Rapid Acquisition of Preference in Concurrent Chains: Effects of "d"-Amphetamine on Sensitivity to Reinforcement Delay

ERIC Educational Resources Information Center

Ta, Wei-Min; Pitts, Raymond C.; Hughes, Christine E.; McLean, Anthony P.; Grace, Randolph C.

2008-01-01

The purpose of this study was to examine effects of "d"-amphetamine on choice controlled by reinforcement delay. Eight pigeons responded under a concurrent-chains procedure in which one terminal-link schedule was always fixed- interval 8 s, and the other terminal-link schedule changed from session to session between fixed-interval 4 s and…

24-Month-Olds Use Conceptual Similarity to Solve New Problems after a Delay

ERIC Educational Resources Information Center

Hayne, Harlene; Gross, Julien

2015-01-01

In this experiment, we used the deferred imitation paradigm to assess 24-month-olds' ability to use conceptual similarity to solve new problems after a delay. Infants in the experimental condition participated in four sessions that were each separated by 24 h. In Session 1, the experimenter modeled three target actions using one set of stimuli and…

Intertrial Sources of Stimulus Control and Delayed Matching-to-Sample Performance in Humans

ERIC Educational Resources Information Center

Williams, Dean C.; Johnston, Mark D.; Saunders, Kathryn J.

2006-01-01

Two experiments compared delayed matching-to-sample (DMTS) accuracy under 2 procedures in adults with mental retardation. In the trial-unique procedure, every trial in a session contained different stimuli. Thus, comparison stimuli that were correct on one trial were never incorrect on other trials in that session (or vice versa). In the 2-sample…

BCAT Setup

NASA Image and Video Library

2011-10-24

ISS029-E-032412 (24 Oct. 2011) --- NASA Mike Fossum, Expedition 29 commander, conducts a session with the Binary Colloidal Alloy Test-6 (BCAT-6) experiment in the Kibo laboratory of the International Space Station.

BCAT Setup

NASA Image and Video Library

2011-10-24

ISS029-E-032414 (24 Oct. 2011) --- NASA Mike Fossum, Expedition 29 commander, conducts a session with the Binary Colloidal Alloy Test-6 (BCAT-6) experiment in the Kibo laboratory of the International Space Station.

BCAT Setup

NASA Image and Video Library

2011-10-24

ISS029-E-032422 (24 Oct. 2011) --- NASA Mike Fossum, Expedition 29 commander, conducts a session with the Binary Colloidal Alloy Test-6 (BCAT-6) experiment in the Kibo laboratory of the International Space Station.

BCAT Setup

NASA Image and Video Library

2011-10-24

ISS029-E-032410 (24 Oct. 2011) --- NASA Mike Fossum, Expedition 29 commander, conducts a session with the Binary Colloidal Alloy Test-6 (BCAT-6) experiment in the Kibo laboratory of the International Space Station.

Impaired flexibility in decision making in rats after administration of the pharmacological stressor yohimbine.

PubMed

Schwager, Andrea L; Haack, Andrew K; Taha, Sharif A

2014-10-01

Stress-induced disruption of decision making has been hypothesized to contribute to drug-seeking behaviors and addiction. Noradrenergic signaling plays a central role in mediating stress responses. However, the effects of acute stress on decision making, and the role of noradrenergic signaling in regulating these effects, have not been well characterized. To characterize changes in decision making caused by acute pharmacological stress, the effects of yohimbine (an α2-adrenergic antagonist) were examined in a delay discounting task. Noradrenergic contributions to decision making were further characterized by examining the effects of propranolol (a β antagonist), prazosin (an α1 antagonist), and guanfacine (an α2 agonist). Sprague-Dawley rats were administered drugs prior to performance on a delay discounting task, in which the delay preceding the large reward increased within each session (ascending delays). To dissociate drug-induced changes in delay sensitivity from behavioral inflexibility, drug effects were subsequently tested in a modified version of the discounting task, in which the delay preceding the large reward decreased within each session (descending delays). Yohimbine increased choice of the large reward when tested with ascending delays but decreased choice of the same large reward when tested with descending delays, suggesting that drug effects could be attributed to perseverative choice of the lever preferred at the beginning of the session. Propranolol increased choice of the large reward when tested with ascending delays. Prazosin and guanfacine had no effect on reward choice. The stress-like effects of yohimbine administration may impair decision making by causing inflexible, perseverative behavior.

BCAT setup in Kibo

NASA Image and Video Library

2014-06-03

ISS040-E-006891 (3 June 2014) --- NASA astronaut Reid Wiseman, Expedition 40 flight engineer, conducts a session with the Binary Colloidal Alloy Test (BCAT) experiment in the Kibo laboratory of the International Space Station.

Gaming used as an informal instructional technique: effects on learner knowledge and satisfaction.

PubMed

Webb, Travis P; Simpson, Deborah; Denson, Steven; Duthie, Edmund

2012-01-01

Jeopardy!, Concentration, quiz bowls, and other gaming formats have been incorporated into health sciences classroom and online education. However, there is limited information about the impact of these strategies on learner engagement and outcomes. To address this gap, we hypothesized that gaming would lead to a significant increase in retained short- and long-term medical knowledge with high learner session satisfaction. Using the Jeopardy! game show model as a primary instructional technique to teach geriatrics, 8 PGY2 General Surgery residents were divided into 2 teams and competed to provide the "question" to each stated "answer" during 5 protected block curriculum units (1-h/U). A surgical faculty facilitator acted as the game host and provided feedback and brief elaboration of quiz answers/questions as necessary. Each quiz session contained two 25-question rounds. Paper-based pretests and posttests contained questions related to all core curriculum unit topics with 5 geriatric gaming questions per test. Residents completed the pretests 3 days before the session and a delayed posttest of geriatric topics on average 9.2 weeks (range, 5-12 weeks) after the instructional session. The cumulative average percent correct was compared between pretests and posttests using the Student t test. The residents completed session evaluation forms using Likert scale ratings after each gaming session and each protected curriculum block to assess educational value. A total of 25 identical geriatric preunit and delayed postunit questions were administered across the instructional sessions. The combined pretest average score across all 8 residents was 51.5% for geriatric topics compared with 59.5% (p = 0.12) for all other unit topics. Delayed posttest geriatric scores demonstrated a statistically significant increase in retained medical knowledge with an average of 82.6% (p = 0.02). The difference between delayed posttest geriatric scores and posttest scores of all other unit topics was not significant. Residents reported a high level of satisfaction with the gaming sessions: The average session content rating was 4.9 compared with the overall block content rating of 4.6 (scale, 1-5, 5 = Outstanding). The quiz type and competitive gaming sessions can be used as a primary instructional technique leading to significant improvements in delayed posttests of medical knowledge and high resident satisfaction of educational value. Knowledge gains seem to be sustained based on the intervals between the interventions and recorded gains. Copyright © 2012 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

The Effects of Behavioral History on Response Acquisition with Immediate and Delayed Reinforcement

ERIC Educational Resources Information Center

Snycerski, Susan; Laraway, Sean; Huitema, Bradley E.; Poling, Alan

2004-01-01

Effects of prior exposure to the experimental chamber with levers present or absent and variable-time (VT) 60-s water deliveries arranged during one, five, or no 1-hr sessions were examined in rats during a 6-hr response-acquisition session in which presses on one lever produced water delivery immediately or after a 15-s resetting delay, and…

Schedule for CT image guidance in treating prostate cancer with helical tomotherapy

PubMed Central

Beldjoudi, G; Yartsev, S; Bauman, G; Battista, J; Van Dyk, J

2010-01-01

The aim of this study was to determine the effect of reducing the number of image guidance sessions and patient-specific target margins on the dose distribution in the treatment of prostate cancer with helical tomotherapy. 20 patients with prostate cancer who were treated with helical tomotherapy using daily megavoltage CT (MVCT) imaging before treatment served as the study population. The average geometric shifts applied for set-up corrections, as a result of co-registration of MVCT and planning kilovoltage CT studies over an increasing number of image guidance sessions, were determined. Simulation of the consequences of various imaging scenarios on the dose distribution was performed for two patients with different patterns of interfraction changes in anatomy. Our analysis of the daily set-up correction shifts for 20 prostate cancer patients suggests that the use of four fractions would result in a population average shift that was within 1 mm of the average obtained from the data accumulated over all daily MVCT sessions. Simulation of a scenario in which imaging sessions are performed at a reduced frequency and the planning target volume margin is adapted provided significantly better sparing of organs at risk, with acceptable reproducibility of dose delivery to the clinical target volume. Our results indicate that four MVCT sessions on helical tomotherapy are sufficient to provide information for the creation of personalised target margins and the establishment of the new reference position that accounts for the systematic error. This simplified approach reduces overall treatment session time and decreases the imaging dose to the patient. PMID:19505966

Factors Influencing Institutional-Based Pediatric Rehabilitation Services among Caregivers of Children with Developmental Delay in Southwestern Rajasthan.

PubMed

Mishra, Kriti; Siddharth, V

2018-01-01

A limited number of caregivers of children with developmental delay access rehabilitation facilities in India. The study explored utilization of rehabilitation services at a tertiary care setup in southwestern Rajasthan and various factors influencing it. The aim of this study is to explore rehabilitation service utilization among children with developmental delay at a tertiary care setup and to ascertain factors that influence this pattern. This study was conducted at the department of physical medicine and rehabilitation at tertiary care setup. This was an observational study. Children with developmental delay who were advised institutional-based rehabilitation were identified over span of 1 year. Those who failed to return for rehabilitation after the first visit were interviewed telephonically. The interview had semi-structured open-ended questions about their reasons for inability to avail services. SPSS statistics 22 was used for descriptive analysis and correlation of variables. Of 230 children with developmental delay visiting department in 1-year duration, 48 took regular rehabilitation. Parents of 129 children with complete records were asked regarding discontinuation. Factors cited by majority were long distance from institute and service at hospital. Other reasons for discontinuation were related to belief system, family issues, time issues, socioeconomic factors, etc. Socioeconomic status was significantly associated with parental education (C = 0.488, P = 0.000) and financial issues. Location of family had significant association with long distance (C = 0.315, P = 0.000), parental education (C = 0.251, P = 0.003), and belief system (C = 0.265, P = 0.002). Distance from institute and quality of hospital service determined rehabilitation service use at a tertiary institute. Other factors such as socioeconomic status, family support, and social belief system must also be addressed while delivering institutional rehabilitation to children.

Nonlinear femtosecond pump-probe spectroscopy using a power-encoded soliton delay line.

PubMed

Saint-Jalm, Sarah; Andresen, Esben Ravn; Bendahmane, Abdelkrim; Kudlinski, Alexandre; Rigneault, Hervé

2016-01-01

We show femtosecond time-resolved nonlinear pump-probe spectroscopy using a fiber soliton as the probe pulse. Furthermore, we exploit soliton dynamics to record an entire transient trace with a power-encoded delay sweep. The power-encoded delay line takes advantage of the dependency of the soliton trajectory in the (λ,z) space upon input power; the difference in accumulated group delay between trajectories converts a fast power sweep into a fast delay sweep. We demonstrate the concept by performing transient absorption spectroscopy in a test sample and validate it against a conventional pump-probe setup.

Design of MOEMS adjustable optical delay line to reduce link set-up time in a tera-bit/s optical interconnection network.

PubMed

Jing, Wencai; Zhang, Yimo; Zhou, Ge

2002-07-15

A new structure for bit synchronization in a tera-bit/s optical interconnection network has been designed using micro-electro-mechanical system (MEMS) technique. Link multiplexing has been adopted to reduce data packet communication latency. To eliminate link set-up time, adjustable optical delay lines (AODLs) have been adopted to shift the phases of the distributed optical clock signals for bit synchronization. By changing the optical path distance of the optical clock signal, the phase of the clock signal can be shifted at a very high resolution. A phase-shift resolution of 0.1 ps can be easily achieved with 30-microm alternation of the optical path length in vacuum.

Delayed enhancement of multitasking performance: Effects of anodal transcranial direct current stimulation on the prefrontal cortex

PubMed Central

Hsu, Wan-Yu; Zanto, Theodore P.; Anguera, Joaquin A.; Lin, Yung-Yang; Gazzaley, Adam

2015-01-01

Background The dorsolateral prefrontal cortex (DLPFC) has been proposed to play an important role in neural processes that underlie multitasking performance. However, this claim is underexplored in terms of direct causal evidence. Objective The current study aimed to delineate the causal involvement of the DLPFC during multitasking by modulating neural activity with transcranial direct current stimulation (tDCS) prior to engagement in a demanding multitasking paradigm. Methods The study is a single-blind, crossover, sham-controlled experiment. Anodal tDCS or sham tDCS was applied over left DLPFC in forty-one healthy young adults (aged 18–35 years) immediately before they engaged in a 3-D video game designed to assess multitasking performance. Participants were separated into three subgroups: real-sham (i.e., real tDCS in the first session, followed by sham tDCS in the second session one hour later), sham-real (sham tDCS first session, real tDCS second session), and sham-sham (sham tDCS in both sessions). Results The real-sham group showed enhanced multitasking performance and decreased multitasking cost during the second session, compared to first session, suggesting delayed cognitive benefits of tDCS. Interestingly, performance benefits were observed only for multitasking and not on a single-task version of the game. No significant changes were found between the first and second sessions for either the sham-real or the sham-sham groups. Conclusions These results suggest a causal role of left prefrontal cortex in facilitating the simultaneous performance of more than one task, or multitasking. Moreover, these findings reveal that anodal tDCS may have delayed benefits that reflect an enhanced rate of learning. PMID:26073148

Delayed enhancement of multitasking performance: Effects of anodal transcranial direct current stimulation on the prefrontal cortex.

PubMed

Hsu, Wan-Yu; Zanto, Theodore P; Anguera, Joaquin A; Lin, Yung-Yang; Gazzaley, Adam

2015-08-01

The dorsolateral prefrontal cortex (DLPFC) has been proposed to play an important role in neural processes that underlie multitasking performance. However, this claim is underexplored in terms of direct causal evidence. The current study aimed to delineate the causal involvement of the DLPFC during multitasking by modulating neural activity with transcranial direct current stimulation (tDCS) prior to engagement in a demanding multitasking paradigm. The study is a single-blind, crossover, sham-controlled experiment. Anodal tDCS or sham tDCS was applied over left DLPFC in forty-one healthy young adults (aged 18-35 years) immediately before they engaged in a 3-D video game designed to assess multitasking performance. Participants were separated into three subgroups: real-sham (i.e., real tDCS in the first session, followed by sham tDCS in the second session 1 h later), sham-real (sham tDCS first session, real tDCS second session), and sham-sham (sham tDCS in both sessions). The real-sham group showed enhanced multitasking performance and decreased multitasking cost during the second session, compared to first session, suggesting delayed cognitive benefits of tDCS. Interestingly, performance benefits were observed only for multitasking and not on a single-task version of the game. No significant changes were found between the first and second sessions for either the sham-real or the sham-sham groups. These results suggest a causal role of left prefrontal cortex in facilitating the simultaneous performance of more than one task, or multitasking. Moreover, these findings reveal that anodal tDCS may have delayed benefits that reflect an enhanced rate of learning. Copyright © 2015 Elsevier Ltd. All rights reserved.

No evidence for memory interference across sessions in food hoarding marsh tits Poecile palustris under laboratory conditions.

PubMed

Urhan, A Utku; Brodin, Anders

2015-05-01

Scatter hoarding birds are known for their accurate spatial memory. In a previous experiment, we tested the retrieval accuracy in marsh tits in a typical laboratory set-up for this species. We also tested the performance of humans in this experimental set-up. Somewhat unexpectedly, humans performed much better than marsh tits. In the first five attempts, humans relocated almost 90 % of the caches they had hidden 5 h earlier. Marsh tits only relocated 25 % in the first five attempts and just above 40 % in the first ten attempts. Typically, in this type of experiment, the birds will be caching and retrieving many times in the same sites in the same experimental room. This is very different from the conditions in nature where hoarding parids only cache once in a caching site. Hence, it is possible that memories from previous sessions will disturb the formation of new memories. If there is such proactive interference, the prediction is that success should decay over sessions. Here, we have designed an experiment to investigate whether there is such memory interference in this type of experiment. We allowed marsh tits and humans to cache and retrieve in three repeated sessions without prior experience of the arena. The performance did not change over sessions, and on average, marsh tits correctly visited around 25 % of the caches in the first five attempts. The corresponding success in humans was constant across sessions, and it was around 90 % on average. We conclude that the somewhat poor performance of the marsh tits did not depend on proactive memory interference. We also discuss other possible reasons for why marsh tits in general do not perform better in laboratory experiments.

Setup errors and effectiveness of Optical Laser 3D Surface imaging system (Sentinel) in postoperative radiotherapy of breast cancer.

PubMed

Wei, Xiaobo; Liu, Mengjiao; Ding, Yun; Li, Qilin; Cheng, Changhai; Zong, Xian; Yin, Wenming; Chen, Jie; Gu, Wendong

2018-05-08

Breast-conserving surgery (BCS) plus postoperative radiotherapy has become the standard treatment for early-stage breast cancer. The aim of this study was to compare the setup accuracy of optical surface imaging by the Sentinel system with cone-beam computerized tomography (CBCT) imaging currently used in our clinic for patients received BCS. Two optical surface scans were acquired before and immediately after couch movement correction. The correlation between the setup errors as determined by the initial optical surface scan and CBCT was analyzed. The deviation of the second optical surface scan from the reference planning CT was considered an estimate for the residual errors for the new method for patient setup correction. The consequences in terms for necessary planning target volume (PTV) margins for treatment sessions without setup correction applied. We analyzed 145 scans in 27 patients treated for early stage breast cancer. The setup errors of skin marker based patient alignment by optical surface scan and CBCT were correlated, and the residual setup errors as determined by the optical surface scan after couch movement correction were reduced. Optical surface imaging provides a convenient method for improving the setup accuracy for breast cancer patient without unnecessary imaging dose.

An Optimized Online Verification Imaging Procedure for External Beam Partial Breast Irradiation

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

Willis, David J., E-mail: David.Willis@petermac.or; Royal Melbourne Institute of Technology University, Melbourne, Victoria; Kron, Tomas

2011-07-01

The purpose of this study was to evaluate the capabilities of a kilovoltage (kV) on-board imager (OBI)-equipped linear accelerator in the setting of on-line verification imaging for external-beam partial breast irradiation. Available imaging techniques were optimized and assessed for image quality using a modified anthropomorphic phantom. Imaging dose was also assessed. Imaging techniques were assessed for physical clearance between patient and treatment machine using a volunteer. Nonorthogonal kV image pairs were identified as optimal in terms of image quality, clearance, and dose. After institutional review board approval, this approach was used for 17 patients receiving accelerated partial breast irradiation. Imagingmore » was performed before every fraction verification with online correction of setup deviations >5 mm (total image sessions = 170). Treatment staff rated risk of collision and visibility of tumor bed surgical clips where present. Image session duration and detected setup deviations were recorded. For all cases, both image projections (n = 34) had low collision risk. Surgical clips were rated as well as visualized in all cases where they were present (n = 5). The average imaging session time was 6 min, 16 sec, and a reduction in duration was observed as staff became familiar with the technique. Setup deviations of up to 1.3 cm were detected before treatment and subsequently confirmed offline. Nonorthogonal kV image pairs allowed effective and efficient online verification for partial breast irradiation. It has yet to be tested in a multicenter study to determine whether it is dependent on skilled treatment staff.« less

Design of SIP transformation server for efficient media negotiation

NASA Astrophysics Data System (ADS)

Pack, Sangheon; Paik, Eun Kyoung; Choi, Yanghee

2001-07-01

Voice over IP (VoIP) is one of the advanced services supported by the next generation mobile communication. VoIP should support various media formats and terminals existing together. This heterogeneous environment may prevent diverse users from establishing VoIP sessions among them. To solve the problem an efficient media negotiation mechanism is required. In this paper, we propose the efficient media negotiation architecture using the transformation server and the Intelligent Location Server (ILS). The transformation server is an extended Session Initiation Protocol (SIP) proxy server. It can modify an unacceptable session INVITE message into an acceptable one using the ILS. The ILS is a directory server based on the Lightweight Directory Access Protocol (LDAP) that keeps userí*s location information and available media information. The proposed architecture can eliminate an unnecessary response and re-INVITE messages of the standard SIP architecture. It takes only 1.5 round trip times to negotiate two different media types while the standard media negotiation mechanism takes 2.5 round trip times. The extra processing time in message handling is negligible in comparison to the reduced round trip time. The experimental results show that the session setup time in the proposed architecture is less than the setup time in the standard SIP. These results verify that the proposed media negotiation mechanism is more efficient in solving diversity problems.

Parallel Acquisition of Awareness and Differential Delay Eyeblink Conditioning

ERIC Educational Resources Information Center

Weidemann, Gabrielle; Antees, Cassandra

2012-01-01

There is considerable debate about whether differential delay eyeblink conditioning can be acquired without awareness of the stimulus contingencies. Previous investigations of the relationship between differential-delay eyeblink conditioning and awareness of the stimulus contingencies have assessed awareness after the conditioning session was…

Measurement of impulsive choice in rats: Same and alternate form test-retest reliability and temporal tracking

PubMed Central

Peterson, Jennifer R.; Hill, Catherine C.; Kirkpatrick, Kimberly

2016-01-01

Impulsive choice is typically measured by presenting smaller-sooner (SS) versus larger-later (LL) rewards, with biases towards the SS indicating impulsivity. The current study tested rats on different impulsive choice procedures with LL delay manipulations to assess same-form and alternate-form test-retest reliability. In the systematic-GE procedure (Green & Estle, 2003), the LL delay increased after several sessions of training; in the systematic-ER procedure (Evenden & Ryan, 1996), the delay increased within each session; and in the adjusting-M procedure (Mazur, 1987), the delay changed after each block of trials within a session based on each rat’s choices in the previous block. In addition to measuring choice behavior, we also assessed temporal tracking of the LL delays using the median times of responding during LL trials. The two systematic procedures yielded similar results in both choice and temporal tracking measures following extensive training, whereas the adjusting procedure resulted in relatively more impulsive choices and poorer temporal tracking. Overall, the three procedures produced acceptable same form test-retest reliability over time, but the adjusting procedure did not show significant alternate form test-retest reliability with the other two procedures. The results suggest that systematic procedures may supply better measurements of impulsive choice in rats. PMID:25490901

Measuring a Fiber-Optic Delay Line Using a Mode-Locked Laser

NASA Technical Reports Server (NTRS)

Tu, Meirong; McKee, Michael R.; Pak, Kyung S.; Yu, Nan

2010-01-01

The figure schematically depicts a laboratory setup for determining the optical length of a fiber-optic delay line at a precision greater than that obtainable by use of optical time-domain reflectometry or of mechanical measurement of length during the delay-line-winding process. In this setup, the delay line becomes part of the resonant optical cavity that governs the frequency of oscillation of a mode-locked laser. The length can then be determined from frequency-domain measurements, as described below. The laboratory setup is basically an all-fiber ring laser in which the delay line constitutes part of the ring. Another part of the ring - the laser gain medium - is an erbium-doped fiber amplifier pumped by a diode laser at a wavelength of 980 nm. The loop also includes an optical isolator, two polarization controllers, and a polarizing beam splitter. The optical isolator enforces unidirectional lasing. The polarization beam splitter allows light in only one polarization mode to pass through the ring; light in the orthogonal polarization mode is rejected from the ring and utilized as a diagnostic output, which is fed to an optical spectrum analyzer and a photodetector. The photodetector output is fed to a radio-frequency spectrum analyzer and an oscilloscope. The fiber ring laser can generate continuous-wave radiation in non-mode-locked operation or ultrashort optical pulses in mode-locked operation. The mode-locked operation exhibited by this ring is said to be passive in the sense that no electro-optical modulator or other active optical component is used to achieve it. Passive mode locking is achieved by exploiting optical nonlinearity of passive components in such a manner as to obtain ultra-short optical pulses. In this setup, the particular nonlinear optical property exploited to achieve passive mode locking is nonlinear polarization rotation. This or any ring laser can support oscillation in multiple modes as long as sufficient gain is present to overcome losses in the ring. When mode locking is achieved, oscillation occurs in all the modes having the same phase and same polarization. The frequency interval between modes, often denoted the free spectral range (FSR), is given by c/nL, where c is the speed of light in vacuum, n is the effective index of refraction of the fiber, and L is the total length of optical path around the ring. Therefore, the length of the fiber-optic delay line, as part of the length around the ring, can be calculated from the FSRs measured with and without the delay line incorporated into the ring. For this purpose, the FSR measurements are made by use of the optical and radio-frequency spectrum analyzers. In experimentation on a 10-km-long fiber-optic delay line, it was found that this setup made it possible to measure the length to within a fractional error of about 3 10(exp -6), corresponding to a length error of 3 cm. In contrast, measurements by optical time-domain reflectometry and mechanical measurement were found to be much less precise: For optical time-domain reflectometry, the fractional error was found no less than 10(exp -4) (corresponding to a length error of 1 m) and for mechanical measurement, the fractional error was found to be about 10(exp -2) (corresponding to a length error of 100 m).

Comparative investigation of methods to determine the group velocity dispersion of an endlessly single-mode photonic crystal fiber

NASA Astrophysics Data System (ADS)

Baselt, Tobias; Popp, Tobias; Nelsen, Bryan; Lasagni, Andrés. Fabián.; Hartmann, Peter

2017-05-01

Endlessly single-mode fibers, which enable single mode guidance over a wide spectral range, are indispensable in the field of fiber technology. A two-dimensional photonic crystal with a silica central core and a micrometer-spaced hexagonal array of air holes is an established method to achieve endless single-mode guidance. There are two possible ways to determine the dispersion: measurement and calculation. We calculate the group velocity dispersion GVD based on the measurement of the fiber structure parameters, the hole diameter and the pitch of a presumed homogeneous hexagonal array and compare the calculation with two methods to measure the wavelength-dependent time delay. We measure the time delay on a three hundred meter test fiber with a homemade supercontinuum light source, a set of bandpass filters and a fast detector and compare the results with a white light interferometric setup. To measure the dispersion of optical fibers with high accuracy, a time-frequency-domain setup based on a Mach-Zehnder interferometer is used. The experimental setup allows the determination of the wavelength dependent differential group delay of light travelling through a thirty centimeter piece of test fiber in the wavelength range from VIS to NIR. The determination of the GVD using different methods enables the evaluation of the individual methods for characterizing the endlessly single-mode fiber.

Broadband optical frequency comb generator based on driving N-cascaded modulators by Gaussian-shaped waveform

NASA Astrophysics Data System (ADS)

Hmood, Jassim K.; Harun, Sulaiman W.

2018-05-01

A new approach for realizing a wideband optical frequency comb (OFC) generator based on driving cascaded modulators by a Gaussian-shaped waveform, is proposed and numerically demonstrated. The setup includes N-cascaded MZMs, a single Gaussian-shaped waveform generator, and N-1 electrical time delayer. The first MZM is driven directly by a Gaussian-shaped waveform, while delayed replicas of the Gaussian-shaped waveform drive the other MZMs. An analytical model that describes the proposed OFC generator is provided to study the effect of number and chirp factor of cascaded MZM as well as pulse width on output spectrum. Optical frequency combs at frequency spacing of 1 GHz are generated by applying Gaussian-shaped waveform at pulse widths ranging from 200 to 400 ps. Our results reveal that, the number of comb lines is inversely proportional to the pulse width and directly proportional to both number and chirp factor of cascaded MZMs. At pulse width of 200 ps and chirp factor of 4, 67 frequency lines can be measured at output spectrum of two-cascaded MZMs setup. Whereas, increasing the number of cascaded stages to 3, 4, and 5, the optical spectra counts 89, 109 and 123 frequency lines; respectively. When the delay time is optimized, 61 comb lines can be achieved with power fluctuations of less than 1 dB for five-cascaded MZMs setup.

The effects of sleep restriction and altered sleep timing on energy intake and energy expenditure.

PubMed

McNeil, Jessica; Doucet, Éric; Brunet, Jean-François; Hintze, Luzia Jaeger; Chaumont, Isabelle; Langlois, Émilie; Maitland, Riley; Riopel, Alexandre; Forest, Geneviève

2016-10-01

Experimental evidence suggests that sleep restriction increases energy intake (EI) and may alter energy expenditure (EE). However, it is unknown whether the timing of a sleep restriction period impacts EI and EE the following day. Hence, we examined the effects of sleep restriction with an advanced wake-time or delayed bedtime on next day EI and EE. Twelve men and 6 women (age: 23±4years, body fat: 18.8±10.1%) participated in 3 randomized crossover sessions: control (habitual bed- and wake-times), 50% sleep restriction with an advanced wake-time and 50% sleep restriction with a delayed bedtime. Outcome variables included sleep architecture (polysomnography), EI (food menu), total EE and activity times (accelerometry). Carbohydrate intake was greater on day 2 in the delayed bedtime vs. control session (1386±513 vs. 1579±571kcal; P=0.03). Relative moderate-intensity physical activity (PA) time was greater in the delayed bedtime session vs. control and advanced wake-time sessions on day 1 (26.6±19.9 vs. 16.1±10.6 and 17.5±11.8%; P=0.01), whereas vigorous-intensity PA time was greater following advanced wake-time vs. delayed bedtime on day 1 (2.7±3.0 vs. 1.3±2.4%; P=0.004). Greater stage 1 sleep (β=110kcal, 95% CI for β=42 to 177kcal; P=0.004), and a trend for lower REM sleep (β=-20kcal, 95% CI for β=-41 to 2kcal; P=0.07), durations were associated with greater EI between sleep restriction sessions. These findings suggest that the timing of a sleep restriction period impacts energy balance parameters. Additional studies are needed to corroborate these findings, given the increasing prevalence of shift workers and incidences of sleep disorders and voluntary sleep restriction. Copyright © 2016 Elsevier Inc. All rights reserved.

Doubly tagged delayed-choice tunable quantum eraser: coherence, information and measurement

NASA Astrophysics Data System (ADS)

Imran, Muhammad; Tariq, Hinna; Rameez-ul-Islam; Ikram, Manzoor

2018-01-01

We present an idea for the doubly tagged delayed-choice tunable quantum eraser in a cavity QED setup, based on fully controlled resonant as well as dispersive atom-field interactions. Two cavity fields, bound initially in the Bell state, are coupled to a three-level atom. Such an atom is initially prepared in the coherent superposition of the lower two levels and is quite capable of exhibiting Ramsey fringes if taken independently. It is shown that the coherence lost due to tagging can not only be retrieved but that the fringe visibility/path distinguishability can also be conditionally tuned in a delayed manner through local manipulation of the entangled cavity fields. The stringent condition here is the retainment of the system’s coherence during successive manipulations of the individual cavity fields. Such a quantum eraser, therefore, prominently highlights the links among all the counterintuitive features of quantum theory including the conception of time, measurement, state vector reduction, coherence and information in an unambiguous manner. The schematics can be straightforwardly extended to a multipartite scenario and employed to explore multi-player quantum games with the payoff being strangely decided through delayed choice setups.

Effects of amphetamine on delay discounting in rats depend upon the manner in which delay is varied

PubMed Central

Maguire, David R; Henson, Cedric; France, Charles P

2014-01-01

Whether stimulant drugs like amphetamine increase or decrease choice of larger delayed reinforcers over smaller immediately available reinforcers under delay discounting procedures can depend on several factors, including the order in which delay is presented. This study examined whether the order of delay presentation impacts drug effects on discounting in rats (n=8) trained and tested under an ascending order, a descending order, as well as under a fixed delay condition. Responses on one lever delivered 1 food pellet immediately and responses on the other lever delivered 3 food pellets immediately or after a delay (4–32 s). In Experiment 1, the delay to the larger reinforcer varied within session and the order of delay presentation (ascending or descending) varied across conditions. In Experiment 2, the same delay value was presented in all blocks of the session (i.e., delay was fixed), and delay varied across phases. Under the ascending order of delay, amphetamine (0.32–1.78 mg/kg) increased choice of the larger reinforcer in some rats and decreased choice in others. In the same rats responding under the descending and fixed delay conditions, amphetamine markedly decreased choice of the larger reinforcer even in the component associated with no delay. In some subjects, the effects of amphetamine differed depending on the manner in which delay was presented, indicating that drug-induced changes in performance were due, in part, to mechanisms other than altered sensitivity to reinforcer delay. These results also suggest that a history of responding under both orders of delay presentation can modulate drug effects. PMID:24780379

Programmable Differential Delay Circuit With Fine Delay Adjustment

DOEpatents

DeRyckere, John F.; Jenkins, Philip Nord; Cornett, Frank Nolan

2002-07-09

Circuitry that provides additional delay to early arriving signals such that all data signals arrive at a receiving latch with same path delay. The delay of a forwarded clock reference is also controlled such that the capturing clock edge will be optimally positioned near quadrature (depending on latch setup/hold requirements). The circuitry continuously adapts to data and clock path delay changes and digital filtering of phase measurements reduce errors brought on by jittering data edges. The circuitry utilizes only the minimum amount of delay necessary to achieve objective thereby limiting any unintended jitter. Particularly, this programmable differential delay circuit with fine delay adjustment is designed to allow the skew between ASICS to be minimized. This includes skew between data bits, between data bits and clocks as well as minimizing the overall skew in a channel between ASICS.

Up-Down Hand Position Switch May Delay the Fatigue of Non-Dominant Hand Position Rescuers and Improve Chest Compression Quality during Cardiopulmonary Resuscitation: A Randomized Crossover Manikin Study

PubMed Central

Xu, Bing; Wang, Huang-Lei; Xiong, Dan; Sheng, Li-Pin; Yang, Qi-Sheng; Jiang, Shan; Xu, Peng; Chen, Zhi-Qiao; Zhao, Yan

2015-01-01

Previous studies have shown improved external chest compression (ECC) quality and delayed rescuer fatigue when the dominant hand (DH) was in contact with the sternum. However, many rescuers prefer placing the non-dominant hand (NH) in contact with the sternum during ECC. We aimed to investigate the effects of up-down hand position switch on the quality of ECC and the fatigue of rescuers during cardiopulmonary resuscitation (CPR). After completion of a review of the standard adult basic life support (BLS) course, every candidate performed 10 cycles of single adult CPR twice on an adult manikin with either a constant hand position (CH) or a switched hand position (SH) in random order at 7-day intervals. The rescuers’ general characteristics, hand positions, physiological signs, fatigue appearance and ECC qualities were recorded. Our results showed no significant differences in chest compression quality for the DH position rescuers between the CH and SH sessions (p>0.05, resp.). And also no significant differences were found for Borg score (p = 0.437) or cycle number (p = 0.127) of fatigue appearance after chest compressions between the two sessions. However, for NH position rescuers, the appearance of fatigue was delayed (p = 0.046), with a lower Borg score in the SH session (12.67 ± 2.03) compared to the CH session (13.33 ± 1.95) (p = 0.011). Moreover, the compression depth was significantly greater in the SH session (39.3 ± 7.2 mm) compared to the CH session (36.3 ± 8.1 mm) (p = 0.015). Our data suggest that the up-down hand position switch during CPR may delay the fatigue of non-dominant hand position rescuers and improve the quality of chest compressions. PMID:26267353

Prospects for UT1 Measurements from VLBI Intensive Sessions

NASA Technical Reports Server (NTRS)

Boehm, Johannes; Nilsson, Tobias; Schuh, Harald

2010-01-01

Very Long Baseline Interferometry (VLBI) Intensives are one-hour single baseline sessions to provide Universal Time (UT1) in near real-time up to a delay of three days if a site is not e-transferring the observational data. Due to the importance of UT1 estimates for the prediction of Earth orientation parameters, as well as any kind of navigation on Earth or in space, there is not only the need to improve the timeliness of the results but also their accuracy. We identify the asymmetry of the tropospheric delays as the major error source, and we provide two strategies to improve the results, in particular of those Intensives which include the station Tsukuba in Japan with its large tropospheric variation. We find an improvement when (1) using ray-traced delays from a numerical weather model, and (2) when estimating tropospheric gradients within the analysis of Intensive sessions. The improvement is shown in terms of reduction of rms of length-of-day estimates w.r.t. those derived from Global Positioning System observations

First Results of the FAST-S/X Sessions with New VGOS Antennas

NASA Astrophysics Data System (ADS)

Neidhardt, Alexander; de Vicente, Pablo; Bertarini, Alessandra; Artz, Thomas; Halsig, Sebastian; Ivanov, Dmitry; Melnikov, Alexey; Böhm, Johannes; Hellerschmied, Andreas; Mayer, David; Plötz, Christian; Kronschnabl, Gerhard; Nothnagel, Axel; Kurdubov, Sergei; Mikhailov, Andrey; Marshalov, Dmitry; Bezrukov, Ilia; Bondarenko, Yu.

2016-12-01

During the VTC meeting in Ponta Delgada, Portugal, it was decided to form a group with the goal of testing the fast slewing mode of the VGOS antennas on intercontinental baselines. The goal is to observe S/X-schedules regularly using fast slewing modes of the antennas. Two sessions, FAST02 and FAST03, were scheduled with VieVS at the Vienna University of Technology, employing the new VGOS antennas at Yebes in Spain, Wettzell in Germany, and Zelenchukskaya and Badary in Russia. FAST02 was a 24-hour session observed in DDC mode. FAST03 was a six-hour session to test the PFB mode. The correlation was done both in Bonn, where also the main geodetic analysis was made, and at the IAA in Russia. Unfortunately, FAST03 was not successful due to incompatible frequency setups. In this paper, we report on the first results of the FAST02 session.

Non-verbal Communication in a Neonatal Intensive Care Unit: A Video Audit Using Non-verbal Immediacy Scale (NIS-O).

PubMed

Nimbalkar, Somashekhar Marutirao; Raval, Himalaya; Bansal, Satvik Chaitanya; Pandya, Utkarsh; Pathak, Ajay

2018-05-03

Effective communication with parents is a very important skill for pediatricians especially in a neonatal setup. The authors analyzed non-verbal communication of medical caregivers during counseling sessions. Recorded videos of counseling sessions from the months of March-April 2016 were audited. Counseling episodes were scored using Non-verbal Immediacy Scale Observer Report (NIS-O). A total of 150 videos of counseling sessions were audited. The mean (SD) total score on (NIS-O) was 78.96(7.07). Female counseled sessions had significantly higher proportion of low scores (p < 0.001). No video revealed high score. Overall 67(44.67%) sessions revealed low total score. This reflects an urgent need to develop strategies to improve communication skills in a neonatal unit. This study lays down a template on which other Neonatal intensive care units (NICUs) can carry out gap defining audits.

An Experimental Investigation of Hypergolic Ignition Delay of Hydrogen Peroxide with Fuel Mixtures

NASA Technical Reports Server (NTRS)

Blevins, John A.; Gostowski, Rudy; Chianese, Silvio

2003-01-01

An experimental investigation of hypergolicity and ignition delay of fuel mixtures with hydrogen peroxide is presented. Example results of high speed photography and schleiren from drop tests are shown. Also, a discussion of the sensitivity to experimental parameters such as drop size and subsequent uncertainty considerations of ignition delay results is presented. It is shown that using the described setup on the mixtures presented, the precision uncertainty is on the order of 6% of average ignition delay and 5% of average decomposition delay. This represents sufficient repeatability for first order discrimination of ignition delay for propellant development and screening. Two mixtures, each using commonly available amines and transition metal compounds, are presented as examples that result in ignition delays on the order of 10 milliseconds.

Krikalev in Service module with tools

NASA Image and Video Library

2001-03-30

ISS01-E-5150 (December 2000) --- Cosmonaut Sergei K. Krikalev, Expedition One flight engineer, retrieves a tool during an installation and set-up session in the Zvezda service module aboard the International Space Station (ISS). The picture was recorded with a digital still camera.

Making Time for Nature: Visual Exposure to Natural Environments Lengthens Subjective Time Perception and Reduces Impulsivity

PubMed Central

Berry, Meredith S.; Repke, Meredith A.; Nickerson, Norma P.; Conway, Lucian G.; Odum, Amy L.; Jordan, Kerry E.

2015-01-01

Impulsivity in delay discounting is associated with maladaptive behaviors such as overeating and drug and alcohol abuse. Researchers have recently noted that delay discounting, even when measured by a brief laboratory task, may be the best predictor of human health related behaviors (e.g., exercise) currently available. Identifying techniques to decrease impulsivity in delay discounting, therefore, could help improve decision-making on a global scale. Visual exposure to natural environments is one recent approach shown to decrease impulsive decision-making in a delay discounting task, although the mechanism driving this result is currently unknown. The present experiment was thus designed to evaluate not only whether visual exposure to natural (mountains, lakes) relative to built (buildings, cities) environments resulted in less impulsivity, but also whether this exposure influenced time perception. Participants were randomly assigned to either a natural environment condition or a built environment condition. Participants viewed photographs of either natural scenes or built scenes before and during a delay discounting task in which they made choices about receiving immediate or delayed hypothetical monetary outcomes. Participants also completed an interval bisection task in which natural or built stimuli were judged as relatively longer or shorter presentation durations. Following the delay discounting and interval bisection tasks, additional measures of time perception were administered, including how many minutes participants thought had passed during the session and a scale measurement of whether time "flew" or "dragged" during the session. Participants exposed to natural as opposed to built scenes were less impulsive and also reported longer subjective session times, although no differences across groups were revealed with the interval bisection task. These results are the first to suggest that decreased impulsivity from exposure to natural as opposed to built environments may be related to lengthened time perception. PMID:26558610

They Saw a Movie: Long-Term Memory for an Extended Audiovisual Narrative

ERIC Educational Resources Information Center

Furman, Orit; Dorfman, Nimrod; Hasson, Uri; Davachi, Lila; Dudai, Yadin

2007-01-01

We measured long-term memory for a narrative film. During the study session, participants watched a 27-min movie episode, without instructions to remember it. During the test session, administered at a delay ranging from 3 h to 9 mo after the study session, long-term memory for the movie was probed using a computerized questionnaire that assessed…

Compensating Unknown Time-Varying Delay in Opto-Electronic Platform Tracking Servo System.

PubMed

Xie, Ruihong; Zhang, Tao; Li, Jiaquan; Dai, Ming

2017-05-09

This paper investigates the problem of compensating miss-distance delay in opto-electronic platform tracking servo system. According to the characteristic of LOS (light-of-sight) motion, we setup the Markovian process model and compensate this unknown time-varying delay by feed-forward forecasting controller based on robust H∞ control. Finally, simulation based on double closed-loop PI (Proportion Integration) control system indicates that the proposed method is effective for compensating unknown time-varying delay. Tracking experiments on the opto-electronic platform indicate that RMS (root-mean-square) error is 1.253 mrad when tracking 10° 0.2 Hz signal.

The Effects of Aging on Time Reproduction in Delayed Free-Recall

ERIC Educational Resources Information Center

Rakitin, B.C.; Stern, Y.; Malapani, C.

2005-01-01

The experiments presented here demonstrate that normal aging amplifies differences in time production occurring in delayed free-recall testing. Experiment 1 compared the time production ability of two healthy aged groups as well as college-aged participants. During the test session, which followed a 24-h delay and omitted all feedback and examples…

Simple Demonstration of the Seebeck Effect

ERIC Educational Resources Information Center

Molki, Arman

2010-01-01

In this article we propose a simple and low-cost experimental set-up through which science educators can demonstrate the Seebeck effect using a thermocouple and an instrumentation amplifier. The experiment can be set up and conducted during a 1-hour laboratory session. (Contains 3 tables and 3 figures.)

Multiprocessor Z-Buffer Architecture for High-Speed, High Complexity Computer Image Generation.

DTIC Science & Technology

1983-12-01

Oversampling 50 17. "Poking Through" Effects 51 18. Sampling Paths 52 19. Triangle Variables 54 20. Intelligent Tiling Algorithm 61 21. Tiler Functional Blocks...64 * 22. HSD Interface 65 23. Tiling Machine Setup 67 24. Tiling Machine 68 25. Tile Accumulate 69 26. A lx$ Sorting Machine 77 27. A 2x8 Sorting...Delay 227 87. Effect of Triangle Size on Tiler Throughput Rates 229 88. Tiling Machine Setup Stage Performance for Oversample Mode 234 89. Tiling

Fundamental Limits of Delay and Security in Device-to-Device Communication

DTIC Science & Technology

2013-01-01

systematic MDS (maximum distance separable) codes and random binning strategies that achieve a Pareto optimal delayreconstruction tradeoff. The erasure MD...file, and a coding scheme based on erasure compression and Slepian-Wolf binning is presented. The coding scheme is shown to provide a Pareto optimal...ble) codes and random binning strategies that achieve a Pareto optimal delay- reconstruction tradeoff. The erasure MD setup is then used to propose a

The impact of group music therapy on depression and cognition in elderly persons with dementia: a randomized controlled study.

PubMed

Chu, Hsin; Yang, Chyn-Yng; Lin, Yu; Ou, Keng-Liang; Lee, Tso-Ying; O'Brien, Anthony Paul; Chou, Kuei-Ru

2014-04-01

The aims of this study were to determine the effectiveness of group music therapy for improving depression and delaying the deterioration of cognitive functions in elderly persons with dementia. The study had a prospective, parallel-group design with permuted-block randomization. Older persons with dementia (N = 104) were randomly assigned to the experimental or control group. The experimental group received 12 sessions of group music therapy (two 30-min sessions per week for 6 weeks), and the control group received usual care. Data were collected 4 times: (1) 1 week before the intervention, (2) the 6th session of the intervention, (3) the 12th session of the intervention, and (4) 1 month after the final session. Group music therapy reduced depression in persons with dementia. Improvements in depression occurred immediately after music therapy and were apparent throughout the course of therapy. The cortisol level did not significantly decrease after the group music therapy. Cognitive function significantly improved slightly at the 6th session, the 12th session, and 1 month after the sessions ended; in particular, short-term recall function improved. The group music therapy intervention had the greatest impact in subjects with mild and moderate dementia. The group music intervention is a noninvasive and inexpensive therapy that appeared to reduce elders' depression. It also delayed the deterioration of cognitive functions, particularly short-term recall function. Group music therapy may be an appropriate intervention among elderly persons with mild and moderate dementia.

Automated delay measurement system for an Earth station for Two-Way Satellite Time and Frequency Transfer

NASA Technical Reports Server (NTRS)

Dejong, Gerrit; Polderman, Michel C.

1995-01-01

The measurement of the difference of the transmit and receive delays of the signals in a Two-Way Satellite Time and Frequency Transfer (TWSTFT) Earth station is crucial for its nanosecond time transfer capability. Also, the monitoring of the change of this delay difference with time, temperature, humidity, or barometric pressure is important for improving the TWSTFT capabilities. An automated system for this purpose has been developed from the initial design at NMi-VSL. It calibrates separately the transmit and receive delays in cables, amplifiers, upconverters and downconverters, and antenna feeds. The obtained results can be applied as corrections to the TWSTFT measurement when, before and after a measurement session, a calibration session is performed. Preliminary results obtained at NMi-VSL will be shown. Also, if available, the results of a manual version of the system that is planned to be circulated in Sept. 1994 together with a USNO portable station on a calibration trip to European TWSTFT Earth stations.

Acute and delayed responses of C-reactive protein, malondialdehyde and antioxidant markers after resistance training session in elite weightlifters: Effect of time of day.

PubMed

Ammar, Achraf; Chtourou, Hamdi; Hammouda, Omar; Trabelsi, Khaled; Chiboub, Jihen; Turki, Mouna; AbdelKarim, Osama; El Abed, Kais; Ben Ali, Mamdouh; Hoekelmann, Anita; Souissi, Nizar

2015-01-01

The aim of this study was to investigate the effect of an Olympic-Weightlifting-session followed by 48-h recovery period on the oxidative and antioxidant parameters' diurnal variation. Nine weightlifters (21 ± 0.5 years) performed, in randomized order, three Olympic-Weightlifting-sessions at 08 h:00, 14 h:00 and 18 h:00. Blood samples were collected: at rest and 3 min and 48 h after each session. C-reactive protein (CRP), rate of lipid peroxidation and antioxidant activities were assessed. At rest, analysis of variance showed a significant time of day (TOD) effect (p < 0.05) for uric acid, catalase and glutathione peroxidase with higher values at 14 h:00 and 18 h:00 compared with 08 h:00. However, no significant TOD effect for malondialdehyde, total bilirubin and CRP was observed. Given the profound changes (p < 0.001) in the post-training session values, these diurnal variations have been altered immediately and even 48 h after the training sessions. Despite the significant decreases in the post-training values after the 48-h recovery period (p < 0.05), levels of lipid peroxidation and enzymatic defense remained elevated (p < 0.05) 48 h after the morning training session. However, after the afternoon and evening sessions, the same period was sufficient to return values to the baseline levels. In conclusion, the morning session seems to generate the most important acute and delayed lipid peroxidation responses. Therefore, weightlifting coaches should avoid scheduling their training sessions in the morning-hours.

Consulting a traditional healer and negative illness perceptions are associated with non-adherence to treatment in Indonesian women with breast cancer.

PubMed

Iskandarsyah, Aulia; de Klerk, Cora; Suardi, Dradjat R; Sadarjoen, Sawitri S; Passchier, Jan

2014-10-01

The aim of the present study was to test the association between psychosocial factors and delay in uptake of treatment and treatment non-adherence in Indonesian women with breast cancer. Seventy consecutive patients with breast cancer who were treated at the Hasan Sadikin Hospital in Indonesia were recruited. They completed a demographic form, the non-adherence questionnaire, the Breast Cancer Knowledge Test, the Brief Illness Perception Questionnaire, the Multidimensional Health Locus of Control Scales, the Satisfaction with Cancer Information Profile and the Distress Thermometer. Seventeen (24%) out of 70 patients reported that they had delayed initiating treatment at the hospital, and nine (13%) out of 70 patients had missed two or more consecutive treatment sessions. In the bivariate analyses, we found no significant differences on any of the psychological variables between patients who delayed initiating treatment and those patients who did not, whereas patients who had missed two or more consecutive sessions had lower satisfaction with the type and timing of information provided and more negative illness perceptions than patients who had not missed their sessions. In multivariate regression analyses, consulting a traditional healer before diagnosis was associated with treatment delay (β = 1.27, p = 0.04). More negative illness perceptions (β = 0.10, p = 0.02) and whether a traditional healer had been consulted after diagnosis (β = 1.67, p = 0.03) were associated with missing treatment sessions. Indonesian health professionals need to be aware of patients' negative illness perceptions and their unrealistic belief in traditional healers. Copyright © 2014 John Wiley & Sons, Ltd.

Clinical experience with a 3D surface patient setup system for alignment of partial-breast irradiation patients

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

Bert, Christoph; Metheany, Katherine G.; Doppke, Karen P.

2006-03-15

Purpose: To assess the utility of surface imaging on patient setup for accelerated partial-breast irradiation (APBI). Methods and Material: A photogrammetry system was used in parallel to APBI setup by laser and portal imaging. Surface data were acquired after laser and port-film setup for 9 patients. Surfaces were analyzed in comparison to a reference surface from the first treatment session by use of rigid transformations. The surface model after laser setup was used in a simulated photogrammetry setup procedure. In addition, breathing data were acquired by surface acquisition at a frame rate of 7 Hz. Results: Mean 3D displacement wasmore » 7.3 mm (SD, 4.4 mm) and 7.6 mm (SD, 4.2 mm) for laser and port film, respectively. Simulated setup with the photogrammetry system yielded mean displacement of 1 mm (SD, 1.2 mm). Distance analysis resulted in mean distances of 3.7 mm (SD, 4.9 mm), 4.3 mm (SD, 5.6 mm), and 1.6 mm (SD, 2.4 mm) for laser, port film, and photogrammetry, respectively. Breathing motion at isocenter was smaller than 3.7 mm, with a mean of 1.9 mm (SD, 1.1 mm). Conclusions: Surface imaging for PBI setup appears promising. Alignment of the 3D breast surface achieved by stereo-photogrammetry shows greater breast topology congruence than when patients are set up by laser or portal imaging. A correlation of breast surface and CTV must be quantitatively established.« less

Disequilibrium dynamics in a Keynesian model with time delays

NASA Astrophysics Data System (ADS)

Gori, Luca; Guerrini, Luca; Sodini, Mauro

2018-05-01

The aim of this research is to analyse a Keynesian goods market closed economy by considering a continuous-time setup with fixed delays. The work compares dynamic results based on linear and nonlinear adjustment mechanisms through which the aggregate supply (production) reacts to a disequilibrium in the goods market and consumption depends on income at a preceding date. Both analytical and geometrical (stability switching curves) techniques are used to characterise the stability properties of the stationary equilibrium.

Network complexity and synchronous behavior--an experimental approach.

PubMed

Neefs, P J; Steur, E; Nijmeijer, H

2010-06-01

We discuss synchronization in networks of Hindmarsh-Rose neurons that are interconnected via gap junctions, also known as electrical synapses. We present theoretical results for interactions without time-delay. These results are supported by experiments with a setup consisting of sixteen electronic equivalents of the Hindmarsh-Rose neuron. We show experimental results of networks where time-delay on the interaction is taken into account. We discuss in particular the influence of the network topology on the synchronization.

Pulsatile desynchronizing delayed feedback for closed-loop deep brain stimulation

PubMed Central

Lysyansky, Borys; Rosenblum, Michael; Pikovsky, Arkady; Tass, Peter A.

2017-01-01

High-frequency (HF) deep brain stimulation (DBS) is the gold standard for the treatment of medically refractory movement disorders like Parkinson’s disease, essential tremor, and dystonia, with a significant potential for application to other neurological diseases. The standard setup of HF DBS utilizes an open-loop stimulation protocol, where a permanent HF electrical pulse train is administered to the brain target areas irrespectively of the ongoing neuronal dynamics. Recent experimental and clinical studies demonstrate that a closed-loop, adaptive DBS might be superior to the open-loop setup. We here combine the notion of the adaptive high-frequency stimulation approach, that aims at delivering stimulation adapted to the extent of appropriately detected biomarkers, with specifically desynchronizing stimulation protocols. To this end, we extend the delayed feedback stimulation methods, which are intrinsically closed-loop techniques and specifically designed to desynchronize abnormal neuronal synchronization, to pulsatile electrical brain stimulation. We show that permanent pulsatile high-frequency stimulation subjected to an amplitude modulation by linear or nonlinear delayed feedback methods can effectively and robustly desynchronize a STN-GPe network of model neurons and suggest this approach for desynchronizing closed-loop DBS. PMID:28273176

Teaching Cancer Patients the Value of Correct Positioning During Radiotherapy Using Visual Aids and Practical Exercises.

PubMed

Hansen, Helle; Nielsen, Berit Kjærside; Boejen, Annette; Vestergaard, Anne

2018-06-01

The aim of this study was to investigate if teaching patients about positioning before radiotherapy treatment would (a) reduce the residual rotational set-up errors, (b) reduce the number of repositionings and (c) improve patients' sense of control by increasing self-efficacy and reducing distress. Patients were randomized to either standard care (control group) or standard care and a teaching session combining visual aids and practical exercises (intervention group). Daily images from the treatment sessions were evaluated off-line. Both groups filled in a questionnaire before and at the end of the treatment course on various aspects of cooperation with the staff regarding positioning. Comparisons of residual rotational set-up errors showed an improvement in the intervention group compared to the control group. No significant differences were found in number of repositionings, self-efficacy or distress. Results show that it is possible to teach patients about positioning and thereby improve precision in positioning. Teaching patients about positioning did not seem to affect self-efficacy or distress scores at baseline and at the end of the treatment course.

Triple dose of gadolinium-DTPA and delayed MRI in patients with benign multiple sclerosis.

PubMed Central

Filippi, M; Capra, R; Campi, A; Colombo, B; Prandini, F; Marcianò, N; Gasparotti, R; Comi, G

1996-01-01

OBJECTIVES--To evaluate whether a triple dose of gadolinium-DTPA (Gd-DTPA) or delayed MRI increase the number, size, and conspicuousness of enhancing lesions in patients with benign multiple sclerosis. METHODS--T1 weighted brain MRI was carried out on 20 patients with benign multiple sclerosis (expanded disability status scale < 3 with a disease duration > 10 years) in two sessions. In the first session, one scan was obtained before and two scans five to seven minutes and 20-30 minutes after the injection of 0.1 mmol/kg Gd-DTPA (standard dose). In the second session, six to 24 hours later, the same procedure was repeated with 0.3 mmol/kg Gd-DTPA (triple dose). RESULTS--Nine enhancing lesions were found in seven patients (35%) using the standard dose of Gd-DTPA. The numbers of enhancing lesions increased to 13 (P = 0.03) and the number of patients with such lesions to eight (40%) on the delayed standard dose scans. On the early triple dose scans, we found 19 enhancing lesions in 10 patients (50%). The number of enhancing lesions was significantly higher (P = 0.01) than that obtained with the early standard dose. The number of enhancing lesions was 18 and the number of "active" patients 11 (55%) on the delayed triple dose scans. The enhancing areas increased progressively from the early standard dose scans to the delayed triple dose scans. The contrast ratios of the lesions detected in early standard dose scans was lower than those of lesions present in the early (P = 0.01) and delayed (P = 0.04) triple dose scans. CONCLUSIONS--More enhancing lesions were detected in patients with benign multiple sclerosis with both delay of MRI and the use of triple dose of Gd-DTPA suggesting that the amount of inflammation in the lesions of such patients is mild and heterogeneous. Images PMID:8778257

Standardized method to quantify the variation in voxel value distribution in patient-simulated CBCT data sets.

PubMed

Spin-Neto, R; Gotfredsen, E; Wenzel, A

2015-01-01

To suggest a standardized method to assess the variation in voxel value distribution in patient-simulated CBCT data sets and the effect of time between exposures (TBE). Additionally, a measurement of reproducibility, Aarhus measurement of reproducibility (AMORe), is introduced, which could be used for quality assurance purposes. Six CBCT units were tested [Cranex(®) 3D/CRAN (Soredex Oy, Tuusula, Finland); Scanora(®) 3D/SCAN (Soredex Oy); NewTom™ 5G/NEW5 (QR srl, Verona, Italy); i-CAT/ICAT (Imaging Sciences International, Hatfield, PA); 3D Accuitomo FPD80/ACCU (Morita, Kyoto, Japan); and NewTom VG/NEWV (QR srl)]. Two sets of volumetric data of a wax-imbedded dry human skull (containing a titanium implant) were acquired by each CBCT unit at two sessions on separate days. Each session consisted 21 exposures: 1 "initial" followed by a 30-min interval (initial data set), 10 acquired with 30-min TBE (data sets 1-10) and 10 acquired with 15-min TBE (data sets 11-20). CBCT data were exported as digital imaging and communications in medicine files and converted to text files containing x, y and z positions and grey shade for each voxel. Subtractions were performed voxel-by-voxel in two set-ups: (1) between two consecutive data sets and (2) between any subsequent data set and data set 1. The mean grey shade variation for each voxel was calculated for each unit/session. The largest mean grey shade variation was found in the subtraction set-up 2 (27-447 shades of grey, depending on the unit). Considering subtraction set-up 1, the highest variation was seen for NEW5, between data sets 1 and the initial. Discrepancies in voxel value distribution were found by comparing the initial examination of the day with the subsequent examinations. TBE had no predictable effect on the variation of CBCT-derived voxel values. AMORe ranged between 0 and 64.

Massed Trials versus Trials Embedded into Game Play: Child Outcomes and Preference

ERIC Educational Resources Information Center

Ledford, Jennifer R.; Chazin, Kate T.; Harbin, Emilee R.; Ward, Sarah E.

2017-01-01

Limited data are available regarding how response prompting procedures should be used in early childhood settings. The purpose of this study was to compare the efficiency of progressive time delay instruction presented via two trial arrangements: massed and embedded. During massed trial sessions, a short instructional session was conducted,…

Recent developments in heterodyne laser interferometry at Harbin Institute of Technology

NASA Astrophysics Data System (ADS)

Hu, P. C.; Tan, J. B. B.; Yang, H. X. X.; Fu, H. J. J.; Wang, Q.

2013-01-01

In order to fulfill the requirements for high-resolution and high-precision heterodyne interferometric technologies and instruments, the laser interferometry group of HIT has developed some novel techniques for high-resolution and high-precision heterodyne interferometers, such as high accuracy laser frequency stabilization, dynamic sub-nanometer resolution phase interpolation and dynamic nonlinearity measurement. Based on a novel lock point correction method and an asymmetric thermal structure, the frequency stabilized laser achieves a long term stability of 1.2×10-8, and it can be steadily stabilized even in the air flowing up to 1 m/s. In order to achieve dynamic sub-nanometer resolution of laser heterodyne interferometers, a novel phase interpolation method based on digital delay line is proposed. Experimental results show that, the proposed 0.62 nm, phase interpolator built with a 64 multiple PLL and an 8-tap digital delay line achieves a static accuracy better than 0.31nm and a dynamic accuracy better than 0.62 nm over the velocity ranging from -2 m/s to 2 m/s. Meanwhile, an accuracy beam polarization measuring setup is proposed to check and ensure the light's polarization state of the dual frequency laser head, and a dynamic optical nonlinearity measuring setup is built to measure the optical nonlinearity of the heterodyne system accurately and quickly. Analysis and experimental results show that, the beam polarization measuring setup can achieve an accuracy of 0.03° in ellipticity angles and an accuracy of 0.04° in the non-orthogonality angle respectively, and the optical nonlinearity measuring setup can achieve an accuracy of 0.13°.

Petting away pre-exam stress: The effect of therapy dog sessions on student well-being.

PubMed

Ward-Griffin, Emma; Klaiber, Patrick; Collins, Hanne K; Owens, Rhea L; Coren, Stanley; Chen, Frances S

2018-03-12

Recently, many universities have implemented programmes in which therapy dogs and their handlers visit college campuses. Despite the immense popularity of therapy dog sessions, few randomized studies have empirically tested the efficacy of such programmes. The present study evaluates the efficacy of such a therapy dog programme in improving the well-being of university students. This research incorporates two components: (a) a pre/post within-subjects design, in which 246 participants completed a brief questionnaire immediately before and after a therapy dog session and (b) an experimental design with a delayed-treatment control group, in which all participants completed baseline measures and follow-up measures approximately 10 hr later. Only participants in the experimental condition experienced the therapy dog session in between the baseline and follow-up measures. Analyses of pre/post data revealed that the therapy dog sessions had strong immediate benefits, significantly reducing stress and increasing happiness and energy levels. In addition, participants in the experimental group reported a greater improvement in negative affect, perceived social support, and perceived stress compared with those in the delayed-treatment control group. Our results suggest that single, drop-in, therapy dog sessions have large and immediate effects on students' well-being, but also that the effects after several hours are small. Copyright © 2018 John Wiley & Sons, Ltd.

Time domain passivity controller for 4-channel time-delay bilateral teleoperation.

PubMed

Rebelo, Joao; Schiele, Andre

2015-01-01

This paper presents an extension of the time-domain passivity control approach to a four-channel bilateral controller under the effects of time delays. Time-domain passivity control has been used successfully to stabilize teleoperation systems with position-force and position-position controllers; however, the performance with such control architectures is sub-optimal both with and without time delays. This work extends the network representation of the time-domain passivity controller to the four-channel architecture, which provides perfect transparency to the user without time delay. The proposed architecture is based on modelling the controllers as dependent voltage sources and using only series passivity controllers. The obtained results are shown on a one degree-of-freedom setup and illustrate the stabilization behaviour of the proposed controller when time delay is present in the communication channel.

A Machine Learning Concept for DTN Routing

NASA Technical Reports Server (NTRS)

Dudukovich, Rachel; Hylton, Alan; Papachristou, Christos

2017-01-01

This paper discusses the concept and architecture of a machine learning based router for delay tolerant space networks. The techniques of reinforcement learning and Bayesian learning are used to supplement the routing decisions of the popular Contact Graph Routing algorithm. An introduction to the concepts of Contact Graph Routing, Q-routing and Naive Bayes classification are given. The development of an architecture for a cross-layer feedback framework for DTN (Delay-Tolerant Networking) protocols is discussed. Finally, initial simulation setup and results are given.

Experimental Control of a Fast Chaotic Time-Delay Opto-Electronic Device

DTIC Science & Technology

2003-01-01

chaotic sources such as the erbium-doped Þber laser. The basic idea is to use the message as a driving signal for the chaotic system. The message...47 x 3.10 Block diagram of feedback loop. Light from the interferometer is con- verted into an electrical signal by the photodiode (PD). All...a time delay of τD. Finally, the electrical signal is converted back into light by the laser diode (LD). . . . . . . . . . . . . . . . . 48 3.11 Setup

Multi-Kilovolt Solid-State Picosecond Switch Studies

DTIC Science & Technology

2013-06-01

waveforms for the SiC device. Figure 7 shows the nanosecond driving pulse and the delayed avalanche breakdown of the SiC device. The driving...of the sharpened pulse RS VS VOLTAGE SOURCE TEST DEVICE VOLTAGE MONITOR R1 R2 TO SCOPE Figure 6. Simplified SiC avalanche diode test setup 0 2 4...Measured waveforms showing nanosecond driving pulse and subnanosecond delayed avalanche dreakdown of SiC device 50 µm 75 µm 10 µm p+ n+n Anode Cathode

Delayed Face Recognition in Children and Adolescents with Autism Spectrum Disorders

PubMed Central

Tehrani-Doost, Mehdi; Ghanbari-Motlagh, Maria; Shahrivar, Zahra

2012-01-01

Objective Children with autism spectrum disorders (ASDs) have great problems in social interactions including face recognition. There are many studies reporting deficits in face memory in individuals with ASDs. On the other hand, some studies indicate that this kind of memory is intact in this group. In the present study, delayed face recognition has been investigated in children and adolescents with ASDs compared to the age and sex matched typically developing group. Methods In two sessions, Benton Facial Recognition Test was administered to 15 children and adolescents with ASDs (high functioning autism and Asperger syndrome) and to 15 normal participants, ages 8-17 years. In the first condition, the long form of Benton Facial Recognition Test was used without any delay. In the second session, this test was administered with 15 seconds delay after one week. The reaction times and correct responses were measured in both conditions as the dependent variables. Results Comparison of the reaction times and correct responses in the two groups revealed no significant difference in delayed and non-delayed conditions. Furthermore, no significant difference was observed between the two conditions in ASDs patients when comparing the variables. Although a significant correlation (p<0.05) was found between delayed and non-delayed conditions, it was not significant in the normal group. Moreover, data analysis revealed no significant difference between the two groups in the two conditions when the IQ was considered as covariate. Conclusion In this study, it was found that the ability to recognize faces in simultaneous and delayed conditions is similar between adolescents with ASDs and their normal counterparts. PMID:22952545

Is immediate adjunctive CBT more beneficial than delayed CBT in treating depression?: A Pilot Study.

PubMed

Rizvi, Sakina J; Zaretsky, Ari; Schaffer, Ayal; Levitt, Anthony

2015-03-01

Cognitive-behavioral therapy (CBT) is an efficacious first-line therapy for patients with major depressive disorder (MDD). Due to the limited accessibility of CBT, long wait lists result in delayed treatment, which may affect treatment outcomes. The goal of this pilot study was to obtain preliminary data from a randomized controlled trial to determine whether delayed CBT reduces the effectiveness of the therapy compared to immediate CBT in patients with MDD receiving pharmacotherapy. Patients were randomized to receive immediate CBT (n=18) or to begin CBT after 6 months (n=20) and received 14 weekly sessions, followed by two additional booster sessions. During the active treatment months, patients in the immediate group demonstrated reductions in scores on the Beck Depression Inventory II (BDI-II) that were similar to those in the delayed CBT group. However, when the analysis was performed using only data from patients in the delayed group who were still in a depressive episode, there was an overall greater decrease in BDI-II scores in the immediate group vs. the delayed group over the active treatment months, but not specifically at the 6-month endpoint. These findings suggest delays in depression treatment, similar to what occurs with real-world wait list times, may not have a significant impact on the effectiveness of CBT in patients who are already receiving treatment as usual. However, such delays may affect the effectiveness of CBT in those patients who remain depressed during the time delay. A larger trial is necessary to confirm these findings. (Journal of Psychiatric Practice 2015;21:107-113).

Effects of environmental and pharmacological manipulations on a novel delayed nonmatching-to-sample 'working memory' procedure in unrestrained rhesus monkeys.

PubMed

Hutsell, Blake A; Banks, Matthew L

2015-08-15

Working memory is a domain of 'executive function.' Delayed nonmatching-to-sample (DNMTS) procedures are commonly used to examine working memory in both human laboratory and preclinical studies. The aim was to develop an automated DNMTS procedure maintained by food pellets in rhesus monkeys using a touch-sensitive screen attached to the housing chamber. Specifically, the DNMTS procedure was a 2-stimulus, 2-choice recognition memory task employing unidimensional discriminative stimuli and randomized delay interval presentations. DNMTS maintained a delay-dependent decrease in discriminability that was independent of the retention interval distribution. Eliminating reinforcer availability during a single delay session or providing food pellets before the session did not systematically alter accuracy, but did reduce total choices. Increasing the intertrial interval enhanced accuracy at short delays. Acute Δ(9)-THC pretreatment produced delay interval-dependent changes in the forgetting function at doses that did not alter total choices. Acute methylphenidate pretreatment only decreased total choices. All monkeys were trained to perform NMTS at the 1s training delay within 60 days of initiating operant touch training. Furthermore, forgetting functions were reliably delay interval-dependent and stable over the experimental period (∼6 months). Consistent with previous studies, increasing the intertrial interval improved DNMTS performance, whereas Δ(9)-THC disrupted DNMTS performance independent of changes in total choices. Overall, the touchscreen-based DNMTS procedure described provides an efficient method for training and testing experimental manipulations on working memory in unrestrained rhesus monkeys. Copyright © 2015 Elsevier B.V. All rights reserved.

Dynamic sample size detection in learning command line sequence for continuous authentication.

PubMed

Traore, Issa; Woungang, Isaac; Nakkabi, Youssef; Obaidat, Mohammad S; Ahmed, Ahmed Awad E; Khalilian, Bijan

2012-10-01

Continuous authentication (CA) consists of authenticating the user repetitively throughout a session with the goal of detecting and protecting against session hijacking attacks. While the accuracy of the detector is central to the success of CA, the detection delay or length of an individual authentication period is important as well since it is a measure of the window of vulnerability of the system. However, high accuracy and small detection delay are conflicting requirements that need to be balanced for optimum detection. In this paper, we propose the use of sequential sampling technique to achieve optimum detection by trading off adequately between detection delay and accuracy in the CA process. We illustrate our approach through CA based on user command line sequence and naïve Bayes classification scheme. Experimental evaluation using the Greenberg data set yields encouraging results consisting of a false acceptance rate (FAR) of 11.78% and a false rejection rate (FRR) of 1.33%, with an average command sequence length (i.e., detection delay) of 37 commands. When using the Schonlau (SEA) data set, we obtain FAR = 4.28% and FRR = 12%.

Hostility, Cigarette Smoking, and Responses to a Lab-based Social Stressor

PubMed Central

Kahler, Christopher W.; Leventhal, Adam M.; Colby, Suzanne M.; Gwaltney, Chad J.; Kamarck, Thomas W.; Monti, Peter M.

2013-01-01

High trait hostility is associated with persistent cigarette smoking. To better understand mechanisms that may account for this association, we examined the effects of acute smoking abstinence and delayed versus immediate smoking reinstatement on responses to a social stressor among 48 low hostile (LH) and 48 high hostile (HH) smokers. Participants completed two laboratory sessions, one before which they had smoked ad lib and one before which they had abstained for the prior 12 hours. During each session, participants completed a stressful speaking task and then smoked immediately after the stressor or after a 15-minute delay. The effect of immediate vs. delayed smoking reinstatement on recovery in negative mood was significantly moderated by hostility. When reinstatement was delayed, HH participants showed significant increases in negative mood over time, whereas LH participants showed little change. When reinstatement was immediate, HH and LH smokers showed similar significant decreases in negative mood. Smoking abstinence did not moderate hostility effects. Cigarette smoking may prevent continuing increases in negative mood following social stress in HH smokers, which may partially explain their low rates of quitting. PMID:19968406

Arbitrary digital pulse sequence generator with delay-loop timing

NASA Astrophysics Data System (ADS)

Hošák, Radim; Ježek, Miroslav

2018-04-01

We propose an idea of an electronic multi-channel arbitrary digital sequence generator with temporal granularity equal to two clock cycles. We implement the generator with 32 channels using a low-cost ARM microcontroller and demonstrate its capability to produce temporal delays ranging from tens of nanoseconds to hundreds of seconds, with 24 ns timing granularity and linear scaling of delay with respect to the number of delay loop iterations. The generator is optionally synchronized with an external clock source to provide 100 ps jitter and overall sequence repeatability within the whole temporal range. The generator is fully programmable and able to produce digital sequences of high complexity. The concept of the generator can be implemented using different microcontrollers and applied for controlling of various optical, atomic, and nuclear physics measurement setups.

Ikeda-like chaos on a dynamically filtered supercontinuum light source

NASA Astrophysics Data System (ADS)

Chembo, Yanne K.; Jacquot, Maxime; Dudley, John M.; Larger, Laurent

2016-08-01

We demonstrate temporal chaos in a color-selection mechanism from the visible spectrum of a supercontinuum light source. The color-selection mechanism is governed by an acousto-optoelectronic nonlinear delayed-feedback scheme modeled by an Ikeda-like equation. Initially motivated by the design of a broad audience live demonstrator in the framework of the International Year of Light 2015, the setup also provides a different experimental tool to investigate the dynamical complexity of delayed-feedback dynamics. Deterministic hyperchaos is analyzed here from the experimental time series. A projection method identifies the delay parameter, for which the chaotic strange attractor originally evolving in an infinite-dimensional phase space can be revealed in a two-dimensional subspace.

No effects of transcranial DLPFC stimulation on implicit task sequence learning and consolidation.

PubMed

Savic, Branislav; Cazzoli, Dario; Müri, René; Meier, Beat

2017-08-29

Neurostimulation of the dorsolateral prefrontal cortex (DLPFC) can modulate performance in cognitive tasks. In a recent study, however, transcranial direct current stimulation (tDCS) of the DLPFC did not affect implicit task sequence learning and consolidation in a paradigm that involved bimanual responses. Because bimanual performance increases the coupling between homologous cortical areas of the hemispheres and left and right DLPFC were stimulated separately the null findings may have been due to the bimanual setup. The aim of the present study was to test the effect of neuro-stimulation on sequence learning in a uni-manual setup. For this purpose two experiments were conducted. In Experiment 1, the DLPFC was stimulated with tDCS. In Experiment 2 the DLPFC was stimulated with transcranial magnetic stimulation (TMS). In both experiments, consolidation was measured 24 hours later. The results showed that sequence learning was present in all conditions and sessions, but it was not influenced by stimulation. Likewise, consolidation of sequence learning was robust across sessions, but it was not influenced by stimulation. These results replicate and extend previous findings. They indicate that established tDCS and TMS protocols on the DLPFC do not influence implicit task sequence learning and consolidation.

Alcohol Increases Delay and Probability Discounting of Condom-Protected Sex: A Novel Vector for Alcohol-Related HIV Transmission.

PubMed

Johnson, Patrick S; Sweeney, Mary M; Herrmann, Evan S; Johnson, Matthew W

2016-06-01

Alcohol use, especially at binge levels, is associated with sexual HIV risk behavior, but the mechanisms through which alcohol increases sexual risk taking are not well-examined. Delay discounting, that is, devaluation of future consequences as a function of delay to their occurrence, has been implicated in a variety of problem behaviors, including risky sexual behavior. Probability discounting is studied with a similar framework as delay discounting, but is a distinct process in which a consequence is devalued because it is uncertain or probabilistic. Twenty-three, nondependent alcohol users (13 male, 10 female; mean age = 25.3 years old) orally consumed alcohol (1 g/kg) or placebo in 2 separate experimental sessions. During sessions, participants completed tasks examining delay and probability discounting of hypothetical condom-protected sex (Sexual Delay Discounting Task, Sexual Probability Discounting Task) and of hypothetical and real money. Alcohol decreased the likelihood that participants would wait to have condom-protected sex versus having immediate, unprotected sex. Alcohol also decreased the likelihood that participants would use an immediately available condom given a specified level of sexually transmitted infection (STI) risk. Alcohol did not affect delay discounting of money, but it did increase participants' preferences for larger, probabilistic monetary rewards over smaller, certain rewards. Acute, binge-level alcohol intoxication may increase sexual HIV risk by decreasing willingness to delay sex in order to acquire a condom in situations where one is not immediately available, and by decreasing sensitivity to perceived risk of STI contraction. These findings suggest that delay and probability discounting are critical, but heretofore unrecognized, processes that may mediate the relations between alcohol use and HIV risk. Copyright © 2016 by the Research Society on Alcoholism.

Cognitive Therapy for Depression: A Comparison of Individual Psychotherapy and Bibliotherapy for Depressed Older Adults

ERIC Educational Resources Information Center

Floyd, Mark; Scogin, Forrest; McKendree-Smith, Nancy L.; Floyd, Donna L.; Rokke, Paul D.

2004-01-01

Thirty-one community-residing older adults age 60 or over either received 16 sessions of individual cognitive psychotherapy (Beck, Rush, Shaw, & Emery, 1979) or read Feeling Good (Burns, 1980) for bibliotherapy. Posttreatment comparisons with the delayed-treatment control indicated that both treatments were superior to a delayed-treatment control.…

No Effects of Non-invasive Brain Stimulation on Multiple Sessions of Object-Location-Memory Training in Healthy Older Adults.

PubMed

Külzow, Nadine; Cavalcanti de Sousa, Angelica Vieira; Cesarz, Magda; Hanke, Julie-Marie; Günsberg, Alida; Harder, Solvejg; Koblitz, Swantje; Grittner, Ulrike; Flöel, Agnes

2017-01-01

Object-location memory (OLM) is known to decline with normal aging, a process accelerated in pathological conditions like mild cognitive impairment (MCI). In order to maintain cognitive health and to delay the transition from healthy to pathological conditions, novel strategies are being explored. Tentative evidence suggests that combining cognitive training and anodal transcranial direct current stimulation (atDCS), both reported to induce small and often inconsistent behavioral improvements, could generate larger or more consistent improvements or both, compared to each intervention alone. Here, we explored the combined efficacy of these techniques on OLM. In a subject-blind sham-controlled cross-over design 32 healthy older adults underwent a 3-day visuospatial training paired with either anodal (20 min) or sham (30 s) atDCS (1 mA, temporoparietal). Subjects were asked to learn the correct object-location pairings on a street map, shown over five learning blocks on each training day. Acquisition performance was assessed by accuracy on a given learning block in terms of percentage of correct responses. Training success (performance on last training day) and delayed memory after 1-month were analyzed by mixed model analysis and were controlled for gender, age, education, sequence of stimulation and baseline performance. Exploratory analysis of atDCS effects on within-session (online) and between-session (offline) memory performance were conducted. Moreover, transfer effects on similar trained (visuospatial) and less similar (visuo-constructive, verbal) untrained memory tasks were explored, both immediately after training, and on follow-up. We found that atDCS paired with OLM-training did not enhance success in training or performance in 1-month delayed memory or transfer tasks. In sum, this study did not support the notion that the combined atDCS-training approach improves immediate or delayed OLM in older adults. However, specifics of the experimental design, and a non-optimal timing of atDCS between sessions might have masked beneficial effects and should be more systematically addressed in future studies.

Rapid Acquisition of Choice and Timing and the Provenance of the Terminal-Link Effect

ERIC Educational Resources Information Center

Kyonka, Elizabeth G. E.; Grace, Randolph C.

2010-01-01

Eight pigeons responded in a concurrent-chains procedure in which terminal-link schedules changed pseudorandomly across sessions. Pairs of terminal-link delays either summed to 15 s or to 45 s. Across sessions, the location of the shorter terminal link changed according to a pseudorandom binary sequence. On some terminal links, food was withheld…

Suggestibility, Social Support, and Memory for a Novel Experience in Young Children

ERIC Educational Resources Information Center

Quas, J.A.; Wallin, A.R.; Papini, S.; Lench, H.; Scullin, M.H.

2005-01-01

This study examined 5- and 6-year-olds' suggestibility and interviewer demeanor as joint predictors of their memory for a novel experience. Session 1 consisted of children taking part in a novel laboratory event. Session 2 took place after approximately a 1-week delay and consisted of children completing both a memory test concerning what happened…

Within-session spacing improves delayed recall in children.

PubMed

Zigterman, Jessica R; Simone, Patricia M; Bell, Matthew C

2015-01-01

Multiple retrievals of a memory over a spaced manner improve long-term memory performance in infants, children, younger and older adults; however, few studies have examined spacing effects with young school-age children. To expand the understanding of the spacing benefit in children, the current study presented weakly associated English word-pairs to children aged 7-11 and cued their recall two times immediately (massed), after a delay of 5 or 10 items (spaced) or not at all (control). After this encoding session with or without two retrievals, participants were tested two times for memory of all word-pairs: immediately and 30 minutes after the encoding session. Multiple retrievals significantly improved memory on the tests. However, words repeated in a spaced design were remembered at higher rates than those that were massed, while gap size between repetitions (5 or 10) did not differentially impact performance. The data show that a within-session spacing strategy can benefit children's ability to remember word-pairs after 30 minutes. Thus, asking students to recall what they have learned within a lesson is a technique that can be used in a classroom to improve long-term recall.

P300 amplitude variation is related to ventral striatum BOLD response during gain and loss anticipation: an EEG and fMRI experiment.

PubMed

Pfabigan, Daniela M; Seidel, Eva-Maria; Sladky, Ronald; Hahn, Andreas; Paul, Katharina; Grahl, Arvina; Küblböck, Martin; Kraus, Christoph; Hummer, Allan; Kranz, Georg S; Windischberger, Christian; Lanzenberger, Rupert; Lamm, Claus

2014-08-01

The anticipation of favourable or unfavourable events is a key component in our daily life. However, the temporal dynamics of anticipation processes in relation to brain activation are still not fully understood. A modified version of the monetary incentive delay task was administered during separate functional magnetic resonance imaging (fMRI) and electroencephalogram (EEG) sessions in the same 25 participants to assess anticipatory processes with a multi-modal neuroimaging set-up. During fMRI, gain and loss anticipation were both associated with heightened activation in ventral striatum and reward-related areas. EEG revealed most pronounced P300 amplitudes for gain anticipation, whereas CNV amplitudes distinguished neutral from gain and loss anticipation. Importantly, P300, but not CNV amplitudes, were correlated to neural activation in the ventral striatum for both gain and loss anticipation. Larger P300 amplitudes indicated higher ventral striatum blood oxygen level dependent (BOLD) response. Early stimulus evaluation processes indexed by EEG seem to be positively related to higher activation levels in the ventral striatum, indexed by fMRI, which are usually associated with reward processing. The current results, however, point towards a more general motivational mechanism processing salient stimuli during anticipation. Copyright © 2014. Published by Elsevier Inc.

Recall memory in children with Down syndrome and typically developing peers matched on developmental age.

PubMed

Milojevich, H; Lukowski, A

2016-01-01

Whereas research has indicated that children with Down syndrome (DS) imitate demonstrated actions over short delays, it is presently unknown whether children with DS recall information over lengthy delays at levels comparable with typically developing (TD) children matched on developmental age. In the present research, 10 children with DS and 10 TD children participated in a two-session study to examine basic processes associated with hippocampus-dependent recall memory. At the first session, the researcher demonstrated how to complete a three-step action sequence with novel stimuli; immediate imitation was permitted as an index of encoding. At the second session, recall memory was assessed for previously modelled sequences; children were also presented with two novel three-step control sequences. The results indicated that group differences were not apparent in the encoding of the events or the forgetting of information over time. Group differences were also not observed when considering the recall of individual target actions at the 1-month delay, although TD children produced more target actions overall at the second session relative to children with DS. Group differences were found when considering memory for temporal order information, such that TD children evidenced recall relative to novel control sequences, whereas children with DS did not. These findings suggest that children with DS may have difficulty with mnemonic processes associated with consolidation/storage and/or retrieval processes relative to TD children. © 2015 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.

Effects of electromagnetic radiation (bright light, extremely low-frequency magnetic fields, infrared radiation) on the circadian rhythm of melatonin synthesis, rectal temperature, and heart rate.

PubMed

Griefahn, Barbara; Künemund, Christa; Blaszkewicz, Meinolf; Lerchl, Alexander; Degen, Gisela H

2002-10-01

Electromagnetic spectra reduce melatonin production and delay the nadirs of rectal temperature and heart rate. Seven healthy men (16-22 yrs) completed 4 permuted sessions. The control session consisted of a 24-hours bedrest at < 30 lux, 18 degrees C, and < 50 dBA. In the experimental sessions, either light (1500 lux), magnetic field (16.7 Hz, 0.2 mT), or infrared radiation (65 degrees C) was applied from 5 pm to 1 am. Salivary melatonin level was determined hourly, rectal temperature and heart rate were continuously recorded. Melatonin synthesis was completely suppressed by light but resumed thereafter. The nadirs of rectal temperature and heart rate were delayed. The magnetic field had no effect. Infrared radiation elevated rectal temperature and heart rate. Only bright light affected the circadian rhythms of melatonin synthesis, rectal temperature, and heart rate, however, differently thus causing a dissociation, which might enhance the adverse effects of shiftwork in the long run.

Towards Gesture-Based Multi-User Interactions in Collaborative Virtual Environments

NASA Astrophysics Data System (ADS)

Pretto, N.; Poiesi, F.

2017-11-01

We present a virtual reality (VR) setup that enables multiple users to participate in collaborative virtual environments and interact via gestures. A collaborative VR session is established through a network of users that is composed of a server and a set of clients. The server manages the communication amongst clients and is created by one of the users. Each user's VR setup consists of a Head Mounted Display (HMD) for immersive visualisation, a hand tracking system to interact with virtual objects and a single-hand joypad to move in the virtual environment. We use Google Cardboard as a HMD for the VR experience and a Leap Motion for hand tracking, thus making our solution low cost. We evaluate our VR setup though a forensics use case, where real-world objects pertaining to a simulated crime scene are included in a VR environment, acquired using a smartphone-based 3D reconstruction pipeline. Users can interact using virtual gesture-based tools such as pointers and rulers.

Repetitive sessions of tDCS to improve naming in post-stroke aphasia: Insights from an individual patient data (IPD) meta-analysis.

PubMed

Rosso, Charlotte; Arbizu, Céline; Dhennain, Claire; Lamy, Jean-Charles; Samson, Yves

2018-01-01

Small clinical trials reported that repetitive sessions of tDCS could improve naming abilities in post-stroke aphasia. However, systematic meta-analyses found no effect, but all of these analyses pooled data from both single and repetitive sessions at the group level. The aim of this paper was to perform a meta-analysis based on individual patient data to explore the effects of repetitive tDCS sessions on naming in post-stroke aphasia and in prespecified subgroups. We searched for published sham-controlled trials using the keywords "aphasia OR language" AND "transcranial direct current stimulation OR tDCS" AND "stroke". We computed an active and sham improvement ratio by dividing the difference between naming scores after and before the active or sham sessions, respectively, by the total number of picture items. Because of heterogeneity (I2 = 66%, p: 0.002), we used random-effects models to estimate the standardized mean difference (SMD) for the naming outcome. We then analyzed subgroups according to number of sessions, polarity, side/location of the active electrode, post-stroke delay, aphasia severity and comprehension disorders. Seven eligible studies were identified, including 68 chronic stroke patients. tDCS was beneficial on naming ability (35% ±34% in the active vs. 25% ±37% in the sham condition). An SMD of 0.8 (95% CI: 0.27-1.33) was found for the naming outcome. Additionally, there was a dose-dependent effect (5 vs. >5 sessions). We also demonstrated a prevalence of anodal vs. cathodal condition and left vs. right targeting electrode. Finally, repetitive sessions were beneficial regardless of the severity of aphasia, comprehension disorders or post-stroke delay. Repetitive sessions of tDCS are likely to be valuable in enhancing naming accuracy in post-stroke aphasia.

Beta-delayed proton emission from 20Mg

NASA Astrophysics Data System (ADS)

Lund, M. V.; Andreyev, A.; Borge, M. J. G.; Cederkäll, J.; De Witte, H.; Fraile, L. M.; Fynbo, H. O. U.; Greenlees, P. T.; Harkness-Brennan, L. J.; Howard, A. M.; Huyse, M.; Jonson, B.; Judson, D. S.; Kirsebom, O. S.; Konki, J.; Kurcewicz, J.; Lazarus, I.; Lica, R.; Lindberg, S.; Madurga, M.; Marginean, N.; Marginean, R.; Marroquin, I.; Mihai, C.; Munch, M.; Nacher, E.; Negret, A.; Nilsson, T.; Page, R. D.; Pascu, S.; Perea, A.; Pucknell, V.; Rahkila, P.; Rapisarda, E.; Riisager, K.; Rotaru, F.; Sotty, C.; Stanoiu, M.; Tengblad, O.; Turturica, A.; Van Duppen, P.; Vedia, V.; Wadsworth, R.; Warr, N.

2016-10-01

Beta-delayed proton emission from 20 Mg has been measured at ISOLDE, CERN, with the ISOLDE Decay Station (IDS) setup including both charged-particle and gamma-ray detection capabilities. A total of 27 delayed proton branches were measured including seven so far unobserved. An updated decay scheme, including three new resonances above the proton separation energy in 20 Na and more precise resonance energies, is presented. Beta-decay feeding to two resonances above the Isobaric Analogue State (IAS) in 20 Na is observed. This may allow studies of the 4032.9(2.4)keV resonance in 19 Ne through the beta decay of 20 Mg, which is important for the astrophysically relevant reaction 15O( α, γ)19Ne . Beta-delayed protons were used to obtain a more precise value for the half-life of 20 Mg, 91.4(1.0)ms.

Development of an experimental setup for analyzing the influence of Magnus effect on the performance of airfoil

NASA Astrophysics Data System (ADS)

Aktharuzzaman, Md; Sarker, Md. Samad; Safa, Wasiul; Sharah, Nahreen; Salam, Md. Abdus

2017-12-01

Magnus effect is a phenomenon where pressure difference is created according to Bernoulli's effect due to induced velocity changes caused by a rotating object in a fluid. Using this concept, the idea of delaying boundary layer separation on airfoil by providing moving surface boundary layer control has been developed. In order to analyze the influence of Magnus effect on the aerodynamic performance of an airfoil, there is no alternative of developing an experimental setup. This paper aims to develop such an experimental setup which will be capable of analyzing the influence of Magnus effect on both symmetric and asymmetric airfoils by placing a cylinder at the leading edge. To provide arrangements for a rotating cylinder at the leading edge of airfoil, necessary modifications and additions have been done in the test section of an AF100 subsonic wind tunnel.

A novel setup for femtosecond pump-repump-probe IR spectroscopy with few cycle CEP stable pulses.

PubMed

Bradler, Maximilian; Werhahn, Jasper C; Hutzler, Daniel; Fuhrmann, Simon; Heider, Rupert; Riedle, Eberhard; Iglev, Hristo; Kienberger, Reinhard

2013-08-26

We present a three-color mid-IR setup for vibrational pump-repump-probe experiments with a temporal resolution well below 100 fs and a freely selectable spectral resolution of 20 to 360 cm(-1) for the pump and repump. The usable probe range without optical realignment is 900 cm(-1). The experimental design employed is greatly simplified compared to the widely used setups, highly robust and includes a novel means for generation of tunable few-cycle pulses with stable carrier-envelope phase. A Ti:sapphire pump system operating with 1 kHz and a modest 150 fs pulse duration supplies the total pump energy of just 0.6 mJ. The good signal-to-noise ratio of the setup allows the determination of spectrally resolved transient probe changes smaller than 6·10(-5) OD at 130 time delays in just 45 minutes. The performance of the spectrometer is demonstrated with transient IR spectra and decay curves of HDO molecules in lithium nitrate trihydrate and ice and a first all MIR pump-repump-probe measurement.

Interleukin-6 and Delayed Onset Muscle Soreness Do Not Vary during the Menstrual Cycle

ERIC Educational Resources Information Center

Chaffin, Morgan E.; Berg, Kris E.; Meendering, Jessica R.; Llewellyn, Tamra L.; French, Jeffrey A.; Davis, Jeremy E.

2011-01-01

The purpose of this study was to determine if a difference in interleukin-6 (IL-6) and delayed onset muscles soreness (DOMS) exists in two different phases of the menstrual cycle. Nine runners performed one 75-min high-intensity interval running session during the early follicular (EF) phase and once during the midluteal (ML) phase of the…

Manipulation of Motivating Operations and Use of a Script-Fading Procedure to Teach Mands for Location to Children with Language Delays

ERIC Educational Resources Information Center

Howlett, Melissa A.; Sidener, Tina M.; Progar, Patrick R.; Sidener, David W.

2011-01-01

The effects of contriving motivating operations (MOs) and script fading on the acquisition of the mand "Where's [object]?" were evaluated in 2 boys with language delays. During each session, trials were alternated in which high-preference items were present (abolishing operation [AO] trials) or missing (establishing operation [EO] trials) from…

Teaching Generalized Reading of Product Warning Labels to Young Adults with Autism Using the Constant Time Delay Procedure

ERIC Educational Resources Information Center

Dogoe, Maud S.; Banda, Devender R.; Lock, Robin H.; Feinstein, Rita

2011-01-01

This study examined the effectiveness of the constant timed delay procedure for teaching two young adults with autism to read, define, and state the contextual meaning of keywords on product warning labels of common household products. Training sessions were conducted in the dyad format using flash cards. Results indicated that both participants…

A test of water vapor radiometer-based troposphere calibration using VLBI observations on a 21-kilometer baseline

NASA Technical Reports Server (NTRS)

Linfield, R. P.; Teitelbaum, L. P.; Skjerve, L. J.; Keihm, S. J.; Walter, S. J.; Mahoney, M. J.; Treuhaft, R. N.

1995-01-01

Simultaneous very long baseline interferometry (VLBI) and water vapor radiometer (WVR) measurements on a 21 km baseline showed that calibration by WVRs removed a significant fraction of the effect of tropospheric delay fluctuations for these experiments. From comparison of the residual delay variations within scans and between scans, the total tropospheric contribution t the delay residuals for each of the three 5 to 20 hour sessions was estimated as 1, 17, and 10%, with the first value being uncertain. The observed improvement in rms residual delay from WVR calibration during these three sessions was 4, 16, and 2%, respectively. The improvement is consistent with the estimated 2 to 3 mm path delay precision of current WVRs. The VLBI measurements, of natural radio sources, were conducted in April and May 1993 at Goldstone, California. Dual-frequency (2.3 and 8.4 GHz) observations were employed to remove the effects of charged particles from the data. Measurements with co-pointed WVRs, located within 50 m of the axis of each antenna, were performed to test the ability of the WVRs to calibrate line-of-sight path delays. Factors that made WVR performance assessment difficult included (1) the fact that the level of tropospheric fluctuations was smaller than is typical for Goldstone during these experiments and (2) VLBI delay variations on longer time scales (i.e., over multiple scans) contained uncalibrated instrumental effects (probably a result of slow temperature variations in the VLBI hardware) that were larger than the tropospheric effects.

Small Private Online Research: A Proposal for A Numerical Methods Course Based on Technology Use and Blended Learning

ERIC Educational Resources Information Center

Cepeda, Francisco Javier Delgado

2017-01-01

This work presents a proposed model in blended learning for a numerical methods course evolved from traditional teaching into a research lab in scientific visualization. The blended learning approach sets a differentiated and flexible scheme based on a mobile setup and face to face sessions centered on a net of research challenges. Model is…

Collider shot setup for Run 2 observations and suggestions

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

Annala, J.; Joshel, B.

1996-01-31

This note is intended to provoke discussion on Collider Run II shot setup. We hope this is a start of activities that will converge on a functional description of what is needed for shot setups in Collider Run II. We will draw on observations of the present shot setup to raise questions and make suggestions for the next Collider run. It is assumed that the reader has some familiarity with the Collider operational issues. Shot setup is defined to be the time between the end of a store and the time the Main Control Room declares colliding beams. This ismore » the time between Tevatron clock events SCE and SCB. This definition does not consider the time experiments use to turn on their detectors. This analysis was suggested by David Finley. The operational scenarios for Run II will require higher levels of reliability and speed for shot setup. See Appendix I and II. For example, we estimate that a loss of 3 pb{sup {minus}1}/week (with 8 hour stores) will occur if shot setups take 90 minutes instead of 30 minutes. In other words: If you do 12 shots for one week and accept an added delay of one minute in each shot, you will loose more than 60 nb{sup {minus}1} for that week alone (based on a normal shot setup of 30 minutes). These demands should lead us to be much more pedantic about all the factors that affect shot setups. Shot setup will be viewed as a distinct process that is composed of several inter- dependent `components`: procedures, hardware, controls, and sociology. These components don`t directly align with the different Accelerator Division departments, but are topical groupings of the needed accelerator functions. Defining these components, and categorizing our suggestions within them, are part of the goal of this document. Of course, some suggestions span several of these components.« less

Haloperidol and Rimonabant Increase Delay Discounting in Rats Fed High-Fat and Standard-Chow Diets

PubMed Central

Boomhower, Steven R.; Rasmussen, Erin B.

2016-01-01

The dopamine and endocannabinoid neurotransmitter systems have been implicated in delay discounting, a measure of impulsive choice, and obesity. The current study was designed to determine the extent to which haloperidol and rimonabant affected delay discounting in rats fed standard-chow and high-fat diets. Sprague-Dawley rats were allowed to free-feed under a high-fat diet (4.73 kcal/g) or a standard-chow diet (3.0 kcal/g) for three months. Then, operant sessions began in which rats (n = 9 standard chow; n = 10 high-fat) chose between one sucrose pellet delivered immediately vs. three sucrose pellets after a series of delays. In another condition, carrot-flavored pellets replaced sucrose pellets. After behavior stabilized, acute injections of rimonabant (0.3-10 mg/kg) and haloperidol (0.003-0.1 mg/kg) were administered i.p. before some choice sessions in both pellet conditions. Haloperidol and rimonabant increased discounting in both groups of rats by decreasing percent choice for the larger reinforcer and area-under-the-curve (AUC) values. Rats in the high-fat diet condition demonstrated increased sensitivity to haloperidol compared to chow-fed controls: haloperidol increased discounting in both dietary groups in the sucrose condition,, but only in the high-fat-fed rats in the carrot-pellet condition. These findings indicate that blocking D2 and CB1 receptors results in increased delay discounting, and that a high-fat diet may alter sensitivity to dopaminergic compounds using the delay-discounting task. PMID:25000488

On-chip programmable ultra-wideband microwave photonic phase shifter and true time delay unit.

PubMed

Burla, Maurizio; Cortés, Luis Romero; Li, Ming; Wang, Xu; Chrostowski, Lukas; Azaña, José

2014-11-01

We proposed and experimentally demonstrated an ultra-broadband on-chip microwave photonic processor that can operate both as RF phase shifter (PS) and true-time-delay (TTD) line, with continuous tuning. The processor is based on a silicon dual-phase-shifted waveguide Bragg grating (DPS-WBG) realized with a CMOS compatible process. We experimentally demonstrated the generation of delay up to 19.4 ps over 10 GHz instantaneous bandwidth and a phase shift of approximately 160° over the bandwidth 22-29 GHz. The available RF measurement setup ultimately limits the phase shifting demonstration as the device is capable of providing up to 300° phase shift for RF frequencies over a record bandwidth approaching 1 THz.

Extending Femtosecond Filamentation of High Power Laser Propagating in the Atmosphere

NASA Astrophysics Data System (ADS)

Eisenmann, Shmuel; Sivan, Yonatan; Fibich, Gadi; Zigler, Arie

2008-06-01

We show experimentally for ultrashort laser pulses propagating in air, that the filamentation distance of intense laser pulses in the atmosphere can be extended and controlled with a simple double-lens setup. Using this method we were able to achieve a 20-fold delay of the filamentation distance of non-chirped 120 fs pulses propagating in air, from 16 m to 330 m. At 330 m, the collapsing pulse is sufficiently powerful to create plasma filaments. We also show that the scatter of the filaments at 330 m can be significantly reduced by tilting the second lens. We derive a simple formula for the filamentation distance, and confirm its agreement with the experimental results. We also observe that delaying the onset of filamentation increases the filament length. To the best of our knowledge, this is the longest distance reported in the literature at which plasma filaments were created and controlled. Finally, we show that the peak power at the onset of collapse is significantly higher with the double-lens setup, compared with the standard negative chirping approach.

On the Development and Mechanics of Delayed Matching-to-Sample Performance

PubMed Central

Kangas, Brian D; Berry, Meredith S; Branch, Marc N

2011-01-01

Despite its frequent use to assess effects of environmental and pharmacological variables on short-term memory, little is known about the development of delayed matching-to-sample (DMTS) performance. This study was designed to examine the dimensions and dynamics of DMTS performance development over a long period of exposure to provide a more secure foundation for assessing stability in future research. Six pigeons were exposed to a DMTS task with variable delays for 300 sessions (i.e., 18,000 total trials; 3,600 trials per retention interval). Percent-correct and log-d measures used to quantify the development of conditional stimulus control under the procedure generally and at each of five retention intervals (0, 2, 4, 8 and 16-s) individually revealed that high levels of accuracy developed relatively quickly under the shorter retention intervals, but increases in accuracy under the longer retention intervals sometimes were not observed until 100–150 sessions had passed, with some still increasing at Session 300. Analyses of errors suggested that retention intervals induced biases by shifting control from the sample stimulus to control by position, something that was predicted by observed response biases during initial training. These results suggest that although it may require a great deal of exposure to DMTS prior to obtaining asymptotic steady state, quantification of model parameters may help predict trends when extended exposure is not feasible. PMID:21541127

A single dose of alcohol does not meaningfully alter circadian phase advances and phase delays to light in humans

PubMed Central

Rizvydeen, Muneer; Fogg, Louis F.; Keshavarzian, Ali

2016-01-01

Central circadian timing influences mental and physical health. Research in nocturnal rodents has demonstrated that when alcohol is consumed, it reaches the central hypothalamic circadian pacemaker (suprachiasmatic nuclei) and can directly alter circadian phase shifts to light. In two separate studies, we examined, for the first time, the effects of a single dose of alcohol on circadian phase advances and phase delays to light in humans. Two 23-day within-subjects placebo-controlled counterbalanced design studies were conducted. Both studies consisted of 6 days of fixed baseline sleep to stabilize circadian timing, a 2-day laboratory session, a 6-day break, and a repeat of 6 days of fixed sleep and a 2-day laboratory session. In the phase advance study (n = 10 light drinkers, 24–45 yr), the laboratory sessions consisted of a baseline dim light phase assessment, sleep episode, alcohol (0.6 g/kg) or placebo, 2-h morning bright light pulse, and final phase assessment. In the phase-delay study (n = 14 light drinkers, 22–44 yr), the laboratory sessions consisted of a baseline phase assessment, alcohol (0.8 g/kg) or placebo, 2-h late night bright light pulse, sleep episode, and final phase assessment. In both studies, alcohol either increased or decreased the observed phase shifts to light (interaction P ≥ 0.46), but the effect of alcohol vs. placebo on phase shifts to light was always on average smaller than 30 min. Thus, no meaningful effects of a single dose of alcohol vs. placebo on circadian phase shifts to light in humans were observed. PMID:26936778

A single dose of alcohol does not meaningfully alter circadian phase advances and phase delays to light in humans.

PubMed

Burgess, Helen J; Rizvydeen, Muneer; Fogg, Louis F; Keshavarzian, Ali

2016-04-15

Central circadian timing influences mental and physical health. Research in nocturnal rodents has demonstrated that when alcohol is consumed, it reaches the central hypothalamic circadian pacemaker (suprachiasmatic nuclei) and can directly alter circadian phase shifts to light. In two separate studies, we examined, for the first time, the effects of a single dose of alcohol on circadian phase advances and phase delays to light in humans. Two 23-day within-subjects placebo-controlled counterbalanced design studies were conducted. Both studies consisted of 6 days of fixed baseline sleep to stabilize circadian timing, a 2-day laboratory session, a 6-day break, and a repeat of 6 days of fixed sleep and a 2-day laboratory session. In the phase advance study (n= 10 light drinkers, 24-45 yr), the laboratory sessions consisted of a baseline dim light phase assessment, sleep episode, alcohol (0.6 g/kg) or placebo, 2-h morning bright light pulse, and final phase assessment. In the phase-delay study (n= 14 light drinkers, 22-44 yr), the laboratory sessions consisted of a baseline phase assessment, alcohol (0.8 g/kg) or placebo, 2-h late night bright light pulse, sleep episode, and final phase assessment. In both studies, alcohol either increased or decreased the observed phase shifts to light (interaction P≥ 0.46), but the effect of alcohol vs. placebo on phase shifts to light was always on average smaller than 30 min. Thus, no meaningful effects of a single dose of alcohol vs. placebo on circadian phase shifts to light in humans were observed. Copyright © 2016 the American Physiological Society.

Testing complex animal cognition: Concept learning, proactive interference, and list memory.

PubMed

Wright, Anthony A

2018-01-01

This article describes an approach for assessing and comparing complex cognition in rhesus monkeys and pigeons by training them in a sequence of synergistic tasks, each yielding a whole function for enhanced comparisons. These species were trained in similar same/different tasks with expanding training sets (8, 16, 32, 64, 128 … 1024 pictures) followed by novel-stimulus transfer eventually resulting in full abstract-concept learning. Concept-learning functions revealed better rhesus transfer throughout and full concept learning at the 128 set, versus pigeons at the 256 set. They were then tested in delayed same/different tasks for proactive interference by inserting occasional tests within trial-unique sessions where the test stimulus matched a previous sample stimulus (1, 2, 4, 8, 16 trials prior). Proactive-interference functions revealed time-based interference for pigeons (1, 10 s delays), but event-based interference for rhesus (no effect of 1, 10, 20 s delays). They were then tested in list-memory tasks by expanding the sample to four samples in trial-unique sessions (minimizing proactive interference). The four-item, list-memory functions revealed strong recency memory at short delays, gradually changing to strong primacy memory at long delays over 30 s for rhesus, and 10 s for pigeons. Other species comparisons and future directions are discussed. © 2018 Society for the Experimental Analysis of Behavior.

Assessing Visual Delays using Pupil Oscillations

NASA Technical Reports Server (NTRS)

Mulligan, Jeffrey B.

2012-01-01

Stark (1962) demonstrated vigorous pupil oscillations by illuminating the retina with a beam of light focussed to a small spot near the edge of the pupil. Small constrictions of the pupil then are sufficient to completely block the beam, amplifying the normal relationship between pupil area and retinal illuminance. In addition to this simple and elegant method, Stark also investigated more complex feedback systems using an electronic "clamping box" which provided arbitrary gain and phase delay between a measurement of pupil area and an electronically controlled light source. We have replicated Stark's results using a video-based pupillometer to control the luminance of a display monitor. Pupil oscillations were induced by imposing a linear relationship between pupil area and display luminance, with a variable delay. Slopes of the period-vs-delay function for 3 subjects are close to the predicted value of 2 (1.96-2.39), and the implied delays range from 254 to 376 508 to 652 milliseconds. Our setup allows us to extend Stark's work by investigating a broader class of stimuli.

Further characterization of an aversive learning task in Drosophila melanogaster: intensity of the stimulus, relearning, and use of rutabaga mutants.

PubMed

Perisse, Emmanuel; Portelli, Geoffrey; Le Goas, Solène; Teste, Elsa; Le Bourg, Eric

2007-11-01

Various learning tasks have been described in Drosophila melanogaster, flies being either tested in groups or at the individual level. Le Bourg and Buecher (Anim Learn Behav 33:330-341, 2002) have designed a task at the individual level: photopositive flies crossing a T-maze learn to prefer the dark exit when the lighted one is associated with the presence of aversive stimuli (humidity and quinine). Previous studies have reported various results (e.g. no effect of age) and the present article further characterizes this task by studying the possible effects of: (1) the intensity of the stimuli (quantity of water or concentration of quinine), (2) various delays between two learning sessions on the learning score at the second session, (3) the rutabaga learning mutation on the learning score. More concentrated quinine solutions increased learning scores but the quantity of water had no effect. Learning scores at the second session were higher with shorter delays between the two learning sessions and retrograde amnesia could decrease this memory score. rutabaga mutants showed learning deficits as in experiments testing groups of flies. This learning task could particularly be used to verify whether learning mutants isolated after experiments testing flies in groups display similar deficits when tested at the individual level.

The Effects of Constant Time Delay Embedded into Teaching Activities for Teaching the Names of Clothes for Preschool Children with Developmental Disabilities

ERIC Educational Resources Information Center

Odluyurt, Serhat

2011-01-01

The general purpose of this study was to examine the effectiveness of constant time delay embedded in activities for teaching clothes name for preschool children with developmental disabilities. This study included four participants having Down syndrome with an age range of 43-46 months. All experimental sessions were conducted in one to one…

Effects of a Signaled Delay to Reinforcement in the Previous and Upcoming Ratios on Between-Ratio Pausing in Fixed-Ratio Schedules

ERIC Educational Resources Information Center

Harris, Aimee; Foster, T. Mary; Levine, Joshua; Temple, William

2012-01-01

Domestic hens responded under multiple fixed-ratio fixed-ratio schedules with equal fixed ratios. One component provided immediate reinforcement and the other provided reinforcement after a delay, signaled by the offset of the key light. The components were presented quasi-randomly so that all four possible transitions occurred in each session.…

Dual-energy CT for detection of contrast enhancement or leakage within high-density haematomas in patients with intracranial haemorrhage.

PubMed

Watanabe, Yoshiyuki; Tsukabe, Akio; Kunitomi, Yuki; Nishizawa, Mitsuo; Arisawa, Atsuko; Tanaka, Hisashi; Yoshiya, Kazuhisa; Shimazu, Takeshi; Tomiyama, Noriyuki

2014-04-01

Our study aimed to elucidate the diagnostic performance of dual-energy CT (DECT) in the detection of contrast enhancement in intracranial haematomas (ICrH) with early phase dual-energy computed tomography angiography (CTA) and compare the results with those obtained by delayed CT enhancement. Thirty-six patients with ICrH were retrospectively included in this study. All patients had undergone single-energy non-contrast CT and contrast-enhanced dual-source DECT. DECT images were post-processed with commercial software, followed by obtaining iodine images and virtual non-contrast images and generating combined images that created the impression of 120-kVp images. Two neuroradiologists, blinded to the patients' data, reviewed two reading sessions: session A (non-contrast CT and combined CT) and session B (non-contrast CT, combined CT, and iodine images) for detection of contrast enhancement in the haematomas. Contrast leakage or enhancement was detected in 23 (57.5 %) out of 40 haemorrhagic lesions in 36 patients on delayed CT. Three enhanced lesions were depicted only in the DECT iodine images. The sensitivity, specificity, positive predictive value, and negative predictive value of session A were 82.6, 94.1, 95.0, and 80.0 %, respectively, and those of session B were 95.7, 94.1, 95.7, and 94.1 %, respectively. DECT emphasised the iodine enhancement and facilitated the detection of contrast enhancement or leakage.

Effectiveness and usability of Scanning Wizard software: a tool for enhancing switch scanning.

PubMed

Koester, Heidi Horstmann; Simpson, Richard C

2017-11-24

Scanning Wizard software helps scanning users improve the setup of their switch and scanning system. This study evaluated Scanning Wizard's effectiveness and usability. Ten people who use switch scanning and ten practitioners used Scanning Wizard in the initial session. Usability was high, based on survey responses averaging over 4.5 out of 5, and qualitative feedback was very positive. Five switch users were able to complete the multi-week protocol, using settings on their own scanning system that were recommended from the Scanning Wizard session. Using these revised settings, text entry rates improved by an average of 71%, ranging from 29% to 172% improvement. Results suggest that Scanning Wizard is a useful tool for improving the configuration of scanning systems for people who use switch scanning to communicate. Implications for Rehabilitation Some individuals with severe physical impairments use switch scanning for spoken and written communication. Scanning Wizard software helps scanning users improve the setup of their switch and scanning system. This study demonstrated high usability of Scanning Wizard (with 10 switch userpractitioner teams) and increased text entry rate by an average of 71% (for five switch users). Results suggest that Scanning Wizard is a useful tool for improving the configuration of scanning systems for people who use switch scanning to communicate.

Individual differences in choice (in)flexibility but not impulsivity in the common marmoset: an automated, operant-behavior choice task.

PubMed

Adriani, Walter; Romani, Chiara; Manciocco, Arianna; Vitale, Augusto; Laviola, Giovanni

2013-11-01

Individual differences in behavioural flexibility are a significant issue in human psychopathology as well as in its animal models. We aimed to investigate individual variations of operant-choice behaviour in the common marmoset (Callithrix jacchus), a small New World primate, using a new operant panel with two hand-poking holes. Experimental subjects (N=16) were presented with a choice between a Small & Soon (SS) vs a Large & Late (LL) food reward. After extensive training (31 daily sessions with no delay, during which a basal, large-reward preference developed), the delay before release of LL was progressively increased (from 0 to 60 s, during 16 daily sessions; indifferent point at delay=9 s). Subjects were classified as either "flexible" or "non-flexible", respectively, based on a decrease (or not) in the preference for LL with increasing delays. Each subject was also classified as "maximizer" (or "non-maximizer") based on capacity (or not) to maximize the food payoff as delay increased. Upon delays shorter than the indifferent point (<9s), none of the subjects showed a shift from LL to SS, denoting a lack of delay-induced, cognitive impulsivity. Individual differences only emerged upon delays longer than the indifferent point (>9 s), when a preference shift could be interpreted as economically-driven. In general, a profile of few unrewarded hand-pokes in reaction to initial delays (i.e., a low motor impulsivity) and of clear-cut basal LL preference seemed to predict elevated flexibility of choices and better food payoff, which was typical of subjects classified as both "flexible & maximizer". These results provide normative data on the marmosets, which can be used as a model for the investigation of 1) individual differences in behavioural flexibility, as well as 2) biological mechanisms rooted in our evolutionary history. Copyright © 2013 Elsevier B.V. All rights reserved.

No Effects of Non-invasive Brain Stimulation on Multiple Sessions of Object-Location-Memory Training in Healthy Older Adults

PubMed Central

Külzow, Nadine; Cavalcanti de Sousa, Angelica Vieira; Cesarz, Magda; Hanke, Julie-Marie; Günsberg, Alida; Harder, Solvejg; Koblitz, Swantje; Grittner, Ulrike; Flöel, Agnes

2018-01-01

Object-location memory (OLM) is known to decline with normal aging, a process accelerated in pathological conditions like mild cognitive impairment (MCI). In order to maintain cognitive health and to delay the transition from healthy to pathological conditions, novel strategies are being explored. Tentative evidence suggests that combining cognitive training and anodal transcranial direct current stimulation (atDCS), both reported to induce small and often inconsistent behavioral improvements, could generate larger or more consistent improvements or both, compared to each intervention alone. Here, we explored the combined efficacy of these techniques on OLM. In a subject-blind sham-controlled cross-over design 32 healthy older adults underwent a 3-day visuospatial training paired with either anodal (20 min) or sham (30 s) atDCS (1 mA, temporoparietal). Subjects were asked to learn the correct object-location pairings on a street map, shown over five learning blocks on each training day. Acquisition performance was assessed by accuracy on a given learning block in terms of percentage of correct responses. Training success (performance on last training day) and delayed memory after 1-month were analyzed by mixed model analysis and were controlled for gender, age, education, sequence of stimulation and baseline performance. Exploratory analysis of atDCS effects on within-session (online) and between-session (offline) memory performance were conducted. Moreover, transfer effects on similar trained (visuospatial) and less similar (visuo-constructive, verbal) untrained memory tasks were explored, both immediately after training, and on follow-up. We found that atDCS paired with OLM-training did not enhance success in training or performance in 1-month delayed memory or transfer tasks. In sum, this study did not support the notion that the combined atDCS-training approach improves immediate or delayed OLM in older adults. However, specifics of the experimental design, and a non-optimal timing of atDCS between sessions might have masked beneficial effects and should be more systematically addressed in future studies. PMID:29375290

The effects of partial sleep restriction and altered sleep timing on appetite and food reward.

PubMed

McNeil, Jessica; Forest, Geneviève; Hintze, Luzia Jaeger; Brunet, Jean-François; Finlayson, Graham; Blundell, John E; Doucet, Éric

2017-02-01

We examined the effects of partial sleep restriction (PSR) with an advanced wake-time or delayed bedtime on measures of appetite, food reward and subsequent energy intake (EI). Twelve men and 6 women (age: 23 ± 4 years, body fat: 18.8 ± 10.1%) participated in 3 randomized crossover sessions: control (habitual bed- and wake-time), 50% PSR with an advanced wake-time and 50% PSR with a delayed bedtime. Outcome variables included sleep architecture (polysomnography), ad libitum EI (validated food menu), appetite sensations (visual analogue scales), satiety quotient (SQ; mm/100 kcal) and food reward (Leeds Food Preference Questionnaire and the relative-reinforcing value (RRV) of preferred food task). Increased fasting and post-standard breakfast appetite ratings were noted following PSR with an advanced wake-time compared to the control and PSR with a delayed bedtime sessions (Fasting hunger ratings: 77 ± 16 vs. 65 ± 18 and 64 ± 16; P = 0.01; Post-meal hunger AUC: 5982 ± 1781 vs. 4508 ± 2136 and 5198 ± 2201; P = 0.03). Increased explicit wanting and liking for high- relative to low-fat foods were also noted during the advanced wake-time vs. control session (Explicit wanting: -3.5 ± 12.5 vs. -9.3 ± 8.9, P = 0.01; Explicit liking: -1.6 ± 8.5 vs. -7.8 ± 9.6, P = 0.002). No differences in the RRV of preferred food, SQ and ad libitum lunch intake were noted between sessions. These findings suggest that appetite sensations and food reward are increased following PSR with an advanced wake-time, rather than delayed bedtime, vs. However, this did not translate into increased EI during a test meal. Given the increasing prevalence of shift workers and incidences of sleep disorders, additional studies are needed to evaluate the prolonged effects of voluntary sleep restriction with altered sleep timing on appetite and EI measurements. Copyright © 2016 Elsevier Ltd. All rights reserved.

Self-regulation strategies may enhance the acute effect of exercise on smoking delay.

PubMed

Hatzigeorgiadis, Antonis; Pappa, Vassiliki; Tsiami, Anastasia; Tzatzaki, Theodora; Georgakouli, Kalliopi; Zourbanos, Nikos; Goudas, Marios; Chatzisarantis, Nikos; Theodorakis, Yannis

2016-06-01

The present study examined the acute effect of a moderate intensity aerobic exercise session combined with self-regulation on smoking delay in physically inactive smokers. Participants were 11 adults (5 males and 6 females) that completed three experimental conditions: control, exercise, and exercise using self-regulation strategies (SR). Following the experimental treatment smoking for the two exercise conditions delayed significantly more than for the control condition; in addition exercise SR delayed smoking marginally more that the plain exercise condition. Findings supported previous research that acute exercise reduces cravings to smoke, and suggests that the use of self-regulation strategies may strengthen exercise for smoking cessation interventions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Performance of the Versatile Array of Neutron Detectors at Low Energy (VANDLE)

DOE PAGES

Peters, W. A.; Ilyushkin, S.; Madurga, M.; ...

2016-08-26

The Versatile Array of Neutron Detectors at Low Energy (VANDLE) is a new, highly efficient plastic-scintillator array constructed for decay and transfer reaction experimental setups that require neutron detection. The versatile and modular design allows for customizable experimental setups including beta-delayed neutron spectroscopy and (d,n) transfer reactions in normal and inverse kinematics. The neutron energy and prompt-photon discrimination is determined through the time of flight technique. Fully digital data acquisition electronics and integrated triggering logic enables some VANDLE modules to achieve an intrinsic efficiency over 70% for 300-keV neutrons, measured through two different methods. A custom Geant4 simulation models aspectsmore » of the detector array and the experimental setups to determine efficiency and detector response. Lastly, a low detection threshold, due to the trigger logic and digitizing data acquisition, allowed us to measure the light-yield response curve from elastically scattered carbon nuclei inside the scintillating plastic from incident neutrons with kinetic energies below 2 MeV.« less

A novel hybrid genetic algorithm to solve the make-to-order sequence-dependent flow-shop scheduling problem

NASA Astrophysics Data System (ADS)

Mirabi, Mohammad; Fatemi Ghomi, S. M. T.; Jolai, F.

2014-04-01

Flow-shop scheduling problem (FSP) deals with the scheduling of a set of n jobs that visit a set of m machines in the same order. As the FSP is NP-hard, there is no efficient algorithm to reach the optimal solution of the problem. To minimize the holding, delay and setup costs of large permutation flow-shop scheduling problems with sequence-dependent setup times on each machine, this paper develops a novel hybrid genetic algorithm (HGA) with three genetic operators. Proposed HGA applies a modified approach to generate a pool of initial solutions, and also uses an improved heuristic called the iterated swap procedure to improve the initial solutions. We consider the make-to-order production approach that some sequences between jobs are assumed as tabu based on maximum allowable setup cost. In addition, the results are compared to some recently developed heuristics and computational experimental results show that the proposed HGA performs very competitively with respect to accuracy and efficiency of solution.

Russian EVA 36.

NASA Image and Video Library

2013-11-09

ISS037-E-028082 (9 Nov. 2013) --- Russian cosmonaut Sergey Ryazanskiy, Expedition 37 flight engineer, attired in a Russian Orlan spacesuit, participates in a session of extravehicular activity (EVA) in support of assembly and maintenance on the International Space Station. During the five-hour, 50-minute spacewalk, Ryazanskiy and Russian cosmonaut Oleg Kotov (out of frame) continued the setup of a combination EVA workstation and biaxial pointing platform that was installed during an Expedition 36 spacewalk on Aug. 22.

Russian EVA 36.

NASA Image and Video Library

2013-11-09

ISS037-E-028067 (9 Nov. 2013) --- Russian cosmonaut Oleg Kotov, Expedition 37 flight engineer, attired in a Russian Orlan spacesuit, participates in a session of extravehicular activity (EVA) in support of assembly and maintenance on the International Space Station. During the five-hour, 50-minute spacewalk, Kotov and Russian cosmonaut Sergey Ryazanskiy (out of frame) continued the setup of a combination EVA workstation and biaxial pointing platform that was installed during an Expedition 36 spacewalk on Aug. 22.

Russian EVA 36.

NASA Image and Video Library

2013-11-09

ISS037-E-028101 (9 Nov. 2013) --- Russian cosmonaut Oleg Kotov, Expedition 37 flight engineer, attired in a Russian Orlan spacesuit, participates in a session of extravehicular activity (EVA) in support of assembly and maintenance on the International Space Station. During the five-hour, 50-minute spacewalk, Kotov and Russian cosmonaut Sergey Ryazanskiy (out of frame) continued the setup of a combination EVA workstation and biaxial pointing platform that was installed during an Expedition 36 spacewalk on Aug. 22.

Russian EVA 36.

NASA Image and Video Library

2013-11-09

ISS037-E-028094 (9 Nov. 2013) --- Russian cosmonaut Oleg Kotov, Expedition 37 flight engineer, attired in a Russian Orlan spacesuit, participates in a session of extravehicular activity (EVA) in support of assembly and maintenance on the International Space Station. During the five-hour, 50-minute spacewalk, Kotov and Russian cosmonaut Sergey Ryazanskiy (out of frame) continued the setup of a combination EVA workstation and biaxial pointing platform that was installed during an Expedition 36 spacewalk on Aug. 22.

Russian EVA 36.

NASA Image and Video Library

2013-11-09

ISS037-E-028107 (9 Nov. 2013) --- Russian cosmonaut Oleg Kotov, Expedition 37 flight engineer, attired in a Russian Orlan spacesuit, participates in a session of extravehicular activity (EVA) in support of assembly and maintenance on the International Space Station. During the five-hour, 50-minute spacewalk, Kotov and Russian cosmonaut Sergey Ryazanskiy (out of frame) continued the setup of a combination EVA workstation and biaxial pointing platform that was installed during an Expedition 36 spacewalk on Aug. 22.

Russian EVA 36.

NASA Image and Video Library

2013-11-09

ISS037-E-028102 (9 Nov. 2013) --- Russian cosmonaut Oleg Kotov, Expedition 37 flight engineer, attired in a Russian Orlan spacesuit, participates in a session of extravehicular activity (EVA) in support of assembly and maintenance on the International Space Station. During the five-hour, 50-minute spacewalk, Kotov and Russian cosmonaut Sergey Ryazanskiy (out of frame) continued the setup of a combination EVA workstation and biaxial pointing platform that was installed during an Expedition 36 spacewalk on Aug. 22.

Delay of smoking gratification as a laboratory model of relapse: effects of incentives for not smoking, and relationship with measures of executive function.

PubMed

Mueller, Eldon T; Landes, Reid D; Kowal, Benjamin P; Yi, Richard; Stitzer, Maxine L; Burnett, Cody A; Bickel, Warren K

2009-09-01

Nineteen nicotine-deprived cigarette smokers received monetary rewards for each minute they chose not to initiate smoking in 2-h laboratory sessions followed by a 30-min period of enforced abstinence from smoking. Reinforcer amounts were delivered according to one of three schedules: increasing, decreasing, and constant. Relapse time (time until first cigarette) was shortest in the decreasing condition, longest in the increasing condition, and intermediate in the constant condition. All differences were significant except in the constant-decreasing comparison. The relationships between a battery of baseline assessments and relapse times were examined. Relapse times were predicted by delay-discounting coefficients (k) for $10 and $1000 in money and for $1000 of cigarettes. Relapse times were also predicted by the number of cigarettes smoked daily and a Wisconsin Card Sorting Test score. Performance on the Stroop Task and the Fagerström Test for Nicotine Dependence differentiated participants dichotomized into those who relapsed 'earlier' in sessions versus those who first smoked 'later'. The variability in some scores from smoking-urges and affect questionnaires administered after smoking-room sessions was explained by measures related to in-session nicotine intake. Results are discussed as they relate to contingency-management procedures, predictors of relapse, and the competing neurobehavioral decision systems theory of addiction.

Delay of Smoking Gratification as a Laboratory Model of Relapse: Effects of Incentives for Not Smoking, and Relationship to Measures of Executive Function

PubMed Central

Mueller, E. Terry; Landes, Reid D.; Kowal, Benjamin P.; Yi, Richard; Stitzer, Maxine L.; Burnett, Cody A.; Bickel, Warren K.

2010-01-01

Nineteen nicotine-deprived cigarette smokers received monetary rewards for each minute they choose not to initiate smoking in 2-hour laboratory sessions followed by a 30-min period of enforced abstinence from smoking. Reinforcer amounts were delivered according to one of three schedules: increasing, decreasing, and constant. Relapse time (time until first smoke) was shortest in the decreasing condition, longest in the increasing condition, and intermediate in the constant condition. All differences were significant except in the constant-decreasing comparison. The relationships between a battery of baseline assessments and relapse times were examined. Relapse times were predicted by delay-discounting coefficients (k) for $10 and $1000 in money, and for $1000 of cigarettes. Relapse times were also predicted by the number of cigarettes smoked daily and a Wisconsin Card Sorting Test score. Performance on the Stroop Task and the Fagerström Test for Nicotine Dependence differentiated participants dichotomized into those who relapsed “earlier” in sessions versus those who first smoked “later.” Variability on some scores from smoking-urges and affect questionnaires administered after smoking-room sessions was explained by measures related to in-session nicotine intake. Results are discussed as they relate to contingency-management procedures, predictors of relapse, and the competing neuro-behavioral decision systems theory of addiction. PMID:19741301

Multifrequency zero-jitter delay-locked loop

NASA Astrophysics Data System (ADS)

Efendovich, Avner; Afek, Yachin; Sella, Coby; Bikowsky, Zeev

1994-01-01

The approach of an all-digital phase locked loop is used in this delay-locked loop circuit. This design is designated to a system with two processing units, a master CPU and a slave system chip, that share the same bus. It allows maximum utilization of the bus, as the minimal skew between the clocks of the two components significantly reduces idle periods, and also set-up and hold times. Changes in the operating frequency are possible, without falling out of synchronization. Due to the special lead-lag phase detector, the jitter of the clock is zero, when the loop is locked, under any working conditions.

Delayed-matching-to-place Task in a Dry Maze to Measure Spatial Working Memory in Mice.

PubMed

Feng, Xi; Krukowski, Karen; Jopson, Timothy; Rosi, Susanna

2017-07-05

The delayed-matching-to-place (DMP) dry maze test is a variant of DMP water maze (Steele and Morris, 1999; Faizi et al. , 2012) which measures spatial working/episodic-like learning and memory that depends on both hippocampal and cortical functions (Wang and Morris, 2010; Euston et al. , 2012). Using this test we can detect normal aging related spatial working memory decline, as well as trauma induced working memory deficits. Furthermore, we recently reported that fractionated whole brain irradiation does not affect working memory in mice (Feng et al. , 2016). Here we describe the experimental setup and procedures of this behavioral test.

Effects of chewing gum on mood, learning, memory and performance of an intelligence test.

PubMed

Smith, Andrew

2009-04-01

Recent research suggests that chewing gum may increase alertness and lead to changes in cognitive performance. The present study examined effects of chewing gum on these functions within the context of a single study. This study had four main aims. The first was to examine whether chewing gum improved learning and memory of information in a story. The second aim was to determine whether chewing gum improved test performance on a validated intellectual task (the Alice Heim task). A third aim was to determine whether chewing gum improved performance on short memory tasks (immediate and delayed recall of a list of words, delayed recognition memory, retrieval from semantic memory, and a working memory task). The final aim was to determine whether chewing gum improved mood (alertness, calm and hedonic tone). A cross-over design was used with gum and no-gum sessions being on consecutive weeks. In each week, volunteers attended for two sessions, two days apart. The first session assessed mood, immediate recall of information from a story and performance on short memory tasks. The second session assessed mood, delayed recall of information from a story and performance of an intelligence test (the Alice Heim test). There were no significant effects of chewing gum on any aspect of recall of the story. Chewing gum improved the accuracy of performing the Alice Heim test which confirms the benefits of gum on test performance seen in an earlier study. Chewing gum had no significant effect on the short memory tasks. Chewing gum increased alertness at the end of the test session in both parts of the study. This effect was in the region of a 10% increase and was highly significant (P < 0.001). The results of this study showed that chewing gum increases alertness. In contrast, no significant effects of chewing gum were observed in the memory tasks. Intellectual performance was improved in the gum condition. Overall, the results suggest further research on the alerting effects of chewing gum and possible improved test performance in these situations.

Maintained Physical Activity Induced Changes in Delay Discounting.

PubMed

Sofis, Michael J; Carrillo, Ale; Jarmolowicz, David P

2017-07-01

Those who discount the subjective value of delayed rewards less steeply are more likely to engage in physical activity. There is limited research, however, showing whether physical activity can change rates of delay discounting. In a two-experiment series, treatment and maintenance effects of a novel, effort-paced physical activity intervention on delay discounting were evaluated with multiple baseline designs. Using a lap-based method, participants were instructed to exercise at individualized high and low effort levels and to track their own perceived effort. The results suggest that treatment-induced changes in discounting were maintained at follow-up for 13 of 16 participants. In Experiment 2, there were statistically significant group-level improvements in physical activity and delay discounting when comparing baseline with both treatment and maintenance phases. Percentage change in delay discounting was significantly correlated with session attendance and relative pace (min/mile) improvement over the course of the 7-week treatment. Implications for future research are discussed.

Bi-frontal direct current stimulation affects delay discounting choices.

PubMed

Hecht, David; Walsh, Vincent; Lavidor, Michal

2013-01-01

In delay discounting tasks, participants decide between receiving a certain amount of money now or a larger sum sometime in the future. This study investigated the effects of transcranial direct current stimulation on delay discounting. Participants made delay discounting choices while receiving a bi-frontal stimulation of right-hemisphere anodal/left-hemisphere cathodal, left-hemisphere anodal/right-hemisphere cathodal, and sham stimulation, in three separate sessions. When the difference between the alternatives was 10% or more, participants generally preferred to wait for the larger sum. Nevertheless, there were more choices of smaller "immediate" gains, instead of the larger delayed options, when the left dorsolateral prefrontal cortex (DLPFC) was facilitated and the right DLPFC inhibited, compared to the sham stimulation. These observations indicate the significant role of the prefrontal cortex in delay discounting choices, and demonstrate that increased left frontal activation combined with decreased right frontal activation can alter decision-making by intensifying a tendency to choose immediate gains.

Opposing acute and chronic behavioural effects of a beta-blocker, propranolol, in the rat.

PubMed

Salmon, P; Gray, J A

1985-01-01

Rats were trained over 40 days to lever-press for food reward under a schedule of differential reinforcement of low rates of response with a 20-s criterion (DRL 20), following seven sessions of continuous reinforcement. The effect of injecting a beta-adrenergic blocker, propranolol (5 mg/kg IP), before and at two different delays after each daily session of DRL were investigated. In Experiment I, rats drugged 5-8 min before every session earned fewer reinforcements compared to controls, and showed impaired temporal discrimination. In Experiment II, this result was not replicated, but similar effects were clear in animals drugged pre-session from the 15th day of acquisition. By contrast, an improved temporal discrimination, and increased number of reinforcements were seen in rats drugged 5-8 min after every session. In Experiment III, the post-session effects were replicated and found also in rats drugged 4-5.5 h after each session. These results suggest that propranolol has an acute effect on DRL responding which resembles that of anxiolytics, and a chronic effect which opposes the acute one.

Effects of occupational therapy services on fine motor and functional performance in preschool children.

PubMed

Case-Smith, J

2000-01-01

This study examined how performance components and variables in intervention influenced fine motor and functional outcomes in preschool children. In a sample of 44 preschool-aged children with fine motor delays who received occupational therapy services, eight fine motor and functional performance assessments were administered at the beginning and end of the academic year. Data on the format and intervention activities of each occupational therapy session were recorded for 8 months. The children received a mean of 23 sessions, in both individual and group format. Most of the sessions (81%) used fine motor activities; 29% addressed peer interaction, and 16% addressed play skills. Visual motor outcomes were influenced by the number of intervention sessions and percent of sessions with play goals. Fine motor outcomes were most influenced by the therapists' emphasis on play and peer interaction goals; functional outcomes were influenced by number of sessions and percent of sessions that specifically addressed self-care goals. The influence of play on therapy outcomes suggests that a focus on play in intervention activities can enhance fine motor and visual motor performance.

Control of the collapse distance in atmospheric propagation

NASA Astrophysics Data System (ADS)

Fibich, Gadi; Sivan, Yonatan; Ehrlich, Yosi; Louzon, Einat; Fraenkel, Moshe; Eisenmann, Shmuel; Katzir, Yiftach; Zigler, Arie

2006-06-01

We show experimentally for ultrashort laser pulses propagating in air, that the collapse/filamentation distance of intense laser pulses in the atmosphere can be extended and controlled with a simple double-lens setup. We derive a simple formula for the filamentation distance, and confirm its agreement with the experimental results. We also observe that delaying the onset of filamentation increases the filament length.

Control of the filamentation distance and pattern in long-range atmospheric propagation

NASA Astrophysics Data System (ADS)

Eisenmann, Shmuel; Louzon, Einat; Katzir, Yiftach; Palchan, Tala; Zigler, Arie; Sivan, Yonatan; Fibich, Gadi

2007-03-01

We use the double-lens setup [10, 11] to achieve a 20-fold delay of the filamentation distance of non-chirped 120 fs pulses propagating in air, from 16m to 330m. At 330m, the collapsing pulse is sufficiently powerful to create plasma filaments. We also show that the scatter of the filaments at 330m can be significantly reduced by tilting the second lens. To the best of our knowledge, this is the longest distance reported in the Literature at which plasma filaments were created and controlled. Finally, we show that the peak power at the onset of collapse is significantly higher with the double-lens setup, compared with the standard negative chirping approach.

GPU-accelerated automatic identification of robust beam setups for proton and carbon-ion radiotherapy

NASA Astrophysics Data System (ADS)

Ammazzalorso, F.; Bednarz, T.; Jelen, U.

2014-03-01

We demonstrate acceleration on graphic processing units (GPU) of automatic identification of robust particle therapy beam setups, minimizing negative dosimetric effects of Bragg peak displacement caused by treatment-time patient positioning errors. Our particle therapy research toolkit, RobuR, was extended with OpenCL support and used to implement calculation on GPU of the Port Homogeneity Index, a metric scoring irradiation port robustness through analysis of tissue density patterns prior to dose optimization and computation. Results were benchmarked against an independent native CPU implementation. Numerical results were in agreement between the GPU implementation and native CPU implementation. For 10 skull base cases, the GPU-accelerated implementation was employed to select beam setups for proton and carbon ion treatment plans, which proved to be dosimetrically robust, when recomputed in presence of various simulated positioning errors. From the point of view of performance, average running time on the GPU decreased by at least one order of magnitude compared to the CPU, rendering the GPU-accelerated analysis a feasible step in a clinical treatment planning interactive session. In conclusion, selection of robust particle therapy beam setups can be effectively accelerated on a GPU and become an unintrusive part of the particle therapy treatment planning workflow. Additionally, the speed gain opens new usage scenarios, like interactive analysis manipulation (e.g. constraining of some setup) and re-execution. Finally, through OpenCL portable parallelism, the new implementation is suitable also for CPU-only use, taking advantage of multiple cores, and can potentially exploit types of accelerators other than GPUs.

Improved half-life determination and β-delayed γ-ray spectroscopy for 18Ne decay

NASA Astrophysics Data System (ADS)

Grinyer, G. F.; Ball, G. C.; Bouzomita, H.; Ettenauer, S.; Finlay, P.; Garnsworthy, A. B.; Garrett, P. E.; Green, K. L.; Hackman, G.; Leslie, J. R.; Pearson, C. J.; Rand, E. T.; Sumithrarachchi, C. S.; Svensson, C. E.; Thomas, J. C.; Triambak, S.; Williams, S. J.

2013-04-01

The half-life of the superallowed Fermi β+ emitter 18Ne has been determined to ±0.07% precision by counting 1042 keV delayed γ rays that follow approximately 8% of all β decays. The deduced half-life, T1/2=1.6648(11) s, includes a 0.7% correction that accounts for systematic losses associated with rate-dependent detector pulse pileup that was determined using a recently developed γ-ray photopeak-counting technique. This result is a factor of two times more precise than, and in excellent agreement with, a previous lower-statistics measurement that employed the same experimental setup. High-resolution β-delayed γ-ray spectroscopy results for the relative γ-ray intensities and β-decay branching ratios to excited states in the daughter 18F are also presented.

Prompt-delayed $$\\gamma$$-ray spectroscopy with AGATA, EXOGAM and VAMOS++

DOE PAGES

Kim, Y. H.; Lemasson, A.; Rejmund, M.; ...

2017-08-10

Here, a new experimental setup to measure prompt-delayed γ-ray coincidences from isotopically identified fission fragments, over a wide time range of 100ns-200μ s, is presented. The fission fragments were isotopically identified, on an event-by-event basis, using the VAMOS++ large acceptance spectrometer. The prompt γ rays emitted at the target position and corresponding delayed γ rays emitted at the focal plane of the spectrometer were detected using, respectively, thirty two crystals of the AGATA γ-ray tracking array and seven EXOGAM HPGe Clover detectors. Finally, fission fragments produced in fusion and transfer-induced fission reactions, using a 238U beam at an energy ofmore » 6.2 MeV/u impinging on a 9Be target, were used to characterize and qualify the performance of the detection system.« less

Simultaneous measurements of kinematics and fMRI: compatibility assessment and case report on recovery evaluation of one stroke patient.

PubMed

Casellato, Claudia; Ferrante, Simona; Gandolla, Marta; Volonterio, Nicola; Ferrigno, Giancarlo; Baselli, Giuseppe; Frattini, Tiziano; Martegani, Alberto; Molteni, Franco; Pedrocchi, Alessandra

2010-09-23

Correlating the features of the actual executed movement with the associated cortical activations can enhance the reliability of the functional Magnetic Resonance Imaging (fMRI) data interpretation. This is crucial for longitudinal evaluation of motor recovery in neurological patients and for investigating detailed mutual interactions between activation maps and movement parameters.Therefore, we have explored a new set-up combining fMRI with an optoelectronic motion capture system, which provides a multi-parameter quantification of the performed motor task. The cameras of the motion system were mounted inside the MR room and passive markers were placed on the subject skin, without any risk or encumbrance. The versatile set-up allows 3-dimensional multi-segment acquisitions including recording of possible mirror movements, and it guarantees a high inter-sessions repeatability.We demonstrated the integrated set-up reliability through compatibility tests. Then, an fMRI block-design protocol combined with kinematic recordings was tested on a healthy volunteer performing finger tapping and ankle dorsal- plantar-flexion. A preliminary assessment of clinical applicability and perspectives was carried out by pre- and post rehabilitation acquisitions on a hemiparetic patient performing ankle dorsal- plantar-flexion. For all sessions, the proposed method integrating kinematic data into the model design was compared with the standard analysis. Phantom acquisitions demonstrated the not-compromised image quality. Healthy subject sessions showed the protocols feasibility and the model reliability with the kinematic regressor. The patient results showed that brain activation maps were more consistent when the images analysis included in the regression model, besides the stimuli, the kinematic regressor quantifying the actual executed movement (movement timing and amplitude), proving a significant model improvement. Moreover, concerning motor recovery evaluation, after one rehabilitation month, a greater cortical area was activated during exercise, in contrast to the usual focalization associated with functional recovery. Indeed, the availability of kinematics data allows to correlate this wider area with a higher frequency and a larger amplitude of movement. The kinematic acquisitions resulted to be reliable and versatile to enrich the fMRI images information and therefore the evaluation of motor recovery in neurological patients where large differences between required and performed motion can be expected.

Simultaneous measurements of kinematics and fMRI: compatibility assessment and case report on recovery evaluation of one stroke patient

PubMed Central

2010-01-01

Background Correlating the features of the actual executed movement with the associated cortical activations can enhance the reliability of the functional Magnetic Resonance Imaging (fMRI) data interpretation. This is crucial for longitudinal evaluation of motor recovery in neurological patients and for investigating detailed mutual interactions between activation maps and movement parameters. Therefore, we have explored a new set-up combining fMRI with an optoelectronic motion capture system, which provides a multi-parameter quantification of the performed motor task. Methods The cameras of the motion system were mounted inside the MR room and passive markers were placed on the subject skin, without any risk or encumbrance. The versatile set-up allows 3-dimensional multi-segment acquisitions including recording of possible mirror movements, and it guarantees a high inter-sessions repeatability. We demonstrated the integrated set-up reliability through compatibility tests. Then, an fMRI block-design protocol combined with kinematic recordings was tested on a healthy volunteer performing finger tapping and ankle dorsal- plantar-flexion. A preliminary assessment of clinical applicability and perspectives was carried out by pre- and post rehabilitation acquisitions on a hemiparetic patient performing ankle dorsal- plantar-flexion. For all sessions, the proposed method integrating kinematic data into the model design was compared with the standard analysis. Results Phantom acquisitions demonstrated the not-compromised image quality. Healthy subject sessions showed the protocols feasibility and the model reliability with the kinematic regressor. The patient results showed that brain activation maps were more consistent when the images analysis included in the regression model, besides the stimuli, the kinematic regressor quantifying the actual executed movement (movement timing and amplitude), proving a significant model improvement. Moreover, concerning motor recovery evaluation, after one rehabilitation month, a greater cortical area was activated during exercise, in contrast to the usual focalization associated with functional recovery. Indeed, the availability of kinematics data allows to correlate this wider area with a higher frequency and a larger amplitude of movement. Conclusions The kinematic acquisitions resulted to be reliable and versatile to enrich the fMRI images information and therefore the evaluation of motor recovery in neurological patients where large differences between required and performed motion can be expected. PMID:20863391

The variation of radiologists' performance over the course of a reading session

NASA Astrophysics Data System (ADS)

Elze, Markus C.; Taylor-Phillips, Sian; Mello-Thoms, Claudia; Krupinski, Elizabeth A.; Gale, Alastair G.; Clarke, Aileen

2013-03-01

The radiologist's task of reviewing many cases successively is highly repetitive and requires a high level of concentration. Fatigue effects have, for example, been shown in studies comparing performance at different times of day. However, little is known about changes in performance during an individual reading session. During a session reading an enriched case set, performance may be affected by both fatigue (i.e. decreasing performance) and training (i.e. increasing performance) effects. In this paper, we reanalyze 3 datasets from 4 studies for changes in radiologist performance during a reading session. Studies feature 8-20 radiologists reading and assessing 27-60 cases in single, uninterrupted sessions. As the studies were not designed for this analysis, study setups range from bone fractures to mammograms and randomization varies between studies. Thus, they are analyzed separately using mixed-effects models. There is some indication that, as time goes on, specificity increases (shown with p<0.05 for 2 out of 3 datasets, no significant difference for the other) while sensitivity may also increase (p<0.05 for 1 out of 3 datasets). The difficulty of `normal' (healthy / non-malignant) and `abnormal' (unhealthy / malignant) cases differs (p<0.05 for 3 out of 3 datasets) and the reader's experience may also be relevant (p<0.05 for 1 out of 3 datasets). These results suggest that careful planning of breaks and session length may help optimize reader performance. Note that the overall results are still inconclusive and a targeted study to investigate fatigue and training effects within a reading session is recommended.

Improving outcomes of preschool language delay in the community: protocol for the Language for Learning randomised controlled trial

PubMed Central

2012-01-01

Background Early language delay is a high-prevalence condition of concern to parents and professionals. It may result in lifelong deficits not only in language function, but also in social, emotional/behavioural, academic and economic well-being. Such delays can lead to considerable costs to the individual, the family and to society more widely. The Language for Learning trial tests a population-based intervention in 4 year olds with measured language delay, to determine (1) if it improves language and associated outcomes at ages 5 and 6 years and (2) its cost-effectiveness for families and the health care system. Methods/Design A large-scale randomised trial of a year-long intervention targeting preschoolers with language delay, nested within a well-documented, prospective, population-based cohort of 1464 children in Melbourne, Australia. All children received a 1.25-1.5 hour formal language assessment at their 4th birthday. The 200 children with expressive and/or receptive language scores more than 1.25 standard deviations below the mean were randomised into intervention or ‘usual care’ control arms. The 20-session intervention program comprises 18 one-hour home-based therapeutic sessions in three 6-week blocks, an outcome assessment, and a final feed-back/forward planning session. The therapy utilises a ‘step up-step down’ therapeutic approach depending on the child’s language profile, severity and progress, with standardised, manualised activities covering the four language development domains of: vocabulary and grammar; narrative skills; comprehension monitoring; and phonological awareness/pre-literacy skills. Blinded follow-up assessments at ages 5 and 6 years measure the primary outcome of receptive and expressive language, and secondary outcomes of vocabulary, narrative, and phonological skills. Discussion A key strength of this robust study is the implementation of a therapeutic framework that provides a standardised yet tailored approach for each child, with a focus on specific language domains known to be associated with later language and literacy. The trial responds to identified evidence gaps, has outcomes of direct relevance to families and the community, includes a well-developed economic analysis, and has the potential to improve long-term consequences of early language delay within a public health framework. Trial registration Current Controlled Trials ISRCTN03981121. PMID:22776103

The relationship between prelinguistic vocalization and later expressive vocabulary in young children with developmental delay.

PubMed

McCathren, R B; Yoder, P J; Warren, S F

1999-08-01

This study tested the relationship between prelinguistic vocalization and expressive vocabulary 1 year later in young children with mild to moderate developmental delays. Three vocalization variables were tested: rate of all vocalization, rate of vocalizations with consonants, and rate of vocalizations used interactively. The 58 toddlers in the study were 17-34 months old, not sensory impaired, and had Bayley Mental Development Indices (Bayley, 1969; Bayley, 1993) from 35-85. In addition, the children had fewer than 3 words in their expressive vocabularies and during classroom observation each showed at least one instance of intentional prelinguistic communication before testing. Selected sections of the Communication and Symbolic Behavior Scales procedures (CSBS; Wetherby & Prizant, 1993) were administered at the beginning and at the end of the study. The vocal measures were obtained in the initial CSBS session. One measure of expressive vocabulary was obtained in the CSBS session at the end of the study. In addition, expressive vocabulary was measured in a nonstructured play session at the end of the study. We predicted that rate of vocalization, rate of vocalizations with consonants, and rate of vocalizations used interactively would all be positively related to later expressive vocabulary. The results confirmed the predictions.

Russian EVA 36

NASA Image and Video Library

2013-11-09

ISS037-E-028569 (9 Nov. 2013) --- Russian cosmonaut Oleg Kotov, Expedition 37 flight engineer, attired in a Russian Orlan spacesuit, uses a still camera during a session of extravehicular activity (EVA) in support of assembly and maintenance on the International Space Station. During the five-hour, 50-minute spacewalk, Kotov and Russian cosmonaut Sergey Ryazanskiy (out of frame) continued the setup of a combination EVA workstation and biaxial pointing platform that was installed during an Expedition 36 spacewalk on Aug. 22.

Vestibular Assessments in Children With Global Developmental Delay: An Exploratory Study.

PubMed

Dannenbaum, Elizabeth; Horne, Victoria; Malik, Farwa; Villeneuve, Myriam; Salvo, Lora; Chilingaryan, Gevorg; Lamontagne, Anouk

2016-01-01

To compare results of 3 clinical vestibular tests between children with global developmental delay (GDD) and children with typical development (TD) and investigate the test-retest reliability. Twenty children with GDD (aged 4.1-12.1 years) and 11 age-matched controls with TD participated. Participants with GDD underwent 2 sessions of testing. Each session consisted of the Clinical Test of Sensory Interaction and Balance (CTSIB), Dynamic Visual Acuity (DVA) test, and the modified Emory Clinical Vestibular Chair Test (m-ECVCT). Up to 33% of the children with GDD had abnormal DVA scores. m-ECVCT results of children with GDD demonstrated larger variance than children with TD. The CTSIB score was significantly reduced in the group with GDD. The test-retest reliability varied, with good reliability for the m-ECVCT and CTSIB, and fair reliability for the DVA. Findings suggest vestibular involvement in children in GDD. The clinical tests demonstrated moderate test-retest reliability.

Intraseptal infusion of oxotremorine impairs memory in a delayed-non-match-to-sample radial maze task.

PubMed

Bunce, J G; Sabolek, H R; Chrobak, J J

2003-01-01

The medial septal nucleus is part of the forebrain circuitry that supports memory. This nucleus is rich in cholinergic receptors and is a putative target for the development of cholinomimetic cognitive-enhancing drugs. Septal neurons, primarily cholinergic and GABAergic, innervate the entire hippocampal formation and regulate hippocampal formation physiology and emergent function. Direct intraseptal drug infusions can produce amnestic or promnestic effects depending upon the type of drug administered. However, intraseptal infusion of the cholinomimetic oxotremorine has been reported to produce both promnestic and amnestic effects when administered prior to task performance. The present study examined whether post-acquisition intraseptal infusion of oxotremorine would be promnestic or amnestic in a delayed-non-match-to-sample radial maze task. In this task rats must remember information about spatial locations visited during a daily sample session and maintain that information over extended retention intervals (hours) in order to perform accurately on the daily test session. Treatments may then be administered during the retention interval. Alterations in maze performance during the test session an hour or more after treatment evidences effects on memory. In the present study, intraseptal infusion of oxotremorine (1.0-10.0 microg) produced a linear dose-related impairment of memory performance. Importantly, we also observed disrupted performance on the day after treatment. This persistent deficit was related only to memory over the retention interval and did not affect indices of short-term memory (ability to avoid repetitive or proactive errors during both the pre- and post-delay sessions). The persistent deficit contrasts with the acute amnestic effects of other intraseptally administered drugs including the cholinomimetics carbachol and tacrine. Thus, intraseptal oxotremorine produced a preferential disruption of memory consolidation as well as a persistent alteration of medial septal circuits. These findings are discussed with regards to multi-stage models of hippocampal-dependent memory formation and the further development of therapeutic strategies in the treatment of mild cognitive impairment as well as age-related decline and Alzheimer's dementia.

High-repetition-rate setup for pump-probe time-resolved XUV-IR experiments employing ion and electron momentum imaging

NASA Astrophysics Data System (ADS)

Pathak, Shashank; Robatjazi, Seyyed Javad; Wright Lee, Pearson; Raju Pandiri, Kanaka; Rolles, Daniel; Rudenko, Artem

2017-04-01

J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan KS, USA We report on the development of a versatile experimental setup for XUV-IR pump-probe experiments using a 10 kHz high-harmonic generation (HHG) source and two different charged-particle momentum imaging spectrometers. The HHG source, based on a commercial KM Labs eXtreme Ultraviolet Ultrafast Source, is capable of delivering XUV radiation of less than 30 fs pulse duration in the photon energy range of 17 eV to 100 eV. It can be coupled either to a conventional velocity map imaging (VMI) setup with an atomic, molecular, or nanoparticle target; or to a novel double-sided VMI spectrometer equipped with two delay-line detectors for coincidence studies. An overview of the setup and results of first pump-probe experiments including studies of two-color double ionization of Xe and time-resolved dynamics of photoionized CO2 molecule will be presented. This project is supported in part by National Science Foundation (NSF-EPSCOR) Award No. IIA-1430493 and in part by the Chemical science, Geosciences, and Bio-Science division, Office of Basic Energy Science, Office of science, U.S. Department of Energy. K.

Kilovoltage Imaging of Implanted Fiducials to Monitor Intrafraction Motion With Abdominal Compression During Stereotactic Body Radiation Therapy for Gastrointestinal Tumors.

PubMed

Yorke, Ellen; Xiong, Ying; Han, Qian; Zhang, Pengpeng; Mageras, Gikas; Lovelock, Michael; Pham, Hai; Xiong, Jian-Ping; Goodman, Karyn A

2016-07-01

To assess intrafraction respiratory motion using a commercial kilovoltage imaging system for abdominal tumor patients with implanted fiducials and breathing constrained by pneumatic compression during stereotactic body radiation therapy (SBRT). A pneumatic compression belt limited respiratory motion in 19 patients with radiopaque fiducials in or near their tumor during SBRT for abdominal tumors. Kilovoltage images were acquired at 5- to 6-second intervals during treatment using a commercial system. Intrafractional fiducial displacements were measured using in-house software. The dosimetric effect of the observed displacements was calculated for 3 sessions for each patient. Intrafraction displacement patterns varied between patients and between individual treatment sessions. Averaged over 19 patients, 73 sessions, 7.6% of craniocaudal displacements exceeded 0.5 cm, and 1.2% exceeded 0.75 cm. The calculated single-session dose to 95% of gross tumor volume differed from planned by an average of -1.2% (range, -11.1% to 4.8%) but only for 4 patients was the total 3-session calculated dose to 95% of gross tumor volume more than 3% different from planned. Our pneumatic compression limited intrafractional abdominal target motion, maintained target position established at setup, and was moderately effective in preserving coverage. Commercially available intrafractional imaging is useful for surveillance but can be made more effective and reliable. Copyright © 2015 Elsevier Inc. All rights reserved.

Kilovoltage imaging of implanted fiducials to monitor intrafraction motion with abdominal compression during stereotactic body radiotherapy for GI tumors

PubMed Central

Yorke, Ellen; Xiong, Ying; Han, Qian; Zhang, Pengpeng; Mageras, Gikas; Lovelock, Michael; Pham, Hai; Xiong, Jian-Ping; Goodman, Karyn A.

2017-01-01

Purpose/Objective To assess intrafraction respiratory motion using a commercial kilovoltage imaging system for abdominal tumor patients with implanted fiducials and breathing constrained by pneumatic compression during stereotactic body radiotherapy (sbrt). Methods and Materials A pneumatic compression belt limited respiratory motion in 19 patients with radiopaque fiducials in or near their tumor during sbrt for abdominal tumors. Kilovoltage images were acquired at 5–6 sec intervals during treatment using a commercial system. Intrafractional fiducial displacements were measured using in-house software. The dosimetric effect of the observed displacements was calculated for three sessions for each patient. Results Intrafraction displacement patterns varied between patients and between individual treatment sessions. Averaged over 19 patients, 73 sessions, 7.6% of craniocaudal displacements exceeded 0.5 cm and 1.2% exceeded 0.75 cm. The calculated single session dose to 95% of gross tumor volume (GTVD95) differed from planned by an average of −1.2% (−11.1%−4.8%) but only for 4 patients was total 3-session calculated GTVD95 over 3% different from planned Conclusions Our pneumatic compression limited intrafractional abdominal target motion, maintained target position established at setup, and was moderately effective in preserving coverage. Commercially available intrafractional imaging is useful for surveillance but can be made more effective and reliable. PMID:26797539

Functional Imagery Training to reduce snacking: Testing a novel motivational intervention based on Elaborated Intrusion theory.

PubMed

Andrade, Jackie; Khalil, Marina; Dickson, Jennifer; May, Jon; Kavanagh, David J

2016-05-01

Functional Imagery Training (FIT) is a new theory-based, manualized intervention that trains positive goal imagery. Multisensory episodic imagery of proximal personal goals is elicited and practised, to sustain motivation and compete with less functional cravings. This study tested the impact of a single session of FIT plus a booster phone call on snacking. In a stepped-wedge design, 45 participants who wanted to lose weight or reduce snacking were randomly assigned to receive a session of FIT immediately or after a 2-week delay. High-sugar and high-fat snacks were recorded using timeline follow back for the previous 3 days, at baseline, 2 and 4 weeks. At 2 weeks, snacking was lower in the immediate group than in the delayed group, and the reduction after FIT was replicated in the delayed group between 2 and 4 weeks. Frequencies of motivational thoughts about snack reduction rose following FIT for both groups, and this change correlated with reductions in snacking and weight loss. By showing that FIT can support change in eating behaviours, these findings show its potential as a motivational intervention for weight management. Copyright © 2016 Elsevier Ltd. All rights reserved.

Real Time Urban Acoustics Using Commerical Technologies

DTIC Science & Technology

2011-08-01

delays, and rendering for binaural or surround sound display [2]. VibeStudio does not include propagation effects of reflections, diffusion, or...available for rending both binaural headphones displays as well as standard and arbitrary surround sound formats. For this reason, minimal detail is...provided in this paper and the reader is referred to [2]. An image illustrating a binaural display scenario and a typical surround sound setup are

The influence of suspension components friction on race car vertical dynamics

NASA Astrophysics Data System (ADS)

Benini, Claudio; Gadola, Marco; Chindamo, Daniel; Uberti, Stefano; Marchesin, Felipe P.; Barbosa, Roberto S.

2017-03-01

This work analyses the effect of friction in suspension components on a race car vertical dynamics. It is a matter of fact that race cars aim at maximising their performance, focusing the attention mostly on aerodynamics and suspension tuning: suspension vertical and rolling stiffness and damping are parameters to be taken into account for an optimal setup. Furthermore, friction in suspension components must not be ignored. After a test session carried out with a F4 on a Four Poster rig, friction was detected on the front suspension. The real data gathered allow the validation of an analytical model with friction, confirming that its influence is relevant for low frequency values closed to the car pitch natural frequency. Finally, some setup proposals are presented to describe what should be done on actual race cars in order to correct vehicle behaviour when friction occurs.

Balance maintenance as an acquired motor skill: Delayed gains and robust retention after a single session of training in a virtual environment.

PubMed

Elion, Orit; Sela, Itamar; Bahat, Yotam; Siev-Ner, Itzhak; Weiss, Patrice L Tamar; Karni, Avi

2015-06-03

Does the learning of a balance and stability skill exhibit time-course phases and transfer limitations characteristic of the acquisition and consolidation of voluntary movement sequences? Here we followed the performance of young adults trained in maintaining balance while standing on a moving platform synchronized with a virtual reality road travel scene. The training protocol included eight 3 min long iterations of the road scene. Center of Pressure (CoP) displacements were analyzed for each task iteration within the training session, as well as during tests at 24h, 4 weeks and 12 weeks post-training to test for consolidation phase ("offline") gains and assess retention. In addition, CoP displacements in reaction to external perturbations were assessed before and after the training session and in the 3 subsequent post-training assessments (stability tests). There were significant reductions in CoP displacements as experience accumulated within session, with performance stabilizing by the end of the session. However, CoP displacements were further reduced at 24h post-training (delayed "offline" gains) and these gains were robustly retained. There was no transfer of the practice-related gains to performance in the stability tests. The time-course of learning the balance maintenance task, as well as the limitation on generalizing the gains to untrained conditions, are in line with the results of studies of manual movement skill learning. The current results support the conjecture that a similar repertoire of basic neuronal mechanisms of plasticity may underlay skill (procedural, "how to" knowledge) acquisition and skill memory consolidation in voluntary and balance maintenance tasks. Copyright © 2015 Elsevier B.V. All rights reserved.

237Np absolute delayed neutron yield measurements

NASA Astrophysics Data System (ADS)

Doré, D.; Ledoux, X.; Nolte, R.; Gagnon-Moisan, F.; Thulliez, L.; Litaize, O.; Roettger, S.; Serot, O.

2017-09-01

237Np absolute delayed neutron yields have been measured at different incident neutron energies from 1.5 to 16 MeV. The experiment was performed at the Physikalisch-Technische Bundesanstalt (PTB) facility where the Van de Graaff accelerator and the cyclotron CV28 delivered 9 different neutron energy beams using p+T, d+D and d+T reactions. The detection system is made up of twelve 3He tubes inserted into a polyethylene cylinder. In this paper, the experimental setup and the data analysis method are described. The evolution of the absolute DN yields as a function of the neutron incident beam energies are presented and compared to experimental data found in the literature and data from the libraries.

Delayed-matching-to-place Task in a Dry Maze to Measure Spatial Working Memory in Mice

PubMed Central

Feng, Xi; Krukowski, Karen; Jopson, Timothy; Rosi, Susanna

2017-01-01

The delayed-matching-to-place (DMP) dry maze test is a variant of DMP water maze (Steele and Morris, 1999; Faizi et al., 2012) which measures spatial working/episodic-like learning and memory that depends on both hippocampal and cortical functions (Wang and Morris, 2010; Euston et al., 2012). Using this test we can detect normal aging related spatial working memory decline, as well as trauma induced working memory deficits. Furthermore, we recently reported that fractionated whole brain irradiation does not affect working memory in mice (Feng et al., 2016). Here we describe the experimental setup and procedures of this behavioral test. PMID:28944261

A gated LaBr3(Ce) detector for border protection applications

NASA Astrophysics Data System (ADS)

Etile, A.; Denis-Petit, D.; Gaudefroy, L.; Meot, V.; Roig, O.

2018-01-01

We report on the dedicated implementation of the blocking technique for a LaBr3(Ce) detector as well as associated electronics and data acquisition system for border protection applications. The detector is meant to perform delayed γ-ray spectroscopy of fission fragments produced via photofission induced by a high intensity pulsed photon beam. The gating technique avoids saturation of the detection chain during irradiation. The resulting setup allows us to successfully perform delayed γ-ray spectroscopy starting only 30 ns after the gating operation. The measured energy resolution ranges from 5% to 6.5% at 662 keV depending on the γ-ray detection time after the gating operation.

Investigations of calcium spectral lines in laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Ching, Sim Yit; Tariq, Usman; Haider, Zuhaib; Tufail, Kashif; Sabri, Salwanie; Imran, Muhammad; Ali, Jalil

2017-03-01

Laser-induced breakdown spectroscopy (LIBS) is a direct and versatile analytical technique that performs the elemental composition analysis based on optical emission produced by laser induced-plasma, with a little or no sample preparation. The performance of the LIBS technique relies on the choice of experimental conditions which must be thoroughly explored and optimized for each application. The main parameters affecting the LIBS performance are the laser energy, laser wavelength, pulse duration, gate delay, geometrical set-up of the focusing and collecting optics. In LIBS quantitative analysis, the gate delay and laser energy are very important parameters that have pronounced impact on the accuracy of the elemental composition information of the materials. The determination of calcium elements in the pelletized samples was investigated and served for the purpose of optimizing the gate delay and laser energy by studying and analyzing the results from emission intensities collected and signal to background ratio (S/B) for the specified wavelengths.

Thickness and air gap measurement of assembled IR objectives

NASA Astrophysics Data System (ADS)

Lueerss, B.; Langehanenberg, P.

2015-05-01

A growing number of applications like surveillance, thermography, or automotive demand for infrared imaging systems. Their imaging performance is significantly influenced by the alignment of the individual lens elements. Besides the lateral orientation of lenses, the air spacing between the lenses is a crucial parameter. Because of restricted mechanical accessibility within an assembled objective, a non-contact technique is required for the testing of these parameters. So far commercial measurement systems were not available for testing of IR objectives since many materials used for infrared imaging are non-transparent at wavelengths below 2 μm. We herewith present a time-domain low coherent interferometer capable of measuring any kind of infrared material (e.g., Ge, Si, etc.) as well as VIS materials. The fiber-optic set-up is based on a Michelson-Interferometer in which the light from a broadband super-luminescent diode is split into a reference arm with a variable optical delay and a measurement arm where the sample is placed. On a photo detector, the reflected signals from both arms are superimposed and recorded as a function of the variable optical path. Whenever the group delay difference is zero, a coherence peak occurs and the relative lens' surface distances are derived from the optical delay. In order to penetrate IR materials, the instrument operates at 2.2 μm. The set-up allows the contactless determination of thicknesses and air gaps inside of assembled infrared objective lenses with accuracy in the micron range. It therefore is a tool for the precise manufacturing or quality control.

Tropospheric Delay Raytracing Applied in VLBI Analysis

NASA Astrophysics Data System (ADS)

MacMillan, D. S.; Eriksson, D.; Gipson, J. M.

2013-12-01

Tropospheric delay modeling error continues to be one of the largest sources of error in VLBI analysis. For standard operational solutions, we use the VMF1 elevation-dependent mapping functions derived from ECMWF data. These mapping functions assume that tropospheric delay at a site is azimuthally symmetric. As this assumption does not reflect reality, we have determined the raytrace delay along the signal path through the troposphere for each VLBI quasar observation. We determined the troposphere refractivity fields from the pressure, temperature, specific humidity and geopotential height fields of the NASA GSFC GEOS-5 numerical weather model. We discuss results from analysis of the CONT11 R&D and the weekly operational R1+R4 experiment sessions. When applied in VLBI analysis, baseline length repeatabilities were better for 66-72% of baselines with raytraced delays than with VMF1 mapping functions. Vertical repeatabilities were better for 65% of sites.

Russian EVA 36

NASA Image and Video Library

2013-11-09

ISS037-E-028787 (9 Nov. 2013) --- Russian cosmonauts Oleg Kotov (left) and Sergey Ryazanskiy, both Expedition 37 flight engineers, attired in Russian Orlan spacesuits, participate in a session of extravehicular activity (EVA) in support of assembly and maintenance on the International Space Station. During the five-hour, 50-minute spacewalk, Kotov and Ryazanskiy continued the setup of a combination EVA workstation and biaxial pointing platform that was installed during an Expedition 36 spacewalk on Aug. 22. Earth’s horizon and the blackness of space provide the backdrop for the scene.

The role of a prone setup in breast radiation therapy.

PubMed

Huppert, Nelly; Jozsef, Gabor; Dewyngaert, Keith; Formenti, Silvia Chiara

2011-01-01

Most patients undergoing breast conservation therapy receive radiotherapy in the supine position. Historically, prone breast irradiation has been advocated for women with large pendulous breasts in order to decrease acute and late toxicities. With the advent of CT planning, the prone technique has become both feasible and reproducible. It was shown to be advantageous not only for women with larger breasts but in most patients since it consistently reduces, if not eliminates, the inclusion of heart and lung within the field. The prone setup has been accepted as the best localizing position for both MRI and stereotactic biopsy, but its adoption has been delayed in radiotherapy. New technological advances including image-modulated radiation therapy and image-guided radiation therapy have made possible the exploration of accelerated fractionation schemes with a concomitant boost to the tumor bed in the prone position, along with better imaging and verification of reproducibility of patient setup. This review describes some of the available techniques for prone breast radiotherapy and the available experience in their application. The NYU prone breast radiotherapy approach is discussed, including a summary of the results from several prospective trials.

75 FR 63530 - Self-Regulatory Organizations; NYSE Arca, Inc.; Order Granting Approval of Proposed Rule Change...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-15

... services such as Bloomberg or Reuters. The relevant futures exchanges also provide delayed futures information on current and past trading sessions and market news free of charge on their respective Web sites...

The rationale for combining an online audiovisual curriculum with simulation to better educate general surgery trainees.

PubMed

AlJamal, Yazan N; Ali, Shahzad M; Ruparel, Raaj K; Brahmbhatt, Rushin D; Yadav, Siddhant; Farley, David R

2014-09-01

Surgery interns' training has historically been weighted toward patient care, operative observation, and sleeping when possible. With more protected free time and less clinical time, real educational hours for trainees in 2013 are precious. We created a 20-session (3 hours each) simulation curriculum (with pre- and post-tests) and a 24/7 online audiovisual (AV) curriculum for surgery interns. Friday morning simulation sessions emphasize operative skills and judgment. AV clips (using operating room, whiteboard, and simulation center videos) take learners through 20 different general surgery operations with follow-up quizzes. We report our early experience with this novel setup. Thirty-two surgical interns (2012-2013) attended simulation sessions on 20 separate subjects (hernia, breast, hepatobiliary, endocrine, etc). Post-test scores improved (P < .05) and trainees enjoyed using surgical skills for 3 hours each Friday morning (mean, >4.5; Likert scale, 1-5). The AV curriculum feedback is similar (mean, >4.3) and usage is available 24/7 preparing learners for both operating room and simulation sessions. Most simulation sessions utilize low-fidelity models to keep costs <$50 per session. Scores on our semiannual Surgical Olympics (mean score of 49.6 in July vs 82.9 in January; P < .05) improved significantly, suggesting that interns are improving their surgical skills and knowledge. Residents enjoy and learn from the step-by-step, in-house, AV curriculum and both appreciate and thrive on the 'hands-on' simulation sessions mimicking operations they see in real operating rooms. The cost of these programs is not prohibitive and the programs offer simulated repetitions for duty-hour-regulated trainees. Copyright © 2014 Mosby, Inc. All rights reserved.

Studying Different Tasks of Implicit Learning across Multiple Test Sessions Conducted on the Web

PubMed Central

Sævland, Werner; Norman, Elisabeth

2016-01-01

Implicit learning is usually studied through individual performance on a single task, with the most common tasks being the Serial Reaction Time (SRT) task, the Dynamic System Control (DSC) task, and Artificial Grammar Learning (AGL). Few attempts have been made to compare performance across different implicit learning tasks within the same study. The current study was designed to explore the relationship between performance on the DSC Sugar factory task and the Alternating Serial Reaction Time (ASRT) task. We also addressed another limitation of traditional implicit learning experiments, namely that implicit learning is usually studied in laboratory settings over a restricted time span lasting for less than an hour. In everyday situations, implicit learning is assumed to involve a gradual accumulation of knowledge across several learning episodes over a longer time span. One way to increase the ecological validity of implicit learning experiments could be to present the learning material repeatedly across shorter test sessions. This can most easily be done by using a web-based setup in which participants can access the material from home. We therefore created an online web-based system for measuring implicit learning that could be administered in either single or multiple sessions. Participants (n = 66) were assigned to either a single session or a multiple session condition. Learning occurred on both tasks, and awareness measures suggested that acquired knowledge was not fully conscious on either of the tasks. Learning and the degree of conscious awareness of the learned regularities were compared across conditions and tasks. On the DSC task, performance was not affected by whether learning had taken place in one or over multiple sessions. On the ASRT task, RT improvement across blocks was larger in the multiple-session condition. Learning in the two tasks was not related. PMID:27375512

New Generation VLBI: Intraday UT1 Estimations

NASA Astrophysics Data System (ADS)

Ipatov, Alexander; Ivanov, Dmitriy; Ilin, Gennadiy; Smolentsev, Sergei; Gayazov, Iskander; Mardyshkin, Vyacheslav; Fedotov, Leonid; Stempkovski, Victor; Vytnov, Alexander; Salnikov, Alexander; Surkis, Igor; Mikhailov, Andrey; Marshalov, Dmitriy; Bezrukov, Ilya; Melnikov, Alexey; Ken, Voytsekh; Kurdubov, Sergei

2016-12-01

IAA finished work on the creation of the new generation radio interferometer with two VGOS antennas co-located at Badary and Zelenchukskaya. 48 single baseline one-hour VLBI sessions (up to four sessions per day) were performed from 04 Nov to 18 Nov 2015. Observations were carried out using wideband S/X receivers, three X-band and one S-band 512 MHz channels at one or two circular polarizations. Sessions consisted of about 60 scans with a 22-second minimum scan duration. The stations' broadband acquisition systems generated 1.5-3 TB data per session, which were transferred via Internet to the IAA FX correlator. The accuracy of the group delay in a single channel was 10-20 ps, which allows the use of every single channel's observations for geodetic analysis without synthesis. 156 single channel NGS-cards were obtained in total. The RMS of the differences between UT1-UTC estimates and IERS finals values is 19 μs.

Enhanced Performance & Functionality of Tunable Delay Lines

DTIC Science & Technology

2012-08-01

Figure 6. Experimental setup. Transmitter is capable of generating 80-Gb/s RZ-DQPSK, 40-Gb/s RZ-DPSK and 40-Gb/s RZ-OOK modulation formats. Phase...Power penalty with respect to B2B of each channel for 2-, 4-, 8-fold multicasting. (c) Pulsewidth as a function of DGD along with eye diagrams of 2...63 Figure 99. Concept. (a) A distributed optical network ; (b) NOLMs for

CHEETAH: circuit-switched high-speed end-to-end transport architecture

NASA Astrophysics Data System (ADS)

Veeraraghavan, Malathi; Zheng, Xuan; Lee, Hyuk; Gardner, M.; Feng, Wuchun

2003-10-01

Leveraging the dominance of Ethernet in LANs and SONET/SDH in MANs and WANs, we propose a service called CHEETAH (Circuit-switched High-speed End-to-End Transport ArcHitecture). The service concept is to provide end hosts with high-speed, end-to-end circuit connectivity on a call-by-call shared basis, where a "circuit" consists of Ethernet segments at the ends that are mapped into Ethernet-over-SONET long-distance circuits. This paper focuses on the file-transfer application for such circuits. For this application, the CHEETAH service is proposed as an add-on to the primary Internet access service already in place for enterprise hosts. This allows an end host that is sending a file to first attempt setting up an end-to-end Ethernet/EoS circuit, and if rejected, fall back to the TCP/IP path. If the circuit setup is successful, the end host will enjoy a much shorter file-transfer delay than on the TCP/IP path. To determine the conditions under which an end host with access to the CHEETAH service should attempt circuit setup, we analyze mean file-transfer delays as a function of call blocking probability in the circuit-switched network, probability of packet loss in the IP network, round-trip times, link rates, and so on.

Long-term memory, sleep, and the spacing effect.

PubMed

Bell, Matthew C; Kawadri, Nader; Simone, Patricia M; Wiseheart, Melody

2014-01-01

Many studies have shown that memory is enhanced when study sessions are spaced apart rather than massed. This spacing effect has been shown to have a lasting benefit to long-term memory when the study phase session follows the encoding session by 24 hours. Using a spacing paradigm we examined the impact of sleep and spacing gaps on long-term declarative memory for Swahili-English word pairs by including four spacing delay gaps (massed, 12 hours same-day, 12 hours overnight, and 24 hours). Results showed that a 12-hour spacing gap that includes sleep promotes long-term memory retention similar to the 24-hour gap. The findings support the importance of sleep to the long-term benefit of the spacing effect.

Technology Insertion (TI)/Industrial Process Improvement (IPI) Task Order Number 1. Data Base Documentation Book for WR-ALC/MANPSC (Bonded Honeycomb)

DTIC Science & Technology

1989-08-14

for a long time In getting those required parts. 6-29-89 VR-ALC Model Validation Heeting Minutes Page Seven MANPSB • This Is a manufacturing RCC. • No...Manpower. 4. Training shop - mechanics get transferred to r-15 Shop. Ninutes of Brainstorming Session June 20. 1969 Horning Session Page Two 5. Two shifts...11. RCC KANPSB completes then ships to storage - delay 10 to 15 days to get the same part back In finlshing the repair. 12. Major repair coordination

The attitudes of family physicians toward a child with delayed growth and development.

PubMed

Aker, Servet; Şahin, Mustafa Kürşat; Kınalı, Ömer; Şimşek Karadağ, Elif; Korkmaz, Tuğba

2017-09-01

Aim The purpose of this study was to assess the attitude of family physicians toward a child with delayed growth and development. Primary healthcare professionals play a key role in monitoring growth and development, the best indicator of the child's health status. If delayed growth and development can be detected early, then it is usually possible to restore functioning. This descriptive study was performed in Samsun, Turkey, in May and June 2015. In total, 325 family physicians were included. The study consisted of two parts. In the first session of the research, the story of an 18-month-old child with delayed growth and development was presented using visual materials. An interview between the child's mother and a member of primary healthcare staff was then enacted by two of the authors using role-playing. Subsequently, participants were given the opportunity to ask the mother and member of primary healthcare staff questions about the case. During the sessions, two observers observed the participants, took notes and compared these after the presentation. In the second part of the study, the participants were asked to complete a questionnaire consisting of three open-ended questions. Findings When asking questions of the mother, family physicians generally used accusatory and judgmental language. One of the questions most commonly put to the mother was 'Do you think you are a good mother?' Family physicians were keen to provide instruction for the patient and relatives. Family physicians to a large extent thought that the problem of a child with delayed growth and development can be resolved through education. Family physicians' manner of establishing relations with the patient and relatives is inappropriate. We therefore think that they should receive on-going in-service training on the subject.

Skin tumor development after UV irradiation and photodynamic therapy is unaffected by short-term pretreatment with 5-fluorouracil, imiquimod and calcipotriol. An experimental hairless mouse study.

PubMed

Bay, Christiane; Togsverd-Bo, Katrine; Lerche, Catharina M; Haedersdal, Merete

2016-01-01

Photodynamic therapy (PDT) delays ultraviolet (UV) radiation-induced squamous cell carcinomas (SCCs) in hairless mice. Efficacy may be enhanced by combining PDT with antineoplastic or pro-differentiating agents. We investigated if pretreatment with 5-fluorouracil (5FU), imiquimod (IMIQ) or calcipotriol (CAL) before PDT further delays tumor onset. Hairless mice (n=224) were exposed 3 times weekly to 3 standard erythema doses (SED) of UV radiation. Methyl-aminolevulinate (MAL)-PDT sessions were given on days 45 and 90 before SCC development. Three applications of topical 5FU, IMIQ or CAL were given before each PDT session. Fluorescence photography quantified protoporphyrin IX (PpIX) formation. PDT delayed UV-induced SCC development by 59 days (212 days UV-MAL-PDT vs. 153 days UV-control, P<0.001). Pretreatment with 5FU, IMIQ or CAL before PDT did not further delay SCC onset compared to PDT alone (207 days UV-5FU-MAL-PDT, 215 days UV-IMIQ-MAL-PDT, 206 days UV-CAL-MAL-PDT vs. 212 days UV-MAL-PDT, P=ns). PpIX fluorescence intensified by 5FU-pretreatment (median 21,392 au UV-5FU-MAL-PDT, P=0.011), decreased after IMIQ-pretreatment (12,452 au UV-IMIQ-MAL-PDT, P<0.001), and was unaffected by CAL-pretreatment (19,567 au UV-CAL-MAL-PDT, P=ns) compared to MAL alone (18,083 au UV-MAL-PDT). Short-term three-day pretreatment with 5FU, IMIQ and CAL before PDT does not further delay tumor onset in UV-exposed hairless mice. Copyright © 2015 Elsevier B.V. All rights reserved.

Acquisition of delayed matching in the pigeon.

PubMed

Berryman, R; Cumming, W W; Nevin, J A

1963-01-01

Pigeons were exposed to three successive matching-to-sample procedures. On a given trial, the sample (red, green or blue light) appeared on a center key; observing responses to this key produced the comparison stimuli on two side keys. Seven different experimental conditions could govern the temporal relations between the sample and comparison stimuli. In the "simultaneous" condition, the center key response was followed immediately by illumination of the side key comparison stimuli, with the center key remaining on. In "zero delay" the center key response simultaneously turned the side keys on and the center key off, while in the "variable delay" conditions, intervals of 1, 2, 4, 10, and 24 sec were interposed between the offset of the sample and the appearance of the comparison stimuli on the side keys. In all conditions, a response to the side key of matching hue produced reinforcement, while a response to the non-matching side key was followed by a blackout. In procedure I all seven experimental conditions were presented in randomly permutated order. After nine sessions of exposure (at 191 trials per session, for a total of 1719 trials) the birds gave no evidence of acquisition in any of the conditions. They were therefore transferred to Procedure II, which required them to match only in the "simultaneous" condition, with both the sample and comparison stimuli present at the same time. With the exception of one bird, all subjects acquired this performance to near 100% levels. Next, in Procedure III, they were once more exposed to presentation of all seven experimental conditions in random order. In contrast to Procedure I, they now acquired the delay performance, and were able to match effectively at delays of about 4 sec.

Delayed hyperbaric oxygen therapy for air emboli after open heart surgery: case report and review of a success story.

PubMed

Niyibizi, Eva; Kembi, Guillaume Elyes; Lae, Claude; Pignel, Rodrigue; Sologashvili, Tornike

2016-12-05

The current case describes a rare diagnosis of iatrogenic air emboli after elective cardiopulmonary bypass that was successfully treated with delayed hyperbaric oxygen therapy, with good clinical evolution in spite of rare complications. A 35 years old male was admitted to the intensive care unit (ICU) for post-operative management after being placed on cardiopulmonary bypass (CPB) for an elective ventricular septal defect closure and aortic valvuloplasty. The patient initially presented with pathologically late awakening and was extubated 17 h after admission. Neurologic clinical status after extubation showed global aphasia, mental slowness and spatio-temporal disorientation. The injected cerebral CT scan was normal; the EEG was inconclusive (it showed metabolic encephalopathy without epileptic activity); and the cerebral MRI done 48 h after surgery showed multiple small subcortical acute ischemic lesions, mainly on the left fronto- parieto- temporo-occipital lobes. He was taken for hyperbaric oxygen therapy (HOT) over 54 h after cardiac surgery. The first session ended abruptly after 20 min when the patient suffered a generalised tonico-clonic seizure, necessitating a moderately rapid decompression, airway management, and antiepileptic treatment. In total, the patient received 7 HOT sessions over 6 days. He demonstrated full neurological recovery at 4 weeks and GOS (Glasgow Outcome Scale) of 5 out of 5 even after a long delay in initial management. Convulsions are a rare complication of HOT either due to reperfusion syndrome or hyperoxic toxicity and can be managed. Prior imaging by MRI or tympanic paracentesis (myringotomy) should not add further delay of treatment. HOT should be initiated upon late awakening and/or neurologic symptoms after CPB heart surgery, after exclusion of formal counter-indications, even if the delay exceeds 48 h.

Voluntary Exercise Impairs Initial Delayed Spatial Alternation Performance in Estradiol Treated Ovariectomized Middle-Aged Rats

PubMed Central

Neese, Steven L.; Korol, Donna L.; Schantz, Susan L.

2013-01-01

Estrogens differentially modulate behavior in the adult female rodent. Voluntary exercise can also impact behavior, often reversing age associated decrements in memory processes. Our research group has published a series of papers reporting a deficit in the acquisition of an operant working memory task, delayed spatial alternation (DSA), following 17β-estradiol treatment to middle-aged ovariectomized (OVX) rats. The current study examined if voluntary exercise could attenuate the 17β-estradiol induced deficits on DSA performance. OVX 12-month old Long- Evans rats were implanted with a Silastic capsule containing 17β-estradiol (10% in cholesterol: low physiological range) or with a blank capsule. A subset of the 17β-estradiol and OVX untreated rats were given free access to a running wheel in their home cage. All rats were tested for 40 sessions on the DSA task. Surprisingly, we found running wheel access to impair initial acquisition of the DSA task in 17β-estradiol treated rats, an effect not seen in OVX untreated rats given running wheel access. This deficit was driven by an increase in perseverative responding on a lever no longer associated with reinforcement. We also report for the first time a 17β-estradiol induced impairment on the DSA task following a long intertrial delay (18-sec), an effect revealed following more extended testing than in our previous studies (15 additional sessions). Overall, running wheel access increased initial error rate on the DSA task in 17β-estradiol treated middle-aged OVX rats, and failed to prevent the 17β-estradiol induced deficits in performance of the operant DSA task in later testing sessions. PMID:24013039

Improved setup and positioning accuracy using a three‐point customized cushion/mask/bite‐block immobilization system for stereotactic reirradiation of head and neck cancer

PubMed Central

Wang, He; Wang, Congjun; Tung, Samuel; Dimmitt, Andrew Wilson; Wong, Pei Fong; Edson, Mark A.; Garden, Adam S.; Rosenthal, David I.; Fuller, Clifton D.; Gunn, Gary B.; Takiar, Vinita; Wang, Xin A.; Luo, Dershan; Yang, James N.; Wong, Jennifer

2016-01-01

The purpose of this study was to investigate the setup and positioning uncertainty of a custom cushion/mask/bite‐block (CMB) immobilization system and determine PTV margin for image‐guided head and neck stereotactic ablative radiotherapy (HN‐SABR). We analyzed 105 treatment sessions among 21 patients treated with HN‐SABR for recurrent head and neck cancers using a custom CMB immobilization system. Initial patient setup was performed using the ExacTrac infrared (IR) tracking system and initial setup errors were based on comparison of ExacTrac IR tracking system to corrected online ExacTrac X‐rays images registered to treatment plans. Residual setup errors were determined using repeat verification X‐ray. The online ExacTrac corrections were compared to cone‐beam CT (CBCT) before treatment to assess agreement. Intrafractional positioning errors were determined using prebeam X‐rays. The systematic and random errors were analyzed. The initial translational setup errors were −0.8±1.3 mm, −0.8±1.6 mm, and 0.3±1.9 mm in AP, CC, and LR directions, respectively, with a three‐dimensional (3D) vector of 2.7±1.4 mm. The initial rotational errors were up to 2.4° if 6D couch is not available. CBCT agreed with ExacTrac X‐ray images to within 2 mm and 2.5°. The intrafractional uncertainties were 0.1±0.6 mm, 0.1±0.6 mm, and 0.2±0.5 mm in AP, CC, and LR directions, respectively, and 0.0∘±0.5°, 0.0∘±0.6°, and −0.1∘±0.4∘ in yaw, roll, and pitch direction, respectively. The translational vector was 0.9±0.6 mm. The calculated PTV margins mPTV(90,95) were within 1.6 mm when using image guidance for online setup correction. The use of image guidance for online setup correction, in combination with our customized CMB device, highly restricted target motion during treatments and provided robust immobilization to ensure minimum dose of 95% to target volume with 2.0 mm PTV margin for HN‐SABR. PACS number(s): 87.55.ne PMID:27167275

Kilovoltage Imaging of Implanted Fiducials to Monitor Intrafraction Motion With Abdominal Compression During Stereotactic Body Radiation Therapy for Gastrointestinal Tumors

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

Yorke, Ellen, E-mail: yorke@mskcc.org; Xiong, Ying; Han, Qian

2016-07-01

Purpose: To assess intrafraction respiratory motion using a commercial kilovoltage imaging system for abdominal tumor patients with implanted fiducials and breathing constrained by pneumatic compression during stereotactic body radiation therapy (SBRT). Methods and Materials: A pneumatic compression belt limited respiratory motion in 19 patients with radiopaque fiducials in or near their tumor during SBRT for abdominal tumors. Kilovoltage images were acquired at 5- to 6-second intervals during treatment using a commercial system. Intrafractional fiducial displacements were measured using in-house software. The dosimetric effect of the observed displacements was calculated for 3 sessions for each patient. Results: Intrafraction displacement patterns variedmore » between patients and between individual treatment sessions. Averaged over 19 patients, 73 sessions, 7.6% of craniocaudal displacements exceeded 0.5 cm, and 1.2% exceeded 0.75 cm. The calculated single-session dose to 95% of gross tumor volume differed from planned by an average of −1.2% (range, −11.1% to 4.8%) but only for 4 patients was the total 3-session calculated dose to 95% of gross tumor volume more than 3% different from planned. Conclusions: Our pneumatic compression limited intrafractional abdominal target motion, maintained target position established at setup, and was moderately effective in preserving coverage. Commercially available intrafractional imaging is useful for surveillance but can be made more effective and reliable.« less

Frequency domain tailoring for intra-pulse frequency mixing.

PubMed

Ernotte, G; Lassonde, P; Légaré, F; Schmidt, B E

2016-10-17

Generating mid infrared (MIR) pulses by difference frequency generation (DFG) is often a trade-off between the maximum stability given by all-inline intra-pulse arrangements and the independent control of pulse parameters with inter-pulse pump-probe like scenarios. We propose a coalescence between both opposing approaches by realizing an all-inline inter-pulse DFG scheme employing a 4-f setup. This allows independent manipulation of the amplitude, delay and polarization of the two corresponding spectral side bands of a supercontinuum source while maintaining 20 attoseconds jitter without any feedback stabilization. After filamentation in air, the broadened Ti:Sa spectrum is tailored in a 4-f setup to generate tunable MIR pulses. In this manner, 2 µm, 4.8 µJ, 26.5 fs and carrier-envelope-phase (CEP) stabilized pulses are generated in a single DFG stage.

Optical setup for two-colour experiments at the low density matter beamline of FERMI

NASA Astrophysics Data System (ADS)

Finetti, Paola; Demidovich, Alexander; Plekan, Oksana; Di Fraia, Michele; Cucini, Riccardo; Callegari, Carlo; Cinquegrana, Paolo; Sigalotti, Paolo; Ivanov, Rosen; Danailov, Miltcho B.; Fava, Claudio; De Ninno, Giovanni; Coreno, Marcello; Grazioli, Cesare; Feifel, Raimund; Squibb, Richard J.; Mazza, Tommaso; Meyer, Michael; Prince, Kevin C.

2017-11-01

The low density matter beamline of the free electron laser facility FERMI is dedicated to the study of atomic, molecular and cluster systems, and here we describe the optical setup available for two-colour experiments. Samples can be exposed to ultrashort pulses from a Ti:Sapphire source (fundamental, or second or third harmonic), and ultrashort light pulses of FERMI in the EUV/soft x-ray region with a well-defined temporal delay, and negligible jitter (<10 fs) compared to the pulse durations (40-100 fs). Detection schemes available include electron, ion and optical spectroscopy. The majority of experiments using this apparatus are pump-and-probe, where either wavelength can be pump or probe, but the system is also useful for other techniques, such as multi-photon spectroscopy, cross-correlation measurements and alignment of molecules in space.

The influence of focused-attention meditation states on the cognitive control of sequence learning.

PubMed

Chan, Russell W; Immink, Maarten A; Lushington, Kurt

2017-10-01

Cognitive control processes influence how motor sequence information is utilised and represented. Since cognitive control processes are shared amongst goal-oriented tasks, motor sequence learning and performance might be influenced by preceding cognitive tasks such as focused-attention meditation (FAM). Prior to a serial reaction time task (SRTT), participants completed either a single-session of FAM, a single-session of FAM followed by delay (FAM+) or no meditation (CONTROL). Relative to CONTROL, FAM benefitted performance in early, random-ordered blocks. However, across subsequent sequence learning blocks, FAM+ supported the highest levels of performance improvement resulting in superior performance at the end of the SRTT. Performance following FAM+ demonstrated greater reliance on embedded sequence structures than FAM. These findings illustrate that increased top-down control immediately after FAM biases the implementation of stimulus-based planning. Introduction of a delay following FAM relaxes top-down control allowing for implementation of response-based planning resulting in sequence learning benefits. Copyright © 2017 Elsevier Inc. All rights reserved.

Direct measurement of beta-delayed neutron emission at and beyond doubly-magic 78Ni

NASA Astrophysics Data System (ADS)

Yokoyama, Rin; Briken Collaboration Collaboration

2017-09-01

An experiment aiming to measure the beta-neutron-gamma decay properties of nuclei around 78Ni produced by in-flight fission of a 238U beam at 345 MeV/u and selected by means of BigRIPS was recently performed using the BRIKEN setup. The BRIKEN detector is composed of the AIDA implantation-decay array as well as 140 3He tubes and 2 HPGe clovers. The counting efficiency of a single beta-delayed neutron (β1 n) is above 60. National Nuclear Security Administration under the Stewardship Sci- ence Academic Alliances program through DOE Award No. DE- NA0002132 and the Office of Nuclear Physics, U.S. Department of Energy under Award No. DE-FG02-96ER40983.

Human Adolescent Phase Response Curves to Bright White Light.

PubMed

Crowley, Stephanie J; Eastman, Charmane I

2017-08-01

Older adolescents are particularly vulnerable to circadian misalignment and sleep restriction, primarily due to early school start times. Light can shift the circadian system and could help attenuate circadian misalignment; however, a phase response curve (PRC) to determine the optimal time for receiving light and avoiding light is not available for adolescents. We constructed light PRCs for late pubertal to postpubertal adolescents aged 14 to 17 years. Participants completed 2 counterbalanced 5-day laboratory sessions after 8 or 9 days of scheduled sleep at home. Each session included phase assessments to measure the dim light melatonin onset (DLMO) before and after 3 days of free-running through an ultradian light-dark (wake-sleep) cycle (2 h dim [~20 lux] light, 2 h dark). In one session, intermittent bright white light (~5000 lux; four 20-min exposures) was alternated with 10 min of dim room light once per day for 3 consecutive days. The time of light varied among participants to cover the 24-h day. For each individual, the phase shift to bright light was corrected for the free-run derived from the other laboratory session with no bright light. One PRC showed phase shifts in response to light start time relative to the DLMO and another relative to home sleep. Phase delay shifts occurred around the hours corresponding to home bedtime. Phase advances occurred during the hours surrounding wake time and later in the afternoon. The transition from delays to advances occurred at the midpoint of home sleep. The adolescent PRCs presented here provide a valuable tool to time bright light in adolescents.

The application of a low-cost 3D depth camera for patient set-up and respiratory motion management in radiotherapy

NASA Astrophysics Data System (ADS)

Tahavori, Fatemeh

Respiratory motion induces uncertainty in External Beam Radiotherapy (EBRT), which can result in sub-optimal dose delivery to the target tissue and unwanted dose to normal tissue. The conventional approach to managing patient respiratory motion for EBRT within the area of abdominal-thoracic cancer is through the use of internal radiological imaging methods (e.g. Megavoltage imaging or Cone-Beam Computed Tomography) or via surrogate estimates of tumour position using external markers placed on the patient chest. This latter method uses tracking with video-based techniques, and relies on an assumed correlation or mathematical model, between the external surrogate signal and the internal target position. The marker's trajectory can be used in both respiratory gating techniques and real-time tracking methods. Internal radiological imaging methods bring with them limited temporal resolution, and additional radiation burden, which can be addressed by external marker-based methods that carry no such issues. Moreover, by including multiple external markers and placing them closer to the internal target organs, the effciency of correlation algorithms can be increased. However, the quality of such external monitoring methods is underpinned by the performance of the associated correlation model. Therefore, several new approaches to correlation modelling have been developed as part of this thesis and compared using publicly-available datasets. Highly competitive results have been obtained when compared against state-of-the-art methods. Marker-based methods also have the disadvantages of requiring manual set-up time for marker placement and patient positioning and potential issues with reproducibility of marker placement. This motivates the investigation of non-contact marker-free methods for use in EBRT, which is the main topic of this thesis. The Microsoft Kinect is used as an example of a low-cost consumer grade 3D depth camera for capturing and analysing external respiratory motion. This thesis makes the first presentation of detailed studies of external respiratory motion captured using such low-cost technology and demonstrates its potential in a healthcare environment. Firstly, the fundamental performance of a range of Microsoft Kinect sensors is assessed for use in radiotherapy (and potentially other healthcare applications), in terms of static and dynamic performance using both phantoms and volunteers. Then external respiratory motion is captured using the above technology from a group of 32 healthy volunteers and Principal Component Analysis (PCA) is applied to a region of interest encompassing the complete anterior surface to demonstrate breathing style. This work demonstrates that this surface motion can be compactly described by the first two PCA eigenvectors. The reproducibility of subject-specific EBRT set-up using conventional laser-based alignment and marker-based Deep Inspiration Breath Hold (DIBH) methods are also studied using the Microsoft Kinect sensor. A cohort of five healthy female volunteers is repeatedly set-up for left-sided breast cancer EBRT and multiple DIBH episodes captured over five separate sessions representing multiple fractionated radiotherapy treatment sessions, but without dose delivery. This provided an independent assessment that subjects were set-up and generally achieved variations within currently accepted margins of clinical practice. Moreover, this work demonstrated the potential role of consumer-grade 3D depth camera technology as a possible replacement for marker based set-up and DIBH management procedures. This brings with it the additional benefits of low cost, and potential through-put benefits, as patient set-up could ultimately be fully automated with this technology, and DIBH could be independently monitored without requiring preparatory manual intervention.

Effects of Pomegranate Juice Supplementation on Oxidative Stress Biomarkers Following Weightlifting Exercise

PubMed Central

Turki, Mouna; Hammouda, Omar; Chtourou, Hamdi; Trabelsi, Khaled; Bouaziz, Mohamed; Abdelkarim, Osama; Hoekelmann, Anita; Ayadi, Fatma; Souissi, Nizar; Bailey, Stephen J.; Driss, Tarak; Yaich, Sourour

2017-01-01

The aim of this study was to test the hypothesis that pomegranate juice supplementation would blunt acute and delayed oxidative stress responses after a weightlifting training session. Nine elite weightlifters (21.0 ± 1 years) performed two Olympic-Weightlifting sessions after ingesting either the placebo or pomegranate juice supplements. Venous blood samples were collected at rest and 3 min and 48 h after each session. Compared to the placebo condition, pomegranate juice supplementation attenuated the increase in malondialdehyde (−12.5%; p < 0.01) and enhanced the enzymatic (+8.6% for catalase and +6.8% for glutathione peroxidase; p < 0.05) and non-enzymatic (+12.6% for uric acid and +5.7% for total bilirubin; p < 0.01) antioxidant responses shortly (3 min) after completion of the training session. Additionally, during the 48 h recovery period, pomegranate juice supplementation accelerated (p < 0.05) the recovery kinetics of the malondialdehyde (5.6%) and the enzymatic antioxidant defenses compared to the placebo condition (9 to 10%). In conclusion, supplementation with pomegranate juice has the potential to attenuate oxidative stress by enhancing antioxidant responses assessed acutely and up to 48 h following an intensive weightlifting training session. Therefore, elite weightlifters might benefit from blunted oxidative stress responses following intensive weightlifting sessions, which could have implications for recovery between training sessions. PMID:28758938

Effects of Pomegranate Juice Supplementation on Oxidative Stress Biomarkers Following Weightlifting Exercise.

PubMed

Ammar, Achraf; Turki, Mouna; Hammouda, Omar; Chtourou, Hamdi; Trabelsi, Khaled; Bouaziz, Mohamed; Abdelkarim, Osama; Hoekelmann, Anita; Ayadi, Fatma; Souissi, Nizar; Bailey, Stephen J; Driss, Tarak; Yaich, Sourour

2017-07-29

The aim of this study was to test the hypothesis that pomegranate juice supplementation would blunt acute and delayed oxidative stress responses after a weightlifting training session. Nine elite weightlifters (21.0 ± 1 years) performed two Olympic-Weightlifting sessions after ingesting either the placebo or pomegranate juice supplements. Venous blood samples were collected at rest and 3 min and 48 h after each session. Compared to the placebo condition, pomegranate juice supplementation attenuated the increase in malondialdehyde (-12.5%; p < 0.01) and enhanced the enzymatic (+8.6% for catalase and +6.8% for glutathione peroxidase; p < 0.05) and non-enzymatic (+12.6% for uric acid and +5.7% for total bilirubin; p < 0.01) antioxidant responses shortly (3 min) after completion of the training session. Additionally, during the 48 h recovery period, pomegranate juice supplementation accelerated ( p < 0.05) the recovery kinetics of the malondialdehyde (5.6%) and the enzymatic antioxidant defenses compared to the placebo condition (9 to 10%). In conclusion, supplementation with pomegranate juice has the potential to attenuate oxidative stress by enhancing antioxidant responses assessed acutely and up to 48 h following an intensive weightlifting training session. Therefore, elite weightlifters might benefit from blunted oxidative stress responses following intensive weightlifting sessions, which could have implications for recovery between training sessions.

Quantum key distribution session with 16-dimensional photonic states.

PubMed

Etcheverry, S; Cañas, G; Gómez, E S; Nogueira, W A T; Saavedra, C; Xavier, G B; Lima, G

2013-01-01

The secure transfer of information is an important problem in modern telecommunications. Quantum key distribution (QKD) provides a solution to this problem by using individual quantum systems to generate correlated bits between remote parties, that can be used to extract a secret key. QKD with D-dimensional quantum channels provides security advantages that grow with increasing D. However, the vast majority of QKD implementations has been restricted to two dimensions. Here we demonstrate the feasibility of using higher dimensions for real-world quantum cryptography by performing, for the first time, a fully automated QKD session based on the BB84 protocol with 16-dimensional quantum states. Information is encoded in the single-photon transverse momentum and the required states are dynamically generated with programmable spatial light modulators. Our setup paves the way for future developments in the field of experimental high-dimensional QKD.

Quantum key distribution session with 16-dimensional photonic states

NASA Astrophysics Data System (ADS)

Etcheverry, S.; Cañas, G.; Gómez, E. S.; Nogueira, W. A. T.; Saavedra, C.; Xavier, G. B.; Lima, G.

2013-07-01

The secure transfer of information is an important problem in modern telecommunications. Quantum key distribution (QKD) provides a solution to this problem by using individual quantum systems to generate correlated bits between remote parties, that can be used to extract a secret key. QKD with D-dimensional quantum channels provides security advantages that grow with increasing D. However, the vast majority of QKD implementations has been restricted to two dimensions. Here we demonstrate the feasibility of using higher dimensions for real-world quantum cryptography by performing, for the first time, a fully automated QKD session based on the BB84 protocol with 16-dimensional quantum states. Information is encoded in the single-photon transverse momentum and the required states are dynamically generated with programmable spatial light modulators. Our setup paves the way for future developments in the field of experimental high-dimensional QKD.

Quantum key distribution session with 16-dimensional photonic states

PubMed Central

Etcheverry, S.; Cañas, G.; Gómez, E. S.; Nogueira, W. A. T.; Saavedra, C.; Xavier, G. B.; Lima, G.

2013-01-01

The secure transfer of information is an important problem in modern telecommunications. Quantum key distribution (QKD) provides a solution to this problem by using individual quantum systems to generate correlated bits between remote parties, that can be used to extract a secret key. QKD with D-dimensional quantum channels provides security advantages that grow with increasing D. However, the vast majority of QKD implementations has been restricted to two dimensions. Here we demonstrate the feasibility of using higher dimensions for real-world quantum cryptography by performing, for the first time, a fully automated QKD session based on the BB84 protocol with 16-dimensional quantum states. Information is encoded in the single-photon transverse momentum and the required states are dynamically generated with programmable spatial light modulators. Our setup paves the way for future developments in the field of experimental high-dimensional QKD. PMID:23897033

Hydrogen Epoch of Reinozation Array (HERA) Calibrated FFT Correlator Simulation

NASA Astrophysics Data System (ADS)

Salazar, Jeffrey David; Parsons, Aaron

2018-01-01

The Hydrogen Epoch of Reionization Array (HERA) project is an astronomical radio interferometer array with a redundant baseline configuration. Interferometer arrays are being used widely in radio astronomy because they have a variety of advantages over single antenna systems. For example, they produce images (visibilities) closely matching that of a large antenna (such as the Arecibo observatory), while both the hardware and maintenance costs are significantly lower. However, this method has some complications; one being the computational cost of correlating data from all of the antennas. A correlator is an electronic device that cross-correlates the data between the individual antennas; these are what radio astronomers call visibilities. HERA, being in its early stages, utilizes a traditional correlator system. The correlator cost scales as N2, where N is the number of antennas in the array. The purpose of a redundant baseline configuration array setup is for the use of a more efficient Fast Fourier Transform (FFT) correlator. FFT correlators scale as Nlog2N. The data acquired from this sort of setup, however, inherits geometric delay and uncalibrated antenna gains. This particular project simulates the process of calibrating signals from astronomical sources. Each signal “received” by an antenna in the simulation is given random antenna gain and geometric delay. The “linsolve” Python module was used to solve for the unknown variables in the simulation (complex gains and delays), which then gave a value for the true visibilities. This first version of the simulation only mimics a one dimensional redundant telescope array detecting a small amount of sources located in the volume above the antenna plane. Future versions, using GPUs, will handle a two dimensional redundant array of telescopes detecting a large amount of sources in the volume above the array.

Intervention Strategies in Counselor Supervision.

ERIC Educational Resources Information Center

West, John; Sonstegard, Manford

This paper contains a model for practicum supervision developed by Dr. Manford Sonstegard. The procedure allows the supervisor, student-counselor, client, and practicum class to participate in the session. Whereas one-way mirrors, audio tapes and audio-visual tapes allow for only delayed feedback from the supervisor, Dr. Sonstegard's approach…

Effects of delays on 6-year-old children’s self-generation and retention of knowledge through integration

PubMed Central

Varga, Nicole L.; Bauer, Patricia J.

2013-01-01

The present research was an investigation of the effect of delay on self-generation and retention of knowledge derived through integration by 6-year-old children. Children were presented with novel facts from passages read aloud to them (stem facts) and tested for self-generation of new knowledge through integration of the facts. In Experiment 1, children integrated the stem facts at Session 1 and retained the self-generated memory traces over 1 week. In Experiment 2, 1-week delays were imposed either between the to-be-integrated facts (between-stem delay) or after the stem facts but before the test (before-test delay). Integration performance was diminished in both conditions. Moreover, memory for individual stem facts was lower in Experiment 2 than in Experiment 1, suggesting that self-generation through integration promoted memory for explicitly taught information. The results indicate the importance of tests for promoting self-generation through integration as well as for retaining newly self-generated and explicitly taught information. PMID:23563162

Security Enhancement Using Cache Based Reauthentication in WiMAX Based E-Learning System

PubMed Central

Rajagopal, Chithra; Bhuvaneshwaran, Kalaavathi

2015-01-01

WiMAX networks are the most suitable for E-Learning through their Broadcast and Multicast Services at rural areas. Authentication of users is carried out by AAA server in WiMAX. In E-Learning systems the users must be forced to perform reauthentication to overcome the session hijacking problem. The reauthentication of users introduces frequent delay in the data access which is crucial in delaying sensitive applications such as E-Learning. In order to perform fast reauthentication caching mechanism known as Key Caching Based Authentication scheme is introduced in this paper. Even though the cache mechanism requires extra storage to keep the user credentials, this type of mechanism reduces the 50% of the delay occurring during reauthentication. PMID:26351658

Security Enhancement Using Cache Based Reauthentication in WiMAX Based E-Learning System.

PubMed

Rajagopal, Chithra; Bhuvaneshwaran, Kalaavathi

2015-01-01

WiMAX networks are the most suitable for E-Learning through their Broadcast and Multicast Services at rural areas. Authentication of users is carried out by AAA server in WiMAX. In E-Learning systems the users must be forced to perform reauthentication to overcome the session hijacking problem. The reauthentication of users introduces frequent delay in the data access which is crucial in delaying sensitive applications such as E-Learning. In order to perform fast reauthentication caching mechanism known as Key Caching Based Authentication scheme is introduced in this paper. Even though the cache mechanism requires extra storage to keep the user credentials, this type of mechanism reduces the 50% of the delay occurring during reauthentication.

Troposphere Delay Raytracing Applied in VLBI Analysis

NASA Astrophysics Data System (ADS)

Eriksson, David; MacMillan, Daniel; Gipson, John

2014-12-01

Tropospheric delay modeling error is one of the largest sources of error in VLBI analysis. For standard operational solutions, we use the VMF1 elevation-dependent mapping functions derived from European Centre for Medium Range Forecasting (ECMWF) data. These mapping functions assume that tropospheric delay at a site is azimuthally symmetric. As this assumption does not reflect reality, we have instead determined the raytrace delay along the signal path through the three-dimensional troposphere refractivity field for each VLBI quasar observation. We calculated the troposphere refractivity fields from the pressure, temperature, specific humidity, and geopotential height fields of the NASA GSFC GEOS-5 numerical weather model. We discuss results using raytrace delay in the analysis of the CONT11 R&D sessions. When applied in VLBI analysis, baseline length repeatabilities were better for 70% of baselines with raytraced delays than with VMF1 mapping functions. Vertical repeatabilities were better for 2/3 of all stations. The reference frame scale bias error was 0.02 ppb for raytracing versus 0.08 ppb and 0.06 ppb for VMF1 and NMF, respectively.

Thermographic measurements of high-speed metal cutting

NASA Astrophysics Data System (ADS)

Mueller, Bernhard; Renz, Ulrich

2002-03-01

Thermographic measurements of a high-speed cutting process have been performed with an infrared camera. To realize images without motion blur the integration times were reduced to a few microseconds. Since the high tool wear influences the measured temperatures a set-up has been realized which enables small cutting lengths. Only single images have been recorded because the process is too fast to acquire a sequence of images even with the frame rate of the very fast infrared camera which has been used. To expose the camera when the rotating tool is in the middle of the camera image an experimental set-up with a light barrier and a digital delay generator with a time resolution of 1 ns has been realized. This enables a very exact triggering of the camera at the desired position of the tool in the image. Since the cutting depth is between 0.1 and 0.2 mm a high spatial resolution was also necessary which was obtained by a special close-up lens allowing a resolution of app. 45 microns. The experimental set-up will be described and infrared images and evaluated temperatures of a titanium alloy and a carbon steel will be presented for cutting speeds up to 42 m/s.

Pump-Flow-Probe X-Ray Absorption Spectroscopy as a Tool for Studying Intermediate States of Photocatalytic Systems.

PubMed

Smolentsev, Grigory; Guda, Alexander; Zhang, Xiaoyi; Haldrup, Kristoffer; Andreiadis, Eugen; Chavarot-Kerlidou, Murielle; Canton, Sophie E; Nachtegaal, Maarten; Artero, Vincent; Sundstrom, Villy

2013-08-29

A new setup for pump-flow-probe X-ray absorption spectroscopy has been implemented at the SuperXAS beamline of the Swiss Light Source. It allows recording X-ray absorption spectra with a time resolution of tens of microseconds and high detection efficiency for samples with sub-mM concentrations. A continuous wave laser is used for the photoexcitation, with the distance between laser and X-ray beams and velocity of liquid flow determining the time delay, while the focusing of both beams and the flow speed define the time resolution. This method is compared with the alternative measurement technique that utilizes a 1 kHz repetition rate laser and multiple X-ray probe pulses. Such an experiment was performed at beamline 11ID-D of the Advanced Photon Source. Advantages, limitations and potential for improvement of the pump-flow-probe setup are discussed by analyzing the photon statistics. Both methods, with Co K-edge probing were applied to the investigation of a cobaloxime-based photo-catalytic reaction. The interplay between optimizing for efficient photoexcitation and time resolution as well as the effect of sample degradation for these two setups are discussed.

Pump-Flow-Probe X-Ray Absorption Spectroscopy as a Tool for Studying Intermediate States of Photocatalytic Systems

PubMed Central

Smolentsev, Grigory; Guda, Alexander; Zhang, XIaoyi; Haldrup, Kristoffer; Andreiadis, Eugen; Chavarot-Kerlidou, Murielle; Canton, Sophie E.; Nachtegaal, Maarten; Artero, Vincent; Sundstrom, Villy

2014-01-01

A new setup for pump-flow-probe X-ray absorption spectroscopy has been implemented at the SuperXAS beamline of the Swiss Light Source. It allows recording X-ray absorption spectra with a time resolution of tens of microseconds and high detection efficiency for samples with sub-mM concentrations. A continuous wave laser is used for the photoexcitation, with the distance between laser and X-ray beams and velocity of liquid flow determining the time delay, while the focusing of both beams and the flow speed define the time resolution. This method is compared with the alternative measurement technique that utilizes a 1 kHz repetition rate laser and multiple X-ray probe pulses. Such an experiment was performed at beamline 11ID-D of the Advanced Photon Source. Advantages, limitations and potential for improvement of the pump-flow-probe setup are discussed by analyzing the photon statistics. Both methods, with Co K-edge probing were applied to the investigation of a cobaloxime-based photo-catalytic reaction. The interplay between optimizing for efficient photoexcitation and time resolution as well as the effect of sample degradation for these two setups are discussed. PMID:24443663

The first signs of prospective memory.

PubMed

Ślusarczyk, Elżbieta; Niedźwieńska, Agnieszka; Białecka-Pikul, Marta

2018-06-05

We conducted a study to examine the impact of motivation and length of delay on performance on prospective memory (PM) tasks in 2-year of children. A total of 158 children aged exactly 24 months were asked to perform a naturalistic PM task. Length of delay (10 min; 35 min) and motivation (high; very high) were between-subjects factors. Two thirds of children had to be excluded from the analysis because of poor retrospective memory for the PM task instructions which were no longer remembered at the end of the session. For the children who did remember the instructions, both motivation and delay had significant effects on PM. Also, their PM performance was reliably above zero, even after the long delay. The findings indicate that when children as young as 24 months are able to remember the PM task instructions they can reliably succeed in PM tasks that are intrinsically motivating for them.

IVS Pilot Project - Tropospheric Parameters

NASA Astrophysics Data System (ADS)

Boehm, J.; Schuh, H.; Engelhardt, G.; MacMillan, D.; Lanotte, R.; Tomasi, P.; Vereshchagina, I.; Haas, R.; Negusini, M.; Gubanov, V.

2003-04-01

In April 2002 the IVS (International VLBI Service for Geodesy and Astrometry) set up the IVS Pilot Project - Tropospheric Parameters and the Institute of Geodesy and Geophysics (IGG), Vienna, was asked to coordinate the project. After a call for participation six IVS Analysis Centers have joined the project and submitted their estimates of tropospheric parameters (wet and total zenith delays, horizontal gradients) for all IVS-R1 and IVS-R4 sessions since January 1st, 2002, on a regular basis. Using a two-step procedure the individual submissions are combined to stable and robust tropospheric parameters with 1h resolution and high accuracy. The zenith delays derived by VLBI are also compared with those provided by IGS (International GPS Service). At collocated sites (VLBI and GPS antennas at the same station) rather constant biases are found between the GPS and VLBI derived zenith delays, although both techniques are subject to the same tropospheric delays. Possible reasons for these biases are discussed.

Preschoolers can make highly accurate judgments of learning.

PubMed

Lipowski, Stacy L; Merriman, William E; Dunlosky, John

2013-08-01

Preschoolers' ability to make judgments of learning (JOLs) was examined in 3 experiments in which they were taught proper names for animals. In Experiment 1, when judgments were made immediately after studying, nearly every child predicted subsequent recall of every name. When judgments were made after a delay, fewer showed this response tendency. The delayed JOLs of those who predicted at least 1 recall failure were still overconfident, however, and were not correlated with final recall. In Experiment 2, children received a second study trial with feedback, made JOLs after a delay, and completed an additional forced-choice judgment task. In this task, an animal whose name had been recalled was pitted against an animal whose name had not been recalled, and the children chose the one they were more likely to remember later. Compared with Experiment 1, more children predicted at least 1 recall failure and predictions were moderately accurate. In the forced-choice task, animal names that had just been successfully recalled were typically chosen over ones that had not. Experiment 3 examined the effect of providing an additional retrieval attempt on delayed JOLs. Half of the children received a single study session, and half received an additional study session with feedback. Children in the practice group showed less overconfidence than those in the no-practice group. Taken together, the results suggest that, with minimal task experience, most preschoolers understand that they will not remember everything and that if they cannot recall something at present, they are unlikely to recall it in the future. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

Causal Modeling the Delayed-Choice Experiment

NASA Astrophysics Data System (ADS)

Chaves, Rafael; Lemos, Gabriela Barreto; Pienaar, Jacques

2018-05-01

Wave-particle duality has become one of the flagships of quantum mechanics. This counterintuitive concept is highlighted in a delayed-choice experiment, where the experimental setup that reveals either the particle or wave nature of a quantum system is decided after the system has entered the apparatus. Here we consider delayed-choice experiments from the perspective of device-independent causal models and show their equivalence to a prepare-and-measure scenario. Within this framework, we consider Wheeler's original proposal and its variant using a quantum control and show that a simple classical causal model is capable of reproducing the quantum mechanical predictions. Nonetheless, among other results, we show that, in a slight variant of Wheeler's gedanken experiment, a photon in an interferometer can indeed generate statistics incompatible with any nonretrocausal hidden variable model, whose dimensionality is the same as that of the quantum system it is supposed to mimic. Our proposal tolerates arbitrary losses and inefficiencies, making it specially suited to loophole-free experimental implementations.

Use of Psychotherapy by Rural and Urban Veterans

ERIC Educational Resources Information Center

Cully, Jeffrey A.; Jameson, John P.; Phillips, Laura L.; Kunik, Mark E.; Fortney, John C.

2010-01-01

Purpose: To examine whether differences exist between rural and urban veterans in terms of initiation of psychotherapy, delay in time from diagnosis to treatment, and dose of psychotherapy sessions. Methods: Using a longitudinal cohort of veterans obtained from national Veterans Affairs databases (October 2003 through September 2004), we extracted…

Eye Movement Desensitization and Reprocessing (EMDR) Treatment for Psychologically Traumatized Individuals.

ERIC Educational Resources Information Center

Wilson, Sandra A.; And Others

1995-01-01

Studies the effects of 3 90-minute Eye Movement Desensitization and Reprocessing (EMDR) treatment sessions on traumatic memories of 80 participants. Participants receiving EMDR showed decreases in complaints and anxiety, and increases in positive cognition. Participants in the delayed-treatment condition showed no improvement in any measures in…

An Efficient Power Saving Mechanism for Delay-Guaranteed Services in IEEE 802.16e

NASA Astrophysics Data System (ADS)

Park, Yunju; Hwang, Gang Uk

As the IEEE 802.16e Wireless Metropolitan Access Network (WMAN) supports the mobility of a mobile station (MS), increasing MS power efficiency has become an important issue. In this paper, we analyze the sleep-mode operation for an efficient power saving mechanism for delay-guaranteed services in the IEEE 802.16e WMAN and observe the effects of the operating parameters related to this operation. For the analysis we use the M/GI/1/K queueing system with multiple vacations, exhaustive services and setup times. In the analysis, we consider the power consumption during the wake-mode period as well as the sleep-mode period. As a performance measure for the power consumption, we propose the power consumption per unit time per effective arrival which considers the power consumption and the packet blocking probability simultaneously. In addition, since we consider delay-guaranteed services, the average packet response delay is also considered as a performance measure. Based on the performance measures, we obtain the optimal sleep-mode operation which minimizes the power consumption per unit time per effective arrival with a given delay requirement. Numerical studies are also provided to investigate the system performance and to show how to achieve our objective.

Effect of 24 sessions of high-intensity aerobic interval training carried out at either high or moderate frequency, a randomized trial.

PubMed

Hatle, Håvard; Støbakk, Per Kristian; Mølmen, Harald Edvard; Brønstad, Eivind; Tjønna, Arnt Erik; Steinshamn, Sigurd; Skogvoll, Eirik; Wisløff, Ulrik; Ingul, Charlotte Björk; Rognmo, Øivind

2014-01-01

The training response of an intensified period of high-intensity exercise is not clear. Therefore, we compared the cardiovascular adaptations of completing 24 high-intensity aerobic interval training sessions carried out for either three or eight weeks, respectively. Twenty-one healthy subjects (23.0±2.1 years, 10 females) completed 24 high-intensity training sessions throughout a time-period of either eight weeks (moderate frequency, MF) or three weeks (high frequency, HF) followed by a detraining period of nine weeks without any training. In both groups, maximal oxygen uptake (VO2max) was evaluated before training, at the 9(th) and 17(th) session and four days after the final 24(th) training session. In the detraining phase VO2max was evaluated after 12 days and thereafter every second week for eight weeks. Left ventricular echocardiography, carbon monoxide lung diffusion transfer factor, brachial artery flow mediated dilatation and vastus lateralis citrate maximal synthase activity was tested before and after training. The cardiovascular adaptation after HF training was delayed compared to training with MF. Four days after ending training the HF group showed no improvement (+3.0%, p = 0.126), whereas the MF group reached their highest VO2max with a 10.7% improvement (p<0.001: group difference p = 0.035). The HF group reached their highest VO2max (6.1% increase, p = 0.026) twelve days into the detraining period, compared to a concomitant reduction to 7.9% of VO2max (p<0.001) above baseline in the MF group (group difference p = 0.609). Both HF and MF training of high-intensity aerobic exercise improves VO2max. The cardiovascular adaptation following a HF programme of high-intensity exercise is however delayed compared to MF training. ClinicalTrials.gov NCT00733941.

IVS Working Group 2 for Product Specification and Observing Programs

NASA Astrophysics Data System (ADS)

Schuh, H.; Charlot, P.; Hase, H.; Himwich, E.; Kingham, K.; Klatt, C.; Ma, C.; Malkin, Z.; Niell, A.; Nothnagel, A.; Schluter, W.; Takashima, K.; Vandenberg, N.

2002-03-01

After the scientific rationale is given in the introduction the Terms of Reference and the proceeding of IVS Working Group 2 are presented. Then the present status and future goals of all international activities within IVS are described. In particular the current products of IVS are described in terms of accuracy, reliability, frequency of observing sessions, temporal resolution of the parameters estimated by VLBI data analysis, time delay from observing to product, i.e. time which has passed after the end of the last session included in the VLBI solution till availability of the final products and frequency of solution (in the case of "global solutions";, when all existing or a high number of VLBI sessions are used to determine so-called global parameters). All IVS products and their potential users are covered in the report. This includes the Earth orientation parameters (EOP), the reference frames (TRF and CRF), geodynamical and geophysical parameters and physical parameters. Measures which should be taken within IVS to meet the goals defined in the first steps are presented. As most of the measures are related to the observing programs, these are the main focus for improving the current status of IVS products. The report shows that due to various requirements of the different users of IVS products the following aspects must be accomplished: - significant improvement of the accuracy of VLBI products, - shorter time delay from observation to availability of results, - almost continuous temporal coverage by VLBI sessions. A first scenario of the IVS observing program for 2002 and 2003 considers an increase of observing time by about 30%-40% and includes sessions carried out by S2 and K4 technology. The midterm observing program for the next 4-5 years seems to be rather ambitious. However, it appears feasible if all efforts are concentrated and the necessary resources are made available. From: Bidzina Kapanadze (Ilia State Iniversity) Address: bidzina_kapanadze@iliauni.edu.ge Database: ast

Wave and setup dynamics on steeply-sloping reefs with large bottom roughness

NASA Astrophysics Data System (ADS)

Buckley, M. L.; Hansen, J.; Lowe, R.

2016-12-01

High-resolution observations from a wave flume were used to investigate the dynamics of wave setup over a steeply-sloping fringing reef profile with the effect of bottom roughness modeled using roughness elements scaled to mimic a coral reef. Results with roughness were compared with smooth bottom runs across sixteen offshore wave and still water level conditions. The time-averaged and depth-integrated force balance was evaluated from observations collected at seventeen locations across the flume, which was found to consist of cross-shore pressure and radiation stress gradients whose sum was balanced by mean quadratic bottom stresses. We found that when radiation stress gradients were calculated from observations of the radiation stress derived from linear wave theory, both wave setdown and setup were under predicted for the majority of wave and water level conditions tested. Inaccuracies in the predicted setdown and setup were improved by including a wave roller model, which provides a correction to the kinetic energy predicted by linear wave theory for breaking waves and produces a spatial delay in the wave forcing that was consistent with the observations. The introduction of roughness had two primary effects. First, the amount of wave energy dissipated during wave breaking was reduced due to frictional wave dissipation that occurred on the reef slope offshore of the breakpoint. Second, offshore directed mean bottom stresses were generated by the interaction of the combined wave-current velocity field with the roughness elements. These two mechanisms acted counter to one another. As a result, setup on the reef flat was comparable (7% mean difference) between corresponding rough and smooth runs. These findings are used to assess prior results from numerical modelling studies of reefs, and also to discuss the broader implications for how steep slopes and large roughness influences setup dynamics for general nearshore systems.

Isolating behavioral mechanisms of intertemporal choice: nicotine effects on delay discounting and amount sensitivity.

PubMed

Locey, Matthew L; Dallery, Jesse

2009-03-01

Many drugs of abuse produce changes in impulsive choice, that is, choice for a smaller-sooner reinforcer over a larger-later reinforcer. Because the alternatives differ in both delay and amount, it is not clear whether these drug effects are due to the differences in reinforcer delay or amount. To isolate the effects of delay, we used a titrating delay procedure. In phase 1, 9 rats made discrete choices between variable delays (1 or 19 s, equal probability of each) and a delay to a single food pellet. The computer titrated the delay to a single food pellet until the rats were indifferent between the two options. This indifference delay was used as the starting value for the titrating delay for all future sessions. We next evaluated the acute effects of nicotine (subcutaneous 1.0, 0.3, 0.1, and 0.03 mg/kg) on choice. If nicotine increases delay discounting, it should have increased preference for the variable delay. Instead, nicotine had very little effect on choice. In a second phase, the titrated delay alternative produced three food pellets instead of one, which was again produced by the variable delay (1 s or 19 s) alternative. Under this procedure, nicotine increased preference for the one pellet alternative. Nicotine-induced changes in impulsive choice are therefore likely due to differences in reinforcer amount rather than differences in reinforcer delay. In addition, it may be necessary to include an amount sensitivity parameter in any mathematical model of choice when the alternatives differ in reinforcer amount.

Gravitational effects from a series of IVS R&D VLBI-sessions with observations close to the Sun

NASA Astrophysics Data System (ADS)

Heinkelmann, R.; Soja, B.; Schuh, H.

2015-08-01

In 2011 and 2012 the IVS observed twelve VLBI research and development (R&D) sessions that include successful observations as angularly close as 3.9° from the heliocenter. Among others, one purpose of these IVS-R&D sessions was to achieve an improvement in the determination of the PPN parameter γ . Besides, by analyzing this specific set of IVS sessions, it was for the first time possible to measure the dispersive effect of the Solar corona with VLBI (Soja et al., 2014). In this work we assess the formal error of the γ-parameter and the contributions of the various terms to the partial derivative of the γ-parameter. Furthermore, we investigate the size of the gravitational delays caused by: (i) Solar monopole field at rest and with approximately linear translation, (ii) rotation of the Solar monopole field, (iii) Solar gravitational field quadrupole expansion, and (iv) Solar higher order term.

Patients' and therapists' experiences of general change mechanisms during bug-in-the-eye and delayed video-based supervised cognitive-behavioral therapy. A randomized controlled trial.

PubMed

Probst, Thomas; Jakob, Marion; Kaufmann, Yvonne M; Müller-Neng, Julia M B; Bohus, Martin; Weck, Florian

2018-04-01

This secondary analysis of a randomized controlled trial investigated whether bug-in-the-eye (BITE) supervision (live computer-based supervision during a psychotherapy session) affects the manner in which patients and therapists experience general change mechanisms (GCMs) during cognitive-behavioral therapy (CBT). A total of 23 therapists were randomized either to the BITE condition or the control condition (delayed video-based [DVB] supervision). After each session, both patients (BITE: n = 19; DVB: n = 23) and therapists (BITE: n = 11; DVB: n = 12) completed the Helping Alliance Questionnaire (HAQ) and the Bernese Post Session Report (BPSR). The HAQ total score and the 3 secondary factors of the BPSR (interpersonal experiences, intrapersonal experiences, problem actuation) functioned as GCMs. Multilevel models were performed. For patients, GCMs did not develop differently between BITE and DVB during CBT. Therapists rated the alliance as well as interpersonal and intrapersonal experiences not significantly different between BITE and DVB during CBT, but they perceived problem actuation to increase significantly more in BITE than in DVB (p < .05). BITE supervision might be helpful in encouraging CBT therapists to apply interventions, which focus on the activation of relevant problems and related emotions. © 2017 Wiley Periodicals, Inc.

Modulation of Posterior Alpha Activity by Spatial Attention Allows for Controlling A Continuous Brain-Computer Interface.

PubMed

Horschig, Jörn M; Oosterheert, Wouter; Oostenveld, Robert; Jensen, Ole

2015-11-01

Here we report that the modulation of alpha activity by covert attention can be used as a control signal in an online brain-computer interface, that it is reliable, and that it is robust. Subjects were instructed to orient covert visual attention to the left or right hemifield. We decoded the direction of attention from the magnetoencephalogram by a template matching classifier and provided the classification outcome to the subject in real-time using a novel graphical user interface. Training data for the templates were obtained from a Posner-cueing task conducted just before the BCI task. Eleven subjects participated in four sessions each. Eight of the subjects achieved classification rates significantly above chance level. Subjects were able to significantly increase their performance from the first to the second session. Individual patterns of posterior alpha power remained stable throughout the four sessions and did not change with increased performance. We conclude that posterior alpha power can successfully be used as a control signal in brain-computer interfaces. We also discuss several ideas for further improving the setup and propose future research based on solid hypotheses about behavioral consequences of modulating neuronal oscillations by brain computer interfacing.

Experimental verification of Pyragas-Schöll-Fiedler control.

PubMed

von Loewenich, Clemens; Benner, Hartmut; Just, Wolfram

2010-09-01

We present an experimental realization of time-delayed feedback control proposed by Schöll and Fiedler. The scheme enables us to stabilize torsion-free periodic orbits in autonomous systems, and to overcome the so-called odd number limitation. The experimental control performance is in quantitative agreement with the bifurcation analysis of simple model systems. The results uncover some general features of the control scheme which are deemed to be relevant for a large class of setups.

DISP: Optimizations towards Scalable MPI Startup

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

Fu, Huansong; Pophale, Swaroop S; Gorentla Venkata, Manjunath

2016-01-01

Despite the popularity of MPI for high performance computing, the startup of MPI programs faces a scalability challenge as both the execution time and memory consumption increase drastically at scale. We have examined this problem using the collective modules of Cheetah and Tuned in Open MPI as representative implementations. Previous improvements for collectives have focused on algorithmic advances and hardware off-load. In this paper, we examine the startup cost of the collective module within a communicator and explore various techniques to improve its efficiency and scalability. Accordingly, we have developed a new scalable startup scheme with three internal techniques, namelymore » Delayed Initialization, Module Sharing and Prediction-based Topology Setup (DISP). Our DISP scheme greatly benefits the collective initialization of the Cheetah module. At the same time, it helps boost the performance of non-collective initialization in the Tuned module. We evaluate the performance of our implementation on Titan supercomputer at ORNL with up to 4096 processes. The results show that our delayed initialization can speed up the startup of Tuned and Cheetah by an average of 32.0% and 29.2%, respectively, our module sharing can reduce the memory consumption of Tuned and Cheetah by up to 24.1% and 83.5%, respectively, and our prediction-based topology setup can speed up the startup of Cheetah by up to 80%.« less

Modeling and analysis of wet friction clutch engagement dynamics

NASA Astrophysics Data System (ADS)

Iqbal, Shoaib; Al-Bender, Farid; Ompusunggu, Agusmian P.; Pluymers, Bert; Desmet, Wim

2015-08-01

In recent years, there has been a significant increase in the usage of wet-friction clutches. Presently researchers across the globe are involved in improving the performance and lifetime of clutches through testing and simulation. To understand the clutch vibrational and dynamical behavior, an SAE#2 test setup mathematical model based on extended reset-integrator friction model is developed in this paper. In order to take into account the different phases of fluid lubrication during engagement cycle, the model includes the experimentally determined Stribeck function. In addition the model considers the viscous effect and the delay in the actuation pressure signal. The model is validated with the experiments performed on the SAE#2 test setup in both time and frequency domains. By analyzing the set of experimental results, we confirmed that the amplitude of shudder vibration is independent of the amplitude of applied contact pressure fluctuation.

The new ClusterTrap setup

NASA Astrophysics Data System (ADS)

Martinez, F.; Marx, G.; Schweikhard, L.; Vass, A.; Ziegler, F.

2011-07-01

ClusterTrap has been designed to investigate properties of atomic clusters in the gas phase with particular emphasis on the dependence on the cluster size and charge state. The combination of cluster source, Penning trap and time-of-flight mass spectrometry allows a variety of experimental schemes including collision-induced dissociation, photo-dissociation, further ionization by electron impact, and electron attachment. Due to the storage capability of the trap extended-delay reaction experiments can be performed. Several recent modifications have resulted in an improved setup. In particular, an electrostatic quadrupole deflector allows the coupling of several sources or detectors to the Penning trap. Furthermore, a linear radio-frequency quadrupole trap has been added for accumulation and ion bunching and by switching the potential of a drift tube the kinetic energy of the cluster ions can be adjusted on their way towards or from the Penning trap. Recently, experiments on multiply negatively charged clusters have been resumed.

Study on coal char ignition by radiant heat flux.

NASA Astrophysics Data System (ADS)

Korotkikh, A. G.; Slyusarskiy, K. V.

2017-11-01

The study on coal char ignition by CO2-continuous laser was carried out. The coal char samples of T-grade bituminous coal and 2B-grade lignite were studied via CO2-laser ignition setup. Ignition delay times were determined at ambient condition in heat flux density range 90-200 W/cm2. The average ignition delay time value for lignite samples were 2 times lower while this difference is larger in high heat flux region and lower in low heat flux region. The kinetic constants for overall oxidation reaction were determined using analytic solution of simplified one-dimensional heat transfer equation with radiant heat transfer boundary condition. The activation energy for lignite char was found to be less than it is for bituminous coal char by approximately 20 %.

Lateral velocity estimation bias due to beamforming delay errors (Conference Presentation)

NASA Astrophysics Data System (ADS)

Rodriguez-Molares, Alfonso; Fadnes, Solveig; Swillens, Abigail; Løvstakken, Lasse

2017-03-01

An artefact has recently been reported [1,2] in the estimation of the lateral blood velocity using speckle tracking. This artefact shows as a net velocity bias in presence of strong spatial velocity gradients such as those that occur at the edges of the filling jets in the heart. Even though this artifact has been found both in vitro and in simulated data, its causes are still undescribed. Here we demonstrate that a potential source of this artefact can be traced to smaller errors in the beamforming setup. By inserting a small offset in the beamforming delay, one can artificially create a net lateral movement in the speckle in areas of high velocity gradient. That offset does not have a strong impact in the image quality and can easily go undetected.

Comparison Campaign of VLBI Data Analysis Software - First Results

NASA Technical Reports Server (NTRS)

Plank, Lucia; Bohm, Johannes; Schuh, Harald

2010-01-01

During the development of the Vienna VLBI Software VieVS at the Institute of Geodesy and Geophysics at Vienna University of Technology, a special comparison setup was developed with the goal of easily finding links between deviations of results achieved with different software packages and certain parameters of the observation. The object of comparison is the computed time delay, a value calculated for each observation including all relevant models and corrections that need to be applied in geodetic VLBI analysis. Besides investigating the effects of the various models on the total delay, results of comparisons between VieVS and Occam 6.1 are shown. Using the same methods, a Comparison Campaign of VLBI data analysis software called DeDeCC is about to be launched within the IVS soon.

Tissue characterization with ballistic photons: counting scattering and/or absorption centres

NASA Astrophysics Data System (ADS)

Corral, F.; Strojnik, M.; Paez, G.

2015-03-01

We describe a new method to separate ballistic from the scattered photons for optical tissue characterization. It is based on the hypothesis that the scattered photons acquire a phase delay. The photons passing through the sample without scattering or absorption preserve their coherence so they may participate in interference. We implement a Mach-Zehnder experimental setup where the ballistic photons pass through the sample with the delay caused uniquely by the sample indices of refraction. We incorporate a movable mirror on the piezoelectric actuator in the sample arm to detect the amplitude of the modulation term. We present the theory that predicts the path-integrated (or total) concentration of the scattering and absorption centres. The proposed technique may characterize samples with transmission attenuation of ballistic photons by a factor of 10-14.

Incidental rewarding cues influence economic decisions in people with obesity.

PubMed

Simmank, Jakob; Murawski, Carsten; Bode, Stefan; Horstmann, Annette

2015-01-01

Recent research suggests that obesity is linked to prominent alterations in learning and decision-making. This general difference may also underlie the preference for immediately consumable, highly palatable but unhealthy and high-calorie foods. Such poor food-related inter-temporal decision-making can explain weight gain; however, it is not yet clear whether this deficit can be generalized to other domains of inter-temporal decision-making, for example financial decisions. Further, little is known about the stability of decision-making behavior in obesity, especially in the presence of rewarding cues. To answer these questions, obese and lean participants (n = 52) completed two sessions of a novel priming paradigm including a computerized monetary delay discounting task. In the first session, general differences between groups in financial delay discounting were measured. In the second session, we tested the general stability of discount rates. Additionally, participants were primed by affective visual cues of different contextual categories before making financial decisions. We found that the obese group showed stronger discounting of future monetary rewards than the lean group, but groups did not differ in their general stability between sessions nor in their sensitivity toward changes in reward magnitude. In the obese group, a fast decrease of subjective value over time was directly related to a higher tendency for opportunistic eating. Obese in contrast to lean people were primed by the affective cues, showing a sex-specific pattern of priming direction. Our findings demonstrate that environments rich of cues, aiming at inducing unhealthy consumer decisions, can be highly detrimental for obese people. It also underscores that obesity is not merely a medical condition but has a strong cognitive component, meaning that current dietary and medical treatment strategies may fall too short.

Incidental rewarding cues influence economic decisions in people with obesity

PubMed Central

Simmank, Jakob; Murawski, Carsten; Bode, Stefan; Horstmann, Annette

2015-01-01

Recent research suggests that obesity is linked to prominent alterations in learning and decision-making. This general difference may also underlie the preference for immediately consumable, highly palatable but unhealthy and high-calorie foods. Such poor food-related inter-temporal decision-making can explain weight gain; however, it is not yet clear whether this deficit can be generalized to other domains of inter-temporal decision-making, for example financial decisions. Further, little is known about the stability of decision-making behavior in obesity, especially in the presence of rewarding cues. To answer these questions, obese and lean participants (n = 52) completed two sessions of a novel priming paradigm including a computerized monetary delay discounting task. In the first session, general differences between groups in financial delay discounting were measured. In the second session, we tested the general stability of discount rates. Additionally, participants were primed by affective visual cues of different contextual categories before making financial decisions. We found that the obese group showed stronger discounting of future monetary rewards than the lean group, but groups did not differ in their general stability between sessions nor in their sensitivity toward changes in reward magnitude. In the obese group, a fast decrease of subjective value over time was directly related to a higher tendency for opportunistic eating. Obese in contrast to lean people were primed by the affective cues, showing a sex-specific pattern of priming direction. Our findings demonstrate that environments rich of cues, aiming at inducing unhealthy consumer decisions, can be highly detrimental for obese people. It also underscores that obesity is not merely a medical condition but has a strong cognitive component, meaning that current dietary and medical treatment strategies may fall too short. PMID:26528158

Sub-nanosecond time-resolved ambient-pressure X-ray photoelectron spectroscopy setup for pulsed and constant wave X-ray light sources

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

Shavorskiy, Andrey; Slaughter, Daniel S.; Zegkinoglou, Ioannis

2014-09-15

An apparatus for sub-nanosecond time-resolved ambient-pressure X-ray photoelectron spectroscopy studies with pulsed and constant wave X-ray light sources is presented. A differentially pumped hemispherical electron analyzer is equipped with a delay-line detector that simultaneously records the position and arrival time of every single electron at the exit aperture of the hemisphere with ∼0.1 mm spatial resolution and ∼150 ps temporal accuracy. The kinetic energies of the photoelectrons are encoded in the hit positions along the dispersive axis of the two-dimensional detector. Pump-probe time-delays are provided by the electron arrival times relative to the pump pulse timing. An average time-resolution ofmore » (780 ± 20) ps (FWHM) is demonstrated for a hemisphere pass energy E{sub p} = 150 eV and an electron kinetic energy range KE = 503–508 eV. The time-resolution of the setup is limited by the electron time-of-flight (TOF) spread related to the electron trajectory distribution within the analyzer hemisphere and within the electrostatic lens system that images the interaction volume onto the hemisphere entrance slit. The TOF spread for electrons with KE = 430 eV varies between ∼9 ns at a pass energy of 50 eV and ∼1 ns at pass energies between 200 eV and 400 eV. The correlation between the retarding ratio and the TOF spread is evaluated by means of both analytical descriptions of the electron trajectories within the analyzer hemisphere and computer simulations of the entire trajectories including the electrostatic lens system. In agreement with previous studies, we find that the by far dominant contribution to the TOF spread is acquired within the hemisphere. However, both experiment and computer simulations show that the lens system indirectly affects the time resolution of the setup to a significant extent by inducing a strong dependence of the angular spread of electron trajectories entering the hemisphere on the retarding ratio. The scaling of the angular spread with the retarding ratio can be well approximated by applying Liouville's theorem of constant emittance to the electron trajectories inside the lens system. The performance of the setup is demonstrated by characterizing the laser fluence-dependent transient surface photovoltage response of a laser-excited Si(100) sample.« less

Rational-Emotive, Self-Instructional, and Behavioral Assertion Training: Enhancing the Generalization and Maintenance of Treatment Gains.

ERIC Educational Resources Information Center

Carmody, Timothy P.

A sample of 63 subassertive adults participated in four 90-minute sessions of group assertion training. The treatment components of challenging maladaptive cognitions and learning self-instructions were examined by comparing Rational-Emotive, Self-Instructional, and Behavioral Assertion Training. A delayed-treatment control group was also…

Double Dissociation of Pharmacologically Induced Deficits in Visual Recognition and Visual Discrimination Learning

ERIC Educational Resources Information Center

Turchi, Janita; Buffalari, Deanne; Mishkin, Mortimer

2008-01-01

Monkeys trained in either one-trial recognition at 8- to 10-min delays or multi-trial discrimination habits with 24-h intertrial intervals received systemic cholinergic and dopaminergic antagonists, scopolamine and haloperidol, respectively, in separate sessions. Recognition memory was impaired markedly by scopolamine but not at all by…

The Building of Multimedia Communications Network based on Session Initiation Protocol

NASA Astrophysics Data System (ADS)

Yuexiao, Han; Yanfu, Zhang

In this paper, we presented a novel design for a distributed multimedia communications network. We introduced the distributed tactic, flow procedure and particular structure. We also analyzed its scalability, stability, robustness, extension, and transmission delay of this architecture. Finally, the result shows our framework is suitable for very large scale communications.

The role of dopamine in the timing of Pavlovian conditioned keypecking in ring doves.

PubMed

Ohyama, T; Horvitz, J C; Kitsos, E; Balsam, P D

2001-01-01

The effect of dopaminergic drugs on the timing of conditioned keypecking in ring doves was studied in two experiments. Subjects were given pairings of a keylight with food and the temporal distribution of keypecks was obtained during unreinforced probe trials. Experiment 1 demonstrated that injections of pimozide before each session immediately decreased response rates but shifted timing distributions gradually to the right over several days of treatment. Experiment 2 showed similar results using a longer interstimulus interval (ISI). No shifts were observed when the drug was injected after training sessions, or when a delay, identical to each subject's average latency to eat during the drug condition, was inserted between keylight offset and food presentation. Consequently, the shifts in timing were mediated neither by mere accumulation of the drug nor a delay from keylight offset to food presentation resulting from the drug's ability to slow motor processes. The results suggest that pimozide modulates response rate through its effect on motor processes or incentive value, and response timing through a conditioned response (CR) to injection-related cues established via their repeated pairings with the drug.

Case Study: Review of Operating Room Utilization at Mayo Clinic Arizona (MCA)

DTIC Science & Technology

2008-05-01

or CRNA in training. The training of staff and the use of advanced technology, such as the Davinci Surgical Robot, may lead to an increase in time...gynecology performed during block-time will involve the use of the Davinci robot. When using the robot for a case, the set-up and prep-time before...1999). It is because of the cost of surgical staff that block-time lost to delays is concerning. MCA implemented block-time because it provides a tool

Time-ordering dependence of measurements in teleportation

NASA Astrophysics Data System (ADS)

Bertlmann, Reinhold A.; Narnhofer, Heide; Thirring, Walter

2013-03-01

We trace back the phenomenon of "delayed-choice entanglement swapping" as it was realized in a recent experiment to the commutativity of the projection operators that are involved in the corresponding measurement process. We also propose an experimental set-up which depends on the order of successive measurements corresponding to noncommutative projection operators. In this case entanglement swapping is used to teleport a quantum state from Alice to Bob, where Bob has now the possibility to examine the noncommutativity within the quantum history.

Signal Delay-Stability of a Ku-Band Two-Way Satellite Time Transfer Terminal

DTIC Science & Technology

1995-12-01

Robnik Space Research Institute, Graz, Austria Abstract A filly automated huo-way time and frequency transfer ( TWSTFT ) system including a sateme...station. Such a system has been operated for longer than a year together with the two-way satellite time and frequency transfer ( TWSTFT ) station of...accuracy. MEASUREMENT SETUP A detailed description of the TWSTFT system used at TUG is given in [I]. The SATSIM used is of the de Jong type13,41 - this

Outcomes of Fat-Augmented Latissimus Dorsi (FALD) Flap Versus Implant-Based Latissimus Dorsi Flap for Delayed Post-radiation Breast Reconstruction.

PubMed

Demiri, Efterpi C; Dionyssiou, Dimitrios D; Tsimponis, Antonios; Goula, Christina-Olga; Pavlidis, Leonidas C; Spyropoulou, Georgia-Alexandra

2018-06-01

Although free abdominal flaps constitute the gold standard in post-radiation delayed breast reconstruction, latissimus dorsi-based methods offer alternative reconstructive options. This retrospective study aims to compare outcomes of delayed breast reconstruction using the fat-augmented latissimus dorsi (FALD) autologous reconstruction and the latissimus dorsi-plus-implant reconstruction in irradiated women. We reviewed the files of 47 post-mastectomy irradiated patients (aged 29-73 years), who underwent delayed latissimus dorsi-based breast reconstruction between 2010 and 2016. Twenty-three patients (Group A) had an extended FALD flap and twenty-four patients (Group B) an implant-based latissimus dorsi reconstruction. Patients' age, BMI, pregnancies, volume of injected fat, implant size, postoperative complications, and secondary surgical procedures were recorded and analyzed. Age, BMI, pregnancies, and donor-site complications were similar in both groups (p > 0.05). Mean fat volume injected initially was 254 cc (ranged 130-380 cc/session); mean implant volume was 323 cc (ranged 225-420 cc). Breast complications were significantly fewer in Group A (one wound dehiscence, two oily cysts) compared to Group B (three cases with wound dehiscence, two extrusions, thirteen severe capsular contractions). Non-statistically significant difference was documented for secondary procedures between groups; although the mean number of additional surgeries/patient was higher in Group A, they referred to secondary lipofilling, whereas in Group B they were revision surgeries for complications. The FALD flap constitutes an alternative method for delayed autologous reconstruction after post-mastectomy irradiation, avoiding implant-related complications. Although additional fat graft sessions might be required, it provides an ideal autogenous reconstructive option for thin nulliparous women, with a small opposite breast and adequate fat donor sites. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Hazard perception skills of young drivers with Attention Deficit Hyperactivity Disorder (ADHD) can be improved with computer based driver training: An exploratory randomised controlled trial.

PubMed

Bruce, C R; Unsworth, C A; Dillon, M P; Tay, R; Falkmer, T; Bird, P; Carey, L M

2017-12-01

Young drivers with Attention Deficit Hyperactivity Disorder (ADHD) are at higher risk of road traffic injuries than their peers. Increased risk correlates with poor hazard perception skill. Few studies have investigated hazard perception training using computer technology with this group of drivers. *Determine the presence and magnitude of the between-group and within- subject change in hazard perception skills in young drivers with ADHD who receive Drive Smart training. *Determine whether training-facilitated change in hazard perception is maintained over time. This was a feasibility study, randomised control trial conducted in Australia. The design included a delayed treatment for the control group. Twenty-five drivers with a diagnosis of ADHD were randomised to the Immediate Intervention or Delayed Intervention group.The Immediate Intervention group received a training session using a computer application entitled Drive Smart. The Delayed Intervention group watched a documentary video initially (control condition), followed by the Drive Smart computer training session. The participant's hazard perception skill was measured using the Hazard Perception Test (HPT). After adjusting for baseline scores, there was a significant betweengroup difference in post-intervention HPT change scores in favour of the Immediate Intervention group. The magnitude of the effect was large. There was no significant within-group delayed intervention effect. A significant maintenance effect was found at 6-week follow-up for the Immediate Intervention group. The hazard perception skills of participants improved following training with large effect size and some maintenance of gain. A multimodal approach to training is indicated to facilitate maintenance. A full-scale trial is feasible. Copyright © 2017 Elsevier Ltd. All rights reserved.

Suggestibility, social support, and memory for a novel experience in young children.

PubMed

Quas, Jodi A; Wallin, Allison R; Papini, Silvia; Lench, Heather; Scullin, Matthew H

2005-08-01

This study examined 5- and 6-year-olds' suggestibility and interviewer demeanor as joint predictors of their memory for a novel experience. Session 1 consisted of children taking part in a novel laboratory event. Session 2 took place after approximately a 1-week delay and consisted of children completing both a memory test concerning what happened during the prior event and the Video Suggestibility Scale for Children (VSSC). During the second session, the interviewer behaved either supportively or nonsupportively. Greater acquiescence on the VSSC was associated with fewer correct responses to misleading questions about the laboratory event in the supportive and nonsupportive conditions and with more errors in response to specific questions in the nonsupportive condition. Results indicate that individual differences in children's suggestibility are related to the accuracy of their memory for separate events, although some of these relations may vary depending on the context in which children are interviewed.

Suggestibility, social support, and memory for a novel experience in young children

PubMed Central

Quas, Jodi A.; Wallin, Allison R.; Papini, Silvia; Lench, Heather; Scullin, Matthew H.

2010-01-01

This study examined 5- and 6-year-olds' suggestibility and interviewer demeanor as joint predictors of their memory for a novel experience. Session 1 consisted of children taking part in a novel laboratory event. Session 2 took place after approximately a 1-week delay and consisted of children completing both a memory test concerning what happened during the prior event and the Video Suggestibility Scale for Children (VSSC). During the second session, the interviewer behaved either supportively or nonsupportively. Greater acquiescence on the VSSC was associated with fewer correct responses to misleading questions about the laboratory event in the supportive and nonsupportive conditions and with more errors in response to specific questions in the nonsupportive condition. Results indicate that individual differences in children's suggestibility are related to the accuracy of their memory for separate events, although some of these relations may vary depending on the context in which children are interviewed. PMID:15904929

Infant Long-Term Memory for Associations Formed during Mere Exposure

PubMed Central

Giles, Amy; Rovee-Collier, Carolyn

2011-01-01

We previously found that young infants spontaneously associate stimuli that they merely see together. Using a sensory preconditioning paradigm with 6- and 9-month-olds, we asked how long such associations remain latent before being forgotten and what exposure conditions affect their persistence. Groups were preexposed to two puppets for 1 hr/day for 2 days, 1 hr on 1 day, or 1 hr on 1 day in two sessions; 1 to 27 days later, target actions were modeled on one puppet, and infants were tested with the other puppet 1 day later. The longest delay after which infants imitated the actions on the other puppet defined how long they remembered the association. The data revealed that the preexposure regimen determined retention. Regardless of exposure time, both ages remembered the association longer after two sessions, and younger infants remembered longer than older infants--for 4 weeks--after two 30-min sessions on 1 day. PMID:21474187

Choice in situations of time-based diminishing returns: immediate versus delayed consequences of action.

PubMed Central

Hackenberg, T D; Hineline, P N

1992-01-01

Pigeons chose between two schedules of food presentation, a fixed-interval schedule and a progressive-interval schedule that began at 0 s and increased by 20 s with each food delivery provided by that schedule. Choosing one schedule disabled the alternate schedule and stimuli until the requirements of the chosen schedule were satisfied, at which point both schedules were again made available. Fixed-interval duration remained constant within individual sessions but varied across conditions. Under reset conditions, completing the fixed-interval schedule not only produced food but also reset the progressive interval to its minimum. Blocks of sessions under the reset procedure were interspersed with sessions under a no-reset procedure, in which the progressive schedule value increased independent of fixed-interval choices. Median points of switching from the progressive to the fixed schedule varied systematically with fixed-interval value, and were consistently lower during reset than during no-reset conditions. Under the latter, each subject's choices of the progressive-interval schedule persisted beyond the point at which its requirements equaled those of the fixed-interval schedule at all but the highest fixed-interval value. Under the reset procedure, switching occurred at or prior to that equality point. These results qualitatively confirm molar analyses of schedule preference and some versions of optimality theory, but they are more adequately characterized by a model of schedule preference based on the cumulated values of multiple reinforcers, weighted in inverse proportion to the delay between the choice and each successive reinforcer. PMID:1548449

Patients' adherence to aspects of haemodialysis regimens in tropical north Queensland, Australia.

PubMed

Smyth, Wendy; Hartig, Vicki; Hayes, Megan; Manickam, Valli

2015-06-01

Patients with end-stage kidney disease often have difficulty in adhering to aspects of their haemodialysis regimens. This study aimed to quantify the number of patients who attended 100% of their scheduled haemodialysis sessions, and the number of patients who gained no more than one kilogram per day between dialysis sessions, over a three-month period. Retrospective chart audit Patients undergoing haemodialysis at an in-hospital centre in tropical Australia. A renal nurse audited the 72 charts pertaining to a 12-week period in 2013. Patients attended 90.1% of all scheduled dialysis sessions. Forty-one patients attended all sessions, with the remaining 31 missing at least one scheduled session. One patient missed 16 scheduled sessions. The following were statistically less likely to attend all their scheduled sessions: Aboriginal and Torres Strait Islander patients; patients on a three times per week dialysis schedule; patients who had relocated from rural or regional towns and younger patients. The average daily weight gain ranged from 0.414 kg to 1.017 kg (mean = 0.885 kg). Younger patients were statistically less likely to adhere to fluid restrictions; patients without diabetes were more likely to adhere to the fluid allowances. Renal services need to assist patients to adhere to their regimens. Initially, this service will examine strategies to maximise the likelihood of patients attending all of their dialysis sessions. Such an outcome will help to delay deterioration in the patients' health status, while minimising additional strain on the health service. © 2015 European Dialysis and Transplant Nurses Association/European Renal Care Association.

Manualized therapy for PTSD: flexing the structure of cognitive processing therapy.

PubMed

Galovski, Tara E; Blain, Leah M; Mott, Juliette M; Elwood, Lisa; Houle, Timothy

2012-12-01

This study tested a modified cognitive processing therapy (MCPT) intervention designed as a more flexible administration of the protocol. Number of sessions was determined by client progress toward a priori defined end-state criteria, "stressor sessions" were inserted when necessary, and therapy was conducted by novice CPT clinicians. A randomized, controlled, repeated measures, semicrossover design was utilized (a) to test the relative efficacy of the MCPT intervention compared with a symptom-monitoring delayed treatment (SMDT) condition and (b) to assess within-group variation in change with a sample of 100 male and female interpersonal trauma survivors with posttraumatic stress disorder (PTSD). Hierarchical linear modeling analyses revealed that MCPT evidenced greater improvement on all primary (PTSD and depression) and secondary (guilt, quality of life, general mental health, social functioning, and health perceptions) outcomes compared with SMDT. After the conclusion of SMDT, participants crossed over to MCPT, resulting in a combined MCPT sample (n = 69). Of the 50 participants who completed MCPT, 58% reached end-state criteria prior to the 12th session, 8% at Session 12, and 34% between Sessions 12 and 18. Maintenance of treatment gains was found at the 3-month follow-up, with only 2 of the treated sample meeting criteria for PTSD. Use of stressor sessions did not result in poorer treatment outcomes. Findings suggest that individuals respond at a variable rate to CPT, with significant benefit from additional therapy when indicated and excellent maintenance of gains. Insertion of stressor sessions did not alter the efficacy of the therapy.

Facilitation of extinction of operant behaviour in C57Bl/6 mice by chlordiazepoxide and D-cycloserine.

PubMed

Leslie, Julian C; Norwood, Kelly; Kennedy, Paul J; Begley, Michael; Shaw, David

2012-09-01

Effects on the extinction of GABAergic drug, chlordiazepoxide (CDP), and glutamatergic drug, D: -cycloserine (DCS), in C57BL/6 mice were compared. Following a palatability test (Experiment 1), Experiments 2-6 involved food-reinforced lever press training followed by extinction sessions at 1- or 4-day intervals. The effects of drugs were examined. Experiment 7 involved a two-lever task. CDP did not affect food palatability (Experiment 1), but facilitated extinction when administered prior to extinction sessions via intracerebral (Experiment 2) or peripheral administration at 1-day (Experiments 3-7) or 4-day intervals (Experiment 6). Reducing the amount of training prior to extinction reduced the delay in the effect of CDP typically seen, and CDP had a larger effect in early sessions on mice that had received less training (Experiment 3). There was some evidence that CDP could be blocked by flumazenil (Experiment 4), and CDP withdrawal reversed extinction facilitation (Experiments 5 and 7). With 4-day intervals, DCS administered immediately following extinction sessions, or pre-session CDP, facilitated extinction with 48-trial sessions (experiment 6B). With six-trial sessions, the co-administration of post-session DCS enhanced facilitation produced by pre-session CDP (experiment 6A). Finally, CDP facilitated extinction in a dose-related fashion following training on a two-lever food-reinforced task (Experiment 7). The findings are consistent with the hypotheses that two neurotransmitter systems have different roles in operant extinction and that glutamatergic systems are involved in extinction learning and GABAergic systems involved in the expression of that learning. This parallels findings with extinction following Pavlovian conditioning, which has been more extensively investigated.

Toward Automated Cochlear Implant Fitting Procedures Based on Event-Related Potentials.

PubMed

Finke, Mareike; Billinger, Martin; Büchner, Andreas

Cochlear implants (CIs) restore hearing to the profoundly deaf by direct electrical stimulation of the auditory nerve. To provide an optimal electrical stimulation pattern the CI must be individually fitted to each CI user. To date, CI fitting is primarily based on subjective feedback from the user. However, not all CI users are able to provide such feedback, for example, small children. This study explores the possibility of using the electroencephalogram (EEG) to objectively determine if CI users are able to hear differences in tones presented to them, which has potential applications in CI fitting or closed loop systems. Deviant and standard stimuli were presented to 12 CI users in an active auditory oddball paradigm. The EEG was recorded in two sessions and classification of the EEG data was performed with shrinkage linear discriminant analysis. Also, the impact of CI artifact removal on classification performance and the possibility to reuse a trained classifier in future sessions were evaluated. Overall, classification performance was above chance level for all participants although performance varied considerably between participants. Also, artifacts were successfully removed from the EEG without impairing classification performance. Finally, reuse of the classifier causes only a small loss in classification performance. Our data provide first evidence that EEG can be automatically classified on single-trial basis in CI users. Despite the slightly poorer classification performance over sessions, classifier and CI artifact correction appear stable over successive sessions. Thus, classifier and artifact correction weights can be reused without repeating the set-up procedure in every session, which makes the technique easier applicable. With our present data, we can show successful classification of event-related cortical potential patterns in CI users. In the future, this has the potential to objectify and automate parts of CI fitting procedures.

Comparing Recalibration Strategies for Electroencephalography-Based Decoders of Movement Intention in Neurological Patients with Motor Disability.

PubMed

López-Larraz, Eduardo; Ibáñez, Jaime; Trincado-Alonso, Fernando; Monge-Pereira, Esther; Pons, José Luis; Montesano, Luis

2017-12-17

Motor rehabilitation based on the association of electroencephalographic (EEG) activity and proprioceptive feedback has been demonstrated as a feasible therapy for patients with paralysis. To promote long-lasting motor recovery, these interventions have to be carried out across several weeks or even months. The success of these therapies partly relies on the performance of the system decoding movement intentions, which normally has to be recalibrated to deal with the nonstationarities of the cortical activity. Minimizing the recalibration times is important to reduce the setup preparation and maximize the effective therapy time. To date, a systematic analysis of the effect of recalibration strategies in EEG-driven interfaces for motor rehabilitation has not yet been performed. Data from patients with stroke (4 patients, 8 sessions) and spinal cord injury (SCI) (4 patients, 5 sessions) undergoing two different paradigms (self-paced and cue-guided, respectively) are used to study the performance of the EEG-based classification of motor intentions. Four calibration schemes are compared, considering different combinations of training datasets from previous and/or the validated session. The results show significant differences in classifier performances in terms of the true and false positives (TPs) and (FPs). Combining training data from previous sessions with data from the validation session provides the best compromise between the amount of data needed for calibration and the classifier performance. With this scheme, the average true (false) positive rates obtained are 85.3% (17.3%) and 72.9% (30.3%) for the self-paced and the cue-guided protocols, respectively. These results suggest that the use of optimal recalibration schemes for EEG-based classifiers of motor intentions leads to enhanced performances of these technologies, while not requiring long calibration phases prior to starting the intervention.

Preschoolers' Person Description and Identification Accuracy: A Comparison of the Simultaneous and Elimination Lineup Procedures

ERIC Educational Resources Information Center

Pozzulo, Joanna D.; Dempsey, Julie; Crescini, Charmagne

2009-01-01

Preschoolers' (3- to 6-year-olds) person description and identification abilities were examined using the simultaneous and elimination lineup procedures. Participants (N = 100) were exposed to a 20-minute mask-making session conducted by a female confederate who acted as the mask-making teacher. After a brief delay (20 min), participants were…

Delayed Stimulus-Specific Improvements in Discourse Following Anomia Treatment Using an Intentional Gesture

ERIC Educational Resources Information Center

Altmann, Lori J. P.; Hazamy, Audrey A.; Carvajal, Pamela J.; Benjamin, Michelle; Rosenbek, John C.; Crosson, Bruce

2014-01-01

Purpose: In this study, the authors assessed how the addition of intentional left-hand gestures to an intensive treatment for anomia affects 2 types of discourse: picture description and responses to open-ended questions. Method: Fourteen people with aphasia completed treatment for anomia comprising 30 treatment sessions over 3 weeks. Seven…

Reducing CO2 and other emissions from shipping : fourth report of session 2008-09 : report, together with formal minutes, oral and written evidence

DOT National Transportation Integrated Search

2009-06-01

The emission of greenhouse gases from shipping is a serious problem for international climate change policy. They are growing and there is a risk of considerable delay before they are brought under control. The advent of carbon budgets means it is no...

Cognitive-Behavioral Treatment for Specific Phobias with a Child Demonstrating Severe Problem Behavior and Developmental Delays

ERIC Educational Resources Information Center

Davis, Thompson E., III; Kurtz, Patricia F.; Gardner, Andrew W.; Carman, Nicole B.

2007-01-01

Cognitive-behavioral treatments (CBTs) are widely used for anxiety disorders in typically developing children; however, there has been no previous attempt to administer CBT for specific phobia (in this case study, one-session treatment) to developmentally or intellectually disabled children. This case study integrates both cognitive-behavioral and…

Synchronization of coupled metronomes on two layers

NASA Astrophysics Data System (ADS)

Zhang, Jing; Yu, Yi-Zhen; Wang, Xin-Gang

2017-12-01

Coupled metronomes serve as a paradigmatic model for exploring the collective behaviors of complex dynamical systems, as well as a classical setup for classroom demonstrations of synchronization phenomena. Whereas previous studies of metronome synchronization have been concentrating on symmetric coupling schemes, here we consider the asymmetric case by adopting the scheme of layered metronomes. Specifically, we place two metronomes on each layer, and couple two layers by placing one on top of the other. By varying the initial conditions of the metronomes and adjusting the friction between the two layers, a variety of synchronous patterns are observed in experiment, including the splay synchronization (SS) state, the generalized splay synchronization (GSS) state, the anti-phase synchronization (APS) state, the in-phase delay synchronization (IPDS) state, and the in-phase synchronization (IPS) state. In particular, the IPDS state, in which the metronomes on each layer are synchronized in phase but are of a constant phase delay to metronomes on the other layer, is observed for the first time. In addition, a new technique based on audio signals is proposed for pattern detection, which is more convenient and easier to apply than the existing acquisition techniques. Furthermore, a theoretical model is developed to explain the experimental observations, and is employed to explore the dynamical properties of the patterns, including the basin distributions and the pattern transitions. Our study sheds new lights on the collective behaviors of coupled metronomes, and the developed setup can be used in the classroom for demonstration purposes.

The facilitative effects of incidental teaching on preposition use by autistic children.

PubMed Central

McGee, G G; Krantz, P J; McClannahan, L E

1985-01-01

In a comparison of incidental teaching and traditional training procedures, three language-delayed autistic children were taught expressive use of prepositions to describe the location of preferred edibles and toys. Traditional highly structured training and incidental teaching procedures were used in a classroom setting, and generalization was assessed during free-play sessions. Results clearly indicate that incidental teaching promoted greater generalization and more spontaneous use of prepositions. These findings have important implications for language programming and teacher training, suggesting that incidental teaching should be included as a standard component of language development curricula for autistic and other developmentally delayed children. PMID:3997695

Manipulation of motivating operations and use of a script-fading procedure to teach mands for location to children with language delays.

PubMed

Howlett, Melissa A; Sidener, Tina M; Progar, Patrick R; Sidener, David W

2011-01-01

The effects of contriving motivating operations (MOs) and script fading on the acquisition of the mand "Where's [object]?" were evaluated in 2 boys with language delays. During each session, trials were alternated in which high-preference items were present (abolishing operation [AO] trials) or missing (establishing operation [EO] trials) from their typical locations. Both participants learned to mand during EO trials and not to mand during AO trials during training. Generalization of manding was demonstrated across novel instructors, stimuli, and settings and maintained 3 to 4 weeks following the intervention.

Centering a DDR Strobe in the Middle of a Data Packet

NASA Technical Reports Server (NTRS)

Johnson, Michael; Nelson, Dave; Seefeldt, James; Roper, Weston; Passow, Craig

2014-01-01

The Orion CEV Northstar ASIC (application- specific integrated circuit) project required a DDR (double data rate) memory bus driver/receiver (DDR PHY block) to interface with external DDR memory. The DDR interface (JESD79C) is based on a source synchronous strobe (DQS\\) that is sent along with each packet of data (DQ). New data is provided concurrently with each edge of strobe and is sent irregularly. In order to capture this data, the strobe needs to be delayed and used to latch the data into a register. A circuit solves the need for training a DDR PRY block by incorporating a PVT-compensated delay element in the strobe path. This circuit takes an external reference clock signal and uses the regular clock to calibrate a known delay through a data path. The compensated delay DQS signal is then used to capture the DQ data in a normal register. This register structure can be configured as a FIFO (first in first out), in order to transfer data from the DDR domain to the system clock domain. This design is different in that it does not rely upon the need for training the system response, nor does it use a PLL (phase locked loop) or a DLL (delay locked loop) to provide an offset of the strobe signal. The circuit is created using standard ASIC building blocks, plus the PVT (process, voltage, and temperature) compensated delay line. The design uses a globally available system clock as a reference, alleviating the need to operate synchronously with the remote memory. The reference clock conditions the PVT compensated delay line to provide a pre-determined amount of delay to any data signal that passes through this delay line. The delay line is programmed in degrees of offset, so that one could think of the clock period representing 360deg of delay. In an ideal environment, delaying the strobe 1/4 of a clock cycle (90deg) would place the strobe in the middle of the data packet. This delayed strobe can then be used to clock the data into a register, satisfying setup and hold requirements of the system.

Securing Real-Time Sessions in an IMS-Based Architecture

NASA Astrophysics Data System (ADS)

Cennamo, Paolo; Fresa, Antonio; Longo, Maurizio; Postiglione, Fabio; Robustelli, Anton Luca; Toro, Francesco

The emerging all-IP mobile network infrastructures based on 3rd Generation IP Multimedia Subsystem philosophy are characterised by radio access technology independence and ubiquitous connectivity for mobile users. Currently, great focus is being devoted to security issues since most of the security threats presently affecting the public Internet domain, and the upcoming ones as well, are going to be suffered by mobile users in the years to come. While a great deal of research activity, together with standardisation efforts and experimentations, is carried out on mechanisms for signalling protection, very few integrated frameworks for real-time multimedia data protection have been proposed in a context of IP Multimedia Subsystem, and even fewer experimental results based on testbeds are available. In this paper, after a general overview of the security issues arising in an advanced IP Multimedia Subsystem scenario, a comprehensive infrastructure for real-time multimedia data protection, based on the adoption of the Secure Real-Time Protocol, is proposed; then, the development of a testbed incorporating such functionalities, including mechanisms for key management and cryptographic context transfer, and allowing the setup of Secure Real-Time Protocol sessions is presented; finally, experimental results are provided together with quantitative assessments and comparisons of system performances for audio sessions with and without the adoption of the Secure Real-Time Protocol framework.

The immediate and the delayed effects of buspirone on zebrafish (Danio rerio) in an open field test: a 3-D approach.

PubMed

Maaswinkel, Hans; Zhu, Liqun; Weng, Wei

2012-10-01

Behavioral changes in zebrafish induced by acute administration of buspirone have been interpreted to be the result of reduced anxiety. The purpose of the current study was to determine whether the effects of short-term and mid-term habituation to an open field corroborated the anxiolytic hypothesis. We exposed single zebrafish for 60 min to 5 mgL buspirone and tested them twice, immediately after exposure and again 3.5 h later. Each session lasted 20 min. Distance from bottom of tank, velocity, duration freezing, distance from center and horizontal distribution, and preferred spatial location were analyzed with a 3-D tracking system. In the early session (starting at 10:30), 20 min habituation of control zebrafish only marginally increased distance from bottom, which was still 90% higher in zebrafish treated with buspirone. When extending the habituation to 3.5 h, the picture became more complex. Distance from bottom did not further increase in control zebrafish. More importantly, some signs of increased anxiety were present in the buspirone group, such as increased freezing, reduced velocity, and increased bottom-dwelling. However, analyzing data of individual fish excluded rebound anxiety as unlikely. The delayed effects might be drug side effects, such as motor impairment and/or dizziness. The immediate and the delayed effects of buspirone have the appearance to be unrelated. Copyright © 2012 Elsevier B.V. All rights reserved.

In vivo chlorine-35, sodium-23 and proton magnetic resonance imaging of the rat brain.

PubMed

Kirsch, Stefan; Augath, Mark; Seiffge, David; Schilling, Lothar; Schad, Lothar R

2010-07-01

In this study we demonstrate the feasibility of combined chlorine-35, sodium-23 and proton magnetic resonance imaging (MRI) at 9.4 Tesla, and present the first in vivo chlorine-35 images obtained by means of MRI. With the experimental setup used in this study all measurements could be done in one session without changing the setup or moving the subject. The multinuclear measurement requires a total measurement time of 2 h and provides morphological (protons) and physiological (sodium-23, chlorine-35) information in one scanning session. Chlorine-35, sodium-23 and high resolution proton images were acquired from a phantom, a healthy rat and from a rat displaying a focal cerebral infarction. Compared to the healthy tissue a signal enhancement of a factor of 2.2 +/- 0.2 in the chlorine-35 and a factor of 2.9 +/- 0.6 in the sodium-23 images is observed in the areas of infarction. Exemplary unlocalized measurement of the in vivo longitudinal and transversal relaxation time of chlorine-35 in a healthy rat showed multi-exponential behaviour. A biexponential fit revealed a fast and a slow relaxing component with T(1,a) = (1.7 +/- 0.4) ms, T(1,b) = (25.1 +/- 1.4) ms, amplitudes of A = 0.26 +/- 0.02, (1-A) = 0.74 +/- 0.02 and T(2,a) = (1.3 +/- 0.1) ms, T(2,b) = (11.8 +/- 1.1) ms, A = 0.64 +/- 0.02, (1-A) = 0.36 +/- 0.02. Combined proton, sodium-23 and chlorine-35 MRI may provide a new approach for non-invasive studies of ionic regulatory processes under physiological and pathological conditions in vivo.

Preparing pre-service teachers to integrate technology into inquiry-based science education: Three case studies in The Netherlands

NASA Astrophysics Data System (ADS)

Tran, Trinh-Ba; van den Berg, Ed; Ellermeijer, Ton; Beishuizen, Jos

2016-05-01

Integration of technology ( e.g. measuring with sensors, video measurement, and modeling) into secondary-school science teaching is a need globally recognized. A central issue of incorporating these technologies in teaching is how to turn manipulations of equipment and software into manipulations of ideas. Therefore, preparation for pre-service teachers to apply ICT tools should be combined with the issues of minds-on inquiring and meaning-making. From this perspective, we developed a course within the post-graduate teacher-education program in the Netherlands. During the course, pre-service teachers learnt not only to master ICT skills but also to design, teach, and evaluate an inquiry-based lesson in which the ICT tool was integrated. Besides three life sessions, teachers' learning scenario also consisted of individual tasks which teachers could carry out mostly in the school or at home with support materials and online assistance. We taught three iterations of the course within a design-research framework in 2013, 2014 and collected data on the teacher learning processes and outcomes. The analyses of these data from observation, interviews, questionnaires, and documents were to evaluate implementation of the course, then suggest for revisions of the course set-up, which was executed and then assessed again in a subsequent case study. Main outcomes of the three case studies can be summarized as follows: within a limited time (3 life sessions spread over 2-3 months), the heterogeneous groups of pre-service teachers achieved a reasonable level of competence regarding the use of ICT tools in inquiry-based lessons. The blended set-up with support materials, especially the Coach activities and the lesson-plan form for an ICT-integrated inquiry-based lesson, contributed to this result under the condition that the course participants really spent considerable time outside the life sessions. There was a need for more time for hands-on, in-group activities in life sessions and more detailed feedback on individual reports of pre-service teachers. The majority of the pre-service teachers were able to design a lesson plan aimed at a certain inquiry level with integration of ICT, but just a few could implement it faithfully in the classroom. There was still a considerable difference between intended inquiry activities and actual realized inquiry which parallels results from the literature for experienced teachers. The participants had to struggle with science --ICT conceptual issues as well as getting their students to focus on inquiry and concept learning in the classroom. Each evaluation guided iteration of the course resulted in better learning outcomes.

Experimental measurement and numerical analysis of group velocity dispersion in cladding modes of an endlessly single-mode photonic crystal fiber

NASA Astrophysics Data System (ADS)

Baselt, Tobias; Taudt, Christopher; Nelsen, Bryan; Lasagni, Andrés. Fabián.; Hartmann, Peter

2017-06-01

The optical properties of the guided modes in the core of photonic crystal fibers (PCFs) can be easily manipulated by changing the air-hole structure in the cladding. Special properties can be achieved in this case such as endless singlemode operation. Endlessly single-mode fibers, which enable single-mode guidance over a wide spectral range, are indispensable in the field of fiber technology. A two-dimensional photonic crystal with a silica central core and a micrometer-spaced hexagonal array of air holes is an established method to achieve endless single-mode properties. In addition to the guidance of light in the core, different cladding modes occur. The coupling between the core and the cladding modes can affect the endlessly single-mode guides. There are two possible ways to determine the dispersion: measurement and calculation. We calculate the group velocity dispersion (GVD) of different cladding modes based on the measurement of the fiber structure parameters, the hole diameter and the pitch of a presumed homogeneous hexagonal array. Based on the scanning electron image, a calculation was made of the optical guiding properties of the microstructured cladding. We compare the calculation with a method to measure the wavelength-dependent time delay. We measure the time delay of defined cladding modes with a homemade supercontinuum light source in a white light interferometric setup. To measure the dispersion of cladding modes of optical fibers with high accuracy, a time-domain white-light interferometer based on a Mach-Zehnder interferometer is used. The experimental setup allows the determination of the wavelengthdependent differential group delay of light travelling through a thirty centimeter piece of test fiber in the wavelength range from VIS to NIR. The determination of the GVD using different methods enables the evaluation of the individual methods for characterizing the cladding modes of an endlessly single-mode fiber.

Health education for STD patients in a New Delhi hospital.

PubMed

Hiramani, A B; Srivastava, U; Misra, R S

1985-09-01

The impact of sexually transmitted disease (STD) education on patients who presented for treatment of syphillis, gonorrhea, chancroid, or gonorrhea and chancroid at the STD clinic of a hospital in New Delhi, India, was assessed. 1st a pilot study of 31 patients was undertaken to determine their level of knowledge about syphilis, gonorrhea, and chancroid. This information was then used to design appropriate educational materials, including folders, photographs, flip-charts, and posters. The impact of these materials on the knowledge level of a group of patients with 1 or more of the 3 diseases was then assessed. 107 patients who presented at the clinic for treatment were interviewed in order to obtain baseline information on their STD knowledge levels. Individual education sessions were held with 80 of the 107 patients. Some of the educational materials were used during the education sessions and the patients were instructed to read the remaining materials on their own. Approximately 18 days following the education sessions, 56 of the 80 patients were retested on their knowledge of STDs. The remaining patients were lost to followup. Analysis of the data indicated that the majority of the 107 respondents were unmarried, between 20-25 years of age, and earning less than Rs.600. The baseline test indicated that most of the patients had some knowledge about their own diseases, but little knowledge about the other 2 diseases. Many of the respondents had misconceptions about the causes and effects of the diseases. The results of the retests following the educational sessions indicated that the patients with syphilis or gonorrhea tripled their knowledge level of the 3 STDs and that patients with chancroid more than doubled their STD knowledge level. 2/3 of the 56 patients said that the program increased their understanding of STDs. The educational method preferred by the largest proportion of respondents (64%) was the individual educational sessions. The folders and photographs were ranked as 2nd and 3rd in preference. Many of the patients had delayed seeking treatment for their condition. The major reason for the delay was that the patient did not understand the seriousness of the disease.

Comparing headphone and speaker effects on simulated driving.

PubMed

Nelson, T M; Nilsson, T H

1990-12-01

Twelve persons drove for three hours in an automobile simulator while listening to music at sound level 63dB over stereo headphones during one session and from a dashboard speaker during another session. They were required to steer a mountain highway, maintain a certain indicated speed, shift gears, and respond to occasional hazards. Steering and speed control were dependent on visual cues. The need to shift and the hazards were indicated by sound and vibration effects. With the headphones, the driver's average reaction time for the most complex task presented--shifting gears--was about one-third second longer than with the speaker. The use of headphones did not delay the development of subjective fatigue.

Losing track of time through delayed body representations.

PubMed

Fritz, Thomas H; Steixner, Agnes; Boettger, Joachim; Villringer, Arno

2015-01-01

The ability to keep track of time is perceived as crucial in most human societies. However, to lose track of time may also serve an important social role, associated with recreational purpose. To this end a number of social technologies are employed, some of which may relate to a manipulation of time perception through a modulation of body representation. Here, we investigated an influence of real-time or delayed videos of own-body representations on time perception in an experimental setup with virtual mirrors. Seventy participants were asked to either stay in the installation until they thought that a defined time (90 s) had passed, or they were encouraged to stay in the installation as long as they wanted and after exiting were asked to estimate the duration of their stay. Results show that a modulation of body representation by time-delayed representations of the mirror-video displays influenced time perception. Furthermore, these time-delayed conditions were associated with a greater sense of arousal and intoxication. We suggest that feeding in references to the immediate past into working memory could be the underlying mental mechanism mediating the observed modulation of time perception. We argue that such an influence on time perception would probably not only be achieved visually, but might also work with acoustic references to the immediate past (e.g., with music).

Microchannel plate cross-talk mitigation for spatial autocorrelation measurements

NASA Astrophysics Data System (ADS)

Lipka, Michał; Parniak, Michał; Wasilewski, Wojciech

2018-05-01

Microchannel plates (MCP) are the basis for many spatially resolved single-particle detectors such as ICCD or I-sCMOS cameras employing image intensifiers (II), MCPs with delay-line anodes for the detection of cold gas particles or Cherenkov radiation detectors. However, the spatial characterization provided by an MCP is severely limited by cross-talk between its microchannels, rendering MCP and II ill-suited for autocorrelation measurements. Here, we present a cross-talk subtraction method experimentally exemplified for an I-sCMOS based measurement of pseudo-thermal light second-order intensity autocorrelation function at the single-photon level. The method merely requires a dark counts measurement for calibration. A reference cross-correlation measurement certifies the cross-talk subtraction. While remaining universal for MCP applications, the presented cross-talk subtraction, in particular, simplifies quantum optical setups. With the possibility of autocorrelation measurements, the signal needs no longer to be divided into two camera regions for a cross-correlation measurement, reducing the experimental setup complexity and increasing at least twofold the simultaneously employable camera sensor region.

A fast signal subspace approach for the determination of absolute levels from phased microphone array measurements

NASA Astrophysics Data System (ADS)

Sarradj, Ennes

2010-04-01

Phased microphone arrays are used in a variety of applications for the estimation of acoustic source location and spectra. The popular conventional delay-and-sum beamforming methods used with such arrays suffer from inaccurate estimations of absolute source levels and in some cases also from low resolution. Deconvolution approaches such as DAMAS have better performance, but require high computational effort. A fast beamforming method is proposed that can be used in conjunction with a phased microphone array in applications with focus on the correct quantitative estimation of acoustic source spectra. This method bases on an eigenvalue decomposition of the cross spectral matrix of microphone signals and uses the eigenvalues from the signal subspace to estimate absolute source levels. The theoretical basis of the method is discussed together with an assessment of the quality of the estimation. Experimental tests using a loudspeaker setup and an airfoil trailing edge noise setup in an aeroacoustic wind tunnel show that the proposed method is robust and leads to reliable quantitative results.

Feasibility study of 235U and 239Pu characterization in radioactive waste drums using neutron-induced fission delayed gamma rays

NASA Astrophysics Data System (ADS)

Nicol, T.; Pérot, B.; Carasco, C.; Brackx, E.; Mariani, A.; Passard, C.; Mauerhofer, E.; Collot, J.

2016-10-01

This paper reports a feasibility study of 235U and 239Pu characterization in 225 L bituminized waste drums or 200 L concrete waste drums, by detecting delayed fission gamma rays between the pulses of a deuterium-tritium neutron generator. The delayed gamma yields were first measured with bare samples of 235U and 239Pu in REGAIN, a facility dedicated to the assay of 118 L waste drums by Prompt Gamma Neutron Activation Analysis (PGNAA) at CEA Cadarache, France. Detectability in the waste drums is then assessed using the MCNPX model of MEDINA (Multi Element Detection based on Instrumental Neutron Activation), another PGNAA cell dedicated to 200 L drums at FZJ, Germany. For the bituminized waste drum, performances are severely hampered by the high gamma background due to 137Cs, which requires the use of collimator and shield to avoid electronics saturation, these elements being very penalizing for the detection of the weak delayed gamma signal. However, for lower activity concrete drums, detection limits range from 10 to 290 g of 235U or 239Pu, depending on the delayed gamma rays of interest. These detection limits have been determined by using MCNPX to calculate the delayed gamma useful signal, and by measuring the experimental gamma background in MEDINA with a 200 L concrete drum mock-up. The performances could be significantly improved by using a higher interrogating neutron emission and an optimized experimental setup, which would allow characterizing nuclear materials in a wide range of low and medium activity waste packages.

High speed multiphoton axial scanning through an optical fiber in a remotely scanned temporal focusing setup

PubMed Central

Straub, Adam; Durst, Michael E.; Xu, Chris

2011-01-01

Simultaneous spatial and temporal focusing is used to acquire high speed (200Hz), chemically specific axial scans of mouse skin through a single-mode fiber. The temporal focus is remotely scanned by modulating the group delay dispersion (GDD) at the proximal end of the fiber. No moving parts or electronics are required at the distal end. A novel GDD modulation technique is implemented using a piezo bimorph mirror in a folded grating pair to achieve a large GDD tuning range at high speed. PMID:21326638

Ambulatory Voice Biofeedback: Relative Frequency and Summary Feedback Effects on Performance and Retention of Reduced Vocal Intensity in the Daily Lives of Participants with Normal Voices

ERIC Educational Resources Information Center

Van Stan, Jarrad H.; Mehta, Daryush D.; Sternad, Dagmar; Petit, Robert; Hillman, Robert E.

2017-01-01

Purpose: Ambulatory voice biofeedback has the potential to significantly improve voice therapy effectiveness by targeting carryover of desired behaviors outside the therapy session (i.e., retention). This study applies motor learning concepts (reduced frequency and delayed, summary feedback) that demonstrate increased retention to ambulatory voice…

Direct Written Corrective Feedback, Learner Differences, and the Acquisition of Second Language Article Use for Generic and Specific Plural Reference

ERIC Educational Resources Information Center

Stefanou, Charis; Revesz, Andrea

2015-01-01

This article reports on a classroom-based study that investigated the effectiveness of direct written corrective feedback in relation to learner differences in grammatical sensitivity and knowledge of metalanguage. The study employed a pretest-posttest-delayed posttest design with two treatment sessions. Eighty-nine Greek English as a foreign…

Adolescent Methylmercury Exposure Affects Choice and Delay Discounting in Mice

PubMed Central

Boomhower, Steven R.; Newland, M. Christopher

2016-01-01

The developing fetus is vulnerable to low-level exposure to methylmercury (MeHg), an environmental neurotoxicant, but the consequences of exposure during the adolescent period remain virtually unknown. The current experiments were designed to assess the effects of low-level MeHg exposure during adolescence on delay discounting, preference for small, immediate reinforcers over large, delayed ones, using a mouse model. Thirty-six male C57BL/6n mice were exposed to 0, 0.3, or 3.0 ppm mercury (as MeHg) via drinking water from postnatal day 21 through 59, encompassing the murine adolescent period. As adults, mice lever-pressed for a 0.01-cc droplet of milk solution delivered immediately or four 0.01-cc droplets delivered after a delay. Delays ranged from 1.26 to 70.79 seconds, all presented within a session. A model based on the Generalized Matching Law indicated that sensitivity to reinforcer magnitude was lower for MeHg-exposed mice relative to controls; responding in MeHg-exposed mice was relatively indifferent to the larger reinforcer. Sensitivity to reinforcer delay was reduced (delay discounting was decreased) in the 0.3-ppm group, but not in the 3.0-ppm group, compared to controls. Adolescence is a developmental period during which the brain and behavior may be vulnerable to MeHg exposure. As with gestational exposure, the effects are reflected in the impact of reinforcing stimuli. PMID:27677934

Napping facilitates word learning in early lexical development.

PubMed

Horváth, Klára; Myers, Kyle; Foster, Russell; Plunkett, Kim

2015-10-01

Little is known about the role that night-time sleep and daytime naps play in early cognitive development. Our aim was to investigate how napping affects word learning in 16-month-olds. Thirty-four typically developing infants were assigned randomly to nap and wake groups. After teaching two novel object-word pairs to infants, we tested their initial performance with an intermodal preferential looking task in which infants are expected to increase their target looking time compared to a distracter after hearing its auditory label. A second test session followed after approximately a 2-h delay. The delay contained sleep for the nap group or no sleep for the wake group. Looking behaviour was measured with an automatic eye-tracker. Vocabulary size was assessed using the Oxford Communicative Development Inventory. A significant interaction between group and session was found in preferential looking towards the target picture. The performance of the nap group increased after the nap, whereas that of the wake group did not change. The gain in performance correlated positively with the expressive vocabulary size in the nap group. These results indicate that daytime napping helps consolidate word learning in infancy. © 2015 European Sleep Research Society.

Within-session and one-week practice effects on a motor task in amnestic mild cognitive impairment.

PubMed

Schaefer, Sydney Y; Duff, Kevin

2017-06-01

Practice effects on neuropsychological tests, which are improvements in test scores due to repeated exposure to testing materials, are robust in healthy elders, but muted in older adults with cognitive disorders. Conversely, few studies have investigated practice effects on motor tasks involving procedural memory, particularly across test-retest periods exceeding 24 hours. The current study examined one-week practice effects on a novel upper extremity motor task in 54 older adults with amnestic mild cognitive impairment. Results indicate that these individuals with primary memory deficits did improve on this motor task within a brief training session as well as across one week. These practice effects were unrelated to demographic characteristics or global cognition. One-week practice effects were, however, negatively related to delayed memory function, with larger practice effects being associated with poorer delayed memory and potentially better visuospatial ability. The presence of longer term practice effects on a procedural motor task not only has implications for how longitudinal assessments with similar measures involving implicit memory might be interpreted, but may also inform future rehabilitative strategies for patients with more severe declarative memory deficits.

Cessation of oscillations in a chemo-mechanical oscillator

NASA Astrophysics Data System (ADS)

Phogat, Richa; Tiwari, Ishant; Kumar, Pawan; Rivera, Marco; Parmananda, Punit

2018-06-01

In this paper, different methods for cessation of oscillations in a chemo-mechanical oscillator [mercury beating heart (MBH)] are presented. The first set of experiments were carried out on a single MBH oscillator. To achieve cessation of oscillations, two protocols, namely, inverted feedback and delayed feedback were employed. In the second set of experiments, two quasi-identical MBH oscillators are considered. They are first synchronized via a bidirectional attractive coupling. These two synchronized oscillators are thereafter coupled with a unidirectional repulsive coupling and the system dynamics were observed. Subsequently, in the next protocol, the effect of a unidirectional delay coupling on the two synchronized oscillators was explored. The cessation of oscillations in all the above experimental setups was observed as the feedback/coupling was switched on at a suitable strength. Oscillatory dynamics of the system were restored when the feedback/coupling was switched off.

Characterization of a remote optical element with bi-photons

NASA Astrophysics Data System (ADS)

Puhlmann, D.; Henkel, C.; Heuer, A.; Pieplow, G.; Menzel, R.

2016-02-01

We present a simple setup that exploits the interference of entangled photon pairs. ‘Signal’ photons are sent through a Mach-Zehnder-like interferometer, while ‘idlers’ are detected in a variable polarization state. Two-photon interference (in coincidence detection) is observed with very high contrast and for significant time delays between signal and idler detection events. This is explained by quantum erasure of the polarization tag and a delayed choice protocol involving a non-local virtual polarizer. The phase of the two-photon fringes is scanned by varying the path length in the signal beam or by rotating a birefringent crystal in the idler beam. We exploit this to characterize one beam splitter of the signal photon interferometer (reflection and transmission amplitudes including losses), using only information about coincidences and control parameters in the idler path. This is possible because our bi-photon state saturates the Greenberger-Yelin-Englert inequality between contrast and predictability.

Time-resolved measurement of single pulse femtosecond laser-induced periodic surface structure formation induced by a pre-fabricated surface groove.

PubMed

Kafka, K R P; Austin, D R; Li, H; Yi, A Y; Cheng, J; Chowdhury, E A

2015-07-27

Time-resolved diffraction microscopy technique has been used to observe the formation of laser-induced periodic surface structures (LIPSS) from the interaction of a single femtosecond laser pulse (pump) with a nano-scale groove mechanically formed on a single-crystal Cu substrate. The interaction dynamics (0-1200 ps) was captured by diffracting a time-delayed, frequency-doubled pulse (probe) from nascent LIPSS formation induced by the pump with an infinity-conjugate microscopy setup. The LIPSS ripples are observed to form asynchronously, with the first one forming after 50 ps and others forming sequentially outward from the groove edge at larger time delays. A 1-D analytical model of electron heating including both the laser pulse and surface plasmon polariton excitation at the groove edge predicts ripple period, melt spot diameter, and qualitatively explains the asynchronous time-evolution of LIPSS formation.

Exposure setup to study potential adverse effects at GSM 1800 and UMTS frequencies on the auditory systems of rats.

PubMed

Lopresto, V; Pinto, R; De Vita, A; Mancini, S; Galloni, P; Marino, C; Ravazzani, P; Lovisolo, G A

2007-01-01

To investigate possible biological effects of exposure to electromagnetic (EM) fields at the frequencies of global system for mobile communication (GSM) 1800 system and universal mobile telecommunication system (UMTS) on the auditory system of rats, an exposure setup for in vivo experiments is presented. The study was carried out in the framework of two European research projects. The target of the investigation was the cochlea. A dosimetric study was performed, both numerically and through direct measurements, to assess the interaction of the radiated fields and the dose distribution in the biological target. For the local exposure of rats, a loop antenna operating at the frequency bands of interest was designed, realised and characterised through numerical and experimental dosimetric procedures. Moreover, an exposure apparatus was set up, consisting of three arrays of four loop antennas, placed on three levels, thus allowing simultaneous exposure of 12 rats to give statistical power to the experiments. To isolate the exposure arrays, the setup was assembled by a wooden rack with EM field absorbing panels, inserted among the levels and at the four sides of the rack. Isolation was verified by direct measurements. Two exposure arrays were simultaneously supplied, whereas the third one was used for sham exposure. Blind exposure was achieved through a black box, hiding physical connections to the microwave power supply. During exposure sessions, rats were restrained in special plastic jigs for repeatable positioning, thus assuring the fixed level of dose in the target.

Density and delay of punishment of free-operant avoidance1

PubMed Central

Baron, Alan; Kaufman, Arnold; Fazzini, Dan

1969-01-01

In two experiments, the free-operant shock-avoidance behavior of rats was punished by electric shock. Two aspects of the schedule of response-produced shock were varied: the frequency of punishment over time (punishment density) and the temporal interval between the punished response and the punishment (punishment delay). The general finding was that response-produced shock suppressed avoidance responding under most of the density-delay combinations studied, and suppression increased as a function of increases in density and decreases in delay. Rate increases of small magnitude also were observed, usually as an initial reaction to the lesser densities and longer delays. Response suppression, while decreasing the number of punishment shocks received, also increased the number of avoidance shocks, so that the total number of shocks received usually was greater than the minimal number possible. The results were discussed from the standpoint of similarities between the effects of punishing positively and negatively reinforced behavior. The finding that subjects did not minimize the total number of shocks suggested that when avoidance behavior is punished, responding is controlled more by the local consequences of responding than by overall shock frequencies during the course of the session. PMID:16811408

Russian EVA 36.

NASA Image and Video Library

2013-11-09

ISS037-E-028076 (9 Nov. 2013) --- Russian cosmonaut Sergey Ryazanskiy, Expedition 37 flight engineer, attired in a Russian Orlan spacesuit, uses a digital still camera to expose a photo of his helmet visor during a session of extravehicular activity (EVA) as work continues on the International Space Station. Also visible in the reflections in the visor are Russian cosmonaut Oleg Kotov, flight engineer, and various components of the space station and a blue and white portion of Earth. During the five-hour, 50-minute spacewalk, Kotov and Ryazanskiy continued the setup of a combination EVA workstation and biaxial pointing platform that was installed during an Expedition 36 spacewalk on Aug. 22.

Comparison of triple dose versus standard dose gadolinium-DTPA for detection of MRI enhancing lesions in patients with primary progressive multiple sclerosis.

PubMed Central

Filippi, M; Campi, A; Martinelli, V; Colombo, B; Yousry, T; Canal, N; Scotti, G; Comi, G

1995-01-01

This study was performed to evaluate whether a triple dose of gadolinium-DTPA (Gd-DTPA) increases the sensitivity of brain MRI for detecting enhancing lesions in patients with primary progressive multiple sclerosis (PPMS). T1 weighted brain MRI was obtained for 10 patients with PPMS in two sessions. In the first session, one scan was obtained five to seven minutes after the injection of 0.1 mmol/kg Gd-DTPA (standard dose). In the second session, six to 24 hours later, one scan before and two scans five to seven minutes and one hour after the injection of 0.3 mmol/kg Gd-DTPA (triple dose) were obtained. Four enhancing lesions were detected in two patients when the standard dose of Gd-DTPA was used. The numbers of enhancing lesions increased to 13 and the numbers of patients with such lesions to five when the triple dose of Gd-DTPA was used and to 14 and six in the one hour delayed scans. The mean contrast ratio for enhancing lesions detected with the triple dose of Gd-DTPA was higher than those for lesions present in both the standard dose (P < 0.0009) and the one hour delayed scans (P = 0.04). These data indicate that with a triple dose of Gd-DTPA many more enhancing lesions can be detected in patients with PPMS. This is important both for planning clinical trials and for detecting the presence of inflammation in vivo in the lesions of such patients. Images PMID:8530944

Establishing books as conditioned reinforcers for preschool children as a function of an observational intervention.

PubMed

Singer-Dudek, Jessica; Oblak, Mara; Greer, R Douglas

2011-01-01

We tested the effects of an observational intervention (Greer & Singer-Dudek, 2008) on establishing children's books as conditioned reinforcers using a delayed multiple baseline design. Three preschool students with mild language and developmental delays served as the participants. Prior to the intervention, books did not function as reinforcers for any of the participants. The observational intervention consisted of a situation in which the participant observed a confederate being presented with access to books contingent on correct responses and the participant received nothing for correct responses. After several sessions of this treatment, the previously neutral books acquired reinforcing properties for maintenance and acquisition responses for all three participants.

ESTABLISHING BOOKS AS CONDITIONED REINFORCERS FOR PRESCHOOL CHILDREN AS A FUNCTION OF AN OBSERVATIONAL INTERVENTION

PubMed Central

Singer-Dudek, Jessica; Oblak, Mara; Greer, R. Douglas

2011-01-01

We tested the effects of an observational intervention (Greer & Singer-Dudek, 2008) on establishing children's books as conditioned reinforcers using a delayed multiple baseline design. Three preschool students with mild language and developmental delays served as the participants. Prior to the intervention, books did not function as reinforcers for any of the participants. The observational intervention consisted of a situation in which the participant observed a confederate being presented with access to books contingent on correct responses and the participant received nothing for correct responses. After several sessions of this treatment, the previously neutral books acquired reinforcing properties for maintenance and acquisition responses for all three participants. PMID:21941376

Comparison of H.323 and SIP for IP telephony signaling

NASA Astrophysics Data System (ADS)

Dalgic, Ismail; Fang, Hanlin

1999-11-01

Two standards currently compete for the dominance of IP telephony signaling: the H.323 protocol suite by ITU-T, and the Session Initiation Protocol (SIP) by IETF. Both of these signaling protocols provide mechanisms for call establishment and teardown, call control and supplementary services, and capability exchange. We investigate and compare these two protocols in terms of Functionality, Quality of Service (QoS), Scalability, Flexibility, Interoperability, and Ease of Implementation. For fairness of comparison, we consider similar scenarios for both protocols. In particular, we focus on scenarios that involve a gatekeeper for H.323, and a Proxy/Redirect server for SIP. The reason is that medium-to-large IP Telephony systems are not manageable without a gatekeeper or proxy server. We consider all three versions of H.323. In terms of functionality and services that can be supported, H.323 version 2 and SIP are very similar. However, supplementary services in H.323 are more rigorously defined, and therefore fewer interoperability issues are expected among its implementations. Furthermore, H.323 has taken more steps to ensure compatibility among its different versions, and to interoperate with PSTN. The two protocols are comparable in their QoS support [similar call setup delays, no support for resource reservation or class of service (CoS) setting], but H.323 version 3 will allow signaling of the requested CoS. SIP's primary advantages are (1) flexibility to add new features, and (2) relative ease of implementation and debugging. Finally, we note that H.323 and SIP are improving themselves by learning from each other, and the differences between them are diminishing with each new version.

X-ray absorption spectroscopy with time-tagged photon counting: application to study the structure of a Co(i) intermediate of H2 evolving photo-catalyst.

PubMed

Smolentsev, Grigory; Guda, Alexander A; Janousch, Markus; Frieh, Cristophe; Jud, Gaudenz; Zamponi, Flavio; Chavarot-Kerlidou, Murielle; Artero, Vincent; van Bokhoven, Jeroen A; Nachtegaal, Maarten

2014-01-01

In order to probe the structure of reaction intermediates of photochemical reactions a new setup for laser-initiated time-resolved X-ray absorption (XAS) measurements has been developed. With this approach the arrival time of each photon in respect to the laser pulse is measured and therefore full kinetic information is obtained. All X-rays that reach the detector are used to measure this kinetic information and therefore the detection efficiency of this method is high. The newly developed setup is optimized for time-resolved experiments in the microsecond range for samples with relatively low metal concentration (∼1mM). This setup has been applied to study a multicomponent photocatalytic system with a Co(dmgBF(2))(2) catalyst (dmg(2-) = dimethylglyoximato dianion), [Ru(bpy)(3)](2+) chromophore (bpy = 2,2'-bipyridine) and methyl viologen as the electron relay. On the basis of the analysis of hundreds of Co K-edge XAS spectra corresponding to different delay times after the laser excitation of the chromophore, the presence of a Co(i) intermediate is confirmed. The calculated X-ray transient signal for a model of Co(i) state with a 0.14 Å displacement of Co out of the dmg ligand plane and with the closest solvent molecule at a distance of 2.06 Å gives reasonable agreement with the experimental data.

Impaired delay and trace eyeblink conditioning in school-age children with fetal alcohol syndrome.

PubMed

Jacobson, Sandra W; Stanton, Mark E; Dodge, Neil C; Pienaar, Mariska; Fuller, Douglas S; Molteno, Christopher D; Meintjes, Ernesta M; Hoyme, H Eugene; Robinson, Luther K; Khaole, Nathaniel; Jacobson, Joseph L

2011-02-01

Classical eyeblink conditioning (EBC) involves contingent temporal pairing of a conditioned stimulus (e.g., tone) with an unconditioned stimulus (e.g., air puff). Impairment of EBC has been demonstrated in studies of alcohol-exposed animals and in children exposed prenatally at heavy levels. Fetal alcohol syndrome (FAS) was diagnosed by expert dysmorphologists in a large sample of Cape Coloured, South African children. Delay EBC was examined in a new sample of 63 children at 11.3 years, and trace conditioning in 32 of the same children at 12.8 years. At each age, 2 sessions of 50 trials each were administered on the same day; 2 more sessions the next day, for children not meeting criterion for conditioning. Six of 34 (17.6%) children born to heavy drinkers were diagnosed with FAS, 28 were heavily exposed nonsyndromal (HE), and 29 were nonexposed controls. Only 33.3% with FAS and 42.9% of HE met criterion for delay conditioning, compared with 79.3% of controls. The more difficult trace conditioning task was also highly sensitive to fetal alcohol exposure. Only 16.7% of the FAS and 21.4% of HE met criterion for trace conditioning, compared with 66.7% of controls. The magnitude of the effect of diagnostic group on trace conditioning was not greater than the effect on short delay conditioning, findings consistent with recent rat studies. Longer latency to onset and peak eyeblink CR in exposed children indicated poor timing and failure to blink in anticipation of the puff. Extended training resulted in some but not all of the children reaching criterion. These data showing alcohol-related delay and trace conditioning deficits extend our earlier findings of impaired EBC in 5-year-olds to school-age. Alcohol-related impairment in the cerebellar circuitry required for both forms of conditioning may be sufficient to account for the deficit in both tasks. Extended training was beneficial for some exposed children. EBC provides a well-characterized model system for assessment of degree of cerebellar-related learning and memory dysfunction in fetal alcohol exposed children. Copyright © 2010 by the Research Society on Alcoholism.

Impaired delay and trace eyeblink conditioning in school-age children with fetal alcohol syndrome

PubMed Central

Jacobson, Sandra W.; Stanton, Mark E.; Dodge, Neil C.; Pienaar, Mariska; Fuller, Douglas S.; Molteno, Christopher D.; Meintjes, Ernesta M.; Hoyme, H. Eugene; Robinson, Luther K.; Khaole, Nathaniel; Jacobson, Joseph L.

2013-01-01

Background Classical eyeblink conditioning (EBC) involves contingent temporal pairing of a conditioned stimulus (e.g., tone) with an unconditioned stimulus (e.g., air puff). Impairment of EBC has been demonstrated in studies of alcohol-exposed animals and in children exposed prenatally at heavy levels. Methods Fetal alcohol syndrome (FAS) was diagnosed by expert dysmorphologists in a large sample of Cape Coloured, South African children. Delay EBC was examined in a new sample of 63 children at 11.3 years, and trace conditioning in 32 of the same children at 12.8 years. At each age, two sessions of 50 trials each were administered on the same day; two more sessions the next day, for children not meeting criterion for conditioning. Results 6 of 34 (17.6%) children born to heavy drinkers were diagnosed with FAS, 28 were heavily exposed nonsyndromal (HE), and 29 were non-exposed controls. Only 33.3% with FAS and 42.9% of HE met criterion for delay conditioning, compared with 79.3% of controls. The more difficult trace conditioning task was also highly sensitive to fetal alcohol exposure. Only 16.7% of the FAS and 21.4% of HE met criterion for trace conditioning, compared with 66.7% of controls. The magnitude of the effect of diagnostic group on trace conditioning was not greater than the effect on short delay conditioning, findings consistent with recent rat studies. Longer latency to onset and peak eyeblink CR in exposed children indicated poor timing and failure to blink in anticipation of the puff. Extended training resulted in some but not all of the children reaching criterion. Conclusions These data showing alcohol-related delay and trace conditioning deficits extend our earlier findings of impaired EBC in 5-year-olds to school-age. Alcohol-related impairment in the cerebellar circuitry required for both forms of conditioning may be sufficient to account for the deficit in both tasks. Extended training was beneficial for some exposed children. EBC provides a well-characterized model system for assessment of degree of cerebellar-related learning and memory dysfunction in fetal alcohol exposed children. PMID:21073484

Scalability Analysis and Use of Compression at the Goddard DAAC and End-to-End MODIS Transfers

NASA Technical Reports Server (NTRS)

Menasce, Daniel A.

1998-01-01

The goal of this task is to analyze the performance of single and multiple FTP transfer between SCF's and the Goddard DAAC. We developed an analytic model to compute the performance of FTP sessions as a function of various key parameters, implemented the model as a program called FTP Analyzer, and carried out validations with real data obtained by running single and multiple FTP transfer between GSFC and the Miami SCF. The input parameters to the model include the mix to FTP sessions (scenario), and for each FTP session, the file size. The network parameters include the round trip time, packet loss rate, the limiting bandwidth of the network connecting the SCF to a DAAC, TCP's basic timeout, TCP's Maximum Segment Size, and TCP's Maximum Receiver's Window Size. The modeling approach used consisted of modeling TCP's overall throughput, computing TCP's delay per FTP transfer, and then solving a queuing network model that includes the FTP clients and servers.

A Randomized, Controlled Pilot Study of a Single-Session Psychoeducation Treatment for Urban, Culturally Diverse, Trauma-Exposed Adults.

PubMed

Ghafoori, Bita; Fisher, Dennis; Korosteleva, Olga; Hong, Madelyn

2016-06-01

This randomized pilot study aimed to determine whether a single session of psychoeducation improved mental health outcomes, attitudes toward treatment, and service engagement among urban, impoverished, culturally diverse, trauma-exposed adults. Sixty-seven individuals were randomly assigned to a single-session psychoeducation treatment or a delayed treatment comparison control group. The control group was found to be superior to the treatment group at posttest with respect to symptoms of posttraumatic stress disorder, anxiety, and occupational and family disability. At follow-up, all participants had completed the psychoeducation treatment, and a mixed-effects model indicated significant improvements over time in symptoms of posttraumatic stress disorder, anxiety, depression, somatization, and attitudes toward treatment. Ninety-eight percent of the participants reported the psychoeducation was helpful at follow-up. Participants also reported a 19.1% increase in mental health service utilization at follow-up compared with baseline. Implications for treatment and future research are discussed.

Infant long-term memory for associations formed during mere exposure.

PubMed

Giles, Amy; Rovee-Collier, Carolyn

2011-04-01

We previously found that young infants spontaneously associate stimuli that they merely see together. Using a sensory preconditioning paradigm with 6- and 9-month-olds, we asked how long such associations remain latent before being forgotten and what exposure conditions affect their persistence. Groups were preexposed to two puppets for 1h/day for 2 days, 1h on 1 day, or 1h on 1 day in two sessions; 1-27 days later, target actions were modeled on one puppet, and infants were tested with the other puppet 1 day later. The longest delay after which infants imitated the actions on the other puppet defined how long they remembered the association. The data revealed that the preexposure regimen determined retention. Regardless of exposure time, both ages remembered the association longer after two sessions, and younger infants remembered longer than older infants--for 4 weeks--after two 30-min sessions on 1 day. Copyright © 2011 Elsevier Inc. All rights reserved.

Reduced mental capacity and behavior of a rider of a bicycle simulator under alcohol stress or under dual task load

NASA Technical Reports Server (NTRS)

Soede, M.

1977-01-01

Experiments were carried out on a bicycle simulator with alcohol administration and a binary choice task in separate sessions, intending to reduce the subject's mental capacity. Before and after such sessions a visual evoked response measurement was done. The subject's performance was analyzed with describing function techniques. The results indicate that the alcohol affects the course-following task as well as the balancing task. The binary choice task is more specifically influencing the course-following task. The dual task shows a more pronounced effect on the recovery of the evoked response. The alcohol is delaying the recovery curve of the evoked response. A tentative explanation can be given which agrees with the performance data.

Project Amistad (Friendship), a Joint Venture between DHS and Family Outreach. Final Report: Innovations in Protective Services.

ERIC Educational Resources Information Center

Dennis-Small, Lucretia

Conducted by the Texas Department of Human Services (DHS), Project Amistad (Friendship) originally set out to recruit and train Black and Hispanic volunteers to conduct lay therapy sessions with Black and Hispanic families in which abuse and neglect of children had occurred. Start-up was significantly delayed due to personnel changes; as a result,…

Learning and Memory Enhancement by Neuropeptides

DTIC Science & Technology

1987-12-31

extxosure to other toxicants ,’e.g. other heavy metals, organic solvents), or arising from disease statee. We study leaming ii, an autoshaping task...Sparber, S.B. Selective leaming impairment of j delayed reinforcement autoshaped behavior caused by low doses of trimethyltin. S EPsychopharn-.acology...impairs acquis:tion of autoshaped behavior, whether given before or after training sessions. manuscript des -")ing this work is in preparation, and an

Neonatal ethanol exposure results in dose-dependent impairments in the acquisition and timing of the conditioned eyeblink response and altered cerebellar interpositus nucleus and hippocampal CA1 unit activity in adult rats.

PubMed

Lindquist, Derick H; Sokoloff, Greta; Milner, Eric; Steinmetz, Joseph E

2013-09-01

Exposure to ethanol in neonatal rats results in reduced neuronal numbers in the cerebellar cortex and deep nuclei of juvenile and adult animals. This reduction in cell numbers is correlated with impaired delay eyeblink conditioning (EBC), a simple motor learning task in which a neutral conditioned stimulus (CS; tone) is repeatedly paired with a co-terminating unconditioned stimulus (US; periorbital shock). Across training, cell populations in the interpositus (IP) nucleus model the temporal form of the eyeblink-conditioned response (CR). The hippocampus, though not required for delay EBC, also shows learning-dependent increases in CA1 and CA3 unit activity. In the present study, rat pups were exposed to 0, 3, 4, or 5 mg/kg/day of ethanol during postnatal days (PD) 4-9. As adults, CR acquisition and timing were assessed during 6 training sessions of delay EBC with a short (280 ms) interstimulus interval (ISI; time from CS onset to US onset) followed by another 6 sessions with a long (880 ms) ISI. Neuronal activity was recorded in the IP and area CA1 during all 12 sessions. The high-dose rats learned the most slowly and, with the moderate-dose rats, produced the longest CR peak latencies over training to the short ISI. The low dose of alcohol impaired CR performance to the long ISI only. The 3E (3 mg/kg/day of ethanol) and 5E (5 mg/kg/day of ethanol) rats also showed slower-than-normal increases in learning-dependent excitatory unit activity in the IP and CA1. The 4E (4 mg/kg/day of ethanol) rats showed a higher rate of CR production to the long ISI and enhanced IP and CA1 activation when compared to the 3E and 5E rats. The results indicate that binge-like ethanol exposure in neonatal rats induces long-lasting, dose-dependent deficits in CR acquisition and timing and diminishes conditioning-related neuronal excitation in both the cerebellum and hippocampus. Published by Elsevier Inc.

Neonatal ethanol exposure results in dose-dependent impairments in the acquisition and timing of the conditioned eyeblink response and altered cerebellar interpositus nucleus and hippocampal CA1 unit activity in adult rats

PubMed Central

Lindquist, Derick H.; Sokoloff, Greta; Milner, Eric; Steinmetz, Joseph E.

2013-01-01

Exposure to ethanol in neonatal rats results in reduced neuronal numbers in the cerebellar cortex and deep nuclei of juvenile and adult animals. This reduction in cell numbers is correlated with impaired delay eyeblink conditioning (EBC), a simple motor learning task in which a neutral conditioned stimulus (CS; tone) is repeatedly paired with a co-terminating unconditioned stimulus (US; periorbital shock). Across training, cell populations in the interpositus (IP) nucleus model the temporal form of the eyeblink conditioned response (CR). The hippocampus, though not required for delay EBC, also shows learning-dependent increases in CA1 and CA3 unit activity. In the present study, rat pups were exposed to 0, 3, 4, or 5 mg/kg/day of ethanol during postnatal days (PD) 4–9. As adults, CR acquisition and timing were assessed during 6 training sessions of delay EBC with a short (280 msec) interstimulus interval (ISI; time from CS onset to US onset) followed by another 6 sessions with a long (880 msec) ISI. Neuronal activity was recorded in the IP and area CA1 during all 12 sessions. The high-dose rats learned the most slowly and, with the moderate-dose rats, produced the longest CR peak latencies over training to the short ISI. The low dose of alcohol impaired CR performance to the long ISI only. The 3E (3 mg/kg/day of ethanol) and 5E (5 mg/kg/day of ethanol) rats also showed slower-than-normal increases in learning-dependent excitatory unit activity in the IP and CA1. The 4E (4 mg/kg/day of ethanol) rats showed a higher rate of CR production to the long ISI and enhanced IP and CA1 activation when compared to the 3E and 5E rats. The results indicate that binge-like ethanol exposure in neonatal rats induces long-lasting, dose-dependent deficits in CR acquisition and timing and diminishes conditioning-related neuronal excitation in both the cerebellum and hippocampus. PMID:23871534

Early Versus Delayed Initiation of Concurrent Palliative Oncology Care: Patient Outcomes in the ENABLE III Randomized Controlled Trial.

PubMed

Bakitas, Marie A; Tosteson, Tor D; Li, Zhigang; Lyons, Kathleen D; Hull, Jay G; Li, Zhongze; Dionne-Odom, J Nicholas; Frost, Jennifer; Dragnev, Konstantin H; Hegel, Mark T; Azuero, Andres; Ahles, Tim A

2015-05-01

Randomized controlled trials have supported integrated oncology and palliative care (PC); however, optimal timing has not been evaluated. We investigated the effect of early versus delayed PC on quality of life (QOL), symptom impact, mood, 1-year survival, and resource use. Between October 2010 and March 2013, 207 patients with advanced cancer at a National Cancer Institute cancer center, a Veterans Affairs Medical Center, and community outreach clinics were randomly assigned to receive an in-person PC consultation, structured PC telehealth nurse coaching sessions (once per week for six sessions), and monthly follow-up either early after enrollment or 3 months later. Outcomes were QOL, symptom impact, mood, 1-year survival, and resource use (hospital/intensive care unit days, emergency room visits, chemotherapy in last 14 days, and death location). Overall patient-reported outcomes were not statistically significant after enrollment (QOL, P = .34; symptom impact, P = .09; mood, P = .33) or before death (QOL, P = .73; symptom impact, P = .30; mood, P = .82). Kaplan-Meier 1-year survival rates were 63% in the early group and 48% in the delayed group (difference, 15%; P = .038). Relative rates of early to delayed decedents' resource use were similar for hospital days (0.73; 95% CI, 0.41 to 1.27; P = .26), intensive care unit days (0.68; 95% CI, 0.23 to 2.02; P = .49), emergency room visits (0.73; 95% CI, 0.45 to 1.19; P = .21), chemotherapy in last 14 days (1.57; 95% CI, 0.37 to 6.7; P = .27), and home death (27 [54%] v 28 [47%]; P = .60). Early-entry participants' patient-reported outcomes and resource use were not statistically different; however, their survival 1-year after enrollment was improved compared with those who began 3 months later. Understanding the complex mechanisms whereby PC may improve survival remains an important research priority. © 2015 by American Society of Clinical Oncology.

Early Versus Delayed Initiation of Concurrent Palliative Oncology Care: Patient Outcomes in the ENABLE III Randomized Controlled Trial

PubMed Central

Bakitas, Marie A.; Tosteson, Tor D.; Li, Zhigang; Lyons, Kathleen D.; Hull, Jay G.; Li, Zhongze; Dionne-Odom, J. Nicholas; Frost, Jennifer; Dragnev, Konstantin H.; Hegel, Mark T.; Azuero, Andres; Ahles, Tim A.

2015-01-01

Purpose Randomized controlled trials have supported integrated oncology and palliative care (PC); however, optimal timing has not been evaluated. We investigated the effect of early versus delayed PC on quality of life (QOL), symptom impact, mood, 1-year survival, and resource use. Patients and Methods Between October 2010 and March 2013, 207 patients with advanced cancer at a National Cancer Institute cancer center, a Veterans Affairs Medical Center, and community outreach clinics were randomly assigned to receive an in-person PC consultation, structured PC telehealth nurse coaching sessions (once per week for six sessions), and monthly follow-up either early after enrollment or 3 months later. Outcomes were QOL, symptom impact, mood, 1-year survival, and resource use (hospital/intensive care unit days, emergency room visits, chemotherapy in last 14 days, and death location). Results Overall patient-reported outcomes were not statistically significant after enrollment (QOL, P = .34; symptom impact, P = .09; mood, P = .33) or before death (QOL, P = .73; symptom impact, P = .30; mood, P = .82). Kaplan-Meier 1-year survival rates were 63% in the early group and 48% in the delayed group (difference, 15%; P = .038). Relative rates of early to delayed decedents' resource use were similar for hospital days (0.73; 95% CI, 0.41 to 1.27; P = .26), intensive care unit days (0.68; 95% CI, 0.23 to 2.02; P = .49), emergency room visits (0.73; 95% CI, 0.45 to 1.19; P = .21), chemotherapy in last 14 days (1.57; 95% CI, 0.37 to 6.7; P = .27), and home death (27 [54%] v 28 [47%]; P = .60). Conclusion Early-entry participants' patient-reported outcomes and resource use were not statistically different; however, their survival 1-year after enrollment was improved compared with those who began 3 months later. Understanding the complex mechanisms whereby PC may improve survival remains an important research priority. PMID:25800768

Effect of the RC time on photocurrent transients and determination of charge carrier mobilities

NASA Astrophysics Data System (ADS)

Kniepert, Juliane; Neher, Dieter

2017-11-01

We present a closed analytical model to describe time dependent photocurrents upon pulsed illumination in the presence of an external RC circuit. In combination with numerical drift diffusion simulations, it is shown that the RC time has a severe influence on the shape of the transients. In particular, the maximum of the photocurrent is delayed due to a delayed recharging of the electrodes. This delay increases with the increasing RC constant. As a consequence, charge carrier mobilities determined from simple extrapolation of the initial photocurrent decay will be in general too small and feature a false dependence on the electric field. Here, we present a recipe to correct charge carrier mobilities determined from measured photocurrent transients by taking into account the RC time of the experimental set-up. We also demonstrate how the model can be used to more reliably determine the charge carrier mobility from experimental data of a typical polymer/fullerene organic solar cell. It is shown that further aspects like a finite rising time of the pulse generator and the current contribution of the slower charger carriers influence the shape of the transients and may lead to an additional underestimation of the transit time.

Metaboreflex activation delays heart rate recovery after aerobic exercise in never‐treated hypertensive men

PubMed Central

Peçanha, Tiago; de Brito, Leandro Campos; Fecchio, Rafael Yokoyama; de Sousa, Patricia Nascimento; da Silva Junior, Natan Daniel; de Abreu, Andrea Pio; da Silva, Giovanio Vieira; Mion‐Junior, Décio

2016-01-01

Key points Recent evidence indicates that metaboreflex regulates heart rate recovery after exercise (HRR).An increased metaboreflex activity during the post‐exercise period might help to explain the reduced HRR observed in hypertensive subjects.Using lower limb circulatory occlusion, the present study showed that metaboreflex activation during the post‐exercise period delayed HRR in never‐treated hypertensive men compared to normotensives.These findings may be relevant for understanding the physiological mechanisms associated with autonomic dysfunction in hypertensive men. Abstract Muscle metaboreflex influences heart rate (HR) regulation after aerobic exercise. Therefore, increased metaboreflex sensitivity may help to explain the delayed HR recovery (HRR) reported in hypertension. The present study assessed and compared the effect of metaboreflex activation after exercise on HRR, cardiac baroreflex sensitivity (cBRS) and heart rate variability (HRV) in normotensive (NT) and hypertensive (HT) men. Twenty‐three never‐treated HT and 25 NT men randomly underwent two‐cycle ergometer exercise sessions (30 min, 70% V˙O2 peak ) followed by 5 min of inactive recovery performed with (occlusion) or without (control) leg circulatory occlusion (bilateral thigh cuffs inflated to a suprasystolic pressure). HRR was assessed via HR reduction after 30, 60 and 300 s of recovery (HRR30s, HRR60s and HRR300s), as well as by the analysis of short‐ and long‐term time constants of HRR. cBRS was assessed by sequence technique and HRV by the root mean square residual and the root mean square of successive differences between adjacent RR intervals on subsequent 30 s segments. Data were analysed using two‐ and three‐way ANOVA. HRR60s and cBRS were significant and similarly reduced in both groups in the occlusion compared to the control session (combined values: 20 ± 10 vs. 26 ± 9 beats min–1 and 2.1 ± 1.2 vs. 3.2 ± 2.4 ms mmHg−1, respectively, P < 0.05). HRR300s and HRV were also reduced in the occlusion session, although these reductions were significantly greater in HT compared to NT (−16 ± 11 vs. −8 ± 15 beats min–1 for HRR300s, P < 0.05). The results support the role of metaboreflex in HRR and suggest that increased metaboreflex sensitivity may partially explain the delayed HRR observed in HT men. PMID:27435799

Metaboreflex activation delays heart rate recovery after aerobic exercise in never-treated hypertensive men.

PubMed

Peçanha, Tiago; de Brito, Leandro Campos; Fecchio, Rafael Yokoyama; de Sousa, Patricia Nascimento; da Silva Junior, Natan Daniel; de Abreu, Andrea Pio; da Silva, Giovanio Vieira; Mion-Junior, Décio; Forjaz, Cláudia Lúcia de Moraes

2016-11-01

Recent evidence indicates that metaboreflex regulates heart rate recovery after exercise (HRR). An increased metaboreflex activity during the post-exercise period might help to explain the reduced HRR observed in hypertensive subjects. Using lower limb circulatory occlusion, the present study showed that metaboreflex activation during the post-exercise period delayed HRR in never-treated hypertensive men compared to normotensives. These findings may be relevant for understanding the physiological mechanisms associated with autonomic dysfunction in hypertensive men. Muscle metaboreflex influences heart rate (HR) regulation after aerobic exercise. Therefore, increased metaboreflex sensitivity may help to explain the delayed HR recovery (HRR) reported in hypertension. The present study assessed and compared the effect of metaboreflex activation after exercise on HRR, cardiac baroreflex sensitivity (cBRS) and heart rate variability (HRV) in normotensive (NT) and hypertensive (HT) men. Twenty-three never-treated HT and 25 NT men randomly underwent two-cycle ergometer exercise sessions (30 min, 70% V̇O2 peak ) followed by 5 min of inactive recovery performed with (occlusion) or without (control) leg circulatory occlusion (bilateral thigh cuffs inflated to a suprasystolic pressure). HRR was assessed via HR reduction after 30, 60 and 300 s of recovery (HRR30s, HRR60s and HRR300s), as well as by the analysis of short- and long-term time constants of HRR. cBRS was assessed by sequence technique and HRV by the root mean square residual and the root mean square of successive differences between adjacent RR intervals on subsequent 30 s segments. Data were analysed using two- and three-way ANOVA. HRR60s and cBRS were significant and similarly reduced in both groups in the occlusion compared to the control session (combined values: 20 ± 10 vs. 26 ± 9 beats min -1 and 2.1 ± 1.2 vs. 3.2 ± 2.4 ms mmHg -1 , respectively, P < 0.05). HRR300s and HRV were also reduced in the occlusion session, although these reductions were significantly greater in HT compared to NT (-16 ± 11 vs. -8 ± 15 beats min -1 for HRR300s, P < 0.05). The results support the role of metaboreflex in HRR and suggest that increased metaboreflex sensitivity may partially explain the delayed HRR observed in HT men. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Probing for suitable climatology to estimate the predictability of monsoon onset over Kerala (MOK), India

NASA Astrophysics Data System (ADS)

Pal, J.; Chaudhuri, S.; Mukherjee, S.; Chowdhury, A. Roy

2017-10-01

Inter-annual variability in the onset of monsoon over Kerala (MOK), India, is investigated using daily temperature; mean sea level pressure; winds at 850, 500 and 200 hPa pressure levels; outgoing longwave radiation (OLR); sea surface temperature (SST) and vertically integrated moisture content anomaly with 32 years (1981-2013) observation. The MOK is classified as early, delayed, or normal by considering the mean monsoon onset date over Kerala to be the 1st of June with a standard deviation of 8 days. The objective of the study is to identify the synoptic setup during MOK and comparison with climatology to estimate the predictability of the onset type (early, normal, or delayed) with 5, 10, and 15 days lead time. The study reveals that an enhanced convection observed over the Bay of Bengal during early MOK is found to shift over the Arabian Sea during delayed MOK. An intense high-pressure zone observed over the western south Indian Ocean during early MOK shifts to the east during delayed MOK. Higher tropospheric temperature (TT) over the western Equatorial Ocean during early MOK and lower TT over the Indian subcontinent intensify the land-ocean thermal contrast that leads to early MOK. The sea surface temperature (SST) over the Arabian Sea is observed to be warmer during delayed than early MOK. During early MOK, the source of 850 hPa southwesterly wind shifts to the west equatorial zone while a COL region has been found during delayed MOK at that level. The study further reveals that the wind speed anomaly at the 200-hPa pressure level coincides inversely with the anomaly of tropospheric temperature.

Investigation of impulsivity in binge-eating rats in a delay-discounting task and its prevention by the d-amphetamine prodrug, lisdexamfetamine.

PubMed

Vickers, Steven P; Goddard, Simon; Brammer, Richard J; Hutson, Peter H; Heal, David J

2017-06-01

Freely-fed, female, rats were trained in a two-lever, delay-discounting task: one lever delivered a single chocolate-flavoured pellet immediately and the other a three-pellet reward after increasing delay (0, 4, 8, 16, 32 s). Rats were divided into two groups (i.e. binge-eating rats given irregular, limited access to chocolate in addition to normal chow and controls maintained on normal chow). Both groups exhibited increased preference for the immediate reward as the delay interval was lengthened. The discounting rate was significantly greater in binge-eating rats than non-binge-eating controls, especially as the behaviour became more established indicating that increased impulsivity and intolerance of delayed reward are part of the psychopathology of binge-eating. Lisdexamfetamine (0.8 mg/kg, orally ( d-amphetamine base)) reversed the reduced preference of binge-eating rats for larger rewards at delay intervals of 4 s, 8 s and 32 s and across all sessions. Lisdexamfetamine-treated binge-eating rats consumed the same number of pellets as vehicle-treated, binge-eating rats and non-binge-eating controls eliminating the possibility lisdexamfetamine's actions on appetite or satiety mediated its effects on operant responding for food pellets in delay-discounting. In summary, binge-eating rats showed increased impulsive choice compared with non-binge-eating controls that was reversed by lisdexamfetamine, complementing results showing lisdexamfetamine reduced impulsiveness scores in patients with binge-eating disorder.

Nucleus accumbens core lesions induce sub-optimal choice and reduce sensitivity to magnitude and delay in impulsive choice tasks

PubMed Central

Steele, Catherine C.; Peterson, Jennifer R.; Marshall, Andrew T.; Stuebing, Sarah L.; Kirkpatrick, Kimberly

2017-01-01

The nucleus accumbens core (NAc) has long been recognized as an important contributor to the computation of reward value that is critical for impulsive choice behavior. Impulsive choice refers to choosing a smaller-sooner (SS) over a larger-later (LL) reward when the LL is more optimal in terms of the rate of reward delivery. Two experiments examined the role of the NAc in impulsive choice and its component processes of delay and magnitude processing. Experiment 1 delivered an impulsive choice task with manipulations of LL reward magnitude, followed by a reward magnitude discrimination task. Experiment 2 tested impulsive choice under manipulations of LL delay, followed by temporal bisection and progressive interval tasks. NAc lesions, in comparison to sham control lesions, produced suboptimal preferences that resulted in lower reward earning rates, and led to reduced sensitivity to magnitude and delay within the impulsive choice task. The secondary tasks revealed intact reward magnitude and delay discrimination abilities, but the lesion rats persisted in responding more as the progressive interval increased during the session. The results suggest that the NAc is most critical for demonstrating good sensitivity to magnitude and delay, and adjusting behavior accordingly. Ultimately, the NAc lesions induced suboptimal choice behavior rather than simply promoting impulsive choice, suggesting that an intact NAc is necessary for optimal decision making. PMID:29146281

Impulsive-choice patterns for food in genetically lean and obese Zucker rats

PubMed Central

Boomhower, Steven R.; Rasmussen, Erin B.; Doherty, Tiffany S.

2012-01-01

Behavioral-economic studies have shown that differences between lean and obese Zuckers in food consumption depend on the response requirement for food. Since a response requirement inherently increases the delay to reinforcement, differences in sensitivity to delay may also be a relevant mechanism of food consumption in the obese Zucker rat. Furthermore, the endocannabinoid neurotransmitter system has been implicated in impulsivity, but studies that attempt to characterize the effects of cannabinoid drugs (e.g., rimonabant) on impulsive choice may be limited by floor effects. The present study aimed to characterize impulsive-choice patterns for sucrose using an adjusting-delay procedure in genetically lean and obese Zuckers. Ten lean and ten obese Zucker rats chose between one lever that resulted in one pellet after a standard delay (either 1 s or 5 s) and a second lever that resulted in two or three pellets after an adjusting delay. After behavior stabilized under baseline, rimonabant (0–10 mg/kg) was administered prior to some choice sessions in the two-pellet condition. Under baseline, obese Zuckers made more impulsive choices than leans in three of the four standard-delay/pellet conditions. Additionally, in the 2-pellet condition, rimonabant increased impulsive choice in lean rats in the 1-s standard-delay condition; however, rimonabant decreased impulsive choice in obese rats in the 1-s and 5-s standard-delay conditions. These data suggest that genetic factors that influence impulsive choice are stronger in some choice conditions than others, and that the endocannabinoid system may be a relevant neuromechanism. PMID:23261877

Choice between delayed food and immediate oxycodone in rats.

PubMed

Secci, Maria E; Factor, Julie A; Schindler, Charles W; Panlilio, Leigh V

2016-12-01

The choice to seek immediate drug effects instead of more meaningful but delayed rewards is a defining feature of addiction. To develop a rodent model of this behavior, we allowed rats to choose between immediate intravenous delivery of the prescription opioid oxycodone (50 μg/kg) and delayed delivery of palatable food pellets. Rats preferred food at delays up to 30 s, but they chose oxycodone and food equally at 60-s delay and preferred oxycodone over food at 120-s delay. Comparison of food-drug choice, food-only, and drug-only conditions indicated that food availability decreased drug intake, but drug availability increased food intake. In the food-only condition, food was effective as a reinforcer even when delayed by 120 s. Pre-session feeding with chow slowed acquisition of food and drug self-administration, but did not affect choice. To establish procedures for testing potential anti-addiction medications, noncontingent pre-treatment with oxycodone or naltrexone (analogous to substitution and antagonist therapies, respectively) were tested on a baseline in which oxycodone was preferred over delayed food. Naltrexone pre-treatment decreased drug intake and increased food intake. Oxycodone pre-treatment decreased drug intake, but also produced extended periods with no food or drug responding. These findings show that the contingencies that induce preference for drugs over more meaningful but less immediate rewards in humans can be modeled in rodents, and they suggest that the model could be useful for assessing the therapeutic potential of treatments and exploring the underlying behavioral and neural mechanisms involved in addiction.

Choice between delayed food and immediate oxycodone in rats

PubMed Central

Secci, Maria E.; Factor, Julie A.; Schindler, Charles W.; Panlilio, Leigh V.

2016-01-01

Rationale The choice to seek immediate drug effects instead of more meaningful but delayed rewards is a defining feature of addiction. Objectives To develop a rodent model of this behavior, we allowed rats to choose between immediate intravenous delivery of the prescription opioid oxycodone (50 μg/kg) and delayed delivery of palatable food pellets. Results Rats preferred food at delays up to 30 s, but they chose oxycodone and food equally at 60-s delay and preferred oxycodone over food at 120-s delay. Comparison of food-drug choice, food-only, and drug-only conditions indicated that food availability decreased drug intake, but drug availability increased food intake. In the food-only condition, food was effective as a reinforcer even when delayed by 120 s. Pre-session feeding with chow slowed acquisition of food and drug self-administration, but did not affect choice. To establish procedures for testing potential anti-addiction medications, noncontingent pretreatment with oxycodone or naltrexone (analogous to substitution and antagonist therapies, respectively) were tested on a baseline in which oxycodone was preferred over delayed food. Naltrexone pretreatment decreased drug intake and increased food intake. Oxycodone pretreatment decreased drug intake, but also produced extended periods with no food or drug responding. Conclusions These findings show that the contingencies that induce preference for drugs over more meaningful but less immediate rewards in humans can be modeled in rodents, and they suggest that the model could be useful for assessing the therapeutic potential of treatments and exploring the underlying behavioral and neural mechanisms involved in addiction. PMID:27678551

Impulsive-choice patterns for food in genetically lean and obese Zucker rats.

PubMed

Boomhower, Steven R; Rasmussen, Erin B; Doherty, Tiffany S

2013-03-15

Behavioral-economic studies have shown that differences between lean and obese Zuckers in food consumption depend on the response requirement for food. Since a response requirement inherently increases the delay to reinforcement, differences in sensitivity to delay may also be a relevant mechanism of food consumption in the obese Zucker rat. Furthermore, the endocannabinoid neurotransmitter system has been implicated in impulsivity, but studies that attempt to characterize the effects of cannabinoid drugs (e.g., rimonabant) on impulsive choice may be limited by floor effects. The present study aimed to characterize impulsive-choice patterns for sucrose using an adjusting-delay procedure in genetically lean and obese Zuckers. Ten lean and ten obese Zucker rats chose between one lever that resulted in one pellet after a standard delay (either 1 s or 5 s) and a second lever that resulted in two or three pellets after an adjusting delay. After behavior stabilized under baseline, rimonabant (0-10 mg/kg) was administered prior to some choice sessions in the two-pellet condition. Under baseline, obese Zuckers made more impulsive choices than leans in three of the four standard-delay/pellet conditions. Additionally, in the 2-pellet condition, rimonabant increased impulsive choice in lean rats in the 1-s standard-delay condition; however, rimonabant decreased impulsive choice in obese rats in the 1-s and 5-s standard-delay conditions. These data suggest that genetic factors that influence impulsive choice are stronger in some choice conditions than others, and that the endocannabinoid system may be a relevant neuromechanism. Copyright © 2012 Elsevier B.V. All rights reserved.

Animal Robot Assisted-therapy for Rehabilitation of Patient with Post-Stroke Depression

NASA Astrophysics Data System (ADS)

Zikril Zulkifli, Winal; Shamsuddin, Syamimi; Hwee, Lim Thiam

2017-06-01

Recently, the utilization of therapeutic animal robots has expanded. This research aims to explore robotics application for mental healthcare in Malaysia through human-robot interaction (HRI). PARO, the robotic seal PARO was developed to give psychological effects on humans. Major Depressive Disorder (MDD) is a common but severe mood disorder. This study focuses on the interaction protocol between PARO and patients with MDD. Initially, twelve rehabilitation patients gave subjective evaluation on their first interaction with PARO. Next, therapeutic interaction environment was set-up with PARO in it to act as an augmentation strategy with other psychological interventions for post-stroke depression. Patient was exposed to PARO for 20 minutes. The results of behavioural analysis complemented with information from HRI survey question. The analysis also observed that the individual interactors engaged with the robot in diverse ways based on their needs Results show positive reaction toward the acceptance of an animal robot. Next, therapeutic interaction is set-up for PARO to contribute as an augmentation strategy with other psychological interventions for post-stroke depression. The outcome is to reduce the stress level among patients through facilitated therapy session with PARO

Forecast Vienna Mapping Functions 1 for real-time analysis of space geodetic observations

NASA Astrophysics Data System (ADS)

Boehm, J.; Kouba, J.; Schuh, H.

2009-05-01

The Vienna Mapping Functions 1 (VMF1) as provided by the Institute of Geodesy and Geophysics (IGG) at the Vienna University of Technology are the most accurate mapping functions for the troposphere delays that are available globally and for the entire history of space geodetic observations. So far, the VMF1 coefficients have been released with a time delay of almost two days; however, many scientific applications require their availability in near real-time, e.g. the Ultra Rapid solutions of the International GNSS Service (IGS) or the analysis of the Intensive sessions of the International VLBI Service (IVS). Here we present coefficients of the VMF1 as well as the hydrostatic and wet zenith delays that have been determined from forecasting data of the European Centre for Medium-Range Weather Forecasts (ECMWF) and provided on global grids. The comparison with parameters derived from ECMWF analysis data shows that the agreement is at the 1 mm level in terms of station height, and that the differences are larger for the wet mapping functions than for the hydrostatic mapping functions and the hydrostatic zenith delays. These new products (VMF1-FC and hydrostatic zenith delays from forecast data) can be used in real-time analysis of geodetic data without significant loss of accuracy.

Parent-Based Sleep Education for Children with Autism Spectrum Disorders

PubMed Central

Malow, Beth A.; Adkins, Karen W.; Reynolds, Ann; Weiss, Shelly K.; Loh, Alvin; Fawkes, Diane; Katz, Terry; Goldman, Suzanne E.; Madduri, Niru; Hundley, Rachel; Clemons, Traci

2013-01-01

This study provided sleep education to parents of children with autism spectrum disorder (ASD) to determine whether an individual or group format was more effective in improving sleep and aspects of daytime behavior and family functioning. Eighty children, ages 2-10 years, with ASD and sleep onset delay completed the study. Actigraphy and parent questionnaires were collected at baseline and one month after treatment. Mode of education did not affect outcomes. Sleep latency, insomnia subscales on the Children's Sleep Habits Questionnaire, and other outcomes related to child and family functioning improved with treatment. Parent-based sleep education, delivered in relatively few sessions, was associated with improved sleep onset delay in children with ASD. Group vs. individualized education did not affect outcome. PMID:23754339

Parent-based sleep education for children with autism spectrum disorders.

PubMed

Malow, Beth A; Adkins, Karen W; Reynolds, Ann; Weiss, Shelly K; Loh, Alvin; Fawkes, Diane; Katz, Terry; Goldman, Suzanne E; Madduri, Niru; Hundley, Rachel; Clemons, Traci

2014-01-01

This study provided sleep education to parents of children with autism spectrum disorder (ASD) to determine whether an individual or group format was more effective in improving sleep and aspects of daytime behavior and family functioning. Eighty children, ages 2-10 years, with ASD and sleep onset delay completed the study. Actigraphy and parent questionnaires were collected at baseline and 1 month after treatment. Mode of education did not affect outcomes. Sleep latency, insomnia subscales on the Children's Sleep Habits Questionnaire, and other outcomes related to child and family functioning improved with treatment. Parent-based sleep education, delivered in relatively few sessions, was associated with improved sleep onset delay in children with ASD. Group versus individualized education did not affect outcome.

New dimensions in surgical training: immersive virtual reality laparoscopic simulation exhilarates surgical staff.

PubMed

Huber, Tobias; Paschold, Markus; Hansen, Christian; Wunderling, Tom; Lang, Hauke; Kneist, Werner

2017-11-01

Virtual reality (VR) and head mount displays (HMDs) have been advanced for multimedia and information technologies but have scarcely been used in surgical training. Motion sickness and individual psychological changes have been associated with VR. The goal was to observe first experiences and performance scores using a new combined highly immersive virtual reality (IVR) laparoscopy setup. During the study, 10 members of the surgical department performed three tasks (fine dissection, peg transfer, and cholecystectomy) on a VR simulator. We then combined a VR HMD with the VR laparoscopic simulator and displayed the simulation on a 360° video of a laparoscopic operation to create an IVR laparoscopic simulation. The tasks were then repeated. Validated questionnaires on immersion and motion sickness were used for the study. Participants' times for fine dissection were significantly longer during the IVR session (regular: 86.51 s [62.57 s; 119.62 s] vs. IVR: 112.35 s [82.08 s; 179.40 s]; p = 0.022). The cholecystectomy task had higher error rates during IVR. Motion sickness did not occur at any time for any participant. Participants experienced a high level of exhilaration, rarely thought about others in the room, and had a high impression of presence in the generated IVR world. This is the first clinical and technical feasibility study using the full IVR laparoscopy setup combined with the latest laparoscopic simulator in a 360° surrounding. Participants were exhilarated by the high level of immersion. The setup enables a completely new generation of surgical training.

Cued Memory Reactivation During SWS Abolishes the Beneficial Effect of Sleep on Abstraction.

PubMed

Hennies, Nora; Lambon Ralph, Matthew A; Durrant, Simon J; Cousins, James N; Lewis, Penelope A

2017-08-01

Extracting regularities from stimuli in our environment and generalizing these to new situations are fundamental processes in human cognition. Sleep has been shown to enhance these processes, possibly by facilitating reactivation-triggered memory reorganization. Here, we assessed whether cued reactivation during slow wave sleep (SWS) promotes the beneficial effect of sleep on abstraction of statistical regularities. We used an auditory statistical learning task, in which the benefit of sleep has been firmly established. Participants were exposed to a probabilistically determined sequence of tones and subsequently tested for recognition of novel short sequences adhering to this same statistical pattern in both immediate and delayed recall sessions. In different groups, the exposure stream was replayed during SWS in the night between the recall sessions (SWS-replay group), in wake just before sleep (presleep replay group), or not at all (control group). Surprisingly, participants who received replay in sleep performed worse in the delayed recall session than the control and the presleep replay group. They also failed to show the association between SWS and task performance that has been observed in previous studies and was present in the controls. Importantly, sleep structure and sleep quality did not differ between groups, suggesting that replay during SWS did not impair sleep but rather disrupted or interfered with sleep-dependent mechanisms that underlie the extraction of the statistical pattern. These findings raise important questions about the scope of cued memory reactivation and the mechanisms that underlie sleep-related generalization. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Hippocampal-dependent Pavlovian conditioning in adult rats exposed to binge-like doses of ethanol as neonates.

PubMed

Lindquist, Derick H

2013-04-01

Binge-like postnatal ethanol exposure produces significant damage throughout the brain in rats, including the cerebellum and hippocampus. In the current study, cue- and context-mediated Pavlovian conditioning were assessed in adult rats exposed to moderately low (3E; 3g/kg/day) or high (5E; 5g/kg/day) doses of ethanol across postnatal days 4-9. Ethanol-exposed and control groups were presented with 8 sessions of trace eyeblink conditioning followed by another 8 sessions of delay eyeblink conditioning, with an altered context presented over the last two sessions. Both forms of conditioning rely on the brainstem and cerebellum, while the more difficult trace conditioning also requires the hippocampus. The hippocampus is also needed to gate or modulate expression of the eyeblink conditioned response (CR) based on contextual cues. Results indicate that the ethanol-exposed rats were not significantly impaired in trace EBC relative to control subjects. In terms of CR topography, peak amplitude was significantly reduced by both doses of alcohol, whereas onset latency but not peak latency was significantly lengthened in the 5E rats across the latter half of delay EBC in the original training context. Neither dosage resulted in significant impairment in the contextual gating of the behavioral response, as revealed by similar decreases in CR production across all four treatment groups following introduction of the novel context. Results suggest ethanol-induced brainstem-cerebellar damage can account for the present results, independent of the putative disruption in hippocampal development and function proposed to occur following postnatal ethanol exposure. Copyright © 2013 Elsevier B.V. All rights reserved.

Cholinergic Modulation of Visual Attention and Working Memory: Dissociable Effects of Basal Forebrain 192-IgG-Saporin Lesions and Intraprefrontal Infusions of Scopolamine

ERIC Educational Resources Information Center

Chudasama, Yogita; Dalley, Jeffrey W.; Nathwani, Falgyni; Bouger, Pascale; Robbins, Trevor W.

2004-01-01

Two experiments examined the effects of reductions in cortical cholinergic function on performance of a novel task that allowed for the simultaneous assessment of attention to a visual stimulus and memory for that stimulus over a variable delay within the same test session. In the first experiment, infusions of the muscarinic receptor antagonist…

The neural transfer effect of working memory training to enhance hedonic processing in individuals with social anhedonia

PubMed Central

Li, Xu; Li, Zhi; Li, Ke; Zeng, Ya-wei; Shi, Hai-song; Xie, Wen-lan; Yang, Zhuo-ya; Lui, Simon S. Y.; Cheung, Eric F. C.; Leung, Ada W. S.; Chan, Raymond C. K.

2016-01-01

Anhedonia, the diminished ability to experience pleasure, is a challenging negative symptom in patients with schizophrenia and can be observed in at-risk individuals with schizotypy. Deficits in hedonic processing have been postulated to be related to decreased motivation to engage in potentially rewarding events. It remains unclear whether non-pharmacological interventions, such as cognitive training, could improve anhedonia. The present study aimed to examine the neural mechanism for alleviating hedonic deficits with working memory (WM) training in individuals with social anhedonia. Fifteen individuals with social anhedonia were recruited and received 20 sessions of training on a dual n-back task, five sessions a week. Functional imaging paradigms of the Monetary Incentive Delay (MID) and the Affective Incentive Delay (AID) tasks were administered both before and after the training to evaluate the neural transfer effects on hedonic processing ability. Enhanced brain activations related to anticipation were observed at the anterior cingulate cortex, the left dorsal striatum and the left precuneus with the AID task, and at the dorsolateral prefrontal cortex and the supramarginal gyrus with the MID task. The present findings support that WM training may improve monetary-based and affective-based hedonic processing in individuals with social anhedonia. PMID:27752140

Two-way satellite time transfer: Overview and recent developments

NASA Technical Reports Server (NTRS)

Dejong, Gerrit

1994-01-01

The experiment using small earth stations for transatlantic two-way satellite time transfer between the USA and Germany has had its 10th anniversary this year. Pseudo-random noise coded time signals were phase modulated and demodulated at each station using a modem. Recently, during the last two weeks of Aug. 1993, six European time laboratories have used the INTELSAT 307E satellite for line-up tests and preliminary time transfer sessions using the same type of MITREX modem. The need for a uniform format for the exchange of data was felt heavily after these sessions. This problem was foreseen and addressed in international working parties. During Apr. 1993, in Task Group 7/2 of the ITU Radiocommunication Sector, a very intense discussion has taken place about what procedure should be recommended for TWSTFT and what items the header and data lines of the resulting data fields should contain. A difficulty is that two different methods of calibration of the earth station delays exist which result in different sets of delay data to be exchanged. Further study and discussions are necessary. Also, a meeting of the CCDS Working Group on TWSTFT addressed this in Oct. 1993. The outcome of the discussions and the prospect for future developments are presented.

The effectiveness of integration of virtual patients in a collaborative learning activity.

PubMed

Marei, Hesham F; Donkers, Jeroen; Van Merrienboer, Jeroen J G

2018-05-07

Virtual patients (VPs) have been recently integrated within different learning activities. To compare between the effect of using VPs in a collaborative learning activity and using VPs in an independent learning activity on students' knowledge acquisition, retention and transfer. For two different topics, respectively 82 and 76 dental students participated in teaching, learning and assessment sessions with VPs. Students from a female campus and from a male campus have been randomly assigned to condition (collaborative and independent), yielding four experimental groups. Each group received a lecture followed by a learning session using two VPs per topic. Students were administrated immediate and delayed written tests as well as transfer tests using two VPs to assess their knowledge in diagnosis and treatment. For the treatment items of the immediate and delayed written tests, females outperformed males in the collaborative VP group but not in the independent VP group. On the female campus, the use of VPs in a collaborative learning activity is more effective than its use as an independent learning activity in enhancing students' knowledge acquisition and retention. However, the collaborative use of VPs by itself is not enough to produce consistent results across different groups of students and attention should be given to all the factors that would affect students' interaction.

A finite state machine read-out chip for integrated surface acoustic wave sensors

NASA Astrophysics Data System (ADS)

Rakshit, Sambarta; Iliadis, Agis A.

2015-01-01

A finite state machine based integrated sensor circuit suitable for the read-out module of a monolithically integrated SAW sensor on Si is reported. The primary sensor closed loop consists of a voltage controlled oscillator (VCO), a peak detecting comparator, a finite state machine (FSM), and a monolithically integrated SAW sensor device. The output of the system oscillates within a narrow voltage range that correlates with the SAW pass-band response. The period of oscillation is of the order of the SAW phase delay. We use timing information from the FSM to convert SAW phase delay to an on-chip 10 bit digital output operating on the principle of time to digital conversion (TDC). The control inputs of this digital conversion block are generated by a second finite state machine operating under a divided system clock. The average output varies with changes in SAW center frequency, thus tracking mass sensing events in real time. Based on measured VCO gain of 16 MHz/V our system will convert a 10 kHz SAW frequency shift to a corresponding mean voltage shift of 0.7 mV. A corresponding shift in phase delay is converted to a one or two bit shift in the TDC output code. The system can handle alternate SAW center frequencies and group delays simply by adjusting the VCO control and TDC delay control inputs. Because of frequency to voltage and phase to digital conversion, this topology does not require external frequency counter setups and is uniquely suitable for full monolithic integration of autonomous sensor systems and tags.

Quantifying infant physical interactions using sensorized toys in a natural play environment.

PubMed

Goyal, Vatsala; Torres, Wilson; Rai, Roshan; Shofer, Frances; Bogen, Daniel; Bryant, Phillip; Prosser, Laura; Johnson, Michelle J

2017-07-01

Infants with developmental delays must be detected early in their development to minimize the progression of motor and neurological impairments. Our objective is to quantify how sensorized toys in a natural play environment can promote infant-toy physical interactions. We created a hanging elephant toy, equipped with an inertial measurement unit (IMU), a pressure transducer, and multiple feedback sensors, to be a hand-grasping toy. We used a 3 DoF robotic model with inputs from the IMU to calculate multiple kinematic metrics and an equation to calculate haptic metrics from the pressure transducer. Six typical infants were tested in the gym set-up. Three infants interacted with the toy for more than half the trial time. The youngest infant exhibited the largest toy displacement with ΔD = 27.6 cm, while the oldest infant squeezed the toy with the largest mean pressure of 4.5 kPa. More data on on both typical and atypical infants needs to be collected. After testing atypical infants in the SmarToyGym set-up, we will be able to identify interaction metrics that differentiate atypical and typical infants.

Experimental setups for FEL-based four-wave mixing experiments at FERMI

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

Bencivenga, Filippo; Zangrando, Marco; Svetina, Cristian

2016-01-01

The recent advent of free-electron laser (FEL) sources is driving the scientific community to extend table-top laser research to shorter wavelengths adding elemental selectivity and chemical state specificity. Both a compact setup (mini-TIMER) and a separate instrument (EIS-TIMER) dedicated to four-wave-mixing (FWM) experiments has been designed and constructed, to be operated as a branch of the Elastic and Inelastic Scattering beamline: EIS. The FWM experiments that are planned at EIS-TIMER are based on the transient grating approach, where two crossed FEL pulses create a controlled modulation of the sample excitations while a third time-delayed pulse is used to monitor themore » dynamics of the excited state. This manuscript describes such experimental facilities, showing the preliminary results of the commissioning of the EIS-TIMER beamline, and discusses original experimental strategies being developed to study the dynamics of matter at the fs–nm time–length scales. In the near future such experimental tools will allow more sophisticated FEL-based FWM applications, that also include the use of multiple and multi-color FEL pulses.« less

Experimental setups for FEL-based four-wave mixing experiments at FERMI

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

Bencivenga, Filippo; Zangrando, Marco; Svetina, Cristian

The recent advent of free-electron laser (FEL) sources is driving the scientific community to extend table-top laser research to shorter wavelengths adding elemental selectivity and chemical state specificity. Both a compact setup (mini-TIMER) and a separate instrument (EIS-TIMER) dedicated to four-wave-mixing (FWM) experiments has been designed and constructed, to be operated as a branch of the Elastic and Inelastic Scattering beamline: EIS. The FWM experiments that are planned at EIS-TIMER are based on the transient grating approach, where two crossed FEL pulses create a controlled modulation of the sample excitations while a third time-delayed pulse is used to monitor themore » dynamics of the excited state. This manuscript describes such experimental facilities, showing the preliminary results of the commissioning of the EIS-TIMER beamline, and discusses original experimental strategies being developed to study the dynamics of matter at the fs–nm time–length scales. In the near future such experimental tools will allow more sophisticated FEL-based FWM applications, that also include the use of multiple and multi-color FEL pulses.« less

How are scientific thinking skills best developed? Direct instruction vs. inquiry practice

NASA Astrophysics Data System (ADS)

Dean, David Worth, Jr.

Despite its support and adoption by most major scientific and educational organizations, some researchers have questioned whether inquiry learning is indeed the best method for acquiring the skills of inquiry. Klahr and colleagues have investigated the development of the control of variables strategy, or controlled comparison (CC), and claim that a brief session of direct instruction, characterized by explicit training of CC, as opposed to allowing children to discover CC through inquiry learning, is sufficient for acquisition, maintenance, and transfer of this core aspect of inquiry. Kuhn and colleagues, however, argue that direct instruction may be insufficient for development of the metastrategic level of understanding necessary to adequately maintain and transfer inquiry skills. In the present study, I attempt to identify the intervention most effective in supporting acquisition, maintenance, and transfer of these skills. Three groups of students received either a direct instruction session followed by standard classroom instruction (DI-only), an introductory session (without direct instruction) followed by practice sessions only (PR-only), or a direct instruction session followed by practice sessions (DI+PR). Practice sessions involved the use of a computer-based inquiry task requiring students to investigate the effects of five potential causal variables on an outcome. The two practice groups worked with this program during 12 sessions over nine weeks. They worked with structurally identical software programs during five weekly maintenance sessions. During this time, the DI-only group received standard classroom instruction. All groups were assessed on familiar and unfamiliar computer-based inquiry tasks at the conclusion of intervention (immediate assessment) and maintenance sessions (delayed assessment). Students in the two practice groups demonstrated improvement in an integrative measure of inquiry skill (valid intent, valid strategy, valid inference, and valid explanation, in combination) as well as most component measures of this skill. Performance of the two practice groups was superior to that of the DI-only group. Direct instruction conferred no additional benefit to the group receiving both direct instruction and practice compared to the practice-only group. Examined over an extended time interval, the merits of brief direct instruction are thus brought into question.

NY TBO Research: Integrated Demand Management (IDM): IDM Concept, Tools, and Training Package

NASA Technical Reports Server (NTRS)

Smith, Nancy

2016-01-01

A series of human-in-the-loop simulation sessions were conducted in the Airspace Operations Laboratory (AOL) to evaluate a new traffic management concept called Integrated Demand Management (IDM). The simulation explored how to address chronic equity, throughput and delay issues associated with New Yorks high-volume airports by operationally integrating three current and NextGen capabilities the Collaborative Trajectory Options Program (CTOP), Time-Based Flow Management (TBFM) and Required Time of Arrival (RTA) in order to better manage traffic demand within the National Air Traffic System. A package of presentation slides was developed to describe the concept, tools, and training materials used in the simulation sessions. The package will be used to outbrief our stakeholders by both presenting orally and disseminating of the materials via email.

Community-based early intervention for language delay: a preliminary investigation.

PubMed

Ciccone, Natalie; Hennessey, Neville; Stokes, Stephanie F

2012-01-01

A trial parent-focused early intervention (PFEI) programme for children with delayed language development is reported in which current research evidence was translated and applied within the constraints of available of clinical resources. The programme, based at a primary school, was run by a speech-language pathologist with speech-language pathology students. To investigate the changes in child language development and parent and child interactions following attendance at the PFEI. Eighteen parents and their children attended six, weekly group sessions in which parents were provided with strategies to maximize language learning in everyday contexts. Pre- and post-programme assessments of vocabulary size and measures of parent-child interaction were collected. Parents and children significantly increased their communicative interactions from pre- to post-treatment. Children's expressive vocabulary size and language skills increased significantly. Large-effect sizes were observed. The positive outcomes of the intervention programme contribute to the evidence base of intervention strategies and forms of service delivery for children at risk of language delay. © 2012 Royal College of Speech and Language Therapists.

Young children's understanding of briefly versus extremely delayed images of the self: emergence of the autobiographical stance.

PubMed

Povinelli, D J; Simon, B B

1998-01-01

Eighty-eight young 3-, 4-, and 5-year-olds were scheduled for 2 testing sessions. On Visit 1, the children were videotaped playing a game while an experimenter covertly placed a large sticker on their head and covertly removed it after the game. One week later, the children were videotaped playing a different game. A sticker was again covertly placed on their heads. Half the children in each age group then observed the video from the previous week, whereas the other half observed the tape from 3 min earlier. Less than half of the 3-year-olds in both conditions reached up for the sticker. In contrast, the majority of 4- and 5-year-olds in the briefly delayed condition reached for the sticker, but few in the extremely delayed condition did so. By 4 years of age, children may have developed a causal understanding of the self's endurance through time.

Statistical equivalence and test-retest reliability of delay and probability discounting using real and hypothetical rewards.

PubMed

Matusiewicz, Alexis K; Carter, Anne E; Landes, Reid D; Yi, Richard

2013-11-01

Delay discounting (DD) and probability discounting (PD) refer to the reduction in the subjective value of outcomes as a function of delay and uncertainty, respectively. Elevated measures of discounting are associated with a variety of maladaptive behaviors, and confidence in the validity of these measures is imperative. The present research examined (1) the statistical equivalence of discounting measures when rewards were hypothetical or real, and (2) their 1-week reliability. While previous research has partially explored these issues using the low threshold of nonsignificant difference, the present study fully addressed this issue using the more-compelling threshold of statistical equivalence. DD and PD measures were collected from 28 healthy adults using real and hypothetical $50 rewards during each of two experimental sessions, one week apart. Analyses using area-under-the-curve measures revealed a general pattern of statistical equivalence, indicating equivalence of real/hypothetical conditions as well as 1-week reliability. Exceptions are identified and discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

Stimulus-driven and knowledge-driven processes in attention to warbles

NASA Astrophysics Data System (ADS)

Dowling, W. Jay; Tillmann, Barbara

2003-10-01

Listeners identified warbles differing in amplitude-modulation rate (3-10 Hz). And measured RT while listeners maintained above 90% correct responses. After a practice session listeners identified target warbles following stimulus-driven or knowledge-driven cues. The stimulus-driven cue was a 250-ms ``beep'' at the target pitch (valid) or another pitch (invalid); the knowledge-driven cue was a midrange ``melody'' pointing to the target pitch (always valid). A 500-ms target warble followed the cue after delays of 0-500 ms (250-750 ms SOA). The listener pressed a key to indicate ``slow'' or ``fast.'' RTs were shortest at the briefest delay. In contrast to results from a memory task, RTs here were much shorter, and we found no evidence for IOR or attentional blink. Listeners began generating responses while the target was still sounding. Invalid ``beeps'' slowed responses at the briefest (but not the longer) delays; adding a valid ``beep'' to the valid ``melody'' did not speed responses.

Reversing Implicit First Impressions through Reinterpretation after a Two-Day Delay

PubMed Central

Mann, Thomas C.; Ferguson, Melissa J.

2016-01-01

People are adept at forming impressions of others, but how easily can impressions be updated? Although implicit first impressions have been characterized as difficult to overturn, recent work shows that they can be reversed through reinterpretation of earlier learning. However, such reversal has been demonstrated only in the same experimental session in which the impression formed, suggesting that implicit updating might be possible only within a brief temporal window, before impressions are consolidated and when memory about the initial information is strongest. Implicit impressions may be unable to be revised when reinterpreting details are learned later, due to memory consolidation or forgetting of the details to be reinterpreted. This study tested whether implicit first impressions can be reversed through reinterpretation after a two-day delay following the initial formation. Results showed that implicit revision emerged after the delay, even among those with poor explicit recall or who were not cued to recall. We discuss implications for theory on impression formation and updating. PMID:28017977

Reversing Implicit First Impressions through Reinterpretation after a Two-Day Delay.

PubMed

Mann, Thomas C; Ferguson, Melissa J

2017-01-01

People are adept at forming impressions of others, but how easily can impressions be updated? Although implicit first impressions have been characterized as difficult to overturn, recent work shows that they can be reversed through reinterpretation of earlier learning. However, such reversal has been demonstrated only in the same experimental session in which the impression formed, suggesting that implicit updating might be possible only within a brief temporal window, before impressions are consolidated and when memory about the initial information is strongest. Implicit impressions may be unable to be revised when reinterpreting details are learned later, due to memory consolidation or forgetting of the details to be reinterpreted. This study tested whether implicit first impressions can be reversed through reinterpretation after a two-day delay following the initial formation. Results showed that implicit revision emerged after the delay, even among those with poor explicit recall or who were not cued to recall. We discuss implications for theory on impression formation and updating.

Identification of neural structures involved in stuttering using vibrotactile feedback.

PubMed

Cheadle, Oliver; Sorger, Clarissa; Howell, Peter

Feedback delivered over auditory and vibratory afferent pathways has different effects on the fluency of people who stutter (PWS). These features were exploited to investigate the neural structures involved in stuttering. The speech signal vibrated locations on the body (vibrotactile feedback, VTF). Eleven PWS read passages under VTF and control (no-VTF) conditions. All combinations of vibration amplitude, synchronous or delayed VTF and vibrator position (hand, sternum or forehead) were presented. Control conditions were performed at the beginning, middle and end of test sessions. Stuttering rate, but not speaking rate, differed between the control and VTF conditions. Notably, speaking rate did not change between when VTF was delayed versus when it was synchronous in contrast with what happens with auditory feedback. This showed that cerebellar mechanisms, which are affected when auditory feedback is delayed, were not implicated in the fluency-enhancing effects of VTF, suggesting that there is a second fluency-enhancing mechanism. Copyright © 2018 Elsevier Inc. All rights reserved.

Enhancement of the NMSU Channel Error Simulator to Provide User-Selectable Link Delays

NASA Technical Reports Server (NTRS)

Horan, Stephen; Wang, Ru-Hai

2000-01-01

This is the third in a continuing series of reports describing the development of the Space-to-Ground Link Simulator (SGLS) to be used for testing data transfers under simulated space channel conditions. The SGLS is based upon Virtual Instrument (VI) software techniques for managing the error generation, link data rate configuration, and, now, selection of the link delay value. In this report we detail the changes that needed to be made to the SGLS VI configuration to permit link delays to be added to the basic error generation and link data rate control capabilities. This was accomplished by modifying the rate-splitting VIs to include a buffer the hold the incoming data for the duration selected by the user to emulate the channel link delay. In sample tests of this configuration, the TCP/IP(sub ftp) service and the SCPS(sub fp) service were used to transmit 10-KB data files using both symmetric (both forward and return links set to 115200 bps) and unsymmetric (forward link set at 2400 bps and a return link set at 115200 bps) link configurations. Transmission times were recorded at bit error rates of 0 through 10(exp -5) to give an indication of the link performance. In these tests. we noted separate timings for the protocol setup time to initiate the file transfer and the variation in the actual file transfer time caused by channel errors. Both protocols showed similar performance to that seen earlier for the symmetric and unsymmetric channels. This time, the delays in establishing the file protocol also showed that these delays could double the transmission time and need to be accounted for in mission planning. Both protocols also showed a difficulty in transmitting large data files over large link delays. In these tests, there was no clear favorite between the TCP/IP(sub ftp) and the SCPS(sub fp). Based upon these tests, further testing is recommended to extend the results to different file transfer configurations.

X-ray absorption spectroscopy with time-tagged photon counting: Application to study the structure of Co(I) intermediate of H2 evolving photo-catalyst

PubMed Central

Smolentsev, Grigory; Guda, Alexander; Janousch, Markus; Frieh, Cristophe; Jud, Gaudenz; Zamponi, Flavio; Chavarot-Kerlidou, Murielle; Artero, Vincent; van Bokhoven, Jeroen A.; Nachtegaal, Maarten

2015-01-01

In order to probe the structure of reaction intermediates of photochemical reactions a new setup for laser-initiated time-resolved X-ray absorption (XAS) measurements has been developed. With this approach the arrival time of each photon in respect to the laser pulse is measured and therefore full kinetic information is obtained. All X-rays that reach the detector are used to measure this kinetic information and therefore the detection efficiency of this method is high. The newly developed setup is optimized for time-resolved experiments in the microsecond range for samples with relatively low metal concentration (~1mM). This setup has been applied to study a multicomponent photocatalytic system with a Co(dmgBF2)2 catalyst (dmg2− = dimethylglyoximato dianion), [Ru(bpy)3]2+ chromophore (bpy=2,2′-bipyridine) and methyl viologen as the electron relay. On the basis of analysis of hundreds of Co K-edge XAS spectra corresponding to different delay times after the laser excitation of the chromophore, the presence of a Co(I) intermediate is confirmed. The calculated X-ray transient signal for a model of Co(I) state with a 0.14 Å displacement of Co out of the dmg ligand plane and with the closest solvent molecule at a distance of 2.06 Å gives reasonable agreement with the experimental data. PMID:25415460

Transfer of learned perception of sensorimotor simultaneity.

PubMed

Pesavento, Michael J; Schlag, John

2006-10-01

Synchronizing a motor response to a predictable sensory stimulus, like a periodic flash or click, relies on feedback (somesthetic, auditory, visual, or other) from the motor response. Practically, this results in a small (<50 ms) asynchrony in which the motor response leads the sensory event. Here we show that the perceived simultaneity in a coincidence-anticipation task (line crossing) is affected by changing the perceived simultaneity in a different task (pacing). In the pace task, human subjects were instructed to press a key in perfect synchrony with a red square flashed every second. In training sessions, feedback was provided by flashing a blue square with each key press, below the red square. There were two types of training pace sessions: one in which the feedback was provided with no delay, the other (adapting), in which the feedback was progressively delayed (up to 100 ms). Subjects' asynchrony was unchanged in the first case, but it was significantly increased in the pace task with delay. In the coincidence-anticipation task, a horizontally moving vertical bar crossed a vertical line in the middle of a screen. Subjects were instructed to press a key exactly when the bar crossed the line. They were given no feedback on their performance. Asynchrony on the line-crossing task was tested after the training pace task with feedback. We found that this asynchrony to be significantly increased even though there never was any feedback on the coincidence-anticipation task itself. Subjects were not aware that their sensorimotor asynchrony had been lengthened (sometimes doubled). We conclude that perception of simultaneity in a sensorimotor task is learned. If this perception is caused by coincidence of signals in the brain, the timing of these signals depends on something-acquired by experience-more adaptable than physiological latencies.

First steps of processing VLBI data of space probes with VieVS

NASA Astrophysics Data System (ADS)

Plank, L.; Böhm, J.; Schuh, H.

2011-07-01

Since 2008 the VLBI group at the Institute of Geodesy and Geophysics (IGG) of the Vienna University of Technology has developed the Vienna VLBI Software VieVS which is capable to process geodetic VLBI data in NGS format. Constantly we are working on upgrading the new software, e.g. by developing a scheduling tool or extending the software from single session solution to a so-called global solution, allowing the joint analysis of many sessions covering several years. In this presentation we report on first steps to enable the processing of space VLBI data with the software. Driven by the recently increasing number of space VLBI applications, our goal is the geodetic usage of such data, primarily concerning frame ties between various reference frames, e. g. by connecting the dynamic reference frame of a space probe with the kinematically defined International Celestial Reference Frame (ICRF). Main parts of the software extension w.r.t. the existing VieVS are the treatment of fast moving targets, the implementation of a delay model for radio emitters at finite distances, and the adequate mathematical model and adjustment of the particular unknowns. Actual work has been done for two mission scenarios so far: On the one hand differential VLBI (D-VLBI) data from the two sub-satellites of the Japanese lunar mission Selene were processed, on the other hand VLBI observations of GNSS satellites were modelled in VieVS. Besides some general aspects, we give details on the calculation of the theoretical delay (delay model for moving sources at finite distances) and its realization in VieVS. First results with real data and comparisons with best fit mission orbit data are also presented.'

Transcranial Magnetic Stimulation to Address Mild Cognitive Impairment in the Elderly: A Randomized Controlled Study

PubMed Central

Drumond Marra, Hellen Livia; Myczkowski, Martin Luiz; Maia Memória, Cláudia; Arnaut, Débora; Leite Ribeiro, Philip; Sardinha Mansur, Carlos Gustavo; Lancelote Alberto, Rodrigo; Boura Bellini, Bianca; Alves Fernandes da Silva, Adriano; Ciampi de Andrade, Daniel; Teixeira, Manoel Jacobsen; Forlenza, Orestes Vicente; Marcolin, Marco Antonio

2015-01-01

Transcranial magnetic stimulation (TMS) is a noninvasive brain stimulation technique with potential to improve memory. Mild cognitive impairment (MCI), which still lacks a specific therapy, is a clinical syndrome associated with increased risk of dementia. This study aims to assess the effects of high-frequency repetitive TMS (HF rTMS) on everyday memory of the elderly with MCI. We conducted a double-blinded randomized sham-controlled trial using rTMS over the left dorsolateral prefrontal cortex (DLPFC). Thirty-four elderly outpatients meeting Petersen's MCI criteria were randomly assigned to receive 10 sessions of either active TMS or sham, 10 Hz rTMS at 110% of motor threshold, 2,000 pulses per session. Neuropsychological assessment at baseline, after the last session (10th) and at one-month follow-up, was applied. ANOVA on the primary efficacy measure, the Rivermead Behavioural Memory Test, revealed a significant group-by-time interaction (p = 0.05), favoring the active group. The improvement was kept after one month. Other neuropsychological tests were heterogeneous. rTMS at 10 Hz enhanced everyday memory in elderly with MCI after 10 sessions. These findings suggest that rTMS might be effective as a therapy for MCI and probably a tool to delay deterioration. PMID:26160997

Retention of Implicit Sequence Learning in Persons who Stutter and Persons with Parkinson's Disease

PubMed Central

Smits-Bandstra, Sarah; Gracco, Vincent

2014-01-01

This study investigated the retention of implicit sequence learning in 14 persons with Parkinson's disease (PPD), 14 persons who stutter (PWS) and 14 control participants. Participants completed a nonsense syllable serial reaction time task in a 120-minute session. Participants named aloud four syllables in response to four visual stimuli. The syllables formed a repeating 8-item sequence not made known to participants. After one week, participants completed a 60-minute retention session that included an explicit learning questionnaire and a sequence generation task. PPD showed retention of general learning equivalent to controls but PWS's reaction times were significantly slower on early trials of the retention test relative to other groups. Controls showed implicit learning during the initial session that was retained on the retention test. In contrast, PPD and PWS did not demonstrate significant implicit learning until the retention test suggesting intact, but delayed, learning and retention of implicit sequencing skills. All groups demonstrated similar limited explicit sequence knowledge. Performance differences between PWS and PPD relative to controls during the initial session and on early retention trials indicated possible dysfunction of the cortico-striato-thalamo-cortical loop. The etiological implications for stuttering, and clinical implications for both populations, of this dysfunction are discussed. PMID:23844763

The flow separation delay in the boundary layer by induced vortices.

PubMed

Chaudhry, Ishtiaq A; Sultan, Tipu; Siddiqui, Farrukh A; Farhan, M; Asim, M

2017-01-01

A series of experiments involving the particle image velocimetry technique are carried out to analyse the quantitative effectiveness of the synthesized vortical structures towards actual flow separation control. The streamwise vortices are synthesized from the synthetic jet actuator and introduced into the attached and separating boundary layer developed on the flat plate surface. Two types of actuators with different geometrical set-ups are used to analyse the evolution of vortical structures in the near wall region and their impact towards achieving separation delay in the boundary layer. First, a single circular jet is synthesized by varying actuator operating parameters and issued into the boundary layer to evaluate the dynamics of the interaction between the vortical structures and the near wall low momentum fluid in the separated region. Second, an array of jets has been issued into the artificially separated region to assess the effectiveness of various vortical structures towards achieving the reattachment of the separated flow in the streamwise direction.

Improving models of democracy: the example of lagged effects of economic development, education, and gender equality.

PubMed

Balaev, Mikhail

2014-07-01

The author examines how time delayed effects of economic development, education, and gender equality influence political democracy. Literature review shows inadequate understanding of lagged effects, which raises methodological and theoretical issues with the current quantitative studies of democracy. Using country-years as a unit of analysis, the author estimates a series of OLS PCSE models for each predictor with a systematic analysis of the distributions of the lagged effects. The second set of multiple OLS PCSE regressions are estimated including all three independent variables. The results show that economic development, education, and gender have three unique trajectories of the time-delayed effects: Economic development has long-term effects, education produces continuous effects regardless of the timing, and gender equality has the most prominent immediate and short term effects. The results call for the reassessment of model specifications and theoretical setups in the quantitative studies of democracy. Copyright © 2014 Elsevier Inc. All rights reserved.

Determination of chlorine, sulfur and carbon in reinforced concrete structures by double-pulse laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Labutin, Timur A.; Popov, Andrey M.; Zaytsev, Sergey M.; Zorov, Nikita B.; Belkov, Mikhail V.; Kiris, Vasilii V.; Raikov, Sergey N.

2014-09-01

Accurate and reliable quantitative determination of non-metal corrosion agents in concrete is still an actual task of analytical use of LIBS. Two double-pulse LIBS systems were tested as a tool for the determination of chlorine, sulfur and carbon in concretes. Both systems had collinear configuration; a laboratory setup was equipped with an ICCD and two lasers (355/532 nm + 540 nm), but a CCD was a detector for a mobile system with one laser (1064 nm). Analytical lines of Cl I at 837.59 nm, S I at 921 nm and C I at 247.86 nm were used to plot calibration curves. Optimal interpulse delays for the laboratory setup were 4 μs for chlorine and 2.8 μs for carbon, while an interpulse delay of 2 μs was optimal for chlorine and sulfur determination with the mobile system. We suggested the normalization of the Cl I line at 837.59 nm to the Mg II line at 279.08 nm (visible at 837.23 nm in the third order) to compensate for pulse-to-pulse fluctuations of chlorine lines. It provided the decrease of the detection limit of chlorine from 400 ppm to 50 ppm. Therefore, we reported that LIBS can be used to determine main corrosive active substances under ambient conditions in concrete below critical threshold values. Moreover, the application of the mobile system for in-situ qualitative assessment of corrosion way of a steel cage of a swimming pool dome was also demonstrated. It was found that chloride corrosion due to the disinfection of water was the main way for corrosion of the open part steel and the steel rebar inside the concrete.

Simulation of a circular phased array for a portable ultrasonic polar scan

NASA Astrophysics Data System (ADS)

Daemen, Jannes; Kersemans, Mathias; Martens, Arvid; Verboven, Erik; Delrue, Steven; Van Paepegem, Wim; Degrieck, Joris; Van Den Abeele, Koen

2018-04-01

The development of new composite materials, often anisotropic in nature, requires intricate approaches to characterize these materials and to detect internal defects. The Ultrasonic Polar Scan (UPS) is able to achieve both goals. During an UPS experiment, a material spot is insonified at several angles Ψ(θ,ϕ), after which the reflected or transmitted signal is recorded. While excellent results have been obtained using an in-house developed 5-axis scanner, UPS measurements with the current set-up are too lengthy and cumbersome for in-situ industrial application. Therefore, we propose to replace the complex mechanical steering of the transducers by a hemispherical phased array consisting of small PZT elements. This allows to create a compact and portable setup without compromising the current data quality. By successively activating a specific set of elements of the array and choosing appropriate inter-element time delays, the beam can be electronically steered from any angle to a fixed position on the targeted sample. Consequently, UPS reflection measurements can be performed at this position from a wide range of angles in a timeframe of seconds. Additionally, by using apodization windows, it is possible to efficiently reduce the intensity of unwanted side lobes and to create a phase profile which closely resembles that of a bounded plane wave, leading to an easier interpretation of the recorded data. The appropriate time delays and apodization parameters can be found though a multi-objective inverse problem in which both the phase profile and the side lobe reduction are optimized. This approach enables the creation of an effective beam profile to be used during UPS experiments for the characterization and inspection of composite materials. Our simulation approach is a crucial step towards a next-generation UPS device for industrial applications and in-field measurements.

Effect of Group Setting on Gross Motor Performance in Children 3-5 Years Old with Motor Delays.

PubMed

Fay, Deanne; Wilkinson, Tawna; Wagoner, Michelle; Brooks, Danna; Quinn, Lauren; Turnell, Andrea

2017-02-01

The purpose of this study was to evaluate differences in gross motor performance of children 3-5 years of age with motor delays when assessed individually compared to assessment in a group setting among peers with typical development (TD). Twenty children with motor delays and 42 children with TD were recruited from a preschool program. A within-subject repeated measures design was used; each child with delay was tested both in an individual setting and in a group setting with two to four peers with TD. Testing sessions were completed 4-8 days apart. Ten different motor skills from the Peabody Developmental Motor Scales-2 were administered. Performance of each item was videotaped and scored by a blinded researcher. Overall gross motor performance was significantly different (p < .05) between the two settings, with 14 of 20 children demonstrating better performance in the group setting. In particular, children performed better on locomotion items (p < .05). The higher scores for locomotion in the group setting may be due to the influence of competition, motivation, or modeling. Assessing a child in a group setting is recommended as part of the evaluation process.

Effect of daily morphine administration and its discontinuation on delay discounting of food in rhesus monkeys

PubMed