study directly compares performance on the modified SDT with the traditional test for measuring attention, the 5-choice serial reaction time task (5CSRTT. Adult male Sprague-Dawley rats were trained on either the 5CSRTT or the SDT. Briefly, the 5CSRTT required rodents to pay attention to a spatial array of 5 apertures and respond with a nose poke when an aperture was illuminated. The SDT required the rat to attend to a light panel and respond either left or right to indicate the presence of a signal. In addition, modifications were made to the reward delivery, timing, control of body positioning and the self-initiation of trials. It was found that less training time was required for the SDT, with both sessions to criteria and daily session duration significantly reduced. Rats performed with a high level of accuracy (>87% on both tasks, however omissions were far more frequent on the 5CSRTT. The signal duration was reduced on both tasks as a manipulation of task difficulty relevant to attention and a similar pattern of decreasing accuracy was observed on both tasks. These results demonstrate some of the advantages of the SDT over the traditional 5CSRTT as being higher throughput with reduced training time, fewer omission responses and their body position at stimulus onset was controlled. In addition, rats performing the SDT had comparable high levels of accuracy. These results highlight the differences and similarities between the 5CSRTT and a modified SDT as tools for assessing attention in preclinical animal

  14. Personality and attention: Levels of neuroticism and extraversion can predict attentional performance during a change detection task.

    Science.gov (United States)

    Hahn, Sowon; Buttaccio, Daniel R; Hahn, Jungwon; Lee, Taehun

    2015-01-01

    The present study demonstrates that levels of extraversion and neuroticism can predict attentional performance during a change detection task. After completing a change detection task built on the flicker paradigm, participants were assessed for personality traits using the Revised Eysenck Personality Questionnaire (EPQ-R). Multiple regression analyses revealed that higher levels of extraversion predict increased change detection accuracies, while higher levels of neuroticism predict decreased change detection accuracies. In addition, neurotic individuals exhibited decreased sensitivity A' and increased fixation dwell times. Hierarchical regression analyses further revealed that eye movement measures mediate the relationship between neuroticism and change detection accuracies. Based on the current results, we propose that neuroticism is associated with decreased attentional control over the visual field, presumably due to decreased attentional disengagement. Extraversion can predict increased attentional performance, but the effect is smaller than the relationship between neuroticism and attention.

  15. Focused ion beam scan routine, dwell time and dose optimization for submicrometre period planar photonic crystal components and stamps in silicon

    NARCIS (Netherlands)

    Hopman, W.C.L.; Ay, F.; Hu, Wenbin; Gadgil, V.J.; Kuipers, L.; Pollnau, Markus; de Ridder, R.M.

    2007-01-01

    Focused ion beam (FIB) milling is receiving increasing attention for nanostructuring in silicon (Si). These structures can for example be used for photonic crystal structures in a silicon-on-insulator (SOI) configuration or for moulds which can have various applications in combination with imprint

  16. The ex-Gaussian distribution of reaction times in adolescents with attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    Gu, Shoou-Lian Hwang; Gau, Susan Shur-Fen; Tzang, Shyh-Weir; Hsu, Wen-Yau

    2013-11-01

    We investigated the three parameters (mu, sigma, tau) of ex-Gaussian distribution of RT derived from the Conners' continuous performance test (CCPT) and examined the moderating effects of the energetic factors (the inter-stimulus intervals (ISIs) and Blocks) among these three parameters, especially tau, an index describing the positive skew of RT distribution. We assessed 195 adolescents with DSM-IV ADHD, and 90 typically developing (TD) adolescents, aged 10-16. Participants and their parents received psychiatric interviews to confirm the diagnosis of ADHD and other psychiatric disorders. Participants also received intelligence (WISC-III) and CCPT assessments. We found that participants with ADHD had a smaller mu, and larger tau. As the ISI/Block increased, the magnitude of group difference in tau increased. Among the three ex-Gaussian parameters, tau was positively associated with omission errors, and mu was negatively associated with commission errors. The moderating effects of ISIs and Blocks on tau parameters suggested that the ex-Gaussian parameters could offer more information about the attention state in vigilance task, especially in ADHD. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. The effect of attention loading on the inhibition of choice reaction time to visual motion by concurrent rotary motion

    Science.gov (United States)

    Looper, M.

    1976-01-01

    This study investigates the influence of attention loading on the established intersensory effects of passive bodily rotation on choice reaction time (RT) to visual motion. Subjects sat at the center of rotation in an enclosed rotating chamber and observed an oscilloscope on which were, in the center, a tracking display and, 10 deg left of center, a RT line. Three tracking tasks and a no-tracking control condition were presented to all subjects in combination with the RT task, which occurred with and without concurrent cab rotations. Choice RT to line motions was inhibited (probability less than .001) both when there was simultaneous vestibular stimulation and when there was a tracking task; response latencies lengthened progressively with increased similarity between the RT and tracking tasks. However, the attention conditions did not affect the intersensory effect; the significance of this for the nature of the sensory interaction is discussed.

  18. Time estimation as a secondary task to measure workload. [attention sharing effect on operator performance

    Science.gov (United States)

    Hart, S. G.

    1975-01-01

    Variation in the length of time productions and verbal estimates of duration was investigated to determine the influence of concurrent activity on operator time perception. The length of 10-, 20-, and 30-sec intervals produced while performing six different compensatory tracking tasks was significantly longer, 23% on the average, than those produced while performing no other task. Verbal estimates of session duration, taken at the end of each of 27 experimental sessions, reflected a parallel increase in subjective underestimation of the passage of time as the difficulty of the task performed increased. These data suggest that estimates of duration made while performing a manual control task provide stable and sensitive measures of the workload imposed by the primary task, with minimal interference.

  19. Attention Switching during Scene Perception: How Goals Influence the Time Course of Eye Movements across Advertisements

    Science.gov (United States)

    Wedel, Michel; Pieters, Rik; Liechty, John

    2008-01-01

    Eye movements across advertisements express a temporal pattern of bursts of respectively relatively short and long saccades, and this pattern is systematically influenced by activated scene perception goals. This was revealed by a continuous-time hidden Markov model applied to eye movements of 220 participants exposed to 17 ads under a…

  20. Visual Attention During Brand Choice : The Impact of Time Pressure and Task Motivation

    NARCIS (Netherlands)

    Pieters, R.; Warlop, L.

    1998-01-01

    Measures derived from eye-movement data reveal that during brand choice consumers adapt to time pressure by accelerating the visual scanning sequence, by filtering information and by changing their scanning strategy. In addition, consumers with high task motivation filter brand information less and

  1. Improving crop classification through attention to the timing of airborne radar acquisitions

    Science.gov (United States)

    Brisco, B.; Ulaby, F. T.; Protz, R.

    1984-01-01

    Radar remote sensors may provide valuable input to crop classification procedures because of (1) their independence of weather conditions and solar illumination, and (2) their ability to respond to differences in crop type. Manual classification of multidate synthetic aperture radar (SAR) imagery resulted in an overall accuracy of 83 percent for corn, forest, grain, and 'other' cover types. Forests and corn fields were identified with accuracies approaching or exceeding 90 percent. Grain fields and 'other' fields were often confused with each other, resulting in classification accuracies of 51 and 66 percent, respectively. The 83 percent correct classification represents a 10 percent improvement when compared to similar SAR data for the same area collected at alternate time periods in 1978. These results demonstrate that improvements in crop classification accuracy can be achieved with SAR data by synchronizing data collection times with crop growth stages in order to maximize differences in the geometric and dielectric properties of the cover types of interest.

  2. Discrete states of attention during active visual fixation revealed by Markovian analysis of the time series of intrusive saccades.

    Science.gov (United States)

    Korda, Alexandra I; Koliaraki, Mariniki; Asvestas, Pantelis A; Matsopoulos, George K; Ventouras, Errikos M; Ktonas, Periklis Y; Smyrnis, Nikolaos

    2016-12-17

    The frequency of intrusive saccades during maintenance of active visual fixation has been used as a measure of sustained visual attention in studies of healthy subjects as well as of neuropsychiatric patient populations. In this study, the mechanism that generates intrusive saccades during active visual fixation was investigated in a population of young healthy men performing three sustained fixation tasks (fixation to a visual target, fixation to a visual target with visual distracters, and fixation straight ahead in the dark). Markov Chain modeling of inter-saccade intervals (ISIs) was utilized. First- and second-order Markov modeling provided indications for the existence of a non-random pattern in the production of intrusive saccades. Accordingly, the system of intrusive saccade generation may operate in two "attractor" states, one in which intrusive saccades occur at short consecutive ISIs and another in which intrusive saccades occur at long consecutive ISIs. These states might correspond to two distinct states of the attention system, one of low focused - high distractibility and another of high focused - low distractibility, such as those proposed in the adaptive gain theory for the control of attention by the noradrenergic system in the brain. To the authors knowledge, this is the first time that Markov Chain modeling has been applied to the analysis of the ISIs of intrusive saccades. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  3. Event- and time-triggered remembering: the impact of attention deficit hyperactivity disorder on prospective memory performance in children.

    Science.gov (United States)

    Talbot, Karley-Dale S; Kerns, Kimberly A

    2014-11-01

    The current study examined prospective memory (PM, both time-based and event-based) and time estimation (TR, a time reproduction task) in children with and without attention deficit hyperactivity disorder (ADHD). This study also investigated the influence of task performance and TR on time-based PM in children with ADHD relative to controls. A sample of 69 children, aged 8 to 13 years, completed the CyberCruiser-II time-based PM task, a TR task, and the Super Little Fisherman event-based PM task. PM performance was compared with children's TR abilities, parental reports of daily prospective memory disturbances (Prospective and Retrospective Memory Questionnaire for Children, PRMQC), and ADHD symptomatology (Conner's rating scales). Children with ADHD scored more poorly on event-based PM, time-based PM, and TR; interestingly, TR did not appear related to performance on time-based PM. In addition, it was found that PRMQC scores and ADHD symptom severity were related to performance on the time-based PM task but not to performance on the event-based PM task. These results provide some limited support for theories that propose a distinction between event-based PM and time-based PM. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. The Effects of Heat Stress on Selective Attention and Reaction Time among Workers of a Hot Industry: Application of Computerized Version of Stroop Test

    Directory of Open Access Journals (Sweden)

    F. Golbabaei

    2015-04-01

    .Conclusion: According to the findings in present study, heat stress causes an increase in reaction time and a decrease in selective attention. Thus, heat can be assumed as a stressor in hot work environments and the heat should be taken into account while design of job and tasks which needed selective attention or reaction time.

  5. Dwelling in New Delhi, dwelling in hybridity

    Directory of Open Access Journals (Sweden)

    Claudia Roselli

    2011-08-01

    Full Text Available I wake up in a ground floor bedroom of a fourth floor building. In the near dining room, the tv is kicking out loud Hindi voices, the musical refrain of a phone company ad. The family hosting me is a family of immigrants. The grandfather and the grandmother arrived in Delhi during the partition time. They originally grew up in Pakistan and met in the place where they live today, when the land was organized as a refugees camp. At the beginning, the refugees camp was only a wasteland. Then, with the passage of time, people started to build small pakka houses, a kind of self-built architecture made of simple oven-cooked red bricks, with a thatched roof.

  6. Spaced learning and innovative teaching: school time, pedagogy of attention and learning awareness

    Directory of Open Access Journals (Sweden)

    Garzia Maeca

    2016-06-01

    Full Text Available Currently, the ‘time’ variable has taken on the function of instructional and pedagogical innovation catalyst, after representing-over the years-a symbol of democratisation, learning opportunity and instruction quality, able to incorporate themes such as school dropout, personalisation and vocation into learning. Spaced Learning is a teaching methodology useful to quickly seize information in long-term memory based on a particular arrangement of the lesson time that comprises three input sessions and two intervals. Herein we refer to a teachers’ training initiative on Spaced Learning within the programme ‘DocentiInFormAzione’ in the EDOC@WORK3.0 Project in Apulia region in 2015. The training experience aimed at increasing teachers’ competencies in the Spaced Learning method implemented in a context of collaborative reflection and reciprocal enrichment. The intent of the article is to show how a process of rooting of the same culture of innovation, which opens to the discovery (or rediscovery of effective teaching practices sustained by scientific evidences, can be successfully implemented and to understand how or whether this innovation- based on the particular organisation of instructional time-links learning awareness to learning outcomes.

  7. Salivary a-Amylase Reflects Change in Attentional Demands during Postural Control: Comparison with Probe Reaction Time

    Science.gov (United States)

    Akizuki, Kazunori; Ohashi, Yukari

    2014-01-01

    Purpose: The influence of attention on postural control and the relationship between attention and falling has been reported in previous studies. Although a dual-task procedure is commonly used to measure attentional demand, such procedures are affected by allocation policy, which is a mental strategy to divide attention between simultaneous…

  8. Visual attention, reaction time, and self-reported alertness upon awakening from sleep bouts of varying lengths.

    Science.gov (United States)

    Matchock, Robert L; Mordkoff, J Toby

    2007-04-01

    The aim of the present study was to examine visual attention, especially the executive control functions that deal with conflict, when participants were in a low arousal state shortly after a nighttime awakening. Fifteen participants spent four consecutive nights at a laboratory and performed a flankers task using two levels of target-distractor spacing (0.75 degrees and 1.50 degrees) and three trial types (compatible, incompatible, and neutral). The first night was a habituation night. For the next three nights, participants went to sleep at 2300 hours and were then awakened at either 2400 hours (1-h sleep bout), 0300 hours (4-h sleep bout), or 0600 hours (7-h sleep bout) and were administered a flankers task and a self-report questionnaire that measured arousal level. These testing times were counter-balanced across participants, and a 2100 hours (pre-sleep) flankers task was also randomly assigned to be completed on one of the testing nights. Response time on neutral-flanker trials was increased if participants were awakened from a sleep bout and was slowest at 0300 hours, appearing to parallel circadian body temperature. In contrast, failures of selective attention, as indexed by the difference between compatible and incompatible trials, increased linearly as a function of the length of the sleep bout. Compared to the 2100 hours pre-sleep condition, self-reported energy was lower and Tiredness was higher after awakening from a sleep bout. Taken together, the current data suggest a dissociation between the processes that perform a non-conflict task and the executive control of attention. Specifically, longer sleep bouts seem to be associated with greater difficulty in inhibiting task-irrelevant information, perhaps due to a sleep inertia effect affecting the anterior cingulate cortex.

  9. Systematically Controlling for the Influence of Age, Sex, Hertz and Time Post-Whole-Body Vibration Exposure on Four Measures of Physical Performance in Community-Dwelling Older Adults: A Randomized Cross-Over Study

    Directory of Open Access Journals (Sweden)

    Harold L. Merriman

    2011-01-01

    Full Text Available Though popular, there is little agreement on what whole-body vibration (WBV parameters will optimize performance. This study aimed to clarify the effects of age, sex, hertz and time on four physical function indicators in community-dwelling older adults (=32. Participants were exposed to 2 min WBV per session at either 2 Hz or 26 Hz and outcome measures were recorded at 2, 20 and 40 min post-WBV. Timed get up-and-go and chair sit-and-reach performances improved post-WBV for both sexes, were significantly different between 2 Hz and 26 Hz treatments (≤0.05 and showed statistically significant interactions between age and gender (≤0.01. Counter movement jump and timed one-legged stance performances showed a similar but non-significant response to 2 Hz and 26 Hz treatments, though male subjects showed a distinct trended response. Age and gender should be statistically controlled and both 2 Hz and 26 Hz exert a treatment effect.

  10. Time-referenced effects of an internal vs. external focus of attention on muscular activity and compensatory variability

    Directory of Open Access Journals (Sweden)

    Ernst-Joachim eHossner

    2010-12-01

    Full Text Available The paralysis-by-analysis phenomenon, i.e., attending to the execution of one’s movement impairs performance, has gathered a lot of attention over recent years (see Wulf, 2007, for a review. Explanations of this phenomenon, e.g., the hypotheses of constrained action (Wulf and colleagues, e.g., McNevin et al., 2003 or of step-by-step execution (Beilock et al., 2002; Masters, 1992, however, do not refer to the level of underlying mechanisms on the level of sensorimotor control. For this purpose, a nodal-point hypothesis is presented here with the core assumption that skilled motor behavior is internally based on sensorimotor chains of nodal points, that attending to intermediate nodal points leads to a muscular re-freezing of the motor system at exactly and exclusively these points in time, and that this re-freezing is accompanied by the disruption of compensatory processes, resulting in an overall decrease of motor performance. Two experiments, on lever sequencing and basketball free throws, respectively, are reported that successfully tested these time-referenced predictions, i.e., showing that muscular activity is selectively increased and compensatory variability selectively decreased at movement-related nodal points if these points are in the focus of attention.

  11. Attention to Attention

    DEFF Research Database (Denmark)

    Tække, Jesper; Paulsen, Michael Eric

    In these years digital media and wireless networks are introduced in upper secondary schools in Denmark. This implies new “attentional objects” like updates on Facebook or tweets on Twitter within instant reach of the pupils and teachers. Also it implies new kinds of attention (awareness) like when...... this interpretation theoretically through systems theory and medium theory. Further we present initial results from the action research project Socio Media Education (SME) in which we work with how teachers and pupils can handle the new attention-demanding situation, so the new media do not mean spoiled teaching...

  12. Executive functioning independently predicts self-rated health and improvement in self-rated health over time among community-dwelling older adults.

    Science.gov (United States)

    McHugh, Joanna Edel; Lawlor, Brian A

    2016-01-01

    Self-rated health, as distinct from objective measures of health, is a clinically informative metric among older adults. The purpose of our study was to examine the cognitive and psychosocial factors associated with self-rated health. 624 participants over the age of 60 were assessed at baseline, and of these, 510 were contacted for a follow-up two years later. Measures of executive function and self-rated health were assessed at baseline, and self-rated health was assessed at follow-up. We employed multiple linear regression analyses to investigate the relationship between executive functioning and self-rated health, while controlling for demographic, psychosocial and biological variables. Controlling for other relevant variables, executive functioning independently and solely predicted self-rated health, both at a cross-sectional level, and also over time. Loneliness was also found to cross-sectionally predict self-rated health, although this relationship was not present at a longitudinal level. Older adults' self-rated health may be related to their executive functioning and to their loneliness. Self-rated health appeared to improve over time, and the extent of this improvement was also related to executive functioning at baseline. Self-rated health may be a judgement made of one's functioning, especially executive functioning, which changes with age and therefore may be particularly salient in the reflections of older adults.

  13. The influences of task repetition, napping, time of day, and instruction on the Sustained Attention to Response Task.

    Science.gov (United States)

    van Schie, Mojca K M; Alblas, Eva E; Thijs, Roland D; Fronczek, Rolf; Lammers, Gert Jan; van Dijk, J Gert

    2014-01-01

    The Sustained Attention to Response Task (SART) helps to quantify vigilance impairments.Previous studies, in which five SART sessions on one day were administered, demonstrated worse performance during the first session than during the others. The present study comprises two experiments to identify a cause of this phenomenon. Experiment 1, counting eighty healthy participants, assessed effects of repetition,napping, and time of day on SART performance through a between-groups design. The SART was performed twice in the morning or twice in the afternoon; half of the participants took a 20-minute nap before the second SART. A strong correlation between error count and reaction time (RT) suggested effects of test instruction. Participants gave equal weight to speed and accuracy in Experiment 1; therefore, results of 20 participants were compared to those of 20 additional participants who were told to prefer accuracy (Experiment 2). The average SART error count in Experiment 1 was 10.1; the median RT was 280 ms. Neither repetition nor napping influenced error count or RT. Time of day did not influence error count, but RT was significantly longer for morning than for afternoon SARTs. The additional participants in Experiment 2 had a 49% lower error count and a 14% higher RT than the participants in Experiment 1. Error counts reduced by 50% from the first to the second session of Experiment 2, irrespective of napping or time of day. Preferring accuracy over speed was associated with a significantly lower error count. The data suggest that a worse performance in the first SART session only occurs when instructing participants to prefer accuracy, which is caused by repetition, not by napping or time of day. We advise that participants are instructed to prefer accuracy over speed when performing the SART and that a full practice session is included.

  14. Effectiveness of a Timing and Coordination Group Exercise Program to Improve Mobility in Community-Dwelling Older Adults: A Randomized Clinical Trial.

    Science.gov (United States)

    Brach, Jennifer S; Perera, Subashan; Gilmore, Sandra; VanSwearingen, Jessie M; Brodine, Deborah; Nadkarni, Neelesh K; Ricci, Edmund

    2017-10-01

    Timing and coordination exercises may be an important addition to community-based health promotion exercise programs to improve walking in older adults. To compare the effectiveness of the On the Move group exercise program, which focuses on the timing and coordination of movement, with a seated strength, endurance, and flexibility program (usual care) at improving function, disability, and walking ability of older adults. Cluster-randomized, single-blind intervention trial. Thirty-two independent living facilities, senior apartment buildings, and senior community centers were randomized to On the Move (16 sites; 152 participants) or usual care (16 sites; 146 participants). Participants were 65 years or older, able to ambulate independently with a gait speed of at least 0.60 m/s, able to follow 2-step commands, and were medically stable. Exercise classes were 50 minutes, twice a week for 12 weeks and had 10 or fewer participants per class. On the Move consisted of warm-up, timing and coordination (stepping and walking patterns), strengthening, and stretching exercises. The usual-care program consisted of warm-up, strength, endurance, and stretching exercises. The primary outcomes were self-report of function and disability (Late Life Function and Disability Instrument) and mobility (6-minute walk distance and gait speed) assessed by blinded individuals. Participants (mean [SD] age, 80.0 [8.1] years) were mostly female (251 [84.2%]) and white (249 [83.6%]) and had a mean (SD) of 2.8 (1.4) chronic conditions. Intervention groups were similar on baseline characteristics. Postintervention, 142 (93.4%) participants in On the Move and 139 (95.2%) participants in usual care completed testing. On the Move had greater mean (SD) improvements than the usual-care group in gait speed (0.05 [0.13] vs -0.01 [0.11] m/s; adjusted difference = 0.05 [0.02] m/s; P = .002) and 6-minute walk distance (20.6 [57.1] vs 4.1 [55.6] m; adjusted difference = 16.7 [7.4] m; P

  15. What time periods of the day are concerning for parents of children with attention deficit hyperactivity disorder?

    Directory of Open Access Journals (Sweden)

    Masahide Usami

    Full Text Available BACKGROUND/AIM: The questionnaire-children with difficulties (QCD is a parent-assessed questionnaire designed to evaluate a child's difficulties in functioning during specific time periods of the day. In this study, the QCD was applied to determine the time periods of the day that are concerning for the parents of children with attention deficit hyperactivity disorder (ADHD. The results were compared with those for a community sample. METHODS: Elementary and junior high school students with ADHD (243 boys, 55 girls and a community sample of children (518 boys, 618 girls were enrolled in this study. Their behaviors were assessed by the QCD, the ADHD-rating scale (ADHD-RS, and the Oppositional Defiant Behavior Inventory (ODBI. The effects of gender (boy/girl and diagnosis (ADHD/community sample on the total QCD score were analyzed across each school grade (elementary/junior high school. Correlation coefficients between QCD and ADHD-RS/ODBI scores were analyzed. RESULTS: The QCD score for the ADHD group was significantly lower than that for the community sample (P 0.41, P 0.40, P < 0.001. CONCLUSIONS: Parents reported that children with ADHD faced greater difficulties in completing basic daily activities compared with the community controls, particularly in the evening. Furthermore, these difficulties were related to the severity of ADHD symptoms. The parents' perceptions depended on the gender, ADHD and oppositional symptoms, and the time period of the day. This study determined that children with ADHD face greater difficulties in daily functioning compared with community sample children, that these difficulties are time-dependent, and that these difficulties were particularly experienced in the evening.

  16. What time periods of the day are concerning for parents of children with attention deficit hyperactivity disorder?

    Science.gov (United States)

    Usami, Masahide; Okada, Takashi; Sasayama, Daimei; Iwadare, Yoshitaka; Watanabe, Kyota; Ushijima, Hirokage; Kodaira, Masaki; Sugiyama, Nobuhiro; Sawa, Tetsuji; Saito, Kazuhiko

    2013-01-01

    The questionnaire-children with difficulties (QCD) is a parent-assessed questionnaire designed to evaluate a child's difficulties in functioning during specific time periods of the day. In this study, the QCD was applied to determine the time periods of the day that are concerning for the parents of children with attention deficit hyperactivity disorder (ADHD). The results were compared with those for a community sample. Elementary and junior high school students with ADHD (243 boys, 55 girls) and a community sample of children (518 boys, 618 girls) were enrolled in this study. Their behaviors were assessed by the QCD, the ADHD-rating scale (ADHD-RS), and the Oppositional Defiant Behavior Inventory (ODBI). The effects of gender (boy/girl) and diagnosis (ADHD/community sample) on the total QCD score were analyzed across each school grade (elementary/junior high school). Correlation coefficients between QCD and ADHD-RS/ODBI scores were analyzed. The QCD score for the ADHD group was significantly lower than that for the community sample (P ADHD-RS and ODBI scores for all children with ADHD (r > 0.41, P ADHD (r > 0.40, P ADHD faced greater difficulties in completing basic daily activities compared with the community controls, particularly in the evening. Furthermore, these difficulties were related to the severity of ADHD symptoms. The parents' perceptions depended on the gender, ADHD and oppositional symptoms, and the time period of the day. This study determined that children with ADHD face greater difficulties in daily functioning compared with community sample children, that these difficulties are time-dependent, and that these difficulties were particularly experienced in the evening.

  17. Dancing in time: feasibility and acceptability of a contemporary dance programme to modify risk factors for falling in community dwelling older adults.

    Science.gov (United States)

    Britten, Laura; Addington, Christine; Astill, Sarah

    2017-04-11

    Falls are a common cause of injury in older adults, with the prevention of falls being a priority for public health departments around the world. This study investigated the feasibility, and impact of an 8 week contemporary dance programme on modifiable physical (physical activity status, mobility, sedentary behaviour patterns) and psychosocial (depressive state, fear of falling) risk factors for falls. An uncontrolled 'pre-post' intervention design was used. Three groups of older (60 yrs.+) adults were recruited from local community groups to participate in a 3 separate, 8 week dance programmes. Each programme comprised two, 90 min dance classes per week. Quantitative measures of physical activity, sedentary behaviour, depression, mobility and fear of falling were measured at baseline (T1) and after 8 weeks of dance (T2). Weekly attendance was noted, and post-study qualitative work was conducted with participants in 3 separate focus groups. A combined thematic analysis of these data was conducted. Of the 38 (Mean Age = 77.3 ± 8.4 yrs., 37 females) who attended the dance sessions, 22 (21 females; 1 male; mean age = 74.8, ±8.44) consented to be part of the study. Mean attendance was 14.6 (±2.6) sessions, and mean adherence was 84.3% (±17). Significant increases in moderate and vigorous physical activity were noted, with a significant decrease in sitting time over the weekdays (p dance programme as a means of being active, health Benefits, and dance-related barriers and facilitators. The recruitment of older adults, good adherence and favourability across all three sites indicate that a dance programme is feasible as an intervention, but this may be limited to females only. Contemporary dance has the potential to positively affect the physical activity, sitting behaviour, falls related efficacy, mobility and incidence of depression in older females which could reduce their incidence of falls. An adequately powered study with control groups are

  18. Seasonal variation of radon concentration in dwellings

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Jarad, F.; Fremlin, J.H.

    1984-05-01

    Estimating long-term exposure of populations to low levels of radon and its decay products in dwellings is a general problem. Some surveys measure the integrated value of radon over long periods of time using passive track detectors. The long-time integrated measurements should give a better estimation of population dose than short-time ones, since they give long-term average exposures for normal living conditions of dwelling inhabitants. Even measurements over a period of three months may not represent the average of the whole year because of possible seasonal variability. Recently, it was shown that winter-to-summer ratios in a few rooms range from 3 to 10, averaging 5.3 emphasizing the danger of brief readings taken in a single season and the importance and usefulness of integrating readings over a full year. In this note, long-term measurements which were carried out in 85 houses in Birmingham plus 19 houses in London are described.

  19. Language Development in Infants and Toddlers with Fragile X Syndrome: Change over Time and the Role of Attention

    Science.gov (United States)

    Kover, Sara T.; McCary, Lindsay M.; Ingram, Alexandra M.; Hatton, Deborah D.; Roberts, Jane E.

    2015-01-01

    Fragile X syndrome (FXS) is associated with significant language and communication delays, as well as problems with attention. This study investigated early language abilities in infants and toddlers with FXS (n = 13) and considered visual attention as a predictor of those skills. We found that language abilities increased over the study period of…

  20. Front-of-Pack Nutrition Labels: Their Effect on Attention and Choices when Consumers have Varying Goals and Time Constraints

    NARCIS (Netherlands)

    Herpen, van E.; Trijp, van J.C.M.

    2011-01-01

    Although front-of-pack nutrition labeling can help consumers make healthier food choices, lack of attention to these labels limits their effectiveness. This study examines consumer attention to and use of three different nutrition labeling schemes (logo, multiple traffic-light label, and nutrition

  1. Deployment of attention to emotional pictures varies as a function of externally-oriented thinking: An eye tracking investigation.

    Science.gov (United States)

    Wiebe, Alex; Kersting, Anette; Suslow, Thomas

    2017-06-01

    Alexithymia is a multidimensional personality construct including the components difficulties identifying feelings (DIF), difficulties describing feelings (DDF), and externally oriented thinking (EOT). Different features of alexithymia are thought to reflect specific deficits in the cognitive processing and regulation of emotions. The aim of the present study was to examine for the first time patterns of deployment of attention as a function of alexithymia components in healthy persons by using eye-tracking technology. It was assumed that EOT is linked to avoidance of negative images. 99 healthy adults viewed freely pictures consisting of anxiety-related, depression-related, positive, and neutral images while gaze behavior was registered. Alexithymia was assessed by the 20-Item Toronto Alexithymia Scale. Measures of anxiety, depression, and (visual-perceptual) intelligence were also administered. A main effect of emotion condition on dwell times was observed. Viewing time was lowest for neutral images, longer for depression-related and happy images, and longest for anxiety-related images. Gender and EOT had significant effects on dwell times. EOT correlated negatively with dwell time on depression-related (but not anxiety-related) images. There were no correlations of dwell times with depression, trait anxiety, intelligence, DIF, or DDF. Alexithymia was assessed exclusively by self-report. Our results show that EOT but not DIF or DDF influences attention deployment to simultaneously presented emotional pictures. EOT may reduce attention allocation to dysphoric information. This attentional characteristic of EOT individuals might have mood protecting effects but also detrimental impacts on social relationships and coping competencies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Age differences in reaction time and attention in a national telephone sample of adults: education, sex, and task complexity matter.

    Science.gov (United States)

    Tun, Patricia A; Lachman, Margie E

    2008-09-01

    This study demonstrated effects of age, education, and sex on complex reaction time in a large national sample (N = 3,616) with a wide range in age (32-85) and education. Participants completed speeded auditory tasks (from the MIDUS [Midlife in the U.S.] Stop and Go Switch Task) by telephone. Complexity ranged from a simple repeated task to an alternating task that involved central executive processes including attention switching and inhibitory control. Increased complexity was associated with slower responses in older adults, those with lower education, and women, even after controlling for differences in health status. Higher levels of education were associated with greater central executive efficiency across adulthood: Overall, adults with college degrees performed on complex tasks like less educated individuals who were 10 years younger, up to age 75. These findings suggest that advanced education can moderate age differences on complex speeded tasks that require central executive processes, at least up to the point in old age at which biological declines predominate. The approach demonstrates the utility of combining laboratory paradigms with survey methods to enable the study of larger, more diverse and representative samples across the lifespan.

  3. The effect of order of dwells on the first dwell gaze bias for eventually chosen items.

    Science.gov (United States)

    Onuma, Takuya; Penwannakul, Yuwadee; Fuchimoto, Jun; Sakai, Nobuyuki

    2017-01-01

    The relationship between choice and eye movement has gained marked interest. The gaze bias effect, i.e., the tendency to look longer at items that are eventually chosen, has been shown to occur in the first dwell (initial cohesion of fixations for an item). In the two-alternative forced-choice (2AFC) paradigm, participants would look at one of the items first (defined as first look; FL), and they would then move and look at another item (second look; SL). This study investigated how the order in which the chosen items were looked at modulates the first dwell gaze bias effect. Participants were asked to assert their preferences and perceptual 2AFC decisions about human faces (Experiment 1) and daily consumer products (Experiment 2), while their eye movements were recorded. The results showed that the first dwell gaze bias was found only when the eventually chosen item was looked at after another one; the chosen item was looked at for longer as compared to the not-chosen item in the SL, but not in the FL. These results indicate that participants actively allocate more time to looking at a subsequently chosen item only after they perceive both items in the SL. Therefore, the selective encoding seems to occur in the early comparison stage of visual decision making, and not in the initial encoding stage. These findings provide insight into the relationship between choice and eye movement.

  4. Balancing dwell times for switching linear systems

    NARCIS (Netherlands)

    Pola, G.; Polderman, Jan W.; Di Benedetto, M.D.

    2004-01-01

    Switching Linear Systems (SLSs) are a subclass of hybrid systems characterized by a Finite State Machine (FSM) and a set of linear dynamical systems, each corresponding to a state of the FSM. The transition between two di?erent states of the FSM is caused by external uncontrollable events that act

  5. Visual Attentional Engagement Deficits in Children with Specific Language Impairment and Their Role in Real-Time Language Processing

    Science.gov (United States)

    Dispaldro, Marco; Leonard, Laurence B.; Corradi, Nicola; Ruffino, Milena; Bronte, Tiziana; Facoetti, Andrea

    2015-01-01

    In order to become a proficient user of language, infants must detect temporal cues embedded within the noisy acoustic spectra of ongoing speech by efficient attentional engagement. According to the neuro-constructivist approach, a multi-sensory dysfunction of attentional engagement – hampering the temporal sampling of stimuli – might be responsible for language deficits typically shown in children with Specific Language Impairment (SLI). In the present study, the efficiency of visual attentional engagement was investigated in 22 children with SLI and 22 typically developing (TD) children by measuring attentional masking (AM). AM refers to impaired identification of the first of two sequentially presented masked objects (O1 and O2) in which the O1-O2 interval was manipulated. Lexical and grammatical comprehension abilities were also tested in both groups. Children with SLI showed a sluggish engagement of temporal attention, and individual differences in AM accounted for a significant percentage of unique variance in grammatical performance. Our results suggest that an attentional engagement deficit – probably linked to a dysfunction of the right fronto-parietal attentional network – might be a contributing factor in these children’s language impairments. PMID:23154040

  6. Do Current and Former Cigarette Smokers have an Attentional Bias for E-cigarette Cues?

    Science.gov (United States)

    Lochbuehler, Kirsten; Wileyto, E Paul; Tang, Kathy Z; Mercincavage, Melissa; Cappella, Joseph N; Strasser, Andrew A

    2017-09-01

    The similarity of e-cigarettes to tobacco cigarettes with regard to shape and usage raises the question of whether e-cigarette cues have the same incentive motivational properties as tobacco cigarette cues. The objective of the present study was to examine whether e-cigarette cues capture and hold smokers' and former smokers' attention and whether the attentional focus is associated with subsequent craving for tobacco cigarettes. It was also examined whether device type (cigalike or mod) moderated this relationship. Participants (46 current daily smokers, 38 former smokers, 48 non-smokers) were randomly assigned to a device type condition in which their eye-movements were assessed while completing a visual probe task. Craving was assessed before and after the task. Smokers, but not former or non-smokers, maintained their gaze longer on e-cigarette than on neutral pictures ( p = 0.004). No difference in dwell time was found between device type. None of the smoking status groups showed faster initial fixations or faster reaction times to e-cigarette compared with neutral cues. Baseline craving was associated with dwell time on e-cigarette cues ( p = 0.004). Longer dwell time on e-cigarette cues was associated with more favorable attitudes towards e-cigarettes. These findings indicate that e-cigarette cues may contribute to craving for tobacco cigarettes and suggest the potential regulation of e-cigarette marketing.

  7. Association of screen time with self-perceived attention problems and hyperactivity levels in French students: a cross-sectional study.

    Science.gov (United States)

    Montagni, Ilaria; Guichard, Elie; Kurth, Tobias

    2016-02-26

    To investigate whether high levels of screen time exposure are associated with self-perceived levels of attention problems and hyperactivity in higher education students. Cross-sectional study among participants of the i-Share cohort. French-speaking students of universities and higher education institutions. 4816 graduate students who were at least 18 years old. Screen time was assessed by self-report of the average time spent on five different screen activities on smartphone, television, computer and tablet and categorised into quartiles. We used the Attention Deficit Hyperactivity Disorder Self-Report Scale (ASRS-v1.1) concerning students' behaviour over the past 6 months to measure self-perceived levels of attention problems and hyperactivity. Responses were summarised into a global score as well as scores for attention problems and hyperactivity. The 4816 participants of this study had a mean age of 20.8 years and 75.5% were female. Multivariable ordinary regression models showed significant associations of screen time exposure with quintiles of the total score of self-perceived attention problems and hyperactivity levels as well as the individual domains. Compared to the lowest screen time exposure category, the ORs (95% CI) were 1.58 (1.37 to 1.82) for each increasing level of quintiles of the global score, 1.57 (1.36 to 1.81) for increasing quintiles of attention levels and 1.25 (1.09 to 1.44) for increasing quartiles of hyperactivity. Results of this large cross-sectional study among French university and higher education students show dose-dependent associations between screen time and self-perceived levels of attention problems and hyperactivity. Further studies are warranted to evaluate whether interventions could positively influence these associations. 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/

  8. Early Language Development in Infants and Toddlers with Fragile X Syndrome: Change over Time and the Role of Attention

    Science.gov (United States)

    Kover, Sara T.; McCary, Lindsay M.; Ingram, Alexandra M.; Hatton, Deborah D.; Roberts, Jane E.

    2017-01-01

    Fragile X syndrome (FXS) is associated with significant language and communication delays, as well as problems with attention. This study investigated early language abilities in infants and toddlers with FXS (n = 13) and considered visual attention as a predictor of those skills. We found that language abilities increased over the study period of 9 to 24 months with moderate correlations among language assessments. In comparison to typically developing infants (n = 11), language skills were delayed beyond chronological age- and developmental level-expectations. Aspects of early visual attention predicted later language ability. Atypical visual attention is an important aspect of the FXS phenotype with implications for early language development, particularly in the domain of vocabulary. PMID:25715182

  9. Time Course of Visual Attention in Infant Categorization of Cats versus Dogs: Evidence for a Head Bias as Revealed through Eye Tracking

    Science.gov (United States)

    Quinn, Paul C.; Doran, Matthew M.; Reiss, Jason E.; Hoffman, James E.

    2009-01-01

    Previous looking time studies have shown that infants use the heads of cat and dog images to form category representations for these animal classes. The present research used an eye-tracking procedure to determine the time course of attention to the head and whether it reflects a preexisting bias or online learning. Six- to 7-month-olds were…

  10. Dwell upon suburbia

    OpenAIRE

    MacDonald, Ian

    2012-01-01

    non-peer-reviewed My thesis project is exploring the way we live today. In our Irish context the suburbs have been spreading out from the cities like a virus, each development clothed to the next as the life-line of the roads deteriorates and clogs. Now that our developments have slowed down we have time to reflect and rethink our form of living before our economy turns around and the pace picks up again. I am questioning our current individualistic mode of consumption exploring the ...

  11. Attention and Recall of Point-of-sale Tobacco Marketing: A Mobile Eye-Tracking Pilot Study

    OpenAIRE

    Maansi Bansal-Travers; Adkison, Sarah E.; O’Connor, Richard J.; Thrasher, James F.

    2016-01-01

     Introduction: As tobacco advertising restrictions have increased, the retail ‘power wall’ behind the counter is increasingly invaluable for marketing tobacco products. Objective: The primary objectives of this pilot study were 3-fold: (1) evaluate the attention paid/fixations on the area behind the cash register where tobacco advertising is concentrated and tobacco products are displayed in a real-world setting, (2) evaluate the duration (dwell-time) of these fixations, and (3) evaluate...

  12. A comparison of ritalin and adderall: efficacy and time-course in children with attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    Pelham, W E; Aronoff, H R; Midlam, J K; Shapiro, C J; Gnagy, E M; Chronis, A M; Onyango, A N; Forehand, G; Nguyen, A; Waxmonsky, J

    1999-04-01

    Very little research has focused on the efficacy of Adderall (Shire-Richwood Inc, Florence, KY) in the treatment of children with attention-deficit/hyperactivity disorder (ADHD), and no studies have compared it with standardized doses of Ritalin (Novartis Pharmaceuticals, East Hanover, NJ). It is thought that Adderall has a longer half-life than Ritalin and might minimize the loss of efficacy that occurs 4 or 5 hours after Ritalin ingestion. We compared two doses of Ritalin and Adderall in the treatment of ADHD in children in an acute study and assessed the medications' time courses. Within-subject, double-blind, placebo-controlled, crossover design lasting 6 weeks. As in our previous work, medication changes occurred on a daily basis in random order over days. Eight-week, weekday (9 hours daily) summer treatment program at the State University of New York at Buffalo, using an intensive behavioral treatment program including a point system and parent training. Twenty-five children (21 boys and 4 girls) diagnosed as ADHD using standardized structured interview and rating scales, mean age 9.6 years, 88% Caucasian, of average intelligence, with no medical conditions that would preclude a trial of stimulant medication. Thirteen were comorbid for oppositional-defiant disorder and another 8 for conduct disorder. Children received 10 mg of Ritalin, 17.5 mg of Ritalin, 7.5 mg of Adderall, 12.5 mg of Adderall, or placebo, twice a day (7:45 AM and 12:15 PM), in random order with conditions changing daily for 24 days. Daily rates of behaviors in recreational and classroom settings, and standardized ratings from counselors, teachers, and parents, were averaged across days within condition within child and compared. Within-subject relative sizes of the medication effects were computed by taking the placebo-minus-drug mean difference divided by the placebo standard deviation for each child, and were compared hourly between first daily ingestion (7:45 AM) and 5:00 PM to assess

  13. The influences of task repetition, napping, time of day, and instruction on the Sustained Attention to Response Task

    NARCIS (Netherlands)

    Schie, M.K.M. van; Alblas, E.E.; Thijs, R.D.; Fronczek, R.; Lammers, G.J.; Dijk, J.G. van

    2014-01-01

    Introduction: The Sustained Attention to Response Task (SART) helps to quantify vigilance impairments. Previous studies, in which five SART sessions on one day were administered, demonstrated worse performance during the first session than during the others. The present study comprises two

  14. Methylphenidate, Interstimulus Interval, and Reaction Time Performance of Children with Attention Deficit/Hyperactivity Disorder : A Pilot Study

    NARCIS (Netherlands)

    van der Meere, J. J.; Shalev, R. S.; Borger, N.; Wiersema, J.R

    2009-01-01

    Thirteen children with attention deficit/hyperactivity disorder (ADHD: DSM-IV-TR) participated in the pilot study. They carried out a Go/No-Go test with a short (2 seconds) and long (6 seconds) interstimulus interval (ISI) when on placebo and a therapeutic dose of methylphenidate (MPH). For the

  15. Dwelling Water Tanks in Diyarbakir

    Directory of Open Access Journals (Sweden)

    Ali Ceylan

    2008-02-01

    Full Text Available BACKGROUND: In this connection, the object of this study has been to identify and compare the microbiological contamination and residue chlorine levels in the main network water that is taken from the Dicle Dam and distributed in Diyarbakir Province Centre and in the tanks of dwellings that use this water as well as the effects of the maintenance, hygiene, and physical conditions of these tanks on microbiological contamination. METHODS: Water samples were taken from both the tank input side network water and tank output side tank waters of 200 dwellings with water tanks in Diyarbakir city centre (tank entrance network side water for 200 and tank output side tank water for 200 within the framework of the research study. RESULTS: Coliform bacteria were detected in 35% of the tank entrance side network water samples and in 52.0% percent of the tank output side water samples. Faecal coliform bacteria were not detected in tank entrance side network water samples, but they existed in 2.5% of the tank output side water samples. Free residue chlorine level was found to be over 0.2 ppm in 67% of tank entrance side network water samples and in 35% of the tank output side water samples. Coliform bacteria were detected in 95.5% of the tank entrance side network water samples, of which free residue chlorine level were below 0.2 ppm. Total germ growth was detected in 52.0% of the tank entrance side network water samples and in 67.5% of the tank output side water samples. The most frequently isolated bacteria both in tank entrance side network and tank output side water samples were found to be Bacillus spp. Bacillus type bacteria were found in 48% of tank entrance side network water samples and 57.5% of the tank output side water samples. Filamentous fungi were prevalent in 8% of all the samples examined within the study and the most commonly isolated filamentous fungi were Aspergillus spp (5.5% and Penicillum spp (2.5%. Water tanks of dwellings contain more

  16. Attentional capture by social stimuli in young infants

    Directory of Open Access Journals (Sweden)

    Maxie eGluckman

    2013-08-01

    Full Text Available We investigated the possibility that a range of social stimuli capture the attention of 6-month-old infants when in competition with other non-face objects. Infants viewed a series of six-item arrays in which one target item was a face, body part, or animal as their eye movements were recorded. Stimulus arrays were also processed for relative salience of each item in terms of color, luminance, and amount of contour. Targets were rarely the most visually salient items in the arrays, yet infants’ first looks toward all three target types were above chance, and dwell times for targets exceeded other stimulus types. Girls looked longer at faces than did boys, but there were no sex differences for other stimuli. These results are interpreted in a context of learning to discriminate between different classes of animate stimuli, perhaps in line with affordances for social interaction, and origins of sex differences in social attention.

  17. Attention for emotional facial expressions in dysphoria: an eye-movement registration study.

    Science.gov (United States)

    Leyman, Lemke; De Raedt, Rudi; Vaeyens, Roel; Philippaerts, Renaat M

    2011-01-01

    Former research demonstrated that depression is associated with dysfunctional attentional processing of emotional information. Most studies examined this bias by registration of response latencies. The present study employed an ecologically valid measurement of attentive processing, using eye-movement registration. Dysphoric and non-dysphoric participants viewed slides presenting sad, angry, happy and neutral facial expressions. For each type of expression, three components of visual attention were analysed: the relative fixation frequency, fixation time and glance duration. Attentional biases were also investigated for inverted facial expressions to ensure that they were not related to eye-catching facial features. Results indicated that non-dysphoric individuals were characterised by longer fixating and dwelling on happy faces. Dysphoric individuals demonstrated a longer dwelling on sad and neutral faces. These results were not found for inverted facial expressions. The present findings are in line with the assumption that depression is associated with a prolonged attentional elaboration on negative information. © 2010 Psychology Press, an imprint of the Taylor & Francis Group, an Informa business

  18. Prevalentie van broek- en/of bedplassen bij hinderen met aandachtsproblemen [Prevalence of daytime and/or night-time incontinence in children with attention problems

    NARCIS (Netherlands)

    Leerdam, F.J.M. van; Reijneveld, S.A.; Hoog, N. de; Heijden, A.J. van der; Hirasing, R.A.

    2005-01-01

    Aim of the study was to assess the prevalence of daytime and/or night-time incontinence in children with a clinical score on Attention Problems. Of the population sample of 4970 children, 4480 participated (response 90.1%). Parents of 4171 children (2069 boys and 2102 girls) aged between 4 and 15

  19. Electrophysiological evidence of the time course of attentional bias in nonpatients reporting symptoms of depression with and without co-occurring anxiety

    Directory of Open Access Journals (Sweden)

    Sarah M. Sass

    2014-04-01

    Full Text Available Anxiety is characterized by attentional biases to threat, but findings are inconsistent for depression. To address this inconsistency, the present study systematically assessed the role of co-occurring anxiety in attentional bias in depression. In addition, the role of emotional valence, arousal, and gender was explored. Ninety-two nonpatients completed the Penn State Worry Questionnaire (PSWQ; Meyer et al., 1990; Molina & Borkovec, 1994 and portions of the Mood and Anxiety Symptom Questionnaire (MASQ; Watson, Clark, et al., 1995; Watson, Weber, et al., 1995. Individuals reporting high levels of depression and low levels of anxiety (depression only, high levels of depression and anxiety (combined, or low levels of both (control completed an emotion-word Stroop task during event-related brain potential (ERP recording. Pleasant and unpleasant words were matched on emotional arousal level. An attentional bias was not evident in the depression-only group. Women in the combined group had larger N200 amplitude for pleasant than unpleasant stimuli, and the combined group as a whole had larger right-lateralized P300 amplitude for pleasant than unpleasant stimuli, consistent with an early and later attentional bias that is specific to unpleasant valence in the combined group. Men in the control group had larger N200 amplitude for pleasant than unpleasant stimuli, consistent with an early attentional bias that is specific to pleasant valence. The present study indicates that the nature and time course of attention prompted by emotional valence and not arousal differentiates depression with and without anxiety, with some evidence of gender moderating early effects. Overall, results suggest that co-occurring anxiety is more important than previously acknowledged in demonstrating evidence of attentional biases in depression.

  20. Predicting physical stability in pressurized metered dose inhalers via dwell and instantaneous force colloidal probe microscopy.

    Science.gov (United States)

    D'Sa, Dexter; Chan, Hak-Kim; Chrzanowski, Wojciech

    2014-09-01

    Colloidal probe microscopy (CPM) is a quantitative predictive tool, which can offer insight into particle behavior in suspension pressurized metered dose inhalers (pMDIs). Although CPM instantaneous force measurements, which involve immediate retraction of the probe upon sample contact, can provide information on inter-particle attractive forces, they lack the ability to appropriately imitate all critical particle pMDI interactions (e.g., particle re-dispersion after prolonged pMDI storage). In this paper, two novel dwell force techniques - indentation and deflection dwell - were employed to mimic long-term particle interactions present in pMDIs, using particles of various internal structures and a model liquid propellant (2H,3H perfluoropentane) as a model system. Dwell measurements involve particle contact for an extended period of time. In deflection dwell mode the probe is held at a specific position, while in indentation dwell mode the probe is forced into the sample with a constant force for the entirety of the contact time. To evaluate the applicability of CPM to predict actual pMDI physical stability, inter-particle force measurements were compared with qualitative and quantitative bulk pMDI measurement techniques (visual quality and light scattering). Measured instantaneous attractive (snap-in) and adhesive (max-pull) forces decreased as a function of increasing surface area, while adhesive forces measured by indentation dwell decreased as a function of dwell contact time for particles containing voids. Instantaneous force measurements provided information on the likelihood of floccule formation, which was predictive of partitioning rates, while indentation dwell force measurements were predictive of formulation re-dispersibility after prolonged storage. Dwell force measurements provide additional information on particle behavior within a pMDI not obtainable via instantaneous measurements. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Association between a history of falls and the ability to multi-task in community-dwelling older people.

    Science.gov (United States)

    Makizako, Hyuma; Furuna, Taketo; Shimada, Hiroyuki; Ihira, Hikaru; Kimura, Mika; Uchiyama, Eiichi; Oddsson, Lars I E

    2010-01-01

    Many older people fall when they perform tasks which require increased attention. The aim of this study was to determine differences in reaction times, during simple-, dual- and triple-task conditions requiring differing levels of motor coordination, balance control and cognitive attention, between groups of fallers and non-fallers in community-dwelling older individuals. The study involved the recruitment of 87 older individuals living at home, 57 women and 30 men aged 75 to 91 years. Reaction times, measured by pushing a handheld button as quickly as possible in response to a visual stimulus, were measured in four conditions: 1) quiet standing (simple-task); 2) counting backward during quiet standing (dual-task with cognitive demand); 3) stepping in place (dual-task with balance demand); and 4) counting backward while stepping in place (triple-task with cognitive and balance demands). Twenty-nine (33.3%) participants had fallen at least once during the past year. There were no statistically significant differences in reaction times between non-fallers and fallers during any of the tasks. Reaction times were significantly longer during the dual- and triple-tasks compared with the simple-task conditions in both groups. The ratio between reaction times during dual-tasks with balance demands (stepping in place) and those in the simple-task condition were significantly related to a history of falls and showed the highest odds ratio (OR 3.16, 95% CI 1.06- 9.45, p=0.04). Relative changes in reaction times during a dual-task with balance demands were related to a history of falls in community-dwelling older individuals. Reaction times in dual-task conditions with a balance demand were more sensitive to past falls than those during a dual-task with cognitive demands.

  2. Dwelling on Everyday Car Journeys

    DEFF Research Database (Denmark)

    Tølbøll, Lene; Jensen, Hanne Louise

    different traffic conditions as well as the emotional states related to the drivers’ thoughts about work and family issues, the materiality of the car and the recreational activities inside the car. Analyses are based on a web-based questionnaire, sent to 373 participating drivers in the Big Data research...... project Intelligent Transportation System Platform North Denmark (Lahrmann 2012). In that project data on e.g. position and speed was collected via an On Board Unit from more than 400 cars in 2012-2014 (Tøfting et. al. 2014). The full dataset includes a driven distance of approximately 14 million km...... experiences related to commuting. The findings will be discussed using theoretical inspiration from Sheller (2004), Bull (2003) and Thrift (2004) and we will suggest that the various emotional experiences of the commuters are of great importance for their ability to use of the car as a dwelling place....

  3. Long term monitoring of window opening behaviour in Danish dwellings

    DEFF Research Database (Denmark)

    Andersen, Rune Vinther; Toftum, Jørn; Olesen, Bjarne W.

    2009-01-01

    ABSTRACT: During the first eight months of 2008, measurements of occupant behaviour and eight environmental variables was carried out in 15 dwellings. Logistical regression was applied to infer the probability of open window as a function of the outdoor temperature. The results were compared...... and outdoor temperature affected when the window was closed and finally the time of day had an impact on the window opening behaviour of the occupants....

  4. How persistent microbubbles shield nanoparticle productivity in laser synthesis of colloids - quantification of their volume, dwell dynamics, and gas composition.

    Science.gov (United States)

    Kalus, Mark-Robert; Bärsch, Niko; Streubel, René; Gökce, Emine; Barcikowski, Stephan; Gökce, Bilal

    2017-03-08

    During laser synthesis of colloids, cavitation bubbles with lifetimes in the microsecond-scale form and shield the laser pulse leading to a decrease in nanoparticle output. A second type of productivity-limiting bubble that severely affects the productivity of the process is often neglected. With lifetimes from milliseconds to seconds, these persistent bubbles are systematically studied in this work by quantifying their composition, amount, size and dwell time in liquids with different viscosities and by relating the results to the nanoparticle productivities. It is found that during synthesis in water, water splitting occurs leading to persistent bubbles consisting of hydrogen and oxygen. In glycols, hydrogen and molecular carbon species containing microbubbles are formed. These persistent microbubbles shield up to 65% of the incoming laser beam depending on the liquid as well as the laser fluence and require attention by means of reducing their dwell time in the ablation zone and enhancing the nanoparticle output by liquid flow. The highest productivities and monodisperse quality are achieved in liquids with the lowest viscosities.

  5. Is it time to turn our attention toward central mechanisms for post-exertional recovery strategies and performance?

    Science.gov (United States)

    Rattray, Ben; Argus, Christos; Martin, Kristy; Northey, Joseph; Driller, Matthew

    2015-01-01

    Key PointsCentral fatigue is accepted as a contributor to overall athletic performance, yet little research directly investigates post-exercise recovery strategies targeting the brainCurrent post-exercise recovery strategies likely impact on the brain through a range of mechanisms, but improvements to these strategies is neededResearch is required to optimize post-exercise recovery with a focus on the brain Post-exercise recovery has largely focused on peripheral mechanisms of fatigue, but there is growing acceptance that fatigue is also contributed to through central mechanisms which demands that attention should be paid to optimizing recovery of the brain. In this narrative review we assemble evidence for the role that many currently utilized recovery strategies may have on the brain, as well as potential mechanisms for their action. The review provides discussion of how common nutritional strategies as well as physical modalities and methods to reduce mental fatigue are likely to interact with the brain, and offer an opportunity for subsequent improved performance. We aim to highlight the fact that many recovery strategies have been designed with the periphery in mind, and that refinement of current methods are likely to provide improvements in minimizing brain fatigue. Whilst we offer a number of recommendations, it is evident that there are many opportunities for improving the research, and practical guidelines in this area.

  6. Is it time to turn our attention towards central mechanisms for post-exertional recovery strategies and performance?

    Directory of Open Access Journals (Sweden)

    Ben eRattray

    2015-03-01

    Full Text Available Post-exercise recovery has largely focused on peripheral mechanisms of fatigue, but there is growing acceptance that fatigue is also contributed to through central mechanisms which demands that attention should be paid to optimising recovery of the brain. In this narrative review we assemble evidence for the role that many currently utilised recovery strategies may have on the brain, as well as potential mechanisms for their action. The review provides discussion of how common nutritional strategies as well as physical modalities and methods to reduce mental fatigue are likely to interact with the brain, and offer an opportunity for subsequent improved performance. We aim to highlight the fact that many recovery strategies have been designed with the periphery in mind, and that refinement of current methods are likely to provide improvements in minimising central fatigue. Whilst we offer a number of recommendations, it is evident that there are many opportunities for improving the research, and practical guidelines in this area.

  7. The geriatric depression scale and the timed up and go test predict fear of falling in community-dwelling elderly women with type 2 diabetes mellitus: a cross-sectional study.

    Science.gov (United States)

    Moreira, Bruno de Souza; Dos Anjos, Daniela Maria da Cruz; Pereira, Daniele Sirineu; Sampaio, Rosana Ferreira; Pereira, Leani Souza Máximo; Dias, Rosângela Corrêa; Kirkwood, Renata Noce

    2016-03-03

    Fear of falling is a common and potentially disabling problem among older adults. However, little is known about this condition in older adults with diabetes mellitus. The aims of this study were to investigate the impact of the fear of falling on clinical, functional and gait variables in older women with type 2 diabetes and to identify which variables could predict the fear of falling in this population. Ninety-nine community-dwelling older women with type 2 diabetes (aged 65 to 89 years) were stratified in two groups based on their Falls Efficacy Scale-International score. Participants with a score mobility and gait deficits. Furthermore, both the GDS-15 and the TUG test predict a fear of falling in this population. Therefore, these instruments should be considered during the assessment of diabetic older women with fear of falling.

  8. Study on construction of temporary dwellings and problems caused by living long time on Hanshin-Awaji Great Earthquake; Hanshin / Awaji daishinsai ni okeru okyu kasetsu jutaku no secchi to chokikan shiyo suru baai no kadai ni kansuru chosa

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, K.; Nakamura, Y. [Nagasaki Univ. (Japan)] Shimizu, Y. [Kumagai Gumi Co. Ltd., Tokyo (Japan)

    1998-10-20

    Two years after the above-titled earthquake, an examination was performed on inhabitants in the temporary dwelling houses in Kobe, center of the calamity, and problems caused by a long stay there were clarified together with a grasp of the evolving problems by comparing the result of survey carried out immediately after the disaster. The number of such temporary dwelling houses amounted to 29,128 within Kobe City and 3,168 outside of the city. According to the room arrangement, they were either one f 4 types : 2-rooms with a kitchen, 1 room with a kitchen, dormitory and those specifically for aged persons. There were 59,449 applications at the first offer of 2,702 houses. The priority of their assignments and so on are explained. As for the housing structure, numerous complaints concerned with the room temperature, noise and so forth. As for the living environment, lack of nearby commodity shop, omission of transportation access, ill drainage of the housing sites were pointed out and the matters of demand to the local authorities included the installation of mail post and street lights. As for the health management, insomnia, stiff shoulder, lumbago and other bad physical conditions were revealed. The financial difficulty and the high house rent were obstacles to migrate to other places. The prolonged temporary lives worsened the apprehension of dwellers for the earthquake, typhoon, fire and alike. Some features for the calamity are described in comparison with the result of survey on those who were compelled to live under similar conditions by the eruption of Mr. Fugen. 6 refs., 13 figs., 15 tabs.

  9. Music and Sound Elements in Time Estimation and Production of Children with Attention Deficit/Hyperactivity Disorder (ADHD

    Directory of Open Access Journals (Sweden)

    Luiz Rogerio Jorgensen Carrer

    2015-09-01

    Full Text Available ADHD involves cognitive and behavioral aspects with impairments in many environments of children and their families’ lives. Music, with its playful, spontaneous, affective, motivational, temporal and rhythmic dimensions can be of great help for studying the aspects of time processing in ADHD. In this article we studied time processing with simple sounds and music in children with ADHD with the hypothesis that children with ADHD have a different performance when compared with children with normal development in tasks of time estimation and production. The main objective was to develop sound and musical tasks to evaluate and correlate the performance of children with ADHD, with and without methylphenidate, compared to a control group with typical development. The study involved 36 participants age 6 to 14 years, recruited at NANI-Unifesp/SP, sub-divided into three groups with 12 children in each. Data was collected through a musical keyboard using Logic Audio Software 9.0 on the computer that recorded the participant's performance in the tasks. Tasks were divided into sections: spontaneous time production, time estimation with simple sounds and time estimation with music. Results: 1. Performance of ADHD groups in temporal estimation of simple sounds in short time intervals (30 ms were statistically lower than control group (p<0,05; 2. In the task comparing musical excerpts of the same duration (7s, ADHD groups considered the tracks longer when the musical notes had longer durations, while in the control group, the duration was related to the density of musical notes in the track. The positive average performance observed in the three groups in most tasks perhaps indicates the possibility that music can, in some way, positively modulate the symptoms of inattention in ADHD.

  10. Dissociating Goal-Directed and Stimulus-Driven Determinants in Attentional Capture

    Directory of Open Access Journals (Sweden)

    Louis K. H. Chan

    2011-05-01

    Full Text Available Although attentional capture is now a commonplace finding, the exact roles played by goal-directed and stimulus-driven determents remain elusive. An unsettled issue is on the relative contribution of attentional set and visual saliency. In the present study, we investigated this issue by mixing color and orientation search trials, so that distractors of either feature dimension fell into the current attentional set. In our test, color features were more salient. As a result, in orientation search, whereas a color distractor produced huge capture (109 ms, an orientation distractor produced moderate capture (50 ms. With color targets, distractors were not interfering. On one hand, these results reflect that relative salience of the target and the distractor is critical for producing capture; on the other hand, a huge capture size associated with a nontarget dimension feature is novel. Similar previous measurements, but without matching the attentional set, consistently report attentional capture of only 20-30 ms. This comparison shows the role played by attentional set. Taken together, we suggest that visual saliency determines search order, and sets the platform for capture. However, attentional dwell time on the distractor is determined by how much it matches the current attentional set, and in turn explains the capture size.

  11. Is that disgust I see? Political ideology and biased visual attention.

    Science.gov (United States)

    Oosterhoff, Benjamin; Shook, Natalie J; Ford, Cameron

    2018-01-15

    Considerable evidence suggests that political liberals and conservatives vary in the way they process and respond to valenced (i.e., negative versus positive) information, with conservatives generally displaying greater negativity biases than liberals. Less is known about whether liberals and conservatives differentially prioritize certain forms of negative information over others. Across two studies using eye-tracking methodology, we examined differences in visual attention to negative scenes and facial expressions based on self-reported political ideology. In Study 1, scenes rated high in fear, disgust, sadness, and neutrality were presented simultaneously. Greater endorsement of socially conservative political attitudes was associated with less attentional engagement (i.e., lower dwell time) of disgust scenes and more attentional engagement toward neutral scenes. Socially conservative political attitudes were not significantly associated with visual attention to fear or sad scenes. In Study 2, images depicting facial expressions of fear, disgust, sadness, and neutrality were presented simultaneously. Greater endorsement of socially conservative political attitudes was associated with greater attentional engagement with facial expressions depicting disgust and less attentional engagement toward neutral faces. Visual attention to fearful or sad faces was not related to social conservatism. Endorsement of economically conservative political attitudes was not consistently associated with biases in visual attention across both studies. These findings support disease-avoidance models and suggest that social conservatism may be rooted within a greater sensitivity to disgust-related information. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Chemogenetic Activation of Midbrain Dopamine Neurons Affects Attention, but not Impulsivity, in the Five-Choice Serial Reaction Time Task in Rats

    NARCIS (Netherlands)

    Boekhoudt, Linde; Voets, Elisa S; Flores-Dourojeanni, Jacques P; Luijendijk-Berg, Mieneke Cm; Vanderschuren, Louk Jmj; Adan, Roger Ah

    2017-01-01

    Attentional impairments and exaggerated impulsivity are key features of psychiatric disorders, such as attention-deficit/hyperactivity disorder, schizophrenia, and addiction. These deficits in attentional performance and impulsive behaviors have been associated with aberrant dopamine (DA) signaling,

  13. Chemogenetic Activation of Midbrain Dopamine Neurons Affects Attention, but not Impulsivity, in the Five-Choice Serial Reaction Time-Task in Rats

    NARCIS (Netherlands)

    Boekhoudt, Linde; Voets, Elisa S; Flores-Dourojeanni, Jacques P; Luijendijk, Mieneke Cm; Vanderschuren, Louk Jmj|info:eu-repo/dai/nl/126514917; Adan, Roger Ah

    2017-01-01

    Attentional impairments and exaggerated impulsivity are key features of psychiatric disorders, such as attention-deficit/hyperactivity disorder, schizophrenia, and addiction. These deficits in attentional performance and impulsive behaviours have been associated with aberrant dopamine (DA)

  14. Resting cardiac vagal tone predicts intraindividual reaction time variability during an attention task in a sample of young and healthy adults.

    Science.gov (United States)

    Williams, DeWayne P; Thayer, Julian F; Koenig, Julian

    2016-12-01

    Intraindividual reaction time variability (IIV), defined as the variability in trial-to-trial response times, is thought to serve as an index of central nervous system function. As such, greater IIV reflects both poorer executive brain function and cognitive control, in addition to lapses in attention. Resting-state vagally mediated heart rate variability (vmHRV), a psychophysiological index of self-regulatory abilities, has been linked with executive brain function and cognitive control such that those with greater resting-state vmHRV often perform better on cognitive tasks. However, research has yet to investigate the direct relationship between resting vmHRV and task IIV. The present study sought to examine this relationship in a sample of 104 young and healthy participants who first completed a 5-min resting-baseline period during which resting-state vmHRV was assessed. Participants then completed an attentional (target detection) task, where reaction time, accuracy, and trial-to-trial IIV were obtained. Results showed resting vmHRV to be significantly related to IIV, such that lower resting vmHRV predicted higher IIV on the task, even when controlling for several covariates (including mean reaction time and accuracy). Overall, our results provide further evidence for the link between resting vmHRV and cognitive control, and extend these notions to the domain of lapses in attention, as indexed by IIV. Implications and recommendations for future research on resting vmHRV and cognition are discussed. © 2016 Society for Psychophysiological Research.

  15. Falls and falls efficacy: the role of sustained attention in older adults.

    Science.gov (United States)

    O'Halloran, Aisling M; Pénard, Nils; Galli, Alessandra; Fan, Chie Wei; Robertson, Ian H; Kenny, Rose Anne

    2011-12-19

    Previous evidence indicates that older people allocate more of their attentional resources toward their gait and that the attention-related changes that occur during aging increase the risk of falls. The aim of this study was to investigate whether performance and variability in sustained attention is associated with falls and falls efficacy in older adults. 458 community-dwelling adults aged ≥ 60 years underwent a comprehensive geriatric assessment. Mean and variability of reaction time (RT), commission errors and omission errors were recorded during a fixed version of the Sustained Attention to Response Task (SART). RT variability was decomposed using the Fast Fourier Transform (FFT) procedure, to help characterise variability associated with the arousal and vigilance aspects of sustained attention.The number of self-reported falls in the previous twelve months, and falls efficacy (Modified Falls Efficacy Scale) were also recorded. Significant increases in the mean and variability of reaction time on the SART were significantly associated with both falls (p older adults. An increase in omission errors was also associated with falls (p attention was a retrospective predictor of falling (p attention is strongly correlated with retrospective falls and to a lesser degree with reduced falls efficacy. This cognitive measure may provide a novel and valuable biomarker for falls in older adults, potentially allowing for early detection and the implementation of preventative intervention strategies.

  16. Frailty Is a Major Related Factor for at Risk of Malnutrition in Community-Dwelling Older Adults.

    Science.gov (United States)

    Chang, Shu-Fang

    2017-01-01

    We investigated the relationships among geriatric syndrome, physiological functions, and body composition in community-dwelling older people with varying nutritional statuses. Other factors correlated with nutritional status in community-dwelling older people were also explored. The World Health Organization has initiated preventive programs for addressing malnutrition. However, few studies have focused on the correlations among geriatric syndrome, physiological functions, and body composition in older people at risk of malnutrition. We conducted a cross-sectional study. Older people who lived in an urban Taiwanese community were recruited for this research study. The inclusion criteria were age 65 years or older, ability to communicate in Taiwanese, clear consciousness, and ability to communicate independently. The nutritional status of participants was evaluated with the Mini Nutritional Assessment-Short Form. The frailty status was assessed with the Study of Osteoporotic Fractures (SOF) index. The SOF index included the following three items: body weight loss of >5% within 1 year, difficulty in standing from a sitting position in a chair without an armrest five times, and feeling deprived of energy. Participants over 65 years of age, living in a community and without mental illness or acute disease were included in the study. Compared with well-nourished older adults, those at risk of malnutrition were predominantly male; presented with lower body weight, lower body mass index values, lower skeletal mass indices, and poorer muscle strength; and were unable to rise from a seated position in a chair without using the armrest five times. Subjects at risk of malnutrition were less energetic, were more commonly characterized as being sarcopenia, and demonstrated frailty. Body composition analysis demonstrated that a skeletal muscle index of approximately 9.93 and a body fat mass of less than 12.25 kg were related to an increased risk of malnutrition. Older people

  17. Problematic video game play in a college sample and its relationship to time management skills and attention-deficit/hyperactivity disorder symptomology.

    Science.gov (United States)

    Tolchinsky, Anatol; Jefferson, Stephen D

    2011-09-01

    Although numerous benefits have been uncovered related to moderate video game play, research suggests that problematic video game playing behaviors can cause problems in the lives of some video game players. To further our understanding of this phenomenon, we investigated how problematic video game playing symptoms are related to an assortment of variables, including time management skills and attention-deficit/hyperactivity disorder (ADHD) symptoms. Additionally, we tested several simple mediation/moderation models to better explain previous theories that posit simple correlations between these variables. As expected, the results from the present study indicated that time management skills appeared to mediate the relationship between ADHD symptoms and problematic play endorsement (though only for men). Unexpectedly, we found that ADHD symptoms appeared to mediate the relation between time management skills and problematic play behaviors; however, this was only found for women in our sample. Finally, future implications are discussed.

  18. Tracking performance under time sharing conditions with a digit processing task: A feedback control theory analysis. [attention sharing effect on operator performance

    Science.gov (United States)

    Gopher, D.; Wickens, C. D.

    1975-01-01

    A one dimensional compensatory tracking task and a digit processing reaction time task were combined in a three phase experiment designed to investigate tracking performance in time sharing. Adaptive techniques, elaborate feedback devices, and on line standardization procedures were used to adjust task difficulty to the ability of each individual subject and manipulate time sharing demands. Feedback control analysis techniques were employed in the description of tracking performance. The experimental results show that when the dynamics of a system are constrained, in such a manner that man machine system stability is no longer a major concern of the operator, he tends to adopt a first order control describing function, even with tracking systems of higher order. Attention diversion to a concurrent task leads to an increase in remnant level, or nonlinear power. This decrease in linearity is reflected both in the output magnitude spectra of the subjects, and in the linear fit of the amplitude ratio functions.

  19. A Bayesian computational basis for auditory selective attention using head rotation and the interaural time-difference cue.

    Directory of Open Access Journals (Sweden)

    Dillon A Hambrook

    Full Text Available The process of resolving mixtures of several sounds into their separate individual streams is known as auditory scene analysis and it remains a challenging task for computational systems. It is well-known that animals use binaural differences in arrival time and intensity at the two ears to find the arrival angle of sounds in the azimuthal plane, and this localization function has sometimes been considered sufficient to enable the un-mixing of complex scenes. However, the ability of such systems to resolve distinct sound sources in both space and frequency remains limited. The neural computations for detecting interaural time difference (ITD have been well studied and have served as the inspiration for computational auditory scene analysis systems, however a crucial limitation of ITD models is that they produce ambiguous or "phantom" images in the scene. This has been thought to limit their usefulness at frequencies above about 1khz in humans. We present a simple Bayesian model and an implementation on a robot that uses ITD information recursively. The model makes use of head rotations to show that ITD information is sufficient to unambiguously resolve sound sources in both space and frequency. Contrary to commonly held assumptions about sound localization, we show that the ITD cue used with high-frequency sound can provide accurate and unambiguous localization and resolution of competing sounds. Our findings suggest that an "active hearing" approach could be useful in robotic systems that operate in natural, noisy settings. We also suggest that neurophysiological models of sound localization in animals could benefit from revision to include the influence of top-down memory and sensorimotor integration across head rotations.

  20. Online Attention Training for Older Adults.

    Science.gov (United States)

    Wennberg, Alexandra; Kueider, Alexandra; Spira, Adam; Adams, Gregory; Rager, Robert; Rebok, George

    Evidence suggests that cognitive training interventions can improve older adults' cognitive performance. Successful training programs are adaptable and train multiple cognitive domains to target individual strengths and weaknesses. Computerized training programs are useful because they allow older adults to easily access training. This pilot study used an online attention training program, ATTENTION WORKOUT™, to enhance three aspects of attention- coordination, allocation, and selective focus -in community-dwelling older adults randomized to either an abbreviated (n=13) or an extended (n=17) practice training program over a 6-week period. Participants in the extended practice group significantly improved on selective focus reading distraction tasks with unrelated words (U=39.5; Z=-2.34; p=.02) and blanks (U=26.5; Z=-3.05; p=.002) as well as a matching attributes task (U=49.5; Z=-2.33; p=.02). The extended practice group significantly improved on three tasks of coordinating attention - radio-tuning (U=30; Z=-2.73; p=.01), circuit-breaker resetting (U=46; Z=-2.24; p=.03), and the combination of the two tasks (U=15; Z=-3.51; pattention training programs, like ATTENTION WORKOUT, can improve attention-related skills in community-dwelling older adults.

  1. Attention visuelle

    OpenAIRE

    Rousserie, Marie

    2015-01-01

    William James, philosophe et psychologue américain, est le premier à parler de l’attention en 1890 dans son livre The Principles of Psychology : il dit que c’est un concept connu mais dont personne ne saurait en donner une définition précise. Il la définit alors ainsi : « L'attention est la prise de possession par l'esprit, sous une forme claire et vive, d'un objet ou d'une suite de pensées parmi plusieurs qui semblent possibles […] Elle implique le retrait de certains objets afin de traiter ...

  2. The Study of the Differences of Attention Bias, Executive Functioning, and Reaction Time of Amphetamine Consumers in Comparison of Non Consumers

    Directory of Open Access Journals (Sweden)

    Nezamaldin Ghasemi

    2012-11-01

    Full Text Available Aim: Addiction to opium can be resulted to different effects. Current research designed in order to comprise if neuro-psychological functions among Amphetamine consumers and normal people. Method: Research design was causal-comparative design which performed in consumers and normal people. Research population was all opium consumers of Bahar city. Addict group included of 33 Amphetamine consumers who were referred to Baharestan addiction withdrawal center by snowball sampling. The comparison group included 39 normal people that matched with addict group with consideration of age, sex, education. All samples were studied by technical management of center and by using of perceptual diagnostic tests. Wisconsin cards, reaction time tests (simple, diagnostic, and selective and attention bias (Stroop was used. Results: the results of the research indicated that Amphetamine consumers were significantly different with normal people in consideration of error number, but there wasn’t significant difference on error in Wisconsin test. In reaction time Amphetamine consumers had least reaction time and highest number of errors, in three states. In simple trial there weren’t significant difference, but two groups were significant different in selective and diagnostic trial on time and number of errors. Also, there wasn’t significant difference on attention bias with consideration of error, but there was significant difference with consideration of time. Conclusion: on the basis of results it can be claimed Amphetamine consumption can be affected on neuro-cognitive functions. Identifying and understanding of these factors can be useful in better understanding of problem, and can be led to different therapeutic treatment.

  3. Primary evaluation of the radon situation in dwellings in Saxony by long-time integrating measurements, comparison of the results with short-time measurements and determination of the radon activity concentration in the ground of the land; Erstbewertung zur Radonsituation von Haeusern im Freistaat Sachsen mittels langzeitintegrierenden Messungen, Vergleich der Ergebnisse mit Kurzzeitmessungen und Erfassung der Radon-Aktivitaetskonzentration in der Bodenluft der Grundstuecke

    Energy Technology Data Exchange (ETDEWEB)

    Alisch-Mark, M.; Keck, D.; Preusse, W.; Taube, A.; Busch, H.; Heinrich, T. [Staatliche Betriebsgesellschaft fuer Umwelt und Landwirtschaft, Sachsen (Germany)

    2016-07-01

    A measurement program was carried out for primary evaluation of dwellings in terms of radon situation. Short-time measurements were compared with annual averages and checked for their suitability for forecasting the annual averages. In 89% of the cases studied, the average annual values could be predicted by short-time measurements, differences were observed depending on the date of the short-time measure. In addition, radon activity concentrations were determined in the soil air in the ground and compared with the expected areas of forecasting map of Saxony. Discrepancies were found primarily in areas which are marked by a smallscale geology. The data obtained showed that the geogenic radon potential and the year of construction of the house represent factors influencing the probability of exceedance of the reference value of 300 Bq/m{sup 3}.

  4. The relation between radon in schools and in dwellings: A case study in a rural region of Southern Serbia.

    Science.gov (United States)

    Žunić, Z S; Bossew, P; Bochicchio, F; Veselinovic, N; Carpentieri, C; Venoso, G; Antignani, S; Simovic, R; Ćurguz, Z; Udovicic, V; Stojanovska, Z; Tollefsen, T

    2017-02-01

    Recognized as a significant health hazard, radon (Rn) has been given increasing attention for years. Surveys of different kinds have been performed in many countries to assess the intensity and the geographical extent of possible Rn problems. Common surveys cover mainly dwellings, the indoor place with highest occupancy, and schools, where people spend a large fraction of their lifetime and which can also be considered exemplary for Rn exposure at workplaces; it has however been observed that relating them is difficult. It was unclear whether residential Rn at a location, or in a region, can be predicted by Rn at a school of that location, or vice versa. To current knowledge, no general rule seems applicable, as few models to describe the relationship between Rn in dwellings and in schools have been developed. In Southern Serbia, a Rn survey in a predominantly rural region was based on measurements in primary schools. The question arose whether or to which degree the results can be considered as indicative or even representative for residential Rn concentrations. To answer the question an additional survey of indoor Rn concentrations in dwellings was initiated, designed and performed in Sokobanja district in 2010-2012 in a manner to be able to detect a relationship if it exists. In the study region, 108 dwellings in 12 villages and towns were selected, with one primary school each. In this paper, we investigate how a relation between Rn in schools and dwellings could be identified and quantified, by developing a model and using experimental data from both the above main and additional surveys. The key criterion is the hypothesis that the relation dwellings - schools, if it exists, is stronger for dwellings closer to a school than for those dwellings further away. We propose methods to test the hypothesis. As result, the hypothesis is corroborated at 95% significance level. More specifically, on town level (typical size about 1 km), the Rn concentration ratio

  5. Attention Sensor

    NARCIS (Netherlands)

    Börner, Dirk; Kalz, Marco; Specht, Marcus

    2014-01-01

    This software sketch was used in the context of an experiment for the PhD project “Ambient Learning Displays”. The sketch comprises a custom-built attention sensor. The sensor measured (during the experiment) whether a participant looked at and thus attended a public display. The sensor was built

  6. Dwelling and Mobility in Postphenomenological Perspective

    DEFF Research Database (Denmark)

    Botin, Lars

    where it can live within familiar frameworks where we have arranged the various elements in a way that makes it meaningful and appropriate in relation to our physical being. Contemporary globalized reality is characterized by a request of flexibility and mobility where the individual is envisioned...... thinking and reflecting. The question is whether Post-phenomenology has potentials for re-installing the sense of place in relation to bodies, and furthermore can contribute on a tool level to appropriate solutions for design. The paper will present state of art research on mobility in a globalized world...... and relate this to major conceptualizations within Post-phenomenology: material hermeneutics, mediating technology and multi-stability. What does these concepts mean in relation to dwelling? Finally, is Heidegger right when he claims that in order to think we have to dwell? Keywords: Mobility, Dwelling, Post...

  7. Falls and falls efficacy: the role of sustained attention in older adults

    Directory of Open Access Journals (Sweden)

    O'Halloran Aisling M

    2011-12-01

    Full Text Available Abstract Background Previous evidence indicates that older people allocate more of their attentional resources toward their gait and that the attention-related changes that occur during aging increase the risk of falls. The aim of this study was to investigate whether performance and variability in sustained attention is associated with falls and falls efficacy in older adults. Methods 458 community-dwelling adults aged ≥ 60 years underwent a comprehensive geriatric assessment. Mean and variability of reaction time (RT, commission errors and omission errors were recorded during a fixed version of the Sustained Attention to Response Task (SART. RT variability was decomposed using the Fast Fourier Transform (FFT procedure, to help characterise variability associated with the arousal and vigilance aspects of sustained attention. The number of self-reported falls in the previous twelve months, and falls efficacy (Modified Falls Efficacy Scale were also recorded. Results Significant increases in the mean and variability of reaction time on the SART were significantly associated with both falls (p Conclusions Greater variability in sustained attention is strongly correlated with retrospective falls and to a lesser degree with reduced falls efficacy. This cognitive measure may provide a novel and valuable biomarker for falls in older adults, potentially allowing for early detection and the implementation of preventative intervention strategies.

  8. The reliability of eyetracking to assess attentional bias to threatening words in healthy individuals.

    Science.gov (United States)

    Skinner, Ian W; Hübscher, Markus; Moseley, G Lorimer; Lee, Hopin; Wand, Benedict M; Traeger, Adrian C; Gustin, Sylvia M; McAuley, James H

    2017-08-15

    Eyetracking is commonly used to investigate attentional bias. Although some studies have investigated the internal consistency of eyetracking, data are scarce on the test-retest reliability and agreement of eyetracking to investigate attentional bias. This study reports the test-retest reliability, measurement error, and internal consistency of 12 commonly used outcome measures thought to reflect the different components of attentional bias: overall attention, early attention, and late attention. Healthy participants completed a preferential-looking eyetracking task that involved the presentation of threatening (sensory words, general threat words, and affective words) and nonthreatening words. We used intraclass correlation coefficients (ICCs) to measure test-retest reliability (ICC > .70 indicates adequate reliability). The ICCs(2, 1) ranged from -.31 to .71. Reliability varied according to the outcome measure and threat word category. Sensory words had a lower mean ICC (.08) than either affective words (.32) or general threat words (.29). A longer exposure time was associated with higher test-retest reliability. All of the outcome measures, except second-run dwell time, demonstrated low measurement error ( .93). Recommendations are discussed for improving the reliability of eyetracking tasks in future research.

  9. Association of screen time with self-perceived attention problems and hyperactivity levels in French students: a cross-sectional study

    National Research Council Canada - National Science Library

    Montagni, Ilaria; Guichard, Elie; Kurth, Tobias

    2016-01-01

    .... We used the Attention Deficit Hyperactivity Disorder Self-Report Scale (ASRS-v1.1) concerning students' behaviour over the past 6 months to measure self-perceived levels of attention problems and hyperactivity...

  10. The Nature of Decision Making in the Practice of Dwelling

    DEFF Research Database (Denmark)

    Fyhn, Håkon; Baron, Nina

    2017-01-01

    There exists a political desire to make buildings more energy efficient and resilient to extreme weather. For existing private housing this is done through refurbishment and retrofitting. In response, various projects and policies aiming to influence decisions made by homeowners in relation...... of dwelling”. We see maintenance, refurbishment and reparations as part of an ongoing practice of dwelling. In this light, decision making is just one of many aspects that contribute to shaping the actions of homeowners when they invest time and money in their properties....

  11. 25 CFR 700.53 - Dwelling, replacement.

    Science.gov (United States)

    2010-04-01

    ... § 700.55. (b) May include existing dwellings for resale, new construction, modular homes, mobile homes... person if, after he receives a replacement housing payment and any available housing assistance payments... supplemental income payments received from public agencies. If the person's monthly income pattern is irregular...

  12. 517 DWELLING DENSITY VARIABILITY ACROSS GOVERNMENT ...

    African Journals Online (AJOL)

    Osondu

    Dolphin II. 576. 6. Iba. 2,388. 7. Iponri. 1,026. 8. Isolo. 3,664. 9. Ojokoro. 534. 10. Ebute-Meta. 528. 11. Femi Okunnu. 405. 12. Ijaiye. 796. Total. 17,679. Source: Iweka (2012). Aim and objectives. The aim of this study was to examine the variability of dwelling density among different classifications of LSDPC's multifamily.

  13. Mechanistic basis of temperature-dependent dwell fatigue in titanium alloys

    Science.gov (United States)

    Zheng, Zebang; Balint, Daniel S.; Dunne, Fionn P. E.

    2017-10-01

    The temperature-dependent dwell sensitivity of Ti-6242 and Ti-6246 alloys has been assessed over a temperature range from - 50∘ C to 390 °C using discrete dislocation plasticity which incorporates both thermal activation of dislocation escape from obstacles and slip transfer across grain boundaries. The worst-case load shedding in Ti-6242 alloy is found to be at or close to 120 °C under dwell fatigue loading, which diminishes and vanishes at temperatures lower than - 50∘ C or higher than 230 °C. Load shedding behaviour is predicted to occur in alloy Ti-6246 also but over a range of higher temperatures which are outside those relevant to in-service conditions. The key controlling dislocation mechanism with respect to load shedding in titanium alloys, and its temperature sensitivity, is shown to be the time constant associated with the thermal activation of dislocation escape from obstacles, with respect to the stress dwell time. The mechanistic basis of load shedding and dwell sensitivity in dwell fatigue loading is presented and discussed in the context of experimental observations.

  14. Functional Balance and Motor Impairment Correlations with Gait Parameters during Timed Up and Go Test across Three Attentional Loading Conditions in Stroke Survivors

    Directory of Open Access Journals (Sweden)

    Haidzir Manaf

    2014-01-01

    Full Text Available The aim of this study was to determine whether stroke survivor’s gait performance during dual-task Timed Up and Go (TUG test is correlated with the level of functional balance and motor impairment. Thirty stroke survivors (22 men, 8 women were recruited for this study. The level of functional balance (Berg Balance Scale and motor impairment (Fugl-Meyer assessment lower extremity were assessed prior to the TUG test. TUG test was conducted under three attentional loading conditions (single, dual motor, and dual-cognitive. The time and number of steps were used to quantify gait parameters. The Spearmen’s rank correlation coefficient was used to evaluate the relationship between these variables. There was moderate to strong negative correlation between functional balance and gait parameters (range −0.53 to −0.73, P<0.05. There was a weak negative correlation observed between the time taken to complete the single task and motor impairment (rs=-0.43; P=0.02 dual motor task and motor impairment (rs=-0.41; P=0.02. However, there were no significant correlations between lower limb motor impairment and the number of steps in all conditions. These findings suggest that functional balance may be an influential domain of successful dual-task TUG in stroke.

  15. Training on Movement Figure-Ground Discrimination Remediates Low-Level Visual Timing Deficits in the Dorsal Stream, Improving High-Level Cognitive Functioning, Including Attention, Reading Fluency, and Working Memory

    National Research Council Canada - National Science Library

    Teri Lawton; John Shelley-Tremblay

    2017-01-01

    ... (PATH to Reading neurotraining) acts to remediate visual timing deficits in the dorsal stream, thereby improving processing speed, reading fluency, and the executive control functions of attention and working memory...

  16. Mechanisms of attention for appetitive and aversive outcomes in Pavlovian conditioning.

    Science.gov (United States)

    Austin, A J; Duka, T

    2010-11-12

    Different mechanisms of attention controlling learning have been proposed in appetitive and aversive conditioning. The aim of the present study was to compare attention and learning in a Pavlovian conditioning paradigm using visual stimuli of varying predictive value of either monetary reward (appetitive conditioning; 10p or 50p) or blast of white noise (aversive conditioning; 97 dB or 102 dB). Outcome values were matched across the two conditions with regard to their emotional significance. Sixty-four participants were allocated to one of the four conditions matched for age and gender. All participants underwent a discriminative learning task using pairs of visual stimuli that signalled a 100%, 50%, or 0% probability of receiving an outcome. Learning was measured using a 9-point Likert scale of expectancy of the outcome, while attention using an eyetracker device. Arousal and emotional conditioning were also evaluated. Dwell time was greatest for the full predictor in the noise groups, while in the money groups attention was greatest for the partial predictor over the other two predictors. The progression of learning was the same for both groups. These findings suggest that in aversive conditioning attention is driven by the predictive salience of the stimulus while in appetitive conditioning attention is error-driven, when emotional value of the outcome is comparable. (c) 2010 Elsevier B.V. All rights reserved.

  17. Dwelling on Courtyards. Exploring the energy efficiency and comfort potential of courtyards for dwellings in the Netherlands

    Directory of Open Access Journals (Sweden)

    Mohammad Taleghani

    2014-11-01

    -S, except for the courtyard. To explore their microclimates the simulations were done for the hottest day in the Netherlands (19th June 2000 according to the temperature data set provided in NEN5060. The results showed that the singular forms provide a long duration of solar radiation exposure for the outdoor environment. This causes the worst comfort situation among the models at the centre of the canyon for a hot summer day. In contrast, the courtyard provides a more protected microclimate which has less solar radiation in summer. Considering the physiological equivalent temperature (PET, the courtyard has the highest number of comfortable hours on a summer day. Regarding the different orientations of the models and their effect on outdoor thermal comfort, it is difficult to specify the differences between the singular E-W and N-S forms because they receive equal amounts of insolation and are equally exposed to wind. Nevertheless, the linear E-W and N-S forms are different in their thermal behaviour. The centre point at the linear E-W form receives sun for about 12 h. In contrast, this point at the linear N-S form receives 4 h of direct sunlight in that day. Therefore, in comparison with the E-W orientation this N-S orientation provides a cooler microclimate. To sum up the above findings, it should be said that this study showed that courtyard buildings as a passive design solution (originally from hot and arid climates can improve energy efficiency and thermal comfort for Dutch dwellings. This building archetype can reduce energy demands for cooling, as a result being a good alternative form for the expected warmer future of the Netherlands. Designing small scale courtyards (single- family house needs attention in winter. Courtyards provide more indoor and outdoor comfort in comparison with linear and singular forms. With this knowledge, it could be said that design strategies taken from one climate may be applicable in other climates but with serious attentions and

  18. Dwelling on Courtyards. Exploring the energy efficiency and comfort potential of courtyards for dwellings in the Netherlands

    Directory of Open Access Journals (Sweden)

    Mohammad Taleghani

    2014-11-01

    -S, except for the courtyard. To explore their microclimates the simulations were done for the hottest day in the Netherlands (19th June 2000 according to the temperature data set provided in NEN5060. The results showed that the singular forms provide a long duration of solar radiation exposure for the outdoor environment. This causes the worst comfort situation among the models at the centre of the canyon for a hot summer day. In contrast, the courtyard provides a more protected microclimate which has less solar radiation in summer. Considering the physiological equivalent temperature (PET, the courtyard has the highest number of comfortable hours on a summer day. Regarding the different orientations of the models and their effect on outdoor thermal comfort, it is difficult to specify the differences between the singular E-W and N-S forms because they receive equal amounts of insolation and are equally exposed to wind. Nevertheless, the linear E-W and N-S forms are different in their thermal behaviour. The centre point at the linear E-W form receives sun for about 12 h. In contrast, this point at the linear N-S form receives 4 h of direct sunlight in that day. Therefore, in comparison with the E-W orientation this N-S orientation provides a cooler microclimate.To sum up the above findings, it should be said that this study showed that courtyard buildings as a passive design solution (originally from hot and arid climates can improve energy efficiency and thermal comfort for Dutch dwellings. This building archetype can reduce energy demands for cooling, as a result being a good alternative form for the expected warmer future of the Netherlands. Designing small scale courtyards (single- family house needs attention in winter. Courtyards provide more indoor and outdoor comfort in comparison with linear and singular forms. With this knowledge, it could be said that design strategies taken from one climate may be applicable in other climates but with serious attentions and

  19. Antifungal activity of thyme (Thymus vulgaris L.) essential oil and thymol against moulds from damp dwellings.

    Science.gov (United States)

    Segvić Klarić, M; Kosalec, I; Mastelić, J; Piecková, E; Pepeljnak, S

    2007-01-01

    To characterize antifungal activities of essential oil of thyme (Thymus vulgaris L.) and pure thymol, as comparative substance, on different mould species isolated from damp dwellings. Fifty samples of wall scrapes were collected from damp dwellings in Zagreb, the capital of Croatia. The members of the following mould genera were recovered from the samples: Aspergillus (44%), Penicillium (18%) Alternaria, Ulocladium, Absidia and Mucor (8%) Cladosporium, Trichoderma and Rhizopus (6%), and Chaetomium (2%). Two strains of Stachybotrys chartarum were isolated from damp dwellings in Slovakia. Antifungal activities of the thyme essential oil, which contains p-cymene (36.5%), thymol (33.0%) and 1,8-cineole (11.3%) as main components, and pure thymol were determined by the dilution method and exposure to vaporous phase of the oil. Minimum inhibitory concentrations (MIC) of both thymol and essential oil were bellow 20 microg ml(-1), except for Mucor spp. (50.20 microg ml(-1)). Thymol exhibited approximately three-times stronger inhibition than essential oil of thyme. The vaporous phase of the thyme essential oil (82 microg l(-1)) in glass chambers strongly suppressed the sporulation of moulds during 60 days of exposure. The thyme essential oil possesses a wide range spectrum of fungicidal activity. The vaporous phase of the oil exhibited long-lasting suppressive activity on moulds from damp dwellings. Essential oil of thyme and thymol could be used for disinfection of mouldy walls in the dwellings in low concentration.

  20. Attention and Recall of Point-of-sale Tobacco Marketing: A Mobile Eye-Tracking Pilot Study

    Directory of Open Access Journals (Sweden)

    Maansi Bansal-Travers

    2016-01-01

    Full Text Available  Introduction: As tobacco advertising restrictions have increased, the retail ‘power wall’ behind the counter is increasingly invaluable for marketing tobacco products. Objective: The primary objectives of this pilot study were 3-fold: (1 evaluate the attention paid/fixations on the area behind the cash register where tobacco advertising is concentrated and tobacco products are displayed in a real-world setting, (2 evaluate the duration (dwell-time of these fixations, and (3 evaluate the recall of advertising displayed on the tobacco power wall. Methods: Data from 13 Smokers (S and 12 Susceptible or non-daily Smokers (SS aged 180–30 from a mobile eye-tracking study. Mobile-eye tracking technology records the orientation (fixation and duration (dwell-time of visual attention. Participants were randomized to one of three purchase tasks at a convenience store: Candy bar Only (CO; N = 10, Candy bar + Specified cigarette Brand (CSB; N = 6, and Candy bar + cigarette Brand of their Choice (CBC; N = 9. A post-session survey evaluated recall of tobacco marketing. Key outcomes were fixations and dwell-time on the cigarette displays at the point-of-sale. Results: Participants spent a median time of 44 seconds during the standardized time evaluated and nearly three-quarters (72% fixated on the power wall during their purchase, regardless of smoking status (S: 77%, SS: 67% or purchase task (CO: 44%, CSB: 71%, CBC: 100%. In the post session survey, nearly all participants (96% indicated they noticed a cigarette brand and 64% were able to describe a specific part of the tobacco wall or recall a promotional offer. Conclusions: Consumers are exposed to point-of-sale tobacco marketing, regardless of smoking status. FDA should consider regulations that limit exposure to point-of-sale tobacco marketing among consumers.

  1. Invasion by Exotic Earthworms Alters Biodiversity and Communities of Litter- and Soil-dwelling Oribatid Mites

    Directory of Open Access Journals (Sweden)

    John C. Maerz

    2011-03-01

    Full Text Available Exotic earthworms are drivers of biotic communities in invaded North American forest stands. Here we used ecologically important oribatid mite (Arachnida: Acari communities, as model organisms to study the responses of litter- and soil-dwelling microarthropod communities to exotic earthworm invasion in a northern temperate forest. Litter- and soil-dwelling mites were sampled in 2008–2009 from forest areas: (1 with no earthworms; (2 those with epigeic and endogeic species, including Lumbricus rubellus Hoffmeister; and (3 those with epigeic, endogeic, and anecic earthworms including L. terrestris L. Species richness and diversity of litter- and soil-dwelling (0–2 cm soil depth oribatid mites was 1–2 times higher in sites without earthworms than in sites with worms. Similarly, litter-dwelling oribatid mites were between 72 and 1,210 times more abundant in earthworm-free sites than in sites with worms. Among earthworm invaded sites, abundance of litter-dwelling oribatid mites in sites without the anecic L. terrestris was twice as high in May and 28 times higher in October, compared to sites with L. terrestris. Species richness, diversity, and abundance of oribatid mites were greater in litter-layers than in the soil-layers that showed a varied response to earthworm invasion. Species compositions of both litter- and soil-dwelling oribatid mite communities of forests with no earthworms were markedly different from those with earthworms. We conclude that exotic earthworm invasions are associated with significant declines of species diversity, numbers, and compositional shifts in litter- and soil-inhabiting communities. These faunal shifts may contribute to earthworm effects on soil processes and food web dynamics in historically earthworm-free, northern temperate forests.

  2. Effects of Short-Term Training of Community-Dwelling Elderly with Modular Interactive Tiles

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop; Jessen, Jari Due

    2014-01-01

    Objective: The objective of this study is to test for the increased mobility, agility, balancing, and general fitness of community-dwelling elderly individuals as a result of short-term training involving playing with modular interactive tiles (Entertainment Robotics, Odense, Denmark) at two...... community activity centers for the elderly. Three different tests from the Senior Fitness Test were used in order to test a variety of health parameters of the community-dwelling elderly, including those parameters related to fall prevention. Materials and Methods: Eighteen community-dwelling elderly...... centers for the elderly. Data were collected using pre-tests and post-tests of the 6-Minute Walk Test (6MWT), the 8-foot Timed Up & Go Test (TUG), and the Chair-Stand Test (CS). Data were analyzed for statistically significant differences and increases of means. Results: The 6MWT, TUG, and CS measurements...

  3. Effect of music on pain for home-dwelling persons with dementia.

    Science.gov (United States)

    Park, Heeok

    2010-09-01

    The purpose of this study was to investigate the effect of music on pain for home-dwelling persons with dementia. A quasiexperimental design was used. Fifteen subjects listened to their preferred music for 30 minutes before peak agitation time, for 2 days per week, followed by no music for 2 weeks. The process was repeated once. The finding of this study showed that mean pain levels after listening to music were significantly lower than before listening to the music (t=2.21, df=28; p music intervention to control pain for home-dwelling persons with dementia.

  4. Attention and reading skills.

    Science.gov (United States)

    Commodari, Elena; Guarnera, Maria

    2005-04-01

    Attention plays a critical role in information processing. Its adequate functioning is required for correct development of complex cognitive abilities and regular scholastic progress. Children with attention deficits often have difficulties in reading, writing, and arithmetic. The present study investigated interactions among reading skills, overall scholastic performance as rated by teachers, and components of attention: visual reaction time, simple immediate span of attention, and selectivity. The sample was 98 students in the first and second years of public junior high school (age range 11-14 years, M = 12.6, SD = 1.2), i.e., with expected already well-established reading. Reading was evaluated using Comprehension, Accuracy, and Speed tests. Overall scholastic performance was obtained by means of teachers' ratings. Simple Reaction Time, Digit Span, and Color-Word Interference, included in a multitask computerized test, assessed attention. Analysis confirmed the hypothesis that the reading skills are strongly predictive of the Scholastic Assessment rated by the teachers. High scholastic ratings were correlated with Reading Speed and Accuracy rather than Reading Comprehension. Poor readers showed worse performances on the Digit Span test which measures simple immediate span of attention. Good and poor readers obtained a similar score on the Color-Word Interference task. This observation seems to contrast with the more common interpretation of this effect, suggesting that reading is an automatic process and, therefore, the semantic dimension overcomes the controlled perceptual one. According to other studies, an alternative explanation is suggested. In conclusion, present results confirm the hypothesis of a strong link among reading speed and accuracy, scholastic assessment as rated by teachers, simple immediate span of attention, and visual reaction time.

  5. Active and passive cooling methods for dwellings

    DEFF Research Database (Denmark)

    Oropeza-Perez, Ivan; Østergaard, Poul Alberg

    2018-01-01

    studies or with a simulation modelling, an assessment of temperature drop of each cooling method within a standard-size dwelling is carried out. Also, a comparison of initial investment, energy consumption, maintenance, retrofitting and required space is done. Thereafter, with this information, a decision...... ventilation, controlled ventilation, roof coating and eco-evaporative cooling are the most suitable passive methods for an extensive use in this country....

  6. Uncertainty analysis of energy consumption in dwellings

    Energy Technology Data Exchange (ETDEWEB)

    Pettersen, Trine Dyrstad

    1997-12-31

    This thesis presents a comprehensive study of an energy estimation model that can be used to examine the uncertainty of predicted energy consumption in a dwelling. The variation and uncertainty of input parameters due to the outdoor climate, the building construction and the inhabitants are studied as a basis for further energy evaluations. The occurring variations of energy consumption in nominal similar dwellings are also investigated due to verification of the simulated energy consumption. The main topics are (1) a study of expected variations and uncertainties in both input parameters used in energy consumption calculations and the energy consumption in the dwelling, (2) the development and evaluation of a simplified energy calculation model that considers uncertainties due to the input parameters, (3) an evaluation of the influence of the uncertain parameters on the total variation so that the most important parameters can be identified, and (4) the recommendation of a simplified procedure for treating uncertainties or possible deviations from average conditions. 90 refs., 182 figs., 73 tabs.

  7. EFFECTS OF NATURAL AND FORCED BASEMENT VENTILATION ON RADON LEVELS IN SINGLE FAMILY DWELLINGS

    Science.gov (United States)

    The report gives, for the first time, results of an extensive study of the effect of ventilation on radon concentrations and radon entry rate in a single-family dwelling. Measurements of radon concentrations, building dynamics, and environmental parameters made in Princeton Unive...

  8. A comparison of the effects of reboxetine and placebo on reaction time in adults with Attention Deficit-Hyperactivity Disorder (ADHD

    Directory of Open Access Journals (Sweden)

    D Ghodsi

    2011-07-01

    Full Text Available   Objective:Some studies have demonstrated that Reaction Time (RT is longer in patients with ADHD which in turn may be associated with educational and occupational impairment and increased driving risks. Any alteration on RT which is induced by the treatment in this population may have great consequences positively or negatively. This study was designed to examine the effects of reboxetine on RT in adults with Attention Deficit-Hyperactivity Disorder (ADHD. Methods:A total of 30 adult patients with ADHD who did not suffer from any other major psychiatric disorder were eligible to participate in this double blind, placebo controlled study. Patients were randomly assigned to receive either reboxetine (4 mg/day for one week, then 8 mg/day or placebo for 4 weeks. RT was assessed at baseline and after 4 weeks by validated software which collects and analyses the data for auditory and visual stimulants. Numbers of correct responses, omission and substitution errors for each stimulus were calculated. Results:Regarding visual tasks and in comparison with baseline scores, the number of correct responses increased significantly and the number of omission errors decreased significantly after 4 weeks of treatment (P<0.05 in both groups. However, with regard to auditory tasks scores, no significant differences were found at the end of the study compared to the baseline in each of the two groups. Additionally, no significant differences were noted between the two groups when both visual and auditory tasks were considered. Conclusion:Results of this study showed that reboxetine did not affect the RT of the patients when both visual and auditory tasks were assessed. Further studies with larger number of patients and for a longer period of time are required to confirm the result of this study.

  9. Recoil-deposited Po-210 in radon dwellings

    Energy Technology Data Exchange (ETDEWEB)

    Samuelsson, C.

    1990-12-31

    Short-lived decay products of Rn-222 plate out on all surfaces in a house containing radon gas. Following the subsequent alpha decays of the mother nuclei, the daughter products Pb-214 and Pb-210 are superficially and permanently absorbed. Due to its long half-life (22 y) the activity of absorbed Pb-210 accumulates in the surface. The activity of Pb-210, or its decay products, can thus reflect the past randon daughter and plate-out history of a house over several decades. Our results and experience from measurements of Po-210 and Rn-222 in 22 dwellings will be presented. In these studies the Po-210 surface activity of one plane glass sheet per dwelling (window panes were not used) has been determined and compared with the period of exposure times the mean radon concentration measured over a two-month period. Considering the large uncertainty in the integrated radon exposure estimate the surface {sup 210}Po correlates well (r=0.73) with the accumulated radon exposure. The {sup 210}Po activity of the glass samples has been measured non-destructively using an open-flow pulse ionization chamber and this detector has also been successfully applied in field exercises.

  10. Recoil-deposited Po-210 in radon dwellings

    Energy Technology Data Exchange (ETDEWEB)

    Samuelsson, C.

    1990-01-01

    Short-lived decay products of Rn-222 plate out on all surfaces in a house containing radon gas. Following the subsequent alpha decays of the mother nuclei, the daughter products Pb-214 and Pb-210 are superficially and permanently absorbed. Due to its long half-life (22 y) the activity of absorbed Pb-210 accumulates in the surface. The activity of Pb-210, or its decay products, can thus reflect the past randon daughter and plate-out history of a house over several decades. Our results and experience from measurements of Po-210 and Rn-222 in 22 dwellings will be presented. In these studies the Po-210 surface activity of one plane glass sheet per dwelling (window panes were not used) has been determined and compared with the period of exposure times the mean radon concentration measured over a two-month period. Considering the large uncertainty in the integrated radon exposure estimate the surface {sup 210}Po correlates well (r=0.73) with the accumulated radon exposure. The {sup 210}Po activity of the glass samples has been measured non-destructively using an open-flow pulse ionization chamber and this detector has also been successfully applied in field exercises.

  11. Psychopathic traits are associated with reduced attention to the eyes of emotional faces among adult male non-offenders.

    Science.gov (United States)

    Gillespie, Steven M; Rotshtein, Pia; Wells, Laura J; Beech, Anthony R; Mitchell, Ian J

    2015-01-01

    Psychopathic traits are linked with impairments in emotional facial expression recognition. These impairments may, in part, reflect reduced attention to the eyes of emotional faces. Although reduced attention to the eyes has been noted among children with conduct problems and callous-unemotional traits, similar findings are yet to be found in relation to psychopathic traits among adult male participants. Here we investigated the relationship of primary (selfish, uncaring) and secondary (impulsive, antisocial) psychopathic traits with attention to the eyes among adult male non-offenders during an emotion recognition task. We measured the number of fixations, and overall dwell time, on the eyes, and the mouth of male and female faces showing the six basic emotions at varying levels of intensity. We found no relationship of primary or secondary psychopathic traits with recognition accuracy. However, primary psychopathic traits were associated with a reduced number of fixations, and lower overall dwell time, on the eyes relative to the mouth across expressions, intensity, and sex. Furthermore, the relationship of primary psychopathic traits with attention to the eyes of angry and fearful faces was influenced by the sex and intensity of the expression. We also showed that a greater number of fixations on the eyes, relative to the mouth, were associated with increased accuracy for angry and fearful expression recognition. These results are the first to show effects of psychopathic traits on attention to the eyes of emotional faces in an adult male sample, and may support amygdala based accounts of psychopathy. These findings may also have methodological implications for clinical studies of emotion recognition.

  12. Psychopathic traits are associated with reduced attention to the eyes of emotional faces among adult male non-offenders

    Directory of Open Access Journals (Sweden)

    Steven Mark Gillespie

    2015-10-01

    Full Text Available Psychopathic traits are linked with impairments in emotional facial expression recognition. These impairments may, in part, reflect reduced attention to the eyes of emotional faces. Although reduced attention to the eyes has been noted among children with conduct problems and callous-unemotional traits, similar findings are yet to be found in relation to psychopathic traits among adult male participants. Here we investigated the relationship of primary (selfish, uncaring and secondary (impulsive, antisocial psychopathic traits with attention to the eyes among adult male non-offenders during an emotion recognition task. We measured the number of fixations, and overall dwell time, on the eyes and the mouth of male and female faces showing the six basic emotions at varying levels of intensity. We found no relationship of primary or secondary psychopathic traits with recognition accuracy. However, primary psychopathic traits were associated with a reduced number of fixations, and lower overall dwell time, on the eyes relative to the mouth across expressions, intensity, and sex. Furthermore, the relationship of primary psychopathic traits with attention to the eyes of angry and fearful faces was influenced by the sex and intensity of the expression. We also showed that a greater number of fixations on the eyes, relative to the mouth, was associated with increased accuracy for angry and fearful expression recognition. These results are the first to show effects of psychopathic traits on attention to the eyes of emotional faces in an adult male sample, and may support amygdala based accounts of psychopathy. These findings may also have methodological implications for clinical studies of emotion recognition.

  13. Occupant behavior and energy consumption in dwellings: An analysis of behavioral models and actual energy consumption in the dutch housing stock

    Directory of Open Access Journals (Sweden)

    Merve Bedir

    2017-11-01

    Full Text Available Much is known about the increasing levels of energy consumption and environmental decay caused by the built environment. Also, more and more attention is shown to the energy consumption of dwellings, from the early design stage until the occupants start living in them. The increasing complexity of building technologies, the occupants’ preferences, and their needs and demands make it difficult to achieve the aimed energy consumption levels. The goal of reducing the energy consumption of dwellings and understanding the share of occupant behavior in it form the context of this research. Several studies have demonstrated the ‘energy performance gap’ between the calculated and the actual energy consumption levels of buildings, and have explored the reasons for it. The energy performance gap is either caused by calculation drawbacks, uncertainties of modeling weather conditions, construction defects regarding air tightness and insulation levels, or by occupant behavior. This research focuses on the last aspect, i.e. analyzing the relationship between occupant behavior and energy consumption in dwellings, understanding the determinants of energy consumption, and finding occupants’ behavioral patterns. There are several dimensions of occupant behavior and energy consumption of dwellings: dwelling characteristics including the energy and indoor comfort management systems, building envelope, lighting and appliances; occupant characteristics including the social, educational and economical; and actual behavior, including the control of heating, ventilation and lighting of spaces, and appliance use, hot water use, washing, bathing, and cleaning. Attempting to understand this complexity asks for a methodology that covers both quantitative and qualitative methods; and both cross-sectional and longitudinal data collection, working interdisciplinary among the domains of design for sustainability, environmental psychology, and building and design

  14. Concepts for evaluation of sound insulation of dwellings

    DEFF Research Database (Denmark)

    Rasmussen, Birgit; Rindel, Jens Holger

    2005-01-01

    Legal sound insulation requirements have existed more than 50 years in some countries, and single-number quantities for evaluation of sound insulation have existed nearly as long time. However, the concepts have changed considerably over time from simple arithmetic averaging of frequency bands......¬ments and classification schemes revealed significant differences of concepts. The paper summarizes the history of concepts, the disadvantages of the present chaos and the benefits of consensus concerning concepts for airborne and impact sound insulation between dwellings and airborne sound insulation of facades...... with a trend towards light-weight constructions are contradictory and challenging. This calls for exchange of data and experience, implying a need for harmonized concepts, including use of spectrum adaptation terms. The paper will provide input for future discussions in EAA TC-RBA WG4: "Sound insulation...

  15. Neural substrates of behavioral variability in attention deficit hyperactivity disorder: based on ex-Gaussian reaction time distribution and diffusion spectrum imaging tractography.

    Science.gov (United States)

    Lin, H-Y; Gau, S S-F; Huang-Gu, S L; Shang, C-Y; Wu, Y-H; Tseng, W-Y I

    2014-06-01

    Increased intra-individual variability (IIV) in reaction time (RT) across various tasks is one ubiquitous neuropsychological finding in attention deficit hyperactivity disorder (ADHD). However, neurobiological underpinnings of IIV in individuals with ADHD have not yet been fully delineated. The ex-Gaussian distribution has been proved to capture IIV in RT. The authors explored the three parameters [μ (mu), σ (sigma), τ (tau)] of an ex-Gaussian RT distribution derived from the Conners' continuous performance test (CCPT) and their correlations with the microstructural integrity of the frontostriatal-caudate tracts and the cingulum bundles. We assessed 28 youths with ADHD (8-17 years; 25 males) and 28 age-, sex-, IQ- and handedness-matched typically developing (TD) youths using the CCPT, Wechsler Intelligence Scale for Children, 3rd edition and magnetic resonance imaging (MRI). Microstructural integrity, indexed by generalized fractional anisotropy (GFA), was measured by diffusion spectrum imaging tractrography on a 3-T MRI system. Youths with ADHD had larger σ (s.d. of Gaussian distribution) and τ (mean of exponential distribution) and reduced GFA in four bilateral frontostriatal tracts. With increased inter-stimulus intervals of CCPT, the magnitude of greater τ in ADHD than TD increased. In ADHD youths, the cingulum bundles and frontostriatal integrity were associated with three ex-Gaussian parameters and with μ (mean of Gaussian distribution) and τ, respectively; while only frontostriatal GFA was associated with μ and τ in TD youths. Our findings suggest the crucial role of the integrity of the cingulum bundles in accounting for IIV in ADHD. Involvement of different brain systems in mediating IIV may relate to a distinctive pathophysiological processing and/or adaptive compensatory mechanism.

  16. Chewing and Attention: A Positive Effect on Sustained Attention

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Hirano

    2015-01-01

    Full Text Available Chewing is crushing food not only to aid swallowing and digestion, but also to help stress relief and regulate cognitive function, especially in attention. It is well known that chewing gum is used for sleepiness prevention during work, learning, and driving, suggesting a link between chewing and sustained attention. We hypothesized that chewing elevates attention and/or alertness, leading to improvements in cognitive performance. We carried out a systematic review of the PubMed database. We inspected the attributes of effects on attention in studies investigating the effects of chewing on attention or alertness conducted with pre-post design in healthy subjects, except elderly. We identified 151 references, 22 of which were included: 14 (64% showed positive attributes of effects on attention, 1 (5% showed negative attributes of effects on attention, 5 (23% showed both positive and negative attributes of effects on attention, and 2 (9% showed no significant attributes of effects on attention. Thus, positive attributes of effects of chewing on attention, especially on sustained attention, were shown in over half of the reports. These effects also appeared with improvement in mood and stress relief and were influenced by time-on-task effect. Further studies are needed, but chewing could be useful for modifying cognitive function.

  17. Chewing and attention: a positive effect on sustained attention.

    Science.gov (United States)

    Hirano, Yoshiyuki; Onozuka, Minoru

    2015-01-01

    Chewing is crushing food not only to aid swallowing and digestion, but also to help stress relief and regulate cognitive function, especially in attention. It is well known that chewing gum is used for sleepiness prevention during work, learning, and driving, suggesting a link between chewing and sustained attention. We hypothesized that chewing elevates attention and/or alertness, leading to improvements in cognitive performance. We carried out a systematic review of the PubMed database. We inspected the attributes of effects on attention in studies investigating the effects of chewing on attention or alertness conducted with pre-post design in healthy subjects, except elderly. We identified 151 references, 22 of which were included: 14 (64%) showed positive attributes of effects on attention, 1 (5%) showed negative attributes of effects on attention, 5 (23%) showed both positive and negative attributes of effects on attention, and 2 (9%) showed no significant attributes of effects on attention. Thus, positive attributes of effects of chewing on attention, especially on sustained attention, were shown in over half of the reports. These effects also appeared with improvement in mood and stress relief and were influenced by time-on-task effect. Further studies are needed, but chewing could be useful for modifying cognitive function.

  18. Falls and falls efficacy: the role of sustained attention in older adults

    LENUS (Irish Health Repository)

    O'Halloran, Aisling M

    2011-12-19

    Abstract Background Previous evidence indicates that older people allocate more of their attentional resources toward their gait and that the attention-related changes that occur during aging increase the risk of falls. The aim of this study was to investigate whether performance and variability in sustained attention is associated with falls and falls efficacy in older adults. Methods 458 community-dwelling adults aged ≥ 60 years underwent a comprehensive geriatric assessment. Mean and variability of reaction time (RT), commission errors and omission errors were recorded during a fixed version of the Sustained Attention to Response Task (SART). RT variability was decomposed using the Fast Fourier Transform (FFT) procedure, to help characterise variability associated with the arousal and vigilance aspects of sustained attention. The number of self-reported falls in the previous twelve months, and falls efficacy (Modified Falls Efficacy Scale) were also recorded. Results Significant increases in the mean and variability of reaction time on the SART were significantly associated with both falls (p < 0.01) and reduced falls efficacy (p < 0.05) in older adults. An increase in omission errors was also associated with falls (p < 0.01) and reduced falls efficacy (p < 0.05). Upon controlling for age and gender affects, logistic regression modelling revealed that increasing variability associated with the vigilance (top-down) aspect of sustained attention was a retrospective predictor of falling (p < 0.01, OR = 1.14, 95% CI: 1.03 - 1.26) in the previous year and was weakly correlated with reduced falls efficacy in non-fallers (p = 0.07). Conclusions Greater variability in sustained attention is strongly correlated with retrospective falls and to a lesser degree with reduced falls efficacy. This cognitive measure may provide a novel and valuable biomarker for falls in older adults, potentially allowing for early detection and the implementation of preventative intervention

  19. Self-Rated Attentiveness Interacts with Transcranial Direct Current Stimulation and Noise Stimulation in Reaction Time in a Go/No-Go Task.

    Science.gov (United States)

    Sikström, Sverker; Jürgensen, Anna-Maria; Haghighi, Maryam; Månsson, Daniel; Smidelik, David; Habekost, Thomas

    2016-01-01

    Previous research has found that stimulating inattentive people with auditory white noise induces enhancement in cognitive performance. This enhancement is believed to occur due to a statistical phenomenon called stochastic resonance, where noise increases the probability of a signal passing the firing threshold in the neural cells. Here we investigate whether people with low attentiveness benefit to a larger extent than attentive people from stimulation by auditory white noise and transcranial direct current stimulation (tDCS). The results show, for both auditory noise and tDCS stimulation, that the changes in performance relative to nonstimulation correlate with the degree of attentiveness in a Go/No-Go task, but not in a N-back task. These results suggest that the benefit of tDCS may interact with inattentiveness.

  20. On the origin of event-related potentials indexing covert attentional selection during visual search: timing of selection by macaque frontal eye field and event-related potentials during pop-out search.

    Science.gov (United States)

    Purcell, Braden A; Schall, Jeffrey D; Woodman, Geoffrey F

    2013-01-01

    Event-related potentials (ERPs) have provided crucial data concerning the time course of psychological processes, but the neural mechanisms producing ERP components remain poorly understood. This study continues a program of research in which we investigated the neural basis of attention-related ERP components by simultaneously recording intracranially and extracranially from macaque monkeys. Here, we compare the timing of attentional selection by the macaque homologue of the human N2pc component (m-N2pc) with the timing of selection in the frontal eye field (FEF), an attentional-control structure believed to influence posterior visual areas thought to generate the N2pc. We recorded FEF single-unit spiking and local field potentials (LFPs) simultaneously with the m-N2pc in monkeys performing an efficient pop-out search task. We assessed how the timing of attentional selection depends on task demands by direct comparison with a previous study of inefficient search in the same monkeys (e.g., finding a T among Ls). Target selection by FEF spikes, LFPs, and the m-N2pc was earlier during efficient pop-out search rather than during inefficient search. The timing and magnitude of selection in all three signals varied with set size during inefficient but not efficient search. During pop-out search, attentional selection was evident in FEF spiking and LFP before the m-N2pc, following the same sequence observed during inefficient search. These observations are consistent with the hypothesis that feedback from FEF modulates neural activity in posterior regions that appear to generate the m-N2pc even when competition for attention among items in a visual scene is minimal.

  1. [Health inequities in mood disorders based on material and social deprivation in dwelling sectors ].

    Science.gov (United States)

    Vanasse, Alain; Courteau, Josiane; Lesage, Alain; Fleury, Marie-Josée; Grégoire, Jean-Pierre; Moisan, Jocelyne; Lauzier, Sophie; Bergeron, Claude

    2012-12-01

    To compare mood disorder (MD) prevalence in Quebec in 2006, and compare health services and medication use, mortality and morbidity in patients with MD based on sex and the dwelling sector level of material and social deprivation. The objective was also to identify subgroups of individuals using health services in a larger proportion and having a higher risk of morbidity and mortality. We conducted a secondary analysis of the Régie de l’assurance maladie du Québec medico-administrative data. The cohort is composed of adults diagnosed with MD and living in Quebec in 2006. Variables include: physician consultation, medication demand, consultation for substance or alcohol abuse, emergency visit, hospitalization for a mental disorder, and death. Dwelling sector types are defined by crossing Pampalon material and social deprivation quintiles. MD prevalence in 2006 was 3.06% (177 850 patients), with prevalence in women 1.7-fold with respect to men. Findings show a higher MD prevalence as well as a higher mortality and morbidity rate in materially and socially deprived dwelling sectors. Young men also represent a specifically vulnerable subgroup for many study variables. Public policies aimed at improving material conditions (income, education, employment) and breaking out social isolation would have an important impact on the population mental health. Public health program development should pay close attention to young men population.

  2. Indoor air mycoflora of residential dwellings in Jos metropolis.

    Science.gov (United States)

    Ayanbimpe, G M; Wapwera, S D; Kuchin, D

    2010-06-01

    The quality of air in the environment where one lives or works can have potential effects on human health. There are strong indications that in many parts of the world, our homes, schools and workplaces are heavily contaminated with air-borne molds and other biological contaminants. This study was carried out to assess the level of fungal contamination of indoor air, health related experiences of residents, and the prevalent fungi species in the homes. The investigation was done between May 2005 and January 2006, using structured questionnaires and the agar plate exposure. 150 houses from 14 locations were examined. 380 fungi belonging to 10 species were isolated, Chaetomium globosum (17%), Aspergillus fumigatus (14%), Stachybotrys alternans (14%) and Alternaria alternata (14%) being the predominant isolates. The indoor air quality of residential dwellings in Jos is poor. Rate of isolation of fungi was not significantly different in the wet and dry periods of the year and residential density affected the occurrence of fungal contaminants. Residents are displeased with fungal presence in their homes and the associated health implications. There is need for proper attention to the quality of the indoor environment.

  3. Indoor air quality in energy-efficient dwellings: Levels and sources of pollutants.

    Science.gov (United States)

    Derbez, M; Wyart, G; Le Ponner, E; Ramalho, O; Ribéron, J; Mandin, C

    2017-09-28

    Worldwide, public policies are promoting energy-efficient buildings and accelerating the thermal renovation of existing buildings. The effects of these changes on the indoor air quality (IAQ) in these buildings remain insufficiently understood. In this context, a field study was conducted in 72 energy-efficient dwellings to describe the pollutants known to be associated with health concerns. Measured parameters included the concentrations of 19 volatile organic compounds and aldehydes, nitrogen dioxide, particulate matter (PM2.5 ), radon, temperature, and relative humidity. The air stuffiness index and night-time air exchange rate were calculated from the monitored carbon dioxide (CO2 ) concentrations. Indoor and outdoor measurements were performed at each dwelling during 1 week in each of the two following seasons: heating and non-heating. Moreover, questionnaires were completed by the occupants to characterize the building, equipment, household, and occupants' habits. Perspective on our results was provided by previous measurements made in low-energy European dwellings. Statistical comparisons with the French housing stock and a pilot study showed higher concentrations of terpenes, that is, alpha-pinene and limonene, and hexaldehyde in our study than in previous studies. Alpha-pinene and hexaldehyde are emitted by wood or wood-based products used for the construction, insulation, decoration, and furnishings of the dwellings, whereas limonene is more associated with discontinuous sources related to human activities. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. More attention must be paid: the neurobiology of attentional effort.

    Science.gov (United States)

    Sarter, Martin; Gehring, William J; Kozak, Rouba

    2006-08-01

    Increases in attentional effort are defined as the motivated activation of attentional systems in response to detrimental challenges on attentional performance, such as the presentation of distractors, prolonged time-on-task, changing target stimulus characteristics and stimulus presentation parameters, circadian phase shifts, stress or sickness. Increases in attentional effort are motivated by the expected performance outcome; in the absence of such motivation, attentional performance continues to decline or may cease altogether. The beneficial effects of increased attentional effort are due in part to the activation of top-down mechanisms that act to optimize input detection and processing, thereby stabilizing or recovering attentional performance in response to challenges. Following a description of the psychological construct "attentional effort", evidence is reviewed indicating that increases in the activity of cortical cholinergic inputs represent a major component of the neuronal circuitry mediating increases in attentional effort. A neuronal model describes how error detection and reward loss, indicating declining performance, are integrated with motivational mechanisms on the basis of neuronal circuits between prefrontal/anterior cingulate and mesolimbic regions. The cortical cholinergic input system is activated by projections of mesolimbic structures to the basal forebrain cholinergic system. In prefrontal regions, increases in cholinergic activity are hypothesized to contribute to the activation of the anterior attention system and associated executive functions, particularly the top-down optimization of input processing in sensory regions. Moreover, and influenced in part by prefrontal projections to the basal forebrain, increases in cholinergic activity in sensory and other posterior cortical regions contribute directly to the modification of receptive field properties or the suppression of contextual information and, therefore, to the mediation of

  5. Structural Properties of Dwelling and Thermal Comfort in Tropical ...

    African Journals Online (AJOL)

    The structural properties of dwelling units, in particular “window types” in 1, 250 apartments and their indoor temperature levels were collected. One hypothesis was formulated: (HO) There is no significant variation in effective temperature index and thus thermal comfort between dwellings built with wooden windows and ...

  6. Survey of Ground Dwelling Arthropods Associated with Two Habitat ...

    African Journals Online (AJOL)

    Little is known about the species composition and ecology of ground dwelling arthropods of Zoological Gardens. Thus, this study was aimed to investigate the species abundance and diversity of ground dwelling arthropods associated with Gallery forest and Rocky outcrop of the Jos Museum Zoological Garden Jos Plateau ...

  7. Positions of human dwellings affect few tropical diseases near ...

    African Journals Online (AJOL)

    Some factors that possibly affect tropical disease distribution was investigated in about 500 randomize human dwellings. The studied factors include wild animals, domestic animals, wild plants, cultivated plants, nature of soil, nature of water, positions of human dwellings, nature of building material and position of animal ...

  8. 24 CFR 990.140 - Occupied dwelling units.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Occupied dwelling units. 990.140... Eligible Unit Months § 990.140 Occupied dwelling units. A PHA is eligible to receive operating subsidy for public housing units for each unit month that those units are under an ACC and occupied by a public...

  9. The meaning of dwelling features : Conceptual and methodological issues

    NARCIS (Netherlands)

    Coolen, H.C.C.H.

    2008-01-01

    This study is about the meaning of dwelling features. It relates the research areas of housing preferences and the meaning of a dwelling with each other and with aspects of the means-end approach as applied in marketing research. It results in a conceptual and methodological framework for studying

  10. The Effect of High Versus Low Teacher Affect and Passive Versus Active Student Activity During Music Listening on Preschool Children's Attention, Piece Preference, Time Spent Listening, and Piece Recognition.

    Science.gov (United States)

    Sims, Wendy L.

    1986-01-01

    Small-group listening lessons and subsequent individual posttests were used to judge 94 three- through five-year-old subjects' attention, paired-comparison piece preference, time spent listening, and piece recognition. Research procedures included a modified multiple baseline design and split-screen video taping of instructional sessions.…

  11. The Attention Cascade Model and Attentional Blink

    Science.gov (United States)

    Shih, Shui-I

    2008-01-01

    An attention cascade model is proposed to account for attentional blinks in rapid serial visual presentation (RSVP) of stimuli. Data were collected using single characters in a single RSVP stream at 10 Hz [Shih, S., & Reeves, A. (2007). "Attentional capture in rapid serial visual presentation." "Spatial Vision", 20(4), 301-315], and single words,…

  12. Functional modular architecture underlying attentional control in aging.

    Science.gov (United States)

    Monge, Zachary A; Geib, Benjamin R; Siciliano, Rachel E; Packard, Lauren E; Tallman, Catherine W; Madden, David J

    2017-07-15

    Previous research suggests that age-related differences in attention reflect the interaction of top-down and bottom-up processes, but the cognitive and neural mechanisms underlying this interaction remain an active area of research. Here, within a sample of community-dwelling adults 19-78 years of age, we used diffusion reaction time (RT) modeling and multivariate functional connectivity to investigate the behavioral components and whole-brain functional networks, respectively, underlying bottom-up and top-down attentional processes during conjunction visual search. During functional MRI scanning, participants completed a conjunction visual search task in which each display contained one item that was larger than the other items (i.e., a size singleton) but was not informative regarding target identity. This design allowed us to examine in the RT components and functional network measures the influence of (a) additional bottom-up guidance when the target served as the size singleton, relative to when the distractor served as the size singleton (i.e., size singleton effect) and (b) top-down processes during target detection (i.e., target detection effect; target present vs. absent trials). We found that the size singleton effect (i.e., increased bottom-up guidance) was associated with RT components related to decision and nondecision processes, but these effects did not vary with age. Also, a modularity analysis revealed that frontoparietal module connectivity was important for both the size singleton and target detection effects, but this module became central to the networks through different mechanisms for each effect. Lastly, participants 42 years of age and older, in service of the target detection effect, relied more on between-frontoparietal module connections. Our results further elucidate mechanisms through which frontoparietal regions support attentional control and how these mechanisms vary in relation to adult age. Copyright © 2017 Elsevier Inc. All

  13. Short-Dwell Cycling Intraperitoneal Cefazolin Plus Ceftazidime in Peritoneal Dialysis Patients.

    Science.gov (United States)

    Peerapornratana, Sadudee; Chariyavilaskul, Pajaree; Kanjanabuch, Talerngsak; Praditpornsilpa, Kearkiat; Eiam-Ong, Somchai; Katavetin, Pisut

    2017-01-01

    ♦ BACKGROUND: Current guidelines suggest that intraperitoneal (IP) antibiotics should be administered only in a long peritoneal dialysis (PD) dwell (≥ 6 hours). The long dwell might result in low ultrafiltration and volume overload. We aim to examine plasma and dialysate concentration of cefazolin and ceftazidime after IP administration in a short-dwell (≤ 2 hours) automated cycling exchange. ♦ METHODS: Stable PD patients without peritonitis were invited to participate in the present study. Patients underwent 5 2-liter exchanges of PD fluid over 10 hours by the PD cycling machine without last fill or additional dwell. Cefazolin and ceftazidime (20 mg/kg each) were added to the first 5-liter bag of 2.5% dextrose PD fluid that was placed on the warmer of the PD cycling machine. Plasma samples were collected at 12 time-points over 24 hours. Dialysate samples from each exchange were also collected. Antibiotic concentrations in plasma and dialysate were then determined by high-performance liquid chromatography (HPLC). ♦ RESULTS: Six stable PD patients without peritonitis participated in the study. Dialysate cefazolin and ceftazidime were consistently high throughout the PD session in all patients (26 - 360 mg/L). Plasma cefazolin and ceftazidime exceeded the minimal inhibitory concentration (MIC) for susceptible organisms (≤ 8 mg/L) within 2 hours (cefazolin 28.5 ± 8.0 and ceftazidime 12.5 ± 3.4 mg/L), peak at 10 hours (51.1 ± 14.1 and 23.0 ± 5.2 mg/L) and sustained well above the MIC at 24 hours (42.0 ± 9.6 and 17.1 ± 3.1 mg/L). ♦ CONCLUSIONS: The short-dwell cycling IP cefazolin and ceftazidime could provide adequate plasma concentration for up to 24 hours. Daily short-dwell cycling IP cefazolin and ceftazidime might be used to treat peritonitis in PD patients already using a PD cycling machine as well as selected continuous ambulatory PD (CAPD) patients who need shorter dwells during peritonitis due to increasing peritoneal solute transport

  14. Ability to negotiate stairs predicts free-living physical activity in community-dwelling people with stroke: an observational study.

    Science.gov (United States)

    Alzahrani, Matar Abdullah; Dean, Catherine M; Ada, Louise

    2009-01-01

    Which clinical measures of walking performance best predict free-living physical activity in community-dwelling people with stroke? Cross-sectional observational study. 42 community-dwelling stroke survivors. Predictors were four clinical measures of walking performance (speed, automaticity, capacity, and stairs ability). The outcome of interest was free-living physical activity, measured as frequency (activity counts) and duration (time on feet), collected using an activity monitor called the Intelligent Device for Energy Expenditure and Physical Activity. Time on feet was predicted by stairs ability alone (B 166, 95% CI 55 to 278) which accounted for 48% of the variance. Activity counts were also predicted by stairs ability alone (B 6486, 95% CI 2922 to 10 050) which accounted for 58% of the variance. The best predictor of free-living physical activity in community-dwelling people with stroke was stairs ability.

  15. Effects of presession attention on the frequency of attention-maintained behavior.

    OpenAIRE

    O'Reilly, M F

    1999-01-01

    The effect of prior attention was systematically manipulated to study its influence on rates of yelling and head hitting, both maintained by positive reinforcement in the form of attention. Higher levels of head hitting occurred in analogue attention conditions when the person was deprived of attention (no social interactions for 1 hr) prior to the analysis in comparison to when the person received high levels of attention (attention delivered on a fixed-time 30-s schedule for 1 hr) prior to ...

  16. Wind turbine sound pressure level calculations at dwellings.

    Science.gov (United States)

    Keith, Stephen E; Feder, Katya; Voicescu, Sonia A; Soukhovtsev, Victor; Denning, Allison; Tsang, Jason; Broner, Norm; Leroux, Tony; Richarz, Werner; van den Berg, Frits

    2016-03-01

    This paper provides calculations of outdoor sound pressure levels (SPLs) at dwellings for 10 wind turbine models, to support Health Canada's Community Noise and Health Study. Manufacturer supplied and measured wind turbine sound power levels were used to calculate outdoor SPL at 1238 dwellings using ISO [(1996). ISO 9613-2-Acoustics] and a Swedish noise propagation method. Both methods yielded statistically equivalent results. The A- and C-weighted results were highly correlated over the 1238 dwellings (Pearson's linear correlation coefficient r > 0.8). Calculated wind turbine SPLs were compared to ambient SPLs from other sources, estimated using guidance documents from the United States and Alberta, Canada.

  17. Health-related quality of life in Brazilian community-dwelling and institutionalized elderly: Comparison between genders.

    Science.gov (United States)

    Cucato, Gabriel Grizzo; Ritti-Dias, Raphael Mendes; Cendoroglo, Maysa Seabra; Carvalho, José Maria Maluf DE; Nasri, Fábio; Costa, Maria Luiza Monteiro; Matos, Luciana Diniz Nagem Janot DE; Franco, Fábio Gazelato DE Mello

    2016-12-01

    To compare the health-related quality of life (HRQL) indicators between institutionalized and community-dwelling elderly men and women. This was a cross-sectional study with a sample of 496 elderly men and women, surveyed by researchers at a private hospital that attends institutionalized and community-dwelling elderly. HRQL (World Health Organization Quality of Life), daily living activities (Katz questionnaire), and instrumental daily living activities (Lawton questionnaire), mini-mental state examination, handgrip strength test, and function capacity (timed up and go test) were obtained. Institutionalized men presented higher scores in physical and psychological domains of HRQL compared to elderly men living alone (p<0.05). Among women, the scores in all domains (physical, psychological, relationship, and environment) were similar between institutionalized and community-dwelling individuals. Institutionalized elderly men reported better scores in physical and psychological domains of HRQL compared to their community-dwelling pairs, while both institutionalized and community-dwelling elderly women presented similar HRQL.

  18. Dwelling on memorability : Effects of long-term picture memorability on the attentional blink

    NARCIS (Netherlands)

    Nieuwenstein, Mark; Linde, Maximilian; van Rijn, Hedderik

    2016-01-01

    Although people have an extraordinary ability to recognize and remember pictures of visual scenes, there are also large and consistent differences in how well different pictures are remembered (Isola et al., 2014). What determines a picture’s worth in memorability is not fully understood. Here, we

  19. Predicting the probability of falls in community-dwelling elderly individuals using the trail-walking test

    OpenAIRE

    Yamada, Minoru; Ichihashi, Noriaki

    2010-01-01

    Background Falling is a common problem in the fast-growing elderly population. Multitasking or engaging in two or more activities at the same time is common in daily living. Objective To determine the usefulness of the trail-walking test (TWT) for predicting a fall in community-dwelling elderly individuals. Methods This was a prospective study in which the TWT was used to evaluate the risk of falling among a group of community-dwelling elderly individuals (n = 171) with a mean age of 80.5 ± 5...

  20. Vegetated fauna overpass enhances habitat connectivity for forest dwelling herpetofauna

    Directory of Open Access Journals (Sweden)

    Mel E. McGregor

    2015-07-01

    Full Text Available The ecological impact of roads and traffic is now widely acknowledged, with a variety of mitigation strategies such as purpose designed fauna underpasses and overpasses commonly installed to facilitate animal movement. Despite often being designed for larger mammals, crossing structures appear to enable safe crossings for a range of smaller, ground dwelling species that exhibit high vulnerability to roads. Less attention has been paid to the extent to which fauna overpasses function as habitat in their own right, an issue particularly relevant to reptiles and amphibians. The Compton Road fauna array (Brisbane, Australia includes a vegetated fauna overpass which connects two urban forest reserves and traverses a major four lane arterial road. The aim of this study was to quantify the extent to which colonisation of the Compton Road fauna overpass by reptile and amphibian species living in adjacent forests occurred. Pitfall sampling at seven sampling sites occurred between June 2005 and February 2010, starting approximately six months after overpass construction, with additional observational detections throughout this period. The overpass yielded higher species diversity and capture rates compared with the forest areas. Species accumulation curves demonstrated a strong and consistent colonisation rate of the overpass throughout the six year monitoring period, while persistent occupation by species on the overpass throughout the six years suggests permanent colonisation of the vegetated structure as an extension of the natural forest habitat. These outcomes demonstrate that the fauna overpass at Compton Road provides suitable habitat for diverse local herpetofauna communities and suggest enhanced habitat connectivity across the road.

  1. Assembly patterns of soil-dwelling lichens after glacier retreat in the European Alps.

    Science.gov (United States)

    Nascimbene, Juri; Mayrhofer, Helmut; Dainese, Matteo; Bilovitz, Peter Othmar

    2017-06-01

    To assess the spatial-temporal dynamics of primary succession following deglaciation in soil-dwelling lichen communities. European Alps (Austria, Switzerland and Italy). Five glacier forelands subjected to relevant glacier retreat during the last century were investigated. In each glacier foreland, three successional stages were selected at increasing distance from the glacier, corresponding to a gradient of time since deglaciation between 25 and 160 years. In each successional stage, soil-dwelling lichens were surveyed within five 1 × 1 m plots. In addition to a classical ecological framework, based on species richness and composition, we applied a functional approach to better elucidate community assembly mechanisms. A positive relationship was found between species richness and time since deglaciation indicating that richer lichen communities can be found at increasing terrain ageing. This pattern was associated with compositional shifts, suggesting that different community assemblages can be found along the successional stages. The analysis of β-diversity revealed a significant nested pattern of species assemblages along the gradient (i.e. earlier successional stages hosted a subset of the species already established in older successional stages), while the turnover component was less relevant. Considering functional groups, we found contrasting patterns in relation to time since deglaciation: the incidence of species with a cyanobacterial photobiont and those reproducing by spores decreased, while that of species reproducing by vegetative propagules increased. This study reveals that community assembly patterns of soil-dwelling lichens in alpine glacier forelands are ruled by mechanisms of directional species accumulation and trait selection that involve a trade-off between different functional strategies. Functional traits that reflect the dispersal and adaptation capability of the species underpin the colonization success of soil-dwelling lichens in

  2. The duration of disgusted and fearful faces is judged longer and shorter than that of neutral faces: the attention-related time distortions as revealed by behavioral and electrophysiological measurements

    Directory of Open Access Journals (Sweden)

    Dandan eZhang

    2014-08-01

    Full Text Available Time perception has been shown to be altered by emotions. This study employed event-related potentials (ERPs to examine the effects of two threat-related emotions on the judgment of time intervals in the range of 490-910 ms. We demonstrated that disgust and fear have distinct influences on time perception. At the behavioral level, disgusted faces were estimated longer and fearful faces were estimated shorter (i.e., the generalization gradient for the disgusted faces was shifted left while the generalization gradient for the fearful faces was shifted right when compared with neutral faces. Accordingly, the contingent negative variation, an online ERP index of timing, displayed larger area in disgust and smaller area in fear conditions when compared with neutral condition (disgust = 1.94 ± 2.35 μV•s, neutral = 1.40 ± 2.5 μV•s, and fear = 1.00 ± 2.26 μV•s. These findings indicated that specific neural mechanisms may underlie the attention effects of different subtypes of threat-related emotions on timing; compared with neutral faces, fearful faces are likely to attract more attentional resources while disgusted faces may attract less attentional resources for emotional processing. The major contribution of the current study is to provide neural correlates of fear vs. disgust divergence in the aspect of time perception and to demonstrate beyond the behavioral level that the categorization of threat-related emotions should be refined so to highlight the adaptability of the human defense system.

  3. Distributed interactive communication in simulated space-dwelling groups.

    Science.gov (United States)

    Brady, Joseph V; Hienz, Robert D; Hursh, Steven R; Ragusa, Leonard C; Rouse, Charles O; Gasior, Eric D

    2004-03-01

    This report describes the development and preliminary application of an experimental test bed for modeling human behavior in the context of a computer generated environment to analyze the effects of variations in communication modalities, incentives and stressful conditions. In addition to detailing the methodological development of a simulated task environment that provides for electronic monitoring and recording of individual and group behavior, the initial substantive findings from an experimental analysis of distributed interactive communication in simulated space dwelling groups are described. Crews of three members each (male and female) participated in simulated "planetary missions" based upon a synthetic scenario task that required identification, collection, and analysis of geologic specimens with a range of grade values. The results of these preliminary studies showed clearly that cooperative and productive interactions were maintained between individually isolated and distributed individuals communicating and problem-solving effectively in a computer-generated "planetary" environment over extended time intervals without benefit of one another's physical presence. Studies on communication channel constraints confirmed the functional interchangeability between available modalities with the highest degree of interchangeability occurring between Audio and Text modes of communication. The effects of task-related incentives were determined by the conditions under which they were available with Positive Incentives effectively attenuating decrements in performance under stressful time pressure. c2003 Elsevier Ltd. All rights reserved.

  4. Radon in Estonian dwellings - Results from a National Radon Survey

    Energy Technology Data Exchange (ETDEWEB)

    Pahapill, Lia; Rulkov, Anne; Rajamaee, Raivo [Estonian Radiation Protection Centre (Kiirguskeskus), Tallinn (Spain); Aakerblom, Gustav [Swedish Radiation Protection Authority, Stockholm (Sweden)

    2003-10-01

    A countrywide survey of radon concentrations in Estonian dwellings was carried out during the period 1998-2001. The survey formed a part of the cooperation program on radiation protection between the Estonian Radiation Protection (Kiirguskeskus) Centre and the Swedish Radiation Protection Authority (SSI). The survey included measurements in a number of dwellings representative for Estonia in detached houses and multifamily buildings (only dwellings on the bottom floor were included in the survey). Altogether, radon concentrations were measured in 515 dwellings, a number large enough to be statistically significant. All measurements were made with alphatrack film detectors of the same type that SSI uses in Sweden. The measurements were made during a 2-3 month period during the winter half-year. Two detectors were used in each dwelling. In Estonia there are 0.17 million dwellings in detached houses and 0.45 million in multi apartment buildings. Of the 1.26 million inhabitants in Estonia. 0.36 million live in detached houses and 0.90 million in multi apartment buildings. Most of the latter were built during the Soviet occupation. Of the dwellings in multifamily buildings 30 % are assumed to be situated on the first floor. The mean radon concentration in dwellings in detached hoses, according to the survey results, is 103 Bq/m{sup 3}, in dwellings on the bottom floor in multi apartment buildings it is 78 Bq/m{sup 3}. In 1% of the dwellings the radon concentration exceeded 400 Bq/m{sup 3}. The highest radon concentration found in the study was 1040 Bq/m{sup 3}. Based on the assumption that the average radon concentration in the dwellings in multi-apartment buildings that are not situated on the bottom floor is 30 Bq/m{sup 3}, and that these dwellings constitute 70% of all dwellings in multi apartment buildings, the mean radon concentration in dwellings in multi apartment buildings is calculated to be 44 Bq/m{sup 3}. The mean value for all Estonia dwellings is calculated

  5. Association of symptoms of attention-deficit/hyperactivity disorder with physical activity, media time, and food intake in children and adolescents.

    Directory of Open Access Journals (Sweden)

    Andreas W A van Egmond-Fröhlich

    Full Text Available INTRODUCTION: The aim of the study was to assess the association between attention deficit/hyperactivity disorder (ADHD symptoms and potentially obesogenic behaviors. METHODS: Data of 11,676 German children and adolescents (6-17 years were analyzed. Television/video exposure, physical activity, food frequency and portion size were assessed using questionnaires. A dietary quality index, energy density and volumes of consumed food, and total energy intake were calculated. The parent-rated hyperactivity/inattention subscale of the Strengths and Difficulties Questionnaire (SDQ-HI was used as a continuous measure of ADHD symptoms. Associations were analyzed with general linear models adjusting for sex, age, socioeconomic status, migrant status, parental BMI, and parental smoking. RESULTS: SDQ-HI scores correlated positively with physical activity, average energy density of food, volume of beverages, total energy intake, and television exposure and negatively with the nutritional quality score (HuSKY even after adjustment for parental variables (BMI, smoking, socioeconomic status, migrant status, age, sex, as well as the other SDQ subscales. The adjusted association of the SDQ-HI scores with the nutritional quality score was stronger in girls and the associations with food volume, food energy, and total energy intake was significant only in girls. CONCLUSIONS: Poor nutritional quality, high energy intake and television exposure appear to be independently associated with ADHD symptoms. The relationship between food energy intake and ADHD symptoms was especially pronounced in girls and this may help to explain the reported association of ADHD symptoms with overweight in adolescent girls.

  6. Combining segmentation and attention: a new foveal attention model

    Directory of Open Access Journals (Sweden)

    Rebeca eMarfil

    2014-08-01

    Full Text Available Artificial vision systems cannot process all the information that they receive from the world in real time because it is highly expensive and inefficient in terms of computational cost. Inspired by biological perception systems, articial attention models pursuit to select only the relevant part of the scene. Besides, it is well established that the units of attention on human vision are not merely spatial but closely related to perceptual objects (proto-objects. This implies a strong bidirectional relationship between segmentation and attention processes. Therefore, while the segmentation process is the responsible to extract the proto-objects from the scene, attention can guide segmentation, arising the concept of foveal attention. When the focus of attention is deployed from one visual unit to another, the rest of the scene is perceived but at a lower resolution that the focused object. The result is a multi-resolution visual perception in which the fovea, a dimple on the central retina, provides the highest resolution vision. In this paper, a bottom-up foveal attention model is presented. In this model the input image is a foveal image represented using a Cartesian Foveal Geometry (CFG, which encodes the field of view of the sensor as a fovea (placed in the focus of attention surrounded by a set of concentric rings with decreasing resolution. Then multirresolution perceptual segmentation is performed by building a foveal polygon using the Bounded Irregular Pyramid (BIP. Bottom-up attention is enclosed in the same structure, allowing to set the fovea over the most salient image proto-object. Saliency is computed as a linear combination of multiple low level features such us colour and intensity contrast, symmetry, orientation and roundness. Obtained results from natural images show that the performance of the combination of hierarchical foveal segmentation and saliency estimation is good in terms of accuracy and speed.

  7. Adaptive thermal comfort opportunities for dwellings: Providing thermal comfort only when and where needed in dwellings in the Netherlands

    Directory of Open Access Journals (Sweden)

    Noortje Alders

    2016-08-01

    different approach to the comfort boundaries used in modern standards was introduced, creating insight in the spread in activity patterns and the comfort demand in the context of individual preferences and vulnerabilities. Information of sociology and thermal comfort studies were brought together creating occupancy and thermal comfort profiles for the Dutch situation. By recognizing the differences in occupancy patterns it becomes possible to design adaptive systems to be able to deliver the comfort demanded only when and where necessary in different occupancy scenarios. This is an opportunity to achieve a significantly better energy performance. Furthermore, a method for dynamic analysis of weather conditions related to the thermal comfort was proposed in order to map the opportunities and threats of weather change. This makes the system able to seize upon every reasonably to be expected situation to create an optimal dynamic filter for the outdoor to indoor thermal environment at any time and place. This preliminary study was performed by presuming a simple shelter that can create shielding from wind and solar radiation without any form of thermal storage or insulation. In this study it is emphasised that there is no need for active cooling in the residential sector of the Netherlands if the dwelling is well designed; blocking solar radiation when needed and to allow built up excess heat to be discarded. An inventory is provided of the possibilities for adaptivity for a thermal comfort system which are used in common practice and which improvements and new techniques can be implemented to increase these possibilities for adaptivity of the Adaptive Thermal Comfort System.  2. The effect of applying the detailed information and adaptive opportunities framed in step 1 on the energy saving and comfort delivery of the Thermal Comfort Systems was researched. Firstly, the most appropriate calculation methods for the research were determined comparing various levels of detail

  8. Adaptive thermal comfort opportunities for dwellings: Providing thermal comfort only when and where needed in dwellings in the Netherlands

    Directory of Open Access Journals (Sweden)

    Noortje Alders

    2016-08-01

    .A different approach to the comfort boundaries used in modern standards was introduced, creating insight in the spread in activity patterns and the comfort demand in the context of individual preferences and vulnerabilities. Information of sociology and thermal comfort studies were brought together creating occupancy and thermal comfort profiles for the Dutch situation. By recognizing the differences in occupancy patterns it becomes possible to design adaptive systems to be able to deliver the comfort demanded only when and where necessary in different occupancy scenarios. This is an opportunity to achieve a significantly better energy performance.Furthermore, a method for dynamic analysis of weather conditions related to the thermal comfort was proposed in order to map the opportunities and threats of weather change. This makes the system able to seize upon every reasonably to be expected situation to create an optimal dynamic filter for the outdoor to indoor thermal environment at any time and place. This preliminary study was performed by presuming a simple shelter that can create shielding from wind and solar radiation without any form of thermal storage or insulation.In this study it is emphasised that there is no need for active cooling in the residential sector of the Netherlands if the dwelling is well designed; blocking solar radiation when needed and to allow built up excess heat to be discarded.An inventory is provided of the possibilities for adaptivity for a thermal comfort system which are used in common practice and which improvements and new techniques can be implemented to increase these possibilities for adaptivity of the Adaptive Thermal Comfort System. 2. The effect of applying the detailed information and adaptive opportunities framed in step 1 on the energy saving and comfort delivery of the Thermal Comfort Systems was researched.Firstly, the most appropriate calculation methods for the research were determined comparing various levels of detail and

  9. Attention as foraging for information and value

    OpenAIRE

    Manohar, Sanjay G.; Husain, Masud

    2013-01-01

    What is the purpose of attention? One avenue of research has led to the proposal that attention might be crucial for gathering information about the environment, while other lines of study have demonstrated how attention may play a role in guiding behavior to rewarded options. Many experiments that study attention require participants to make a decision based on information acquired discretely at one point in time. In real-world situations, however, we are usually not presented with informati...

  10. Attention as foraging for information and reward

    OpenAIRE

    Manohar, Sanjay G.; Masud eHusain

    2013-01-01

    What is the purpose of attention? One avenue of research has led to the proposal that attention might be crucial for gathering information about the environment, while other lines of study have demonstrated attention's role in guiding behavior to rewarded options. Many experiments to study attention require participants to make a decision based on information acquired discretely at one point in time. In real-world situations, however, we are usually not presented with information about wh...

  11. Delta Activity at Sleep Onset and Cognitive Performance in Community-Dwelling Older Adults.

    Science.gov (United States)

    Kawai, Makoto; Beaudreau, Sherry A; Gould, Christine E; Hantke, Nathan C; Jordan, Josh T; O'Hara, Ruth

    2016-04-01

    Frontal intermittent rhythmic delta activity (FIRDA) has long been considered to be an abnormal variant in the electroencephalogram (EEG) among older adults. Prior work also indicates a predominance of slow wave EEG activity among patients with dementia. However, instability of state control occurring with aging generally and among many neurodegenerative diseases raises the possibility that FIRDA might represent the intrusion of sleep related elements of the EEG into the waking state. We examined delta activity at sleep onset (DASO) in community-dwelling, older adults without dementia, and examined whether this activity is related to poorer cognitive performance. 153 community-dwelling, older adults without dementia underwent overnight polysomnography and measures of global cognition, delayed verbal memory, information processing speed, attention, inhibition, verbal naming, and visuospatial ability. Delta activity during sleep/wake transitions (scored either as Waking or N1) was analyzed visually. Participants were 83 women and 70 men, mean age 71.3 ± 0.6 y. DASO was present in 30 participants (19.6%). Age, years of education, sex, and body mass index did not differ between DASO (+) and (-) groups. Multiple regression analyses indicated faster reading of the Stroop color words in DASO (+) subjects (P = 0.007). None of the other cognitive domains differed between the two groups. DASO was relatively common in our sample of community-dwelling, older adults without dementia. DASO was not associated with poorer performance on any cognitive domain. Instead, individuals with DASO demonstrated better performance on a simple reading task. Although these findings suggest that an abnormal EEG activity may represent normal variation, our work underscores the importance of distinguishing DASO from FIRDA when examining sleep in older adults. A commentary on this article appears in this issue on page 725. © 2016 Associated Professional Sleep Societies, LLC.

  12. Attention Mosaics: Studies of Organizational Attention

    OpenAIRE

    Carvalho de Mesquita Ferreira, Luciana

    2010-01-01

    textabstractOrganizational studies emphasizing the role of attention in organizational behavior depart from the idea that organizations, like individuals, have limited capacity to attend to environmental stimuli. The bounded capacity of the organizations to respond to stimuli is conditioned by the limited cognitions of individuals and by the limited capability of organizations to distribute, coordinate and integrate those cognitions. The cross-level nature of organizational attention, its dua...

  13. TRPA1 Mechanoreceptors Mediate the IL-6 Response to a Single PD Dwell in the Rat.

    Science.gov (United States)

    Nilsson, Daniel; Jennische, Eva; Cavallini, Nicola; Braide, Magnus

    2017-01-01

    The development of modern, biocompatible peritoneal dialysis (PD) fluids has not entirely eliminated the local pro-inflammatory effects of PD fluid administration. The present study was performed in order to establish the importance of known signaling pathways connected to mechano-, osmo- and chemo-sensors of the transient receptor potential (TRP) family for the acute inflammatory response to PD. Rats were exposed to a single 4-hour dwell of lactate-buffered, 2.5% glucose, filter-sterilized PD fluid through an implanted PD catheter. In some groups, the PD dwell was preceded by intravenous administration of blockers of TRPV1 (BCTC), TRPA1 (HC030031), or neurokinin 1 (NK1) (Spantide II) receptors. Cytokine messenger ribonucleic acid (mRNA) expressions were quantified in tissue biopsies (real-time polymerase chain reaction [qPCR]), and cytokine concentrations were quantified in dialysate samples by enzyme-linked immunosorbent assay (ELISA). Tissue expressions of TRPV1, TRPA1, and NK1 were evaluated immuno-histochemically. The PD dwell induced peritoneal synthesis of Il1b, Tnf, and Il6 and a secretion of interleukin-6 (IL-6) into the dialysate. The catheter implantation already induced the transcription of Il1b and Tnf but did not significantly affect Il6 transcription. The Il6 response to the PD dwell could be virtually eliminated by blocking TRPA1 but was not affected by TRPV1 blockade. Blocking the substance P receptor, NK1, produced an insignificant trend towards Il6 inhibition. TRPA1 and NK1 showed a stronger immuno-reactivity than TRPV1 on cells of the peritoneal tissue. The results show that IL-6 synthesis and secretion were connected to acute PD fluid exposure, and this response was triggered by TRPA1 receptors, possibly located to non-neuronal cells. Copyright © 2017 International Society for Peritoneal Dialysis.

  14. Prefrailty in community-dwelling older adults is associated with nutrition status.

    Science.gov (United States)

    Chang, Shu-Fang; Lin, Pei-Ling

    2016-02-01

    This study investigated the differences of demographic characteristics and nutrition status between prefrail and nonfrail older adults. Meanwhile, the factors related to the nutrition status of community-dwelling older adults were also studied. The World Health Organisation has actively developed prevention programmes to address geriatric frailty. However, few previous studies have focused on the relationship between prefrailty and nutrition status. This study adopted a cross-sectional and correlational research design. Community-dwelling older adults were recruited for this study. The participants' nutrition status was assessed using the Mini-Nutritional Assessment tool, and their frailty status was evaluated based on the Study of Osteoporotic Fractures indicators. The Study of Osteoporotic Fractures criteria comprise the following three items: >5% loss in total body weight within one year; inability to rise five times from a chair without assistance and a self-reported lack of energy. Inclusion criteria were age ≥65 years, living independently at home and exhibiting neither mental impairment nor acute disease. Data were gathered from 152 participants; most were men, lived alone and had a level of education lower than elementary school. Multiple linear regressions were used to evaluate the association between variables and nutritional status, the results of which revealed that prefrailty and body mass index were independently related to the participants' nutrition status. The results showed that nutritional assessment can be employed with community-dwelling older adults. In particular, prefrailty and body mass index were key factors that affected nutritional status in older adults. Community nurses must understand the risk factors related to nutritional status in community-dwelling older people. If nurses use this approach, prefrail older adults are likely to experience improved confidence in maintaining their health and a decreased incidence of frailty and

  15. [Functional limitation and survival of community dwelling elderly].

    Science.gov (United States)

    Maciel, Alvaro Campos Cavalcanti; Guerra, Ricardo Oliveira

    2008-01-01

    The present study aims to analyze the functional limitation as risk factor of death of elderly dwelling in a community and its relationship with socio-demographic, physical health and neuropsychiatric related factors. A prospective study was carried out in the city of Santa Cruz, Rio Grande do Norte, Brasil. A total of 310 randomly selected elderly formed the baseline (63.5% women, 73.7+/-9.03 years). The Katz Index was used to evaluate the functional capacity for basic activities of daily living. The follow-up period was of 53 months. The statistical methods used were bivariate analysis (Pearson's chi-square), survival analysis by the Kaplan-Meyer method, followed by Cox regression in multivariate analysis, with the respective hazards ratios (HR). A total of 60 elderly (20.5%) died during the study follow-up; the main cause of death was cardiovascular disease. The mean survival time was of about 24.8 months, and the main risk factors identified at Cox regression were cognitive deficit (HR= 4.30) and stroke (HR= 3.49) besides the dependence for the basic activities of daily living (HR = 3.17). The functional limitation was an independent risk factor for death.

  16. Mechanisms of Perceptual Attention

    National Research Council Canada - National Science Library

    Dosher, Barbara

    2000-01-01

    .... Attention may affect the perceived clarity of visual displays and improve performance. In this project, a powerful external noise method was developed to identify and characterize the effect of attention on perceptual performance in visual tasks...

  17. Mechanism of Perceptual Attention

    National Research Council Canada - National Science Library

    Lu, Zhong-Lin

    2000-01-01

    .... Attention may affect the perceived clarity of visual displays and improve performance. In this project, a powerful external noise method was developed to identify and characterize the effect of attention on perceptual performance in visual tasks...

  18. Attention processes in autism

    National Research Council Canada - National Science Library

    Martos-Pérez, J

    2008-01-01

    ... findings that have been obtained so far are also reported. Some attentional processes, such as selective or sustained attention, are not altered in autism or not enough evidence has been found to support such a hypothesis...

  19. Attention decay in science

    CERN Document Server

    Parolo, Pietro Della Briotta; Ghosh, Rumi; Huberman, Bernardo A; Kaski, Kimmo; Fortunato, Santo

    2015-01-01

    The exponential growth in the number of scientific papers makes it increasingly difficult for researchers to keep track of all the publications relevant to their work. Consequently, the attention that can be devoted to individual papers, measured by their citation counts, is bound to decay rapidly. In this work we make a thorough study of the life-cycle of papers in different disciplines. Typically, the citation rate of a paper increases up to a few years after its publication, reaches a peak and then decreases rapidly. This decay can be described by an exponential or a power law behavior, as in ultradiffusive processes, with exponential fitting better than power law for the majority of cases. The decay is also becoming faster over the years, signaling that nowadays papers are forgotten more quickly. However, when time is counted in terms of the number of published papers, the rate of decay of citations is fairly independent of the period considered. This indicates that the attention of scholars depends on th...

  20. Visual Selective Attention in Mice.

    Science.gov (United States)

    Wang, Lupeng; Krauzlis, Richard J

    2018-02-08

    Visual selective attention is a fundamental cognitive ability that allows us to process relevant visual stimuli while ignoring irrelevant distracters and has been extensively studied in human and non-human primate subjects. Mice have emerged as a powerful animal model for studying aspects of the visual system but have not yet been shown to exhibit visual selective attention. Differences in the organization of the visual systems of primates and mice raise the possibility that selective visual attention might not be present in mice, at least not in the forms that are well established in primates. Here, we tested for selective visual attention in mice by using three behavioral paradigms adapted from classic studies of attention. In a Posner-style cueing task, a spatial cue indicated the probable location of the relevant visual event, and we found that accuracy was higher and reaction times were shorter on validly cued trials. In a cue versus no-cue task, an informative spatial cue was provided on half the trials, and mice had higher accuracy and shorter reaction times with spatial cues and also lower detection thresholds measured from psychometric curves. In a filter task, the spatial cue indicated the location of the relevant visual event, and we found that mice could be trained to ignore irrelevant but otherwise identical visual events at uncued locations. Together, these results demonstrate that mice exhibit visual selective attention, paving the way to use classic attention paradigms in mice to study the genetic and neuronal circuit mechanisms of selective attention. Published by Elsevier Ltd.

  1. Attention Competition with Advertisement

    OpenAIRE

    Cetin, Uzay; Bingol, Haluk O.

    2012-01-01

    In the new digital age, information is available in large quantities. Since information consumes primarily the attention of its recipients, the scarcity of attention is becoming the main limiting factor. In this study, we investigate the impact of advertisement pressure on a cultural market where consumers have a limited attention capacity. A model of competition for attention is developed and investigated analytically and by simulation. Advertisement is found to be much more effective when a...

  2. Functional ability, community reintegration and participation restriction among community-dwelling female stroke survivors in Ibadan.

    Science.gov (United States)

    Hamzat, T K; Olaleye, O A; Akinwumi, O B

    2014-01-01

    Stroke is not gender-discriminatory. Yet, the subject of stroke among females has apparently not received significant attention from clinical researchers. The consequences of stroke include functional and psychosocial sequelae which may cause disability, hinder community reintegration and restrict participation. The inter-relationships among functional ability, community reintegration and participation restriction of community-dwelling, female stroke survivors in Ibadan were assessed in this descriptive study. Fifty-two community-dwelling female stroke survivors (mean age = 56.55±9.91 years) were surveyed using consecutive sampling technique. Their functional ability level was measured using the Functional Independence Measure (FIM) while London Handicap Scale (LHS) was used to assess their participation restriction. Data were analyzed using Spearman Rank Correlation Coefficient (rho) and Mann-Whitney U test at p = 0.05. Significantly positive correlations (preintegration (r = 0.54; p = 0.01) as well as between participation restriction and community reintegration (r = 0.34; p = 0.05). Individuals with left hemiplegia had significantly higher mean rank scores in functional ability (30.41) than those who had right hemiplegia (mean rank scores = 21.94). Functional ability which appears to be related to stroke laterality showed positive association with both community reintegration and participation restriction. This suggests that improving the functional ability of the stroke survivors may reduce participation restriction and enhance their reintegration into the community. A similar study which compares male and female stroke survivors in the same community is thus necessary.

  3. Anxiety and Attentional Bias in Preschool-Aged Children: An Eyetracking Study.

    Science.gov (United States)

    Dodd, Helen F; Hudson, Jennifer L; Williams, Tracey; Morris, Talia; Lazarus, Rebecca S; Byrow, Yulisha

    2015-08-01

    Extensive research has examined attentional bias for threat in anxious adults and school-aged children but it is unclear when this anxiety-related bias is first established. This study uses eyetracking technology to assess attentional bias in a sample of 83 children aged 3 or 4 years. Of these, 37 (19 female) met criteria for an anxiety disorder and 46 (30 female) did not. Gaze was recorded during a free-viewing task with angry-neutral face pairs presented for 1250 ms. There was no indication of between-group differences in threat bias, with both anxious and non-anxious groups showing vigilance for angry faces as well as longer dwell times to angry over neutral faces. Importantly, however, the anxious participants spent significantly less time looking at the faces overall, when compared to the non-anxious group. The results suggest that both anxious and non-anxious preschool-aged children preferentially attend to threat but that anxious children may be more avoidant of faces than non-anxious children.

  4. Microbiological characterization of 3193 French dwellings of Elfe cohort children.

    Science.gov (United States)

    Rocchi, S; Reboux, G; Frossard, V; Scherer, E; Valot, B; Laboissière, A; Zaros, C; Vacheyrou, M; Gillet, F; Roussel, S; Raherison, C; Millon, L

    2015-02-01

    Although exposure to indoor microorganisms in early life has already been associated with respiratory illness or allergy protection, only a few studies have performed standardized samplings and specific microbial analysis. Moreover, most do not target the different groups of microorganisms involved in respiratory diseases (fungi, bacteria, dust mites). In our study, ten specific qPCR targets (6 fungal species, 1 family and 2 genera of bacteria, 1 house dust mite) were used to analyze the microorganism composition of electrostatic dust fall collector (EDC) from 3193 dwellings of the Elfe French cohort study. Multivariate analyses allowed us to show that the microbial composition of dwellings, assessed with simultaneous analysis of 10 microorganisms, can be characterized by four entities: three bacteria, house dust mite Dermatophagoïdes pteronyssinus, fungi Alternaria alternata, and five other molds. Some dwellings' intrinsic characteristics (occupational ratio, type of dwelling and presence of pets) clearly influence microorganism distribution, and six different profiles of dwellings, characterized by their composition in microorganisms, have been described across France. The use of these clusters seems promising in the evaluation of allergic risk. Allergic respiratory diseases will develop in the near future in some children of the Elfe cohort and will indicate to what extent our approach can be predictive of respiratory disease. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Training on Movement Figure-Ground Discrimination Remediates Low-Level Visual Timing Deficits in the Dorsal Stream, Improving High-Level Cognitive Functioning, Including Attention, Reading Fluency, and Working Memory

    Science.gov (United States)

    Lawton, Teri; Shelley-Tremblay, John

    2017-01-01

    The purpose of this study was to determine whether neurotraining to discriminate a moving test pattern relative to a stationary background, figure-ground discrimination, improves vision and cognitive functioning in dyslexics, as well as typically-developing normal students. We predict that improving the speed and sensitivity of figure-ground movement discrimination (PATH to Reading neurotraining) acts to remediate visual timing deficits in the dorsal stream, thereby improving processing speed, reading fluency, and the executive control functions of attention and working memory in both dyslexic and normal students who had PATH neurotraining more than in those students who had no neurotraining. This prediction was evaluated by measuring whether dyslexic and normal students improved on standardized tests of cognitive skills following neurotraining exercises, more than following computer-based guided reading (Raz-Kids (RK)). The neurotraining used in this study was visually-based training designed to improve magnocellular function at both low and high levels in the dorsal stream: the input to the executive control networks coding working memory and attention. This approach represents a paradigm shift from the phonologically-based treatment for dyslexia, which concentrates on high-level speech and reading areas. This randomized controlled-validation study was conducted by training the entire second and third grade classrooms (42 students) for 30 min twice a week before guided reading. Standardized tests were administered at the beginning and end of 12-weeks of intervention training to evaluate improvements in academic skills. Only movement-discrimination training remediated both low-level visual timing deficits and high-level cognitive functioning, including selective and sustained attention, reading fluency and working memory for both dyslexic and normal students. Remediating visual timing deficits in the dorsal stream revealed the causal role of visual movement

  6. Training on Movement Figure-Ground Discrimination Remediates Low-Level Visual Timing Deficits in the Dorsal Stream, Improving High-Level Cognitive Functioning, Including Attention, Reading Fluency, and Working Memory.

    Science.gov (United States)

    Lawton, Teri; Shelley-Tremblay, John

    2017-01-01

    The purpose of this study was to determine whether neurotraining to discriminate a moving test pattern relative to a stationary background, figure-ground discrimination, improves vision and cognitive functioning in dyslexics, as well as typically-developing normal students. We predict that improving the speed and sensitivity of figure-ground movement discrimination (PATH to Reading neurotraining) acts to remediate visual timing deficits in the dorsal stream, thereby improving processing speed, reading fluency, and the executive control functions of attention and working memory in both dyslexic and normal students who had PATH neurotraining more than in those students who had no neurotraining. This prediction was evaluated by measuring whether dyslexic and normal students improved on standardized tests of cognitive skills following neurotraining exercises, more than following computer-based guided reading (Raz-Kids (RK)). The neurotraining used in this study was visually-based training designed to improve magnocellular function at both low and high levels in the dorsal stream: the input to the executive control networks coding working memory and attention. This approach represents a paradigm shift from the phonologically-based treatment for dyslexia, which concentrates on high-level speech and reading areas. This randomized controlled-validation study was conducted by training the entire second and third grade classrooms (42 students) for 30 min twice a week before guided reading. Standardized tests were administered at the beginning and end of 12-weeks of intervention training to evaluate improvements in academic skills. Only movement-discrimination training remediated both low-level visual timing deficits and high-level cognitive functioning, including selective and sustained attention, reading fluency and working memory for both dyslexic and normal students. Remediating visual timing deficits in the dorsal stream revealed the causal role of visual movement

  7. Training on Movement Figure-Ground Discrimination Remediates Low-Level Visual Timing Deficits in the Dorsal Stream, Improving High-Level Cognitive Functioning, Including Attention, Reading Fluency, and Working Memory

    Directory of Open Access Journals (Sweden)

    Teri Lawton

    2017-05-01

    Full Text Available The purpose of this study was to determine whether neurotraining to discriminate a moving test pattern relative to a stationary background, figure-ground discrimination, improves vision and cognitive functioning in dyslexics, as well as typically-developing normal students. We predict that improving the speed and sensitivity of figure-ground movement discrimination (PATH to Reading neurotraining acts to remediate visual timing deficits in the dorsal stream, thereby improving processing speed, reading fluency, and the executive control functions of attention and working memory in both dyslexic and normal students who had PATH neurotraining more than in those students who had no neurotraining. This prediction was evaluated by measuring whether dyslexic and normal students improved on standardized tests of cognitive skills following neurotraining exercises, more than following computer-based guided reading (Raz-Kids (RK. The neurotraining used in this study was visually-based training designed to improve magnocellular function at both low and high levels in the dorsal stream: the input to the executive control networks coding working memory and attention. This approach represents a paradigm shift from the phonologically-based treatment for dyslexia, which concentrates on high-level speech and reading areas. This randomized controlled-validation study was conducted by training the entire second and third grade classrooms (42 students for 30 min twice a week before guided reading. Standardized tests were administered at the beginning and end of 12-weeks of intervention training to evaluate improvements in academic skills. Only movement-discrimination training remediated both low-level visual timing deficits and high-level cognitive functioning, including selective and sustained attention, reading fluency and working memory for both dyslexic and normal students. Remediating visual timing deficits in the dorsal stream revealed the causal role of visual

  8. Mindfulness training affects attention--or is it attentional effort?

    Science.gov (United States)

    Jensen, Christian Gaden; Vangkilde, Signe; Frokjaer, Vibe; Hasselbalch, Steen G

    2012-02-01

    Improvements in attentional performance are at the core of proposed mechanisms for stress reduction in mindfulness meditation practices. However, this claim can be questioned because no previous studies have actively manipulated test effort in control groups and controlled for effects of stress reduction per se. In a blinded design, 48 young, healthy meditation novices were randomly assigned to a mindfulness-based stress reduction (MBSR), nonmindfulness stress reduction (NMSR), or inactive control group. At posttest, inactive controls were randomly split into nonincentive and incentive controls, the latter receiving a financial reward to improve attentional performance. Pre- and postintervention, 5 validated attention paradigms were employed along with self-report scales on mindfulness and perceived stress and saliva cortisol samples to measure physiological stress. Attentional effects of MBSR, NMSR, and the financial incentive were comparable or significantly larger in the incentive group on all reaction-time-based measures. However, selective attention in the MBSR group improved significantly more than in any other group. Similarly, only the MBSR intervention improved the threshold for conscious perception and visual working memory capacity. Furthermore, stress-reducing effects of MBSR were supported because those in the MBSR group showed significantly less perceived and physiological stress while increasing their mindfulness levels significantly. We argue that MBSR may contribute uniquely to attentional improvements but that further research focusing on non-reaction-time-based measures and outcomes less confounded by test effort is needed. Critically, our data demonstrate that previously observed improvements of attention after MBSR may be seriously confounded by test effort and nonmindfulness stress reduction.

  9. Attention competition with advertisement.

    Science.gov (United States)

    Cetin, Uzay; Bingol, Haluk O

    2014-09-01

    In the new digital age, information is available in large quantities. Since information consumes primarily the attention of its recipients, the scarcity of attention is becoming the main limiting factor. In this study, we investigate the impact of advertisement pressure on a cultural market where consumers have a limited attention capacity. A model of competition for attention is developed and investigated analytically and by simulation. Advertisement is found to be much more effective when the attention capacity of agents is extremely scarce. We have observed that the market share of the advertised item improves if dummy items are introduced to the market while the strength of the advertisement is kept constant.

  10. Attention competition with advertisement

    Science.gov (United States)

    Cetin, Uzay; Bingol, Haluk O.

    2014-09-01

    In the new digital age, information is available in large quantities. Since information consumes primarily the attention of its recipients, the scarcity of attention is becoming the main limiting factor. In this study, we investigate the impact of advertisement pressure on a cultural market where consumers have a limited attention capacity. A model of competition for attention is developed and investigated analytically and by simulation. Advertisement is found to be much more effective when the attention capacity of agents is extremely scarce. We have observed that the market share of the advertised item improves if dummy items are introduced to the market while the strength of the advertisement is kept constant.

  11. Principles of visual attention

    DEFF Research Database (Denmark)

    Bundesen, Claus; Habekost, Thomas

    The nature of attention is one of the oldest and most central problems in psychology. A huge amount of research has been produced on this subject in the last half century, especially on attention in the visual modality, but a general explanation has remained elusive. Many still view attention...... research as a field that is fundamentally fragmented. This book takes a different perspective and presents a unified theory of visual attention: the TVA model. The TVA model explains the many aspects of visual attention by just two mechanisms for selection of information: filtering and pigeonholing....... These mechanisms are described in a set of simple equations, which allow TVA to mathematically model a large number of classical results in the attention literature. The theory explains psychological and neuroscientific findings by the same equations; TVA is a complete theory of visual attention, linking mind...

  12. Concepts for evaluation of sound insulation of dwellings - from chaos to consensus?

    DEFF Research Database (Denmark)

    Rasmussen, Birgit; Rindel, Jens Holger

    2005-01-01

    Legal sound insulation requirements have existed more than 50 years in some countries, and single-number quantities for evaluation of sound insulation have existed nearly as long time. However, the concepts have changed considerably over time from simple arithmetic averaging of frequency bands......¬ments and classification schemes revealed significant differences of concepts. The paper summarizes the history of concepts, the disadvantages of the present chaos and the benefits of consensus concerning concepts for airborne and impact sound insulation between dwellings and airborne sound insulation of facades...

  13. Chewing and Attention: A Positive Effect on Sustained Attention

    National Research Council Canada - National Science Library

    Hirano, Yoshiyuki; Onozuka, Minoru

    2015-01-01

    .... These findings support the concept that chewing is strongly associated with cognitive function such as learning and memory and keeping and increasing attention [5]. This relationship between chewing and cognitive functions was empirically estimated a long time ago. In 1939, Hollingworth [6] reported that chewing increased relaxation and the performance of cognitive ...

  14. Is it time to shift the attention on early stages embryo development to avoid inconclusive evidence on HPV-related infertility: debate and proposal.

    Science.gov (United States)

    Noventa, Marco; Andrisani, Alessandra; Gizzo, Salvatore; Nardelli, Giovanni B; Ambrosini, Guido

    2014-05-31

    Current evidence about in-vivo effects of HPV cannot definitively clarify the possible negative role of this worldwide common infection in early embryo development. However in-vitro evidence, seems to underline a possible negative effect of HPV in increasing blastocyst apoptosis and in reducing the endometrial implantation of trophoblastic cells. On these bases we believe that a new scientific approach is necessary to better understand the real role of male and female HPV infection in infertility and early pregnancy development. English literature review of manuscripts focused on HPV infection and human reproduction was conducted. We performed a critical analysis of evidence and possible bias affecting both in-vivo and in-vitro studies regarding this topic. The biggest limitation of the in-vivo studies is due to the inappropriate timing of HPV effects evaluation since evidence about in-vitro studies strongly suggests that a large part of HPV negative effects occurs during a very early stage of embryo development. All the efforts of the scientific community to investigate the real role of HPV in human reproduction disorders cannot underestimate the severe BIAS of actual evidence in postulating new hypothesis and research projects which are fundamental to clarify if HPV may be associated with unexplained couples infertility and early miscarriages. If the relationship between HPV gametes infection and early human reproduction step impairment will be confirmed, the HPV male and couple vaccination may represent a reliable option to improve fertility in some couples affected by infertility actually classified as "idiopathic" but maybe linked to HPV infection.

  15. Fostering Spontaneous Visual Attention in Children on the Autism Spectrum: A Proof-of-Concept Study Comparing Singing and Speech.

    Science.gov (United States)

    Thompson, Grace Anne; Abel, Larry Allen

    2018-01-22

    Children on the autism spectrum are reported to have lower rates of social gaze as early as toddlerhood, and this pattern persists across the lifespan. Finding ways to promote more natural and spontaneous engagement in social interactions may help to boost developmental opportunities in the child's home and community settings. This proof-of-concept study hypothesized that a video of a singer would elicit more attention to the performer, particularly to her face, than a video of her reading a story, and that the child's familiarity with the material would enhance attention. Sixteen children on the autism spectrum (7-10 years old) watched 4 videos 1 min long comprising a favorite song or story, and an unfamiliar song and story. Eye movements were recorded, and three-way repeated measures ANOVAs examined the proportion of total valid visual dwell time and fixations, in each trial and each target area. For proportion of both dwell time and fixation counts, children were significantly more likely to look at the performer's face and body and less at the prop during singing than story-telling and when familiar rather than unfamiliar material was presented. These findings raise important issues for supporting children to naturally initiate looking toward a person's face. Autism Res 2018. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. Children on the autism spectrum may have difficulty looking at people, particularly their faces. In this study, children watched videos of someone singing or reading a story. The results show that children look more at the person if they were singing and if the story was familiar to them. Using songs and familiar stories may be a way to help children with autism to naturally engage with others. © 2018 International Society for Autism Research, Wiley Periodicals, Inc.

  16. Attention Mosaics: Studies of Organizational Attention

    NARCIS (Netherlands)

    L. Carvalho de Mesquita Ferreira (Luciana)

    2010-01-01

    textabstractOrganizational studies emphasizing the role of attention in organizational behavior depart from the idea that organizations, like individuals, have limited capacity to attend to environmental stimuli. The bounded capacity of the organizations to respond to stimuli is conditioned by the

  17. Topical Decolonization Does Not Eradicate the Skin Microbiota of Community-Dwelling or Hospitalized Adults.

    Science.gov (United States)

    Burnham, C A; Hogan, Patrick G; Wallace, Meghan A; Deych, Elena; Shannon, William; Warren, David K; Fritz, Stephanie A

    2016-12-01

    Topical antimicrobials are often employed for decolonization and infection prevention and may alter the endogenous microbiota of the skin. The objective of this study was to compare the microbial communities and levels of richness and diversity in community-dwelling subjects and intensive care unit (ICU) patients before and after the use of topical decolonization protocols. We enrolled 15 adults at risk for Staphylococcus aureus infection. Community subjects (n = 8) underwent a 5-day decolonization protocol (twice daily intranasal mupirocin and daily dilute bleach-water baths), and ICU patients (n = 7) received daily chlorhexidine baths. Swab samples were collected from 5 anatomic sites immediately before and again after decolonization. A variety of culture media and incubation environments were used to recover bacteria and fungi; isolates were identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry. Overall, 174 unique organisms were recovered. Unique communities of organisms were recovered from the community-dwelling and hospitalized cohorts. In the community-dwelling cohort, microbial richness and diversity did not differ significantly between collections across time points, although the number of body sites colonized with S. aureus decreased significantly over time (P = 0.004). Within the hospitalized cohort, richness and diversity decreased over time compared to those for the enrollment sampling (from enrollment to final sampling, P = 0.01 for both richness and diversity). Topical antimicrobials reduced the burden of S. aureus while preserving other components of the skin and nasal microbiota. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  18. Estimation of the residential radon levels and the population annual effective dose in dwellings of Al-kharj, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Ahmed M. Maghraby

    2014-10-01

    Full Text Available Indoor radon levels and the annual effective dose are measured in Al-kharj city, Saudi Arabia dwellings using CR-39 detector. The dwellings are classified according their types (schools, homes and working area. The influence of some factors like number of floors and ventilation conditions on indoor radon levels, equilibrium factor and radon effective doses were studied. Can and bare method is used for determine the equilibrium factor between radon and its daughters. Based on the dosemetric approach and epidemiological determinations conversions convention for radon exposures, the annual effective doses are calculated and compared. The average radon concentration varies from 76 ± 38 Bq m−3 in work places to 114 ± 41 Bq m−3 in homes. About 77% of the studied dwellings give radon concentration in the range from 50 to 150 Bq m−3. The overall weighted mean of radon level is equal to 94 ± 41 Bq m−3 which about 2.5 times the global average. The equilibrium factor has a wide range from 0.1 to 0.6 with overall weighted average equal to 0.308 ± 0.13. The variety of living style, constructed materials and ventilation rates are responsible for this wide range and subsequently the obtained high uncertainty (42%. Homes showed larger annual effective dose (3.186 ± 0.75 mSv than other dwellings which locate in the range of the recommended action level but about three times the global average. The result shows that the ventilation condition is the major but not the only factor affects the results. Poor ventilated dwellings showed the maximum annual effective dose on the other hand the number of floor has insignificant difference.

  19. Does mindfulness meditation improve attention in attention deficit hyperactivity disorder?

    Science.gov (United States)

    Modesto-Lowe, Vania; Farahmand, Pantea; Chaplin, Margaret; Sarro, Lauren

    2015-01-01

    Attention deficit hyperactivity disorder (ADHD) manifests by high levels of inattention, impulsiveness and hyperactivity. ADHD starts in childhood and results in impairments that continue into adulthood. While hyperactivity declines over time, inattention and executive function difficulties persist, leading to functional deficits. Adolescents and adults with ADHD have pervasive impairment in interpersonal and family relationships. They may develop addiction, delinquent behavior and comorbid psychiatric disorders. Despite advances in diagnosis and treatment, persistent residual symptoms are common, highlighting the need for novel treatment strategies. Mindfulness training, derived from Eastern meditation practices, may improve self-regulation of attention. It may also be a useful strategy to augment standard ADHD treatments and may be used as a potential tool to reduce impairments in patients with residual symptoms of ADHD. Clinically, this would manifest by an increased ability to suppress task-unrelated thoughts and distractions resulting in improved attention, completion of tasks and potential improvement in occupational and social function. PMID:26740931

  20. Influence of attentional load on spatial attention in acquired and developmental disorders of attention.

    Science.gov (United States)

    Bellgrove, Mark A; Eramudugolla, Ranmalee; Newman, Daniel P; Vance, Alasdair; Mattingley, Jason B

    2013-05-01

    Converging evidence suggests that right-hemisphere dominant spatial attention systems can be modulated by non-spatial processes such as attentional capacity. The severity of neglect in right-hemisphere stroke patients for example, is correlated with impairments in non-lateralized attention. Evidence also suggests the coexistence of lateralized inattention and reduced capacity in developmental disorders of attention, such as attention deficit hyperactivity disorder (ADHD), which is marked by cognitive impairments suggestive of right hemisphere dysfunction. These lines of evidence argue against a coincident damage hypothesis and suggest instead a direct modulation of spatial attention by non-spatial processes. Here we sought experimental evidence for this relationship in both acquired and developmental disorders of attention. Six adult stroke patients with focal right brain injury and 19 children with ADHD were studied in comparison to control groups of both healthy older adults and typically developing children. The participants were required to detect transient, unilateral visual targets while simultaneously monitoring a stream of alphanumeric characters at fixation. Load at fixation was manipulated by asking participants either to ignore the central stream and focus on the peripheral detection task (no report condition), or to monitor the central stream for a probe item that was defined by either a unique feature (low load condition) or a conjunction of features (high load condition). As expected, in all participants greater load at fixation slowed responses to peripheral targets. Crucially, in right brain injured patients but not older healthy adults left target detection was slowed significantly more than central and right target detection. A qualitatively similar pattern was seen in children with ADHD, but not in typically developing children. The imposition of load at fixation slowed responses to left compared with right targets, and this response time

  1. Attention to Advertising

    OpenAIRE

    Nilsson, Carl Patrik

    2006-01-01

    Attention to Advertising Carl Patrik Nilsson, Umeå School of Business, Umeå University SE-901 87 Umeå, Sweden Abstract In advertising, capturing consumers’ attention is imperative. Yet, how attention to advertising works in a World Wide Web context has not been researched extensively. This area is the main focus of this research. The World Wide Web is an interactive medium which has characteristics that deviate from traditional media channels. Considering the unique properties of the World Wi...

  2. Announcements to Attentive Agents

    DEFF Research Database (Denmark)

    Bolander, Thomas; van Ditmarsch, Hans; Herzig, Andreas

    2016-01-01

    In public announcement logic it is assumed that all agents pay attention to the announcement. Weaker observational conditions can be modelled in action model logic. In this work, we propose a version of public announcement logic wherein it is encoded in the states of the epistemic model which...... agents pay attention to the announcement. This logic is called attention-based announcement logic. We give an axiomatization of the logic and prove that complexity of satisfiability is the same as that of public announcement logic, and therefore lower than that of action model logic. An attention...

  3. Donor attention to reading materials.

    Science.gov (United States)

    O'Brien, S F; Osmond, L; Choquet, K; Yi, Q-L; Goldman, M

    2015-11-01

    Mandatory predonation reading materials inform donors about risk factors for transmissible disease, possible complications of donation and changes to the donation process. We aimed to assess the attention to predonation reading materials and factors which may affect attention. A national survey in 2008 of 18,108 blood donors asked about self-assessed attention to reading the materials. In face-to-face interviews, 441 donors completed additional questions about reading the materials and a literacy test. Qualitative interviews of 27 donors assessed their approach to reading. In the national survey, most of the first-time donors said they read all or most of the materials (90.9% first-time vs. 57.6% repeat donors, P reading them carefully (P read materials carefully, skimmed or did not read, most knew that donors are informed of positive transmissible disease test results (97.1%, 95.5, 98.0 P > 0.05), but fewer recalled seeing the definition of sex (77.2%, 56.9, 24.2 P read materials carefully, skimmed or did not read were compared (P > 0.05). Qualitative interviews showed that donors are reluctant to read any more than necessary and decide based on perceived importance or relevance. Attention to predonation reading materials tends to be better among first-time donors. The effectiveness is limited by low motivation to read, especially for repeat donors, as well as poor literacy. © 2015 International Society of Blood Transfusion.

  4. Periodontal care for community-dwelling older adults.

    Science.gov (United States)

    Ellen, R P

    1994-11-01

    The prevalence and severity of periodontitis increases with age. Epidemiologic studies have identified several risk variables associated with advancing periodontitis in older adults: namely tobacco smoking, frequency of dental appointments, infection with anaerobic bacteria considered periodontal pathogens, plaque and calculus accumulation, and some socioeconomic variables. Future morbidity from periodontitis might be reduced by minimizing the impact of these risk-associated variables at younger ages. Treatment of periodontal disease in community-dwelling older adults should be aimed at (1) targeting care to their overall health, functional, and esthetic needs; (2) strategic planning for maximal health and patient satisfaction; (3) documentation of past susceptibility and current risk; (4) control of principal risk factors; (4) investing time in patient education and informed consent; and (5) planning ahead for a potentially catastrophic decline in health. Periodontal treatment needs should be met in an integrated treatment plan that considers the overall prognosis for the dentition and individual teeth and the most efficacious prosthodontic options. Frequent recall for supportive periodontal care is essential. Several medical, physical, and societal impediments to provision of optimal care for older adults should be sought and minimized by the practitioner. Population dynamics and health-oriented activism among older adults are increasing the demand for essential and elective periodontal and prosthodontic services, which are met by implant-supported prostheses. Over the next few decades, as the incidence of tooth loss declines and our knowledge of the pathogenesis of periodontitis and biology of tissue regeneration increases, there will likely be a renewed emphasis on the preservation of the natural periodontium.

  5. Wii Fit Balance Intervention in Community-Dwelling Older Adults.

    Science.gov (United States)

    Orsega-Smith, Elizabeth; Davis, Julie; Slavish, Kelley; Gimbutas, Laura

    2012-12-01

    The purpose of this exploratory study was to investigate the impact of the Nintendo(®) Wii Fit™ (Nintendo of America, Redmond, WA) on functional and perceived balance measures in an older adult population over a 4- or 8-week program. Twenty-five participants (71.60±7.79 years old) from a local senior center played Wii Fit (balance games, hula hooping, and yoga) for 30 minutes 2 days per week in either a 4-week (n=16) or 8-week (n=9) program. An additional nine participants served as a control group. These participants were independent, community-dwelling healthy overweight older adults (mean body mass index, 27.19±4.99 kg/m(2)). Functional balance measures included the 8-foot time up-and-go, 30-second chair stands, and the Berg Balance Scale and perceived balance were measured using the following scales: Activities-specific Balance Confidence (ABC) Scale, Falls Self-Efficacy Scale, and the Activities of Daily Living (ADL) Scale. A paired t test showed significant changes pre-post program in the mean scores of chair stands, Berg Balance Scale, and ADL Scale for the 4-week participants. For the 8-week participants, significant differences were seen pre-post-program for the Berg Balance Scale, ABC Scale, and ADL Scale. There were no statistical change in the control group in the Berg Balance, ABC, and ADL Scales. The results of this study suggest that Wii Fit playing may be a vehicle for physical activity participation in the older adult population. It is necessary that research on the effects of exergaming on functional and perceived balance in the older adult population must continue.

  6. ATTENTIONAL NETWORKS AND SELECTIVE VISUAL SYSTEM

    Directory of Open Access Journals (Sweden)

    ALEJANDRO CASTILLO MORENO

    2006-05-01

    Full Text Available In this paper we checked the principal researches and theories to explain the attention system functioning.We are going to start reviewing along time about the concept of attention, from filter theories andresources distributor theories, to the current theories in which attention is conceived as a control system.From this last point of view, we will emphasize on the attentional networks theory of Posner, thatproposes different systems to explain diverse aspects of attention, but they are related to each other. Atlast in this paper, we will mention experimental results that have been important to characterize theselective attentional mechanisms of the human visual system, using the attentional spotlight model forthis aim.

  7. Thermal comfort in the different settings of low-income dwellings in Surakarta, Indonesia

    NARCIS (Netherlands)

    Arsandrie, Y.; Kurvers, S.R.

    2010-01-01

    As a preparation to develop guidelines and design principles for better dwellings in the tropics, a pilot survey was conducted to get data of the current situation of thermal comfort in the dwellings of low-income people in Surakarta, Central Java - Indonesia. These improper dwellings which locate

  8. The spectrum of worry in the community-dwelling elderly.

    LENUS (Irish Health Repository)

    Golden, Jeannette

    2011-11-01

    In this study, we examine the prevalence and distribution of worry, its content, and its associations with quality of life and depression, based on a large sample of community-dwelling elderly. We will attempt to distinguish between pathological and non-pathological worry based on these associations.

  9. Measurements of radon in dwellings with CR-39 track detectors

    DEFF Research Database (Denmark)

    Majborn, Benny

    1986-01-01

    A passive integrating dosemeter has been designed for measuring natural radiation in dwellings. The dosemeter contains one or two CR-39 track detectors to measure radon and three thermoluminescence dosemeters to measure external radiation. The dosemeter was investigated in a pilot study in 1983/8...

  10. Distribution and status of the desert-dwelling giraffe ( Giraffa ...

    African Journals Online (AJOL)

    The population density and distribution of desert dwelling giraffes was estimated in three study areas in the Hoanib River catchment, northwestern Namibia. Giraffe population densities (0.01 giraffe/km2) were equal to the lowest recorded in Africa with population numbers fluctuating over past decades. Sex ratios, herd sizes ...

  11. Dwelling density variability across government-built multifamily ...

    African Journals Online (AJOL)

    This study examined the variability of dwelling density across different classifications of multifamily apartments built by Lagos State Development and Property Corporation (LSDPC) in Lagos, Nigeria. Six design prototypes used to build several multifamily apartments in four estates were purposively selected as case study.

  12. Relationships between building characteristics and airtightness of Dutch dwellings

    NARCIS (Netherlands)

    Bramiana, C.N.; Entrop, Alexis Gerardus; Halman, Johannes I.M.

    2016-01-01

    Building airtightness is an important parameter to improve the energy efficiency of buildings. By means of a literature study, as well as the use of empirical data on the specific leakage of more than 300 dwellings, this paper provides insights in the relationships between building airtightness and

  13. Sound classification of dwellings in the Nordic countries

    DEFF Research Database (Denmark)

    Rindel, Jens Holger; Turunen-Rise, Iiris

    1997-01-01

    A draft standard INSTA 122:1997 on sound classification of dwellings is for voting as a common national standard in the Nordic countries (Denmark, Norway, Sweden, Finland, Iceland) and in Estonia. The draft standard specifies a sound classification system with four classes A, B, C and D, where...

  14. Evolutionary diversification of coral-dwelling gall crabs (Cryptochiridae)

    NARCIS (Netherlands)

    Meij, Sancia Esmeralda Theonilla van der

    2015-01-01

    Gall crabs (Crustacea : Cryptochiridae) are small, coral-dwelling crabs that live in obligate association with their host corals (Scleractinia), on which they rely for food and shelter. They have been recorded from shallow and deeper waters (over 500 m), but the majority of the species live in reef

  15. Adaptive heating, ventilation and solar shading for dwellings

    NARCIS (Netherlands)

    Alders, E.E.

    2017-01-01

    Calculation of various strategies for the heating of, and the prevention of overheating in, a Dutch standard dwelling that includes (automated) adaptive ventilation systems and solar shading to maintain indoor temperatures at acceptably comfortable temperatures informs this analysis of the costs,

  16. Determinants of quality of life among community‑dwelling persons ...

    African Journals Online (AJOL)

    2016-05-06

    May 6, 2016 ... Context: Recent advancement in technology and medical care has resulted in an increase not only in disability arising from spinal cord injury (SCI) but also its attendant challenges such as poor ... Inclusion and exclusion criteria. This study involved both male and female community‑dwelling persons with ...

  17. Methods of radon remediation in Finnish dwellings; Asuntojen radonkorjauksen menetelmaet

    Energy Technology Data Exchange (ETDEWEB)

    Arvela, H.

    1995-12-01

    A study was made of remedial measures taken in dwellings with high indoor radon concentrations and the results obtained. The data regarding the remedial measures taken in 400 dwellings was obtained from a questionnaire study. The mean annual average indoor radon concentration before the remedies was 1.500 Bq/m{sup 3}, the concentration exceeding in nearly every house the action level of 400 Bq/m{sup 3}. After the measures were taken the mean indoor radon concentration was 500 Bq/m{sup 3}. The resulting indoor radon concentration was less than 400 Bq/m{sup 3} in 60 percent of the dwellings. The best results were achieved using sub-slab-suction and radon well. These methods effectively decrease both the flow of radon bearing air from soil into dwellings and the radon concentration of leakage air. Typical reduction rates in radon concentration were 70-95 percent. The action level was achieved in more than 70 percent of the houses. Sealing the entry routes and improvement of the ventilation resulted typically in reduction rates of 10-50 percent. The goal of the report is to give useful information for the house owners, the do-it-yourself-mitigators, the mitigation firms and the local authorities. The report includes practical guidance, price information and examples of remedial measures. (13 refs., 10 figs., 2 tabs.).

  18. Children Dwelling in the Absence of Home | Dachyshyn | Indo ...

    African Journals Online (AJOL)

    Indo-Pacific Journal of Phenomenology ... The lived experience of children dwelling in the absence of home is explored through the memoirs of Haddy, who as a child of four moved with her family from Fiji to ... The recollections of some refugee children along with situations from the author's own life appear more nominally.

  19. 10 CFR 440.22 - Eligible dwelling units.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Eligible dwelling units. 440.22 Section 440.22 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION WEATHERIZATION ASSISTANCE FOR LOW-INCOME PERSONS § 440.22 Eligible... is occupied by a family unit: (1) Whose income is at or below 200 percent of the poverty level...

  20. Laughter catches attention!

    NARCIS (Netherlands)

    Pinheiro, Ana P; Barros, Carla; Dias, Marcelo; Kotz, Sonja A

    2017-01-01

    In social interactions, emotionally salient and sudden changes in vocal expressions attract attention. However, only a few studies examined how emotion and attention interact in voice processing. We investigated neutral, happy (laughs) and angry (growls) vocalizations in a modified oddball task.

  1. Unmasking the attentional blink

    NARCIS (Netherlands)

    Nieuwenstein, Mark R.; Potter, Mary C.; Theeuwes, Jan

    2009-01-01

    When asked to identify 2 visual targets (T I and T2 for the 1st and 2nd targets. respectively) embedded in a sequence of distractors, observers will often fail to identify T2 when it appears within 200-500 Ins of T1-an effect called the attentional blink. Recent work shows that attention does not

  2. Neural Mechanisms of Attention

    Science.gov (United States)

    1993-05-21

    attention deficit hyperactivity disorder ( ADHD ). These disorders may encompass a number of other cognitive deficits, but many theories focus on the...trial of methylphenidate in black adolescents. Attentional, behavioral, and physiological effects. CLINICAL.PEDIATRICS., 27,74-81. Bruto, V...Nakamura, K., Nishijo, H., & Fukuda, M. (1986). Hypothalamic neuron involvement in integration of reward , aversion, and cue signals. Journal of

  3. Attention and choice

    DEFF Research Database (Denmark)

    Orquin, Jacob Lund; Mueller Loose, Simone

    2013-01-01

    This paper reviews studies on eye movements in decision making, and compares their observations to theoretical predictions concerning the role of attention in decision making. Four decision theories are examined: rational models, bounded rationality, evidence accumulation, and parallel constraint...... satisfaction models. Although most theories were confirmed with regard to certain predictions, none of the theories adequately accounted for the role of attention during decision making. Several observations emerged concerning the drivers and down-stream effects of attention on choice, suggesting...... that attention processes plays an active role in constructing decisions. So far, decision theories have largely ignored the constructive role of attention by assuming that it is entirely determined by heuristics, or that it consists of stochastic information sampling. The empirical observations reveal...

  4. Radon in Dwellings in the Republic of Kalmykia

    Energy Technology Data Exchange (ETDEWEB)

    Aakerblom, Gustav (Aakerblom och Aakerblom HP, Skaerholmen (Sweden)); German, Olga; Soederman, Ann-Louise (Swedish Radiation Safety Authority, Stockholm (Sweden)); Stamat, Ivan; Venkov, Vladimir (Research Inst. of Radiation Hygiene, St. Petersburg (Russian Federation))

    2009-02-15

    The National Radon Survey in the Republic of Kalmykia, Russian Federation during 2006-2007 was carried out in a cooperation project between the Swedish Radiation Protection Authority (SSI) and the Russian Institute of Radiation Hygiene (RIRH). In August 2006 SSI, RIRH, federal and local authorities carried out a field study in Kalmykia when radon daughter measurements (equilibrium equivalent radon concentrations in the air) and gamma radiation measurements were made in 103 buildings. Gamma spectrometry measurements were made at several sites. During the visit the cooperating parties devoted some time to the education of local authorities on radon related issues. During three months in the winter season 2006-2007, long term radon trace measurements were made in 525 randomly chosen dwellings in the Republic of Kalmykia. The radon gas activity varied between 3 and 973 Bq/m3, with a mean value of 122 Bq/m3. In 19 of a total of 835 measurement points, the radon activity exceeded the maximum permitted value in Russia of 200 Bq/m3 of EERC. The year-round radon trace measurement were made in 20 houses in Elista, the capital of the Republic of Kalmykia, for comparison with the three-month measurements. The year-round measurements showed some higher values for the radon activity, and a correction factor of 0.85 was applied. Using data on the number of people living in detached houses and apartments, and applying the radon activities measured, the number of new lung cancer cases caused by radon was calculated to be 20 to 40 of the 100 new cases reported annually. The methods of construction of the dwellings in Kalmykia is greatly influenced by the history and culture. Most of them were built after World War II and there are only a few that are newly built because of the poor economic situation and the low population growth rate in the Republic. Most people live in detached houses, one-storied with 3-5 rooms, built directly on the ground or on coquina blocks or on a cast

  5. Physical activities impact sense of coherence among community-dwelling older adults.

    Science.gov (United States)

    Monma, Takafumi; Takeda, Fumi; Okura, Tomohiro

    2017-11-01

    The objective of the present study was to investigate bidirectional longitudinal relationships between sense of coherence (SOC) and physical activities (PA) among community-dwelling older adults. Self-administered questionnaires were sent to 508 community-dwelling adults aged 65-85 years who expressed their intention to participate in our surveys including cognitive function tests and physical performance tests. Of these, 427 people responded to the baseline survey, and 223 of them participated in the follow-up survey 1 year later. Finally, the number of eligible respondents who had no missing values in all data was 179 (valid response rate: 35.2%). We used the 13-item five-point version of the Sense of Coherence Scale to assess SOC variables, and the Physical Activity Scale for the Elderly to assess PA variables. A structural equation modeling method was used to analyze bidirectional longitudinal relationships between SOC and PA. Cross-lagged effects and synchronous effects models were applied to analyze these relationships. Demographic variables (age, sex, education, living arrangements, medical histories, employment status), cognitive function and physical performance were used as control variables. Leisure-time PA had a cross-lagged effect (β = 0.117, P < 0.05) and a synchronous effect (β = 0.217, P < 0.001) on SOC. In contrast, no significant effect of SOC on any type of PA was observed in either the cross-lagged effects model or the synchronous effects model. Leisure-time PA might contribute to enhancing SOC in community-dwelling older adults. Geriatr Gerontol Int 2017; 17: 2208-2215. © 2017 Japan Geriatrics Society.

  6. Determinants of crime in the sphere of dwelling-communal sector in Russian cities

    Directory of Open Access Journals (Sweden)

    Elena A. Sizykh

    2016-01-01

    Full Text Available Objective to determine the most important factors of crimes in the sphere of dwelling and communal services in Russian cities with a population of over 1 million people. Methods correlation analysis using Pearson coefficient. Results the initial hypothesis is based on the following assumptions about the determination of crime in the dwellingcommunal sector this crime is proportional to the total criminality of the region economy the number of all corruption crimes revealed by divisions of the Russian Ministry of Internal Affairs in all spheres of economic activities in the studied cities production indicators number of investments and amount of financing in the dwellingcommunal sector volume of construction works etc. as well as the degree of monopolization in the dwellingcommunal sector in the region i.e. proportional to the number of municipal utilities. To check the hypotheses we used data on crime and socioeconomic characteristics of the dwellingcommunal sector in 15 largest Russian cities in 2012ndash2013 as well as the data about crime in the sphere of dwelling and communal services and about the corruption crimes in Russian cities in 2012ndash2014. As a result the calculations partially confirmed the hypotheses the dependence of the level of crime in the dwellingcommunal sector of Russian cities on the level of corruption crimes in these cities is high r 063 as well as the dependence on the number of organizations operating in the dwellingcommunal sector r 047. At the same time the correlation was weak between the volume of activity in the dwellingcommunal sector in Russian cities and the level of crime in them absolute value of Pearson coefficient is lower than 04. Scientific novelty for the first time the article investigated the determinants of crime in the sphere of dwelling and communal services in Russian cities on the basis of correlation analysis using Pearson coefficient. Practical significance the main provisions and conclusions

  7. Are You Paying Attention?

    DEFF Research Database (Denmark)

    2016-01-01

    and sustained. To study such attention practices, 16 semi-structured interviews with adult Danes are carried out. Through a thematic analysis of these interviews, the chapter explores how ways of attending relate to individual media and how patterns of daily life enable some practices and constrain others......A still understudied area in media research is how people pay attention to news in daily life. To do so, the chapter develops a theoretical framework grounded in news audience research and practice theory. This framework conceptualizes practices as different ways in which attention is directed....... In the concluding discussion, the chapter relates the findings to further perspectives on attention to news specifically and media content more generally. Accordingly, this chapter contributes to cross-media news research by analyzing ways in which people attend to news and how these ways of attending vary across...

  8. Challenges of Achieving 2012 IECC Air Sealing Requirements in Multifamily Dwellings

    Energy Technology Data Exchange (ETDEWEB)

    Klocke, S. [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Faakye, O. [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Puttagunta, S. [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2014-10-01

    While previous versions of the International Energy Conservation Code (IECC) have included provisions to improve the air tightness of dwellings, for the first time, the 2012 IECC mandates compliance verification through blower door testing. Simply completing the Air Barrier and Insulation Installation checklist through visual inspection is no longer sufficient by itself. In addition, the 2012 IECC mandates a significantly stricter air sealing requirement. In Climate Zones 3 through 8, air leakage may not exceed 3 ACH50, which is a significant reduction from the 2009 IECC requirement of 7 ACH50. This requirement is for all residential buildings, which includes low-rise multifamily dwellings. While this air leakage rate requirement is an important component to achieving an efficient building thermal envelope, currently, the code language doesn't explicitly address differences between single family and multifamily applications. In addition, the 2012 IECC does not provide an option to sample dwellings for larger multifamily buildings, so compliance would have to be verified on every unit. With compliance with the 2012 IECC air leakage requirements on the horizon, several of Consortium for Advanced Residential Building's (CARB’s) multifamily builder partners are evaluating how best to comply with this requirement. Builders are not sure whether it is more practical or beneficial to simply pay for guarded testing or to revise their air sealing strategies to improve compartmentalization to comply with code requirements based on unguarded blower door testing. This report summarizes CARB's research that was conducted to assess the feasibility of meeting the 2012 IECC air leakage requirements in 3 multifamily buildings.

  9. Challenges of Achieving 2012 IECC Air Sealing Requirements in Multifamily Dwellings

    Energy Technology Data Exchange (ETDEWEB)

    Klocke, S.; Faakye, O.; Puttagunta, S.

    2014-10-01

    ​While previous versions of the International Energy Conservation Code (IECC) have included provisions to improve the air tightness of dwellings, for the first time, the 2012 IECC mandates compliance verification through blower door testing. Simply completing the Air Barrier and Insulation Installation checklist through visual inspection is no longer sufficient by itself. In addition, the 2012 IECC mandates a significantly stricter air sealing requirement. In Climate Zones 3 through 8, air leakage may not exceed 3 ACH50, which is a significant reduction from the 2009 IECC requirement of 7 ACH50. This requirement is for all residential buildings, which includes low-rise multifamily dwellings. While this air leakage rate requirement is an important component to achieving an efficient building thermal envelope, currently, the code language doesn't explicitly address differences between single family and multifamily applications. In addition, the 2012 IECC does not provide an option to sample dwellings for larger multifamily buildings, so compliance would have to be verified on every unit. With compliance with the 2012 IECC air leakage requirements on the horizon, several of CARB's multifamily builder partners are evaluating how best to comply with this requirement. Builders are not sure whether it is more practical or beneficial to simply pay for guarded testing or to revise their air sealing strategies to improve compartmentalization to comply with code requirements based on unguarded blower door testing. This report summarizes CARB's research that was conducted to assess the feasibility of meeting the 2012 IECC air leakage requirements in 3 multifamily buildings.

  10. Unmasking the Attentional Blink

    Science.gov (United States)

    Nieuwenstein, Mark R.; Potter, Mary C.; Theeuwes, Jan

    2009-01-01

    When asked to identify 2 visual targets (T1 and T2 for the 1st and 2nd targets, respectively) embedded in a sequence of distractors, observers will often fail to identify T2 when it appears within 200-500 ms of T1--an effect called the "attentional blink". Recent work shows that attention does not blink when the task is to encode a…

  11. Impaired Visual Attention in Children with Dyslexia.

    Science.gov (United States)

    Heiervang, Einar; Hugdahl, Kenneth

    2003-01-01

    A cue-target visual attention task was administered to 25 children (ages 10-12) with dyslexia. Results showed a general pattern of slower responses in the children with dyslexia compared to controls. Subjects also had longer reaction times in the short and long cue-target interval conditions (covert and overt shift of attention). (Contains…

  12. Cognition, emotion, and attention.

    Science.gov (United States)

    Müller-Oehring, Eva M; Schulte, Tilman

    2014-01-01

    Deficits of attention, emotion, and cognition occur in individuals with alcohol abuse and addiction. This review elucidates the concepts of attention, emotion, and cognition and references research on the underlying neural networks and their compromise in alcohol use disorder. Neuroimaging research on adolescents with family history of alcoholism contributes to the understanding of pre-existing brain structural conditions and characterization of cognition and attention processes in high-risk individuals. Attention and cognition interact with other brain functions, including perceptual selection, salience, emotion, reward, and memory, through interconnected neural networks. Recent research reports compromised microstructural and functional network connectivity in alcoholism, which can have an effect on the dynamic tuning between brain systems, e.g., the frontally based executive control system, the limbic emotion system, and the midbrain-striatal reward system, thereby impeding cognitive flexibility and behavioral adaptation to changing environments. Finally, we introduce concepts of functional compensation, the capacity to generate attentional resources for performance enhancement, and brain structure recovery with abstinence. An understanding of the neural mechanisms of attention, emotion, and cognition will likely provide the basis for better treatment strategies for developing skills that enhance alcoholism therapy adherence and quality of life, and reduce the propensity for relapse. © 2014 Elsevier B.V. All rights reserved.

  13. Attention deficits and divorce.

    Science.gov (United States)

    Bouchard, Geneviève; Saint-Aubin, Jean

    2014-09-01

    Building on previous work on the role of attention deficits associated with the regulation of executive control in psychiatric disorders, we examine whether these attention deficits are related to an interpersonal disturbance, the experience of divorce. Attentional capacities of 95 randomly selected couples from the general population were measured with a well-established task, the Attentional Network Task, which assesses the efficiency of 3 attention networks (that is, alerting, orienting, and executive control). Among the 190 participants, 32 had experienced a divorce in the past. ANCOVAs were used to compare divorced people in marital or cohabiting unions with people in first unions in their performance on this purely cognitive task. Our findings indicate that divorced people who are currently living in a cohabiting relationship show significantly lower executive control than other adults living as couples, after controlling for sex, age, income, and education. This subgroup of divorced people not only exhibit greater difficulty in responding to some stimuli while ignoring irrelevant ones but also manifest cognitive deficits in conflict resolution. This study highlights the links between attention and the long-term maintenance of intimate relationships. Our results may have important implications for the identification of people at risk for divorce.

  14. A Real Attention-Getter

    Science.gov (United States)

    2003-01-01

    While most parents would agree that playing videos games is the antithesis of time well spent for their children, recent advances involving NASA biofeedback technology are proving otherwise. The same techniques used to measure brain activity in NASA pilots during flight simulation exercises are now a part of a revolutionary video game system that is helping to improve overall mental awareness for Americans of all ages, including those who suffer from Attention Deficit Hyperactivity Disorder (ADHD).

  15. Attentional Capture in Driving Displays

    Science.gov (United States)

    Arexis, Mahé; Maquestiaux, François; Gaspelin, Nicholas; Ruthruff, Eric; Didierjean, André

    2016-01-01

    Drivers face frequent distraction on the roadways but little is known about situations placing them at risk of misallocating visual attention. To investigate this issue, we asked participants to search for a red target embedded within simulated driving scenes (photographs taken from inside a car) in three experiments. Distraction was induced by presenting, via a GPS unit, red or green distractors positioned in an irrelevant location at which the target never appeared. If the salient distractor captures attention, visual search should be slower on distractor-present trials than distractor-absent trials. In Experiment 1, salient distractors yielded no such capture effect. In Experiment 2, we decreased the frequency of the salient distractor from 50% of trials to only 10% or 20% of trials. Capture effects were almost five times larger for the 10% occurrence group than for the 20% occurrence group. In Experiment 3, the amount of available central resources was manipulated by asking participants to either simultaneously monitor or ignore a stream of spoken digits. Capture effects were much larger for the dual-task group than for the single-task group. In summary, these findings identify risk factors for attentional capture in real-world driving scenes: distractor rarity and diversion of attention. PMID:28369841

  16. Health Warning Labels for Smokeless Tobacco: The Impact of Graphic Images on Attention, Recall, and Craving.

    Science.gov (United States)

    Klein, Elizabeth G; Quisenberry, Amanda J; Shoben, Abigail B; Cooper, Sarah; Ferketich, Amy K; Berman, Micah; Peters, Ellen; Wewers, Mary Ellen

    2017-10-01

    Little research has examined the impacts of graphic health warnings on the users of smokeless tobacco products. A convenience sample of past-month, male smokeless tobacco users (n = 142; 100% male) was randomly assigned to view a smokeless tobacco advertisement with a graphic health warning (GHW) or a text-only warning. Eye-tracking equipment measured viewing time, or dwell time, in milliseconds. Following the advertisement exposure, participants self-reported smokeless tobacco craving and recalled any content in the health warning message (unaided recall). Linear and logistic regression analyses evaluated the proportion of time viewing the GHW, craving, and GHW recall. Participants who viewed a GHW spent a significantly greater proportion of their ad viewing time on GHWs (2.87 seconds or 30%), compared to those viewing a text-only warning (2.05 seconds or 24%). Although there were no significant differences by condition in total advertisement viewing duration, those participants viewing a GHW had increased recall of health warning messages compared to the text-only warning (76% had any warning message recall compared to 53%; p < .05). Self-reported craving after advertisement exposure was lower in the GHW compared to text-only condition, but the difference was not statistically significant (a rating of 4.4 vs. 5.3 on a 10-point scale; p = .08). GHWs attracted greater attention and greater recall of health warning messages compared to text-only warnings among rural male smokeless tobacco users. Among a sample of rural smokeless tobacco users, GHWs attracted more attention and recall of health warning messages compared to text-only warnings when viewed within smokeless tobacco advertising. These findings provide additional empirical support that GHWs are an effective tobacco control tool for all tobacco products and advertisements.

  17. Connectivity supporting attention in children with attention deficit hyperactivity disorder

    Directory of Open Access Journals (Sweden)

    Anita D. Barber

    2015-01-01

    While CON–DMN anti-correlation is associated with improved attention in ADHD, other circuitry supports improved attention in TD children. Greater CON–DMN anti-correlation supported better attentional control in children with ADHD, but worse attentional control in TD children. On the other hand, greater DMN–occipital anti-correlation supported better attentional control in TD children.

  18. Window opening behaviour modelled from measurements in Danish dwellings

    DEFF Research Database (Denmark)

    Andersen, Rune Korsholm; Fabi, Valentina; Toftum, Jorn

    2013-01-01

    environment.Measurements of occupant's window opening behaviour were conducted in 15 dwellings in Denmark during eight months. Indoor and outdoor environmental conditions were monitored in an effort to relate the behaviour of the occupants to the environmental conditions. The dwellings were categorized......A method of defining occupants' window opening behaviour patterns in simulation programs, based on measurements is proposed.Occupants' window opening behaviour has a strong effect on indoor environment and the energy consumed to sustain it. Only few models of window opening behaviour exist...... and these are solely based on the thermal indoor/outdoor environment. Consequently, users of simulation software are often left with little or no guidance for the modelling of occupants' window opening behaviour, resulting in potentially large discrepancies between real and simulated energy consumption and indoor...

  19. A search profile for dwellings with elevated radon levels

    DEFF Research Database (Denmark)

    Damkjær, A.; Andersen, C.E.; Majborn, B.

    1996-01-01

    A search profile for dwellings with elevated radon levels has been employed to investigate possibly radon-prone areas in Denmark and to find houses suitable for radon mitigation studies. The profile is defined as dwellings which are single-family houses with slab-on-grade foundation or partly...... basement/slab-on-grade foundation built on either fractured granitic basement rocks, or fractured limestone. Clayey till areas were also included in the profile in order to confirm earlier findings. Three areas representing these surface geologies were selected for indoor radon measurements with CR-39...... track detectors, and a total of 200 houses matching the profile underwent radon measurements during the winter 1994-95. The distribution of the measured radon concentrations were found in most cases to comply with log-normal distributions. Measurements in the living rooms of houses in each of the three...

  20. Sound classification of dwellings - Comparison of schemes in Europe

    DEFF Research Database (Denmark)

    Rasmussen, Birgit

    2009-01-01

    , facade sound insulation and installation noise. The quality classes reflect dierent levels of acoustical comfort. The paper presents and compares the sound classification schemes in Europe. The schemes have been implemented and revised gradually since the 1990es. However, due to lack of coordination......, there are significant discrepancies. Descriptors, number of quality classes, class intervals, class levels and status of the classification schemes in relation to legal requirements vary. In some countries the building code and the classification standard are incoherent. In other countries, they are strongly......National sound classification schemes for dwellings exist in nine countries in Europe, and proposals are under preparation in more countries. The schemes specify class criteria concerning several acoustic aspects, the main criteria being about airborne and impact sound insulation between dwellings...

  1. On sine dwell or broadband methods for modal testing

    Science.gov (United States)

    Chen, Jay-Chung; Wada, Ben K.

    1987-01-01

    For large, complex spacecraft structural systems, the objectives of the modal test are outlined. Based on these objectives, the comparison criteria for the modal test methods, namely, the broadband excitation and the sine dwell methods are established. Using the Galileo spacecraft modal test and the Centaur G Prime upper stage vehicle modal test as examples, the relative advantages or disadvantages of each method are examined. The usefulness or shortcoming of the methods are given from a practicing engineer's view point.

  2. Comparison of sine dwell and broadband methods for modal testing

    Science.gov (United States)

    Chen, Jay-Chung

    1989-01-01

    The objectives of modal tests for large complex spacecraft structural systems are outlined. The comparison criteria for the modal test methods, namely, the broadband excitation and the sine dwell methods, are established. Using the Galileo spacecraft modal test and the Centaur G Prime upper stage vehicle modal test as examples, the relative advantage or disadvantage of each method is examined. The usefulness or shortcomings of the methods are given from a practical engineering viewpoint.

  3. The joint choice of tenure, dwelling type and size

    DEFF Research Database (Denmark)

    Frenkel, Amnon; Bendit, Eduard; Kaplan, Sigal

    involving tenure, dwelling type and size. However, the increasing importance attributed to leisure activities as a lifestyle choice, in particular in knowledge-based economy, suggests that lifestyle may have a significant effect on these housing preferences. The current study investigates the hypothesis...... to reside in small rented apartments increases with the tendency to lead an active lifestyle full of cultural, entertainment and sport activities....

  4. Radon concentration levels in dwellings and mine atmospheres in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Segovia, N.; Pena, P. [Instituto Nacional de Investigaciones Nucleares, Mexico City (Mexico); Mireles, F.; Davila, I.; Quirino, L. [Universidad Autonoma de Zacatecas (Mexico). Centro Regional de Estudios Nucleares

    1993-12-31

    Atmospheric radon surveys have been conducted in dwellings and mine atmospheres from the city of Zacatecas and single family homes in Mexico City. The monitoring was performed with track detectors, LR115 type II. The radon concentration values in most of the atmospheres studied were less than 150 Bq/m{sup 3}; the maximum value at the top soil in mines reached 1200 Bq/m{sup 3}. (author).

  5. Falls and fall prevention in community-dwelling older adults

    OpenAIRE

    Tuvemo Johnson, Susanna

    2018-01-01

    Falls are the primary cause of injuries among older adults, and accidents that result from falls can lead to personal suffering and extensive societal burdens. The overall aims of this thesis were to explore and describe falls and fall prevention strategies in community-dwelling older adults and to evaluate a fall prevention home exercise program, the Otago Exercise Program (OEP), with or without motivational interviewing (MI). Methods: Qualitative and quantitative research methods were uses....

  6. Twelve-week physical and leisure activity programme improved cognitive function in community-dwelling elderly subjects: a randomized controlled trial.

    Science.gov (United States)

    Kamegaya, Tadahiko; Araki, Yumi; Kigure, Hanami; Yamaguchi, Haruyasu

    2014-03-01

    Japan is one of the most rapidly ageing societies in the world. A number of municipalities have started services for the prevention of cognitive decline for community-dwelling elderly individuals, but the effectiveness of these services is currently insufficient. Our study explored the efficacy of a comprehensive intervention programme consisting of physical and leisure activities to prevent cognitive decline in community-dwelling elderly subjects. We administered a 12-week intervention programme consisting of physical and leisure activities aimed at enhancing participants' motivation to participate and support one another by providing a pleasant atmosphere, empathetic communication, praise, and errorless support. This programme for the prevention of cognitive decline was conducted as a service by the city of Maebashi. All participants underwent the Five-Cog test, which evaluated the cognitive domains of attention, memory, visuospatial function, language, and reasoning. Executive function was evaluated by the Wechsler Digit Symbol Substitution Test and Yamaguchi Kanji-Symbol Substitution Test. Subjective health status, level of social support, functional capacity, subjective quality of life, and depressive symptoms were assessed with a questionnaire. Grip strength test, timed up-and-go test, 5-m maximum walking times test, and functional reach test were performed to evaluate physical function. Fifty-two participants were randomly allocated to intervention (n = 26) and control (n = 26) groups. Twenty-six participants, aged between 65-87 years, received intervention once a week at a community centre. The programme was conducted by health-care professionals, with the help of senior citizen volunteers. The intervention group (n = 19) showed significant improvement on the analogy task of the Five-Cog test (F(1,38) = 4.242, P = 0.046) and improved quality of life (F(1,38) = 4.773, P = 0.035) as compared to the control group (n = 24). A community-based 12-week

  7. Attentional and affective consequences of technology supported mindfulness training: a randomised, active control, efficacy trial.

    Science.gov (United States)

    Bhayee, Sheffy; Tomaszewski, Patricia; Lee, Daniel H; Moffat, Graeme; Pino, Lou; Moreno, Sylvain; Farb, Norman A S

    2016-11-29

    Mindfulness training (MT) programs represent an approach to attention training with well-validated mental health benefits. However, research supporting MT efficacy is based predominantly on weekly-meeting, facilitator-led, group-intervention formats. It is unknown whether participants might benefit from neurofeedback-assisted, technology-supported MT (N-tsMT), in which meditation is delivered individually, without the need for a facilitator, travel to a training site, or the presence of a supportive group environment. Mirroring the validation of group MT interventions, the first step in addressing this question requires identifying whether N-tsMT promotes measurable benefits. Here, we report on an initial investigation of a commercial N-tsMT system. In a randomized, active control trial, community-dwelling healthy adult participants carried out 6 weeks of daily practice, receiving either N-tsMT (n = 13), or a control condition of daily online math training (n = 13). Training effects were assessed on target measures of attention and well-being. Participants also completed daily post-training surveys assessing effects on mood, body awareness, calm, effort, and stress. Analysis revealed training effects specific to N-tsMT, with attentional improvements in overall reaction time on a Stroop task, and well-being improvements via reduced somatic symptoms on the Brief Symptom Inventory. Attention and well-being improvements were correlated, and effects were greatest for the most neurotic participants. However, secondary, exploratory measures of attention and well-being did not show training-specific effects. N-tsMT was associated with greater body awareness and calm, and initially greater effort that later converged with effort in the control condition. Preliminary findings indicate that N-tsMT promotes modest benefits for attention and subjective well-being in a healthy community sample relative to an active control condition. However, the findings would benefit

  8. Functional ability of community dwelling elderly. Criterion-related validity of a new measure of functional ability

    DEFF Research Database (Denmark)

    Schultz-Larsen, K; Avlund, K; Kreiner, S

    1992-01-01

    consumption and general practitioner (GP) consultations. The measure of functional ability was developed with the intention of achieving a high degree of discrimination among a group of community dwelling elderly. Data were derived from a sample survey of 70-year-old men and women conducted in 1984...... of diagnosed chronic diseases. At the same time these outcome measures together with diagnosed diseases were considered to predict drug consumption and GP consultations. It was shown that functional ability as measured by the new index scales were strongly influenced by diagnosed diseases: arteriostenosis...... but not self-rated health was a strong predictor for drug consumption and frequent contacts with GP. It is concluded that the new measure of functional ability is suitable for health studies of community dwelling elderly, in particular as a summary statement of the individual's health status....

  9. Modelling auditory attention.

    Science.gov (United States)

    Kaya, Emine Merve; Elhilali, Mounya

    2017-02-19

    Sounds in everyday life seldom appear in isolation. Both humans and machines are constantly flooded with a cacophony of sounds that need to be sorted through and scoured for relevant information-a phenomenon referred to as the 'cocktail party problem'. A key component in parsing acoustic scenes is the role of attention, which mediates perception and behaviour by focusing both sensory and cognitive resources on pertinent information in the stimulus space. The current article provides a review of modelling studies of auditory attention. The review highlights how the term attention refers to a multitude of behavioural and cognitive processes that can shape sensory processing. Attention can be modulated by 'bottom-up' sensory-driven factors, as well as 'top-down' task-specific goals, expectations and learned schemas. Essentially, it acts as a selection process or processes that focus both sensory and cognitive resources on the most relevant events in the soundscape; with relevance being dictated by the stimulus itself (e.g. a loud explosion) or by a task at hand (e.g. listen to announcements in a busy airport). Recent computational models of auditory attention provide key insights into its role in facilitating perception in cluttered auditory scenes.This article is part of the themed issue 'Auditory and visual scene analysis'. © 2017 The Authors.

  10. Kyphosis and incident falls among community-dwelling older adults.

    Science.gov (United States)

    McDaniels-Davidson, C; Davis, A; Wing, D; Macera, C; Lindsay, S P; Schousboe, J T; Nichols, J F; Kado, D M

    2017-10-10

    Hyperkyphosis commonly affects older persons and is associated with morbidity and mortality. Many have hypothesized that hyperkyphosis increases fall risk. Within this prospective study of older adults, kyphosis was significantly associated with incident falls over 1 year. Measures of hyperkyphosis could enhance falls risk assessments during primary care office visits. To determine the association between four measures of kyphosis and incident and injurious falls in older persons. Community-dwelling adults aged 65 and older (n = 72) residing in southern California were invited to participate in a prospective cohort study. Participants had kyphosis assessed four ways. Two standing measures included a flexicurve ruler placed against the back to derive a kyphotic index and the Debrunner kyphometer, a protractor used to measure the kyphotic angle in degrees. Two lying measures included the blocks method (number of 1.7 cm blocks needed to achieve a neutral head position while lying supine) and traditional Cobb angle calculation derived from DXA based lateral vertebral assessment. Baseline demographic, clinical, and other health information (including a timed up and go (TUG) test) were assessed at a clinic visit. Participants were followed monthly through email or postcard for 1 year, with falls outcomes confirmed through telephone interview. Mean age was 77.8 (± 7.1) among the 52 women and 20 men. Over 12 months, 64% of participants experienced at least one incident fall and 35% experienced an injurious fall. Each standard deviation increase in kyphosis resulted in more than doubling the adjusted odds of an incident fall, even after adjusting for TUG. Odds of injurious falls were less consistent across measures; after adjusting for TUG, only the blocks method was associated with injurious falls. Each kyphosis measure was independently associated with incident falls. Findings were inconsistent for injurious falls; the blocks measure suggested the strongest

  11. The reliability and preliminary validity of game-based fall risk assessment in community-dwelling older adults.

    Science.gov (United States)

    Yamada, Minoru; Aoyama, Tomoki; Nakamura, Masatoshi; Tanaka, Buichi; Nagai, Koutatsu; Tatematsu, Noriatsu; Uemura, Kazuki; Nakamura, Takashi; Tsuboyama, Tadao; Ichihashi, Noriaki

    2011-01-01

    The purpose of this study was to examine whether the Nintendo Wii Fit program could be used for fall risk assessment in healthy, community-dwelling older adults. Forty-five community-dwelling older women participated in this study. The "Basic Step" and "Ski Slalom" modules were selected from the Wii Fit game program. The following 5 physical performance tests were performed: the 10-m walk test under single- and dual-task conditions, the Timed Up and Go test under single- and dual-task conditions, and the Functional Reach test. Compared with the faller group, the nonfaller group showed a significant difference in the Basic Step (P Ski Slalom (P = .453). The discriminating criterion between the 2 groups was a score of 111 points on the Basic Step (P < .001). The Basic Step showed statistically significant, moderate correlations between the dual-task lag of walking (r = -.547) and the dual-task lag of the Timed Up and Go test (r = -.688). These results suggest that game-based fall risk assessment using the Basic Step has a high generality and is useful in community-dwelling older adults. Copyright © 2011 Mosby, Inc. All rights reserved.

  12. Factors Influencing Dwell Fatigue Cracking in Notches of Powder Metallurgy Superalloys

    Science.gov (United States)

    Gabb, T. P.; Telesman, J.; Ghosn, L.; Garg, A.; Gayda, J.

    2011-01-01

    The influences of heat treatment and cyclic dwells on the notch fatigue resistance of powder metallurgy disk superalloys were investigated for low solvus high refractory (LSHR) and ME3 disk alloys. Disks were processed to produce material conditions with varied microstructures and associated mechanical properties. Notched specimens were first subjected to baseline dwell fatigue cycles having a dwell at maximum load, as well as tensile, stress relaxation, creep rupture, and dwell fatigue crack growth tests at 704 C. Several material heat treatments displayed a bimodal distribution of fatigue life with the lives varying by two orders-of-magnitude, while others had more consistent fatigue lives. This response was compared to other mechanical properties, in search of correlations. The wide scatter in baseline dwell fatigue life was observed only for material conditions resistant to stress relaxation. For selected materials and conditions, additional tests were then performed with the dwells shifted in part or in total to minimum tensile load. The tests performed with dwells at minimum load exhibited lower fatigue lives than max dwell tests, and also exhibited early crack initiation and a substantial increase in the number of initiation sites. These results could be explained in part by modeling evolution of peak stresses in the notch with continued dwell fatigue cycling. Fatigue-environment interactions were determined to limit life for the fatigue cycles with dwells.

  13. Lung function in relation to farm dwelling and farming activities in rural dwelling children.

    Science.gov (United States)

    Balakrishnan, Lakshmi; Rennie, Donna; Dosman, James; Pahwa, Punam; Karunanayake, Chandima; Hagel, Louise; Lawson, Joshua

    2017-10-01

    The relationship between farming exposures and pulmonary function in a rural paediatric population was evaluated. Baseline data collection records of the Saskatchewan Rural Health Study (SRHS), a population-based study, were used. A subset of children (6-14 years old) participated in clinical testing, including anthropometric measures and pulmonary function testing (PFT), using spirometry (n = 584). PFTs followed ATS criteria and all statistical analyses were controlled for age, sex and height. Among clinical testing participants, 47.5% were females and 54.5% were farm dwelling. Of those living on farms, 77.5% were livestock farms. Mean percent predicted value (PPV) for forced expiratory volume in 1 s (FEV 1 ) and forced vital capacity (FVC) among children living on a farm were 104.8% and 105.4%, respectively. Mean PPV for FEV 1 and FVC among children not living on a farm were 102.7% and 101.4%, respectively. After adjustment, higher FEV 1 (=0.079, SE = 0.033, P = 0.03) and FVC (=0.110, SE = 0.039, P = 0.006) were seen among children living on a farm. A trend towards lower FEV 1 /FVC ratio (-0.013, SE = 0.008, P = 0.09) among children living on a farm was seen compared with children not living on a farm. Higher FVC and lower FEV 1 /FVC ratio were seen in children who regularly emptied grain bins (P children living on a farm in the first year of life. Since the majority of the population was Caucasian (91%), the results were not race-corrected. We addressed the lack of knowledge regarding the association between lung function and rural exposures, and found that differences in lung function were seen between children living on a farm and not living on a farm in rural areas and certain farming activities, specifically emptying grain bins, where lung function was generally better in those living on a farm. © 2017 Asian Pacific Society of Respirology.

  14. Cognitive Penetration and Attention

    Science.gov (United States)

    Gross, Steven

    2017-01-01

    Zenon Pylyshyn argues that cognitively driven attentional effects do not amount to cognitive penetration of early vision because such effects occur either before or after early vision. Critics object that in fact such effects occur at all levels of perceptual processing. We argue that Pylyshyn’s claim is correct—but not for the reason he emphasizes. Even if his critics are correct that attentional effects are not external to early vision, these effects do not satisfy Pylyshyn’s requirements that the effects be direct and exhibit semantic coherence. In addition, we distinguish our defense from those found in recent work by Raftopoulos and by Firestone and Scholl, argue that attention should not be assimilated to expectation, and discuss alternative characterizations of cognitive penetrability, advocating a kind of pluralism. PMID:28275358

  15. Attention in Urban Foraging

    Directory of Open Access Journals (Sweden)

    Malcolm McCullough

    2013-05-01

    Full Text Available This position paper argues how there has to be much more to smart city learning than just wayshowing, and something better as augmented reality than covering the world with instructions. Attention has become something for many people to know better in an age of information superabundance. Embodied cognition explains how the work-ings of attention are not solely a foreground task, as if attention is something to pay. As digital media appear in ever more formats and contexts, their hybrids with physical form increasing influence how habitual engagement with persistent situations creates learning. Ambient information can just add to the distraction by multitasking, or it can support more favorable processes of shifting among different kinds of information with a particular intent. As one word for this latter process, foraging deserves more consideration in smart city learning

  16. Attention: an evolving construct.

    Science.gov (United States)

    Joyce, Arthur; Hrin, Skip

    2015-01-01

    We review the implications of large-scale brain systems on the construct of attention by first focusing on significant theories and discoveries during the previous 150 years and then considering how the comparatively recent discovery of large-scale brain systems may render previous conceptualizations of attention outdated. Seven functional brain networks are briefly reviewed and the implications of emerging principles of brain functioning for test construction and neuropsychological evaluation are considered. To remain a relevant discipline moving into the 21st century, the field of neuropsychology needs to apply the principles that have been discovered about brain networks to better inform our understanding of attention as well as our ever-refining evaluation of this construct.

  17. Visual attention capacity

    DEFF Research Database (Denmark)

    Habekost, Thomas; Starrfelt, Randi

    2009-01-01

    Psychophysical studies have identified two distinct limitations of visual attention capacity: processing speed and apprehension span. Using a simple test, these cognitive factors can be analyzed by Bundesen's Theory of Visual Attention (TVA). The method has strong specificity and sensitivity...... to patient testing, and review existing TVA-based patient studies organized by lesion anatomy. Lesions in three anatomical regions affect visual capacity: The parietal lobes, frontal cortex and basal ganglia, and extrastriate cortex. Visual capacity thus depends on large, bilaterally distributed anatomical...... networks that include several regions outside the visual system. The two visual capacity parameters are functionally separable, but seem to rely on largely overlapping brain areas....

  18. Attention modulates emotional expression processing.

    Science.gov (United States)

    Wronka, Eligiusz; Walentowska, Wioleta

    2011-08-01

    To investigate the time course of emotional expression processing, we recorded ERPs to facial stimuli. The first task was to discriminate emotional expressions. Enhanced negativity of the face-specific N170 was elicited by emotional as opposed to neutral faces, followed by the occipital negativity (240-340 ms poststimulus). The second task was to classify face gender. Here, N170 was unaffected by the emotional expression. However, emotional expression effect was expressed in the anterior positivity (160-250 ms poststimulus) and subsequent occipital negativity (240-340 ms poststimulus). Results support the thesis that structural encoding relevant to gender recognition and simultaneous expression analysis are independent processes. Attention modulates facial emotion processing 140-185 ms poststimulus. Involuntary differentiation of facial expression was observed later (160-340 ms poststimulus), suggesting unintentional attention capture. Copyright © 2011 Society for Psychophysiological Research.

  19. Exposure to ultrafine particles in relation to indoor events and dwelling characteristics

    DEFF Research Database (Denmark)

    Spilak, Michal; Frederiksen, Marie; Kolarik, Barbara

    2014-01-01

    Exposure to ultrafine particles (UFP) in homes is associated with health risks such as cardiovascular disease and/or respiratory problems. These risks are heightened by the long time that people spend indoors. Therefore reducing the particle concentration in homes leads to improved health among i....... Furthermore, the winter season was associated significantly with high UFP levels indoors. Results of our study also indicated that owning a pet, wood-type floors and floor levels close to the ground are associated with increased UFP levels....... occupants. The use of particle filtration units may be an effective way of reducing UFP indoors. The purpose of this study was to evaluate associations between UFP concentrations and dwelling characteristics, estimate UFP removal rates indoors and to assess the effectiveness of installed particle filtration...... rate was increased from 0.33 h-1 to 1.94 h-1. We found human activities to be far more relevant to high UFP concentrations than dwelling characteristics. Window–opening habits reduce exposure to UFP during peaks caused by occupant behaviour and increase exposure to UFP during low indoor activity...

  20. Prevalence and risk factors of fecal incontinence in community-dwelling men.

    Science.gov (United States)

    Shamliyan, Tatyana A; Bliss, Donna Z; Du, Jing; Ping, Ryan; Wilt, Timothy J; Kane, Robert L

    2009-01-01

    Fecal incontinence (FI) in community-dwelling men affects quality of life and increases the risk of institutionalization. Observational studies and randomized, controlled trials (RCTs) on epidemiology and prevention of FI published in English from 1990 to November 2007 were identified in several databases to abstract rates and adjusted odds ratios (ORs) of incontinence and to synthesize evidence with random effects models. Twenty-one observational studies and 4 RCTs were eligible for analysis. Pooled prevalence of FI in elderly men increased with age to 5% to 6%. Men over age 85 years (OR 2.5; 95% confidence interval [CI], 1.3-5) and with kidney diseases (OR 1.9; 95% CI, 1.2-3.3) had higher odds of incident FI. Significantly impaired cognitive status and general health were associated with FI. Men had increased risk of incontinence after radical prostatectomy or radiation for prostate cancer. Lower doses of radiation caused inconsistent reduction in FI across 2 RCTs. The prevalence of incontinence increased with age and functional dependency. Cognitive impairment, poor general health, surgery, and radiation for prostate cancer were associated with incontinence in community-dwelling men. No effective interventions are known at the present time.

  1. Sustained Attention Ability Affects Simple Picture Naming

    Directory of Open Access Journals (Sweden)

    Suzanne R. Jongman

    2017-07-01

    Full Text Available Sustained attention has previously been shown as a requirement for language production. However, this is mostly evident for difficult conditions, such as a dual-task situation. The current study provides corroborating evidence that this relationship holds even for simple picture naming. Sustained attention ability, indexed both by participants’ reaction times and individuals’ hit rate (the proportion of correctly detected targets on a digit discrimination task, correlated with picture naming latencies. Individuals with poor sustained attention were consistently slower and their RT distributions were more positively skewed when naming pictures compared to individuals with better sustained attention. Additionally, the need to sustain attention was manipulated by changing the speed of stimulus presentation. Research has suggested that fast event rates tax sustained attention resources to a larger degree than slow event rates. However, in this study the fast event rate did not result in increased difficulty, neither for the picture naming task nor for the sustained attention task. Instead, the results point to a speed-accuracy trade-off in the sustained attention task (lower accuracy but faster responses in the fast than in the slow event rate, and to a benefit for faster rates in the picture naming task (shorter naming latencies with no difference in accuracy. Performance on both tasks was largely comparable, supporting previous findings that sustained attention is called upon during language production.

  2. Selective Attention and Drug Related Attention Bias in Methadone Maintenance Patients

    Directory of Open Access Journals (Sweden)

    Majid Nejati

    2011-12-01

    Full Text Available One of the main problems of the drug abusers is drug related attention bias, which causes craving, and as a result drive the drug abusers to take narcotics. Methadone is used as a maintenance treatment for drug abusers. The purpose of this study is evaluation of the effect of Methadone maintenance therapy (MMT on selective attention and drug related attention bias. This study investigated drug cue-related attention bias and selective attention in 16 methadone-maintained patients before and 45 days after methadone therapy period. Stroop color-word test and addiction Stroop test were used as measurement methods. Results show less reaction time and higher accuracy in Color-Word Stroop Test after MMT and less delay for addict related word in addiction Stroop test. It is concluded that methadone can improve selective attention capability and reduce drug related attention bias.

  3. Attention as foraging for information and reward

    Directory of Open Access Journals (Sweden)

    Sanjay G Manohar

    2013-11-01

    Full Text Available What is the purpose of attention? One avenue of research has led to the proposal that attention might be crucial for gathering information about the environment, while other lines of study have demonstrated attention's role in guiding behavior to rewarded options. Many experiments to study attention require participants to make a decision based on information acquired discretely at one point in time. In real-world situations, however, we are usually not presented with information about which option to select in such a manner. Rather we must initially search for information, weighing up reward values of options before we commit to a decision.Here, we propose that attention plays a role in both foraging for information and foraging for value.When foraging for information, attention is guided towards the unknown. When foraging for reward, attention is guided towards high reward values, allowing decision-making to proceed by accept-or-reject decisions on the currently attended option. According to this account, attention can be regarded as a low-cost alternative to moving around and engaging with the environment—teleforaging—before a decision is made to interact physically with the world.To track the timecourse of attention, we asked participants to seek out and acquire information about two gambles by directing their gaze, before choosing one of them. Participants often made multiple refixations on items before making a decision. Their eye movements revealed that early in the trial, attention was guided towards information, i.e. towards locations that reduced uncertainty about value. In contrast, late in the trial, attention was guided by expected value of the options. At the end of the decision period, participants were generally attending to the item they eventually chose. We suggest that attentional foraging shifts from an uncertainty-driven to a reward-driven mode during the evolution of a decision, allowing choices to be made by an engage

  4. Attention as foraging for information and value.

    Science.gov (United States)

    Manohar, Sanjay G; Husain, Masud

    2013-01-01

    What is the purpose of attention? One avenue of research has led to the proposal that attention might be crucial for gathering information about the environment, while other lines of study have demonstrated how attention may play a role in guiding behavior to rewarded options. Many experiments that study attention require participants to make a decision based on information acquired discretely at one point in time. In real-world situations, however, we are usually not presented with information about which option to select in such a manner. Rather we must initially search for information, weighing up reward values of options before we commit to a decision. Here, we propose that attention plays a role in both foraging for information and foraging for value. When foraging for information, attention is guided toward the unknown. When foraging for reward, attention is guided toward high reward values, allowing decision-making to proceed by accept-or-reject decisions on the currently attended option. According to this account, attention can be regarded as a low-cost alternative to moving around and physically interacting with the environment-"teleforaging"-before a decision is made to interact physically with the world. To track the timecourse of attention, we asked participants to seek out and acquire information about two gambles by directing their gaze, before choosing one of them. Participants often made multiple refixations on items before making a decision. Their eye movements revealed that early in the trial, attention was guided toward information, i.e., toward locations that reduced uncertainty about value. In contrast, late in the trial, attention was guided by expected value of the options. At the end of the decision period, participants were generally attending to the item they eventually chose. We suggest that attentional foraging shifts from an uncertainty-driven to a reward-driven mode during the evolution of a decision, permitting decisions to be made by

  5. Attention in schizophrenia and in epileptic psychosis

    Directory of Open Access Journals (Sweden)

    I.C.J Kairalla

    2008-01-01

    Full Text Available The adaptive behavior of human beings is usually supported by rapid monitoring of outstanding events in the environment. Some investigators have suggested that a primary attention deficit might trigger symptoms of schizophrenia. In addition, researchers have long discussed the relationship between schizophrenia and the schizophrenia-like psychosis of epilepsy (SLPE. On the basis of these considerations, the objective of the present study was to investigate attention performance of patients with both disorders. Patient age was 18 to 60 years, and all patients had received formal schooling for at least four years. Patients were excluded if they had any systemic disease with neurologic or psychiatric comorbidity, or a history of brain surgery. The computer-assisted TAVIS-2R test was applied to all patients and to a control group to evaluate and discriminate between selective, alternating and sustained attention. The TAVIS-2R test is divided into three parts: one for selective attention (5 min, the second for alternating attention (5 min, and the third for the evaluation of vigilance or sustained attention (10 min. The same computer software was used for statistical analysis of reaction time, omission errors, and commission errors. The sample consisted of 36 patients with schizophrenia, 28 with interictal SLPE, and 47 healthy controls. The results of the selective attention tests for both patient groups were significantly lower than that for controls. The patients with schizophrenia and SLPE performed differently in the alternating and sustained attention tests: patients with SLPE had alternating attention deficits, whereas patients with schizophrenia showed deficits in sustained attention. These quantitative results confirmed the qualitative clinical observations for both patient groups, that is, that patients with schizophrenia had difficulties in focusing attention, whereas those with epilepsy showed perseveration in attention focus.

  6. Habitual attention in older and young adults.

    Science.gov (United States)

    Jiang, Yuhong V; Koutstaal, Wilma; Twedell, Emily L

    2016-12-01

    Age-related decline is pervasive in tasks that require explicit learning and memory, but such reduced function is not universally observed in tasks involving incidental learning. It is unknown if habitual attention, involving incidental probabilistic learning, is preserved in older adults. Previous research on habitual attention investigated contextual cuing in young and older adults, yet contextual cuing relies not only on spatial attention but also on context processing. Here we isolated habitual attention from context processing in young and older adults. Using a challenging visual search task in which the probability of finding targets was greater in 1 of 4 visual quadrants in all contexts, we examined the acquisition, persistence, and spatial-reference frame of habitual attention. Although older adults showed slower visual search times and steeper search slopes (more time per additional item in the search display), like young adults they rapidly acquired a strong, persistent search habit toward the high-probability quadrant. In addition, habitual attention was strongly viewer-centered in both young and older adults. The demonstration of preserved viewer-centered habitual attention in older adults suggests that it may be used to counter declines in controlled attention. This, in turn, suggests the importance, for older adults, of maintaining habit-related spatial arrangements. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  7. Solar Energy Gain and Space-Heating Energy Supply Analyses for Solid-Wall Dwelling Retrofitted with the Experimentally Achievable U-value of Novel Triple Vacuum Glazing

    Directory of Open Access Journals (Sweden)

    Saim Memon

    2017-06-01

    Full Text Available A considerable effort is devoted to devising retrofit solutions for reducing space-heating energy in the domestic sector. Existing UK solid-wall dwellings, which have both heritage values and historic fabric, are being improved but they tend to have meagre thermal performance, partly, due to the heat-loss through glazings. This paper takes comparative analyses approach to envisage space-heating supply required in order to maintain thermal comfort temperatures and attainable solar energy gains to households with the retrofit of an experimentally achievable thermal performance of the fabricated sample of triple vacuum glazing to a UK solid-wall dwelling. 3D dynamic thermal models (timely regimes of heating, occupancy, ventilation and internal heat gains of an externally-insulated solid-wall detached dwelling with a range of existing glazing types along with triple vacuum glazings are modelled. A dramatic decrease of space-heating load and moderate increase of solar gains are resulted with the dwelling of newly achievable triple vacuum glazings (having centre-of-pane U-value of 0.33 Wm-2K-1 compared to conventional glazing types. The space-heating annual cost of single glazed dwellings was minimised to 15.31% (≈USD 90.7 with the retrofit of triple-vacuum glazings. An influence of total heat-loss through the fabric of solid-wall dwelling was analysed with steady-state calculations which indicates a fall of 10.23 % with triple vacuum glazings compared to single glazings.

  8. Managerial Attention in International SMEs

    NARCIS (Netherlands)

    Fan, Jiasi

    2017-01-01

    Managerial attention affects organizational strategies and the resulting consequences. In the international business context, it is noted that how much attention managers give to the international marketplace, i.e., international attention, has profound implications for large global companies’

  9. Visual attention during spatial language comprehension.

    Directory of Open Access Journals (Sweden)

    Michele Burigo

    Full Text Available Spatial terms such as "above", "in front of", and "on the left of" are all essential for describing the location of one object relative to another object in everyday communication. Apprehending such spatial relations involves relating linguistic to object representations by means of attention. This requires at least one attentional shift, and models such as the Attentional Vector Sum (AVS predict the direction of that attention shift, from the sausage to the box for spatial utterances such as "The box is above the sausage". To the extent that this prediction generalizes to overt gaze shifts, a listener's visual attention should shift from the sausage to the box. However, listeners tend to rapidly look at referents in their order of mention and even anticipate them based on linguistic cues, a behavior that predicts a converse attentional shift from the box to the sausage. Four eye-tracking experiments assessed the role of overt attention in spatial language comprehension by examining to which extent visual attention is guided by words in the utterance and to which extent it also shifts "against the grain" of the unfolding sentence. The outcome suggests that comprehenders' visual attention is predominantly guided by their interpretation of the spatial description. Visual shifts against the grain occurred only when comprehenders had some extra time, and their absence did not affect comprehension accuracy. However, the timing of this reverse gaze shift on a trial correlated with that trial's verification time. Thus, while the timing of these gaze shifts is subtly related to the verification time, their presence is not necessary for successful verification of spatial relations.

  10. Mental training enhances attentional stability: neural and behavioral evidence

    NARCIS (Netherlands)

    Lutz, A.; Slagter, H.A.; Rawlings, N.B.; Francis, A.D.; Greischar, L.L.; Davidson, R.J.

    2009-01-01

    The capacity to stabilize the content of attention over time varies among individuals, and its impairment is a hallmark of several mental illnesses. Impairments in sustained attention in patients with attention disorders have been associated with increased trial-to-trial variability in reaction time

  11. Understanding and Working with Attention Deficit Disorder Students

    Science.gov (United States)

    Buttery, Thomas J.

    2009-01-01

    From a holistic perspective the term attention refers to a student's capacity to focus, direct and sustain their attention on a particular stimulus within their environment for a significant period of time. The development of students' attention spans develops progressively from the time they enter school. From the beginning some students have…

  12. Phenomenology of Joint Attention

    African Journals Online (AJOL)

    denise

    of phenomenology by offering a phenomenology of joint attention. The first section reviews elementary. Husserlian phenomenology and introduces a system for symbolically representing the structure of intentional mental states. The second section summarizes Edith Stein's phenomenological description of empathy, the ...

  13. Attention, Predation, Counterintuition

    DEFF Research Database (Denmark)

    Clasen, Mathias

    2012-01-01

    of Dracula to account for the novel’s impact and resilience. Dracula connected squarely with late-Victorian anxieties, but the novel also appeals to trans-historical adaptive dispositions. I analyze Stoker’s use of narrative strategies to grab and sustain attention, and Count Dracula as a supercharged...

  14. The Attention Economy

    Directory of Open Access Journals (Sweden)

    Süreyya Çankırı

    2013-11-01

    Full Text Available Understanding the New Currency of Business (originally published by Harvard Business School Press stands out as a new and significant work. The book analyses the psychological dimensions of attention while presenting its key applications in advertising, e­commerce, information management and strategy.

  15. Survey of Occupant behavour and control of the indoor environment in Danish Dwellings

    DEFF Research Database (Denmark)

    Andersen, Rune Vinther; Toftum, Jørn; Olesen, Bjarne W.

    2007-01-01

    : Outdoor temperature, wind speed and solar radiation, the outdoor temperature had the largest effect on the proportion of dwellings with windows open and heating on. The solar radiation had a small effect on the proportion of dwellings with lights on, while none of the parameters seemed to affect...... the proportion of dwellings with solar shading in use. The most significant reason listed for opening the windows in summer and winter was to obtain more air movement. Danish dwellings and European offices were affected in the same way by the outdoor temperature, when it comes to the proportion of dwellings....../offices with windows open or heating on. The outdoor temperature did not seem to affect the proportion of dwellings with solar shading in use....

  16. Two systems drive attention to rewards

    Directory of Open Access Journals (Sweden)

    Christopher K Kovach

    2014-02-01

    Full Text Available How options are framed can dramatically influence choice preference. While salience of information plays a central role in this effect, precisely how it is mediated by attentional processes remains unknown. Current models assume a simple relationship between attention and choice, according to which attention should uniformly bias preference towards the attended item over the whole time-course of a decision between similarly valued items. To test this prediction we considered how framing alters attention during a simple choice between two options, using eye movements as a sensitive online measure of attention. In one condition participants selected the less preferred item to discard and in the other, the more preferred item to kee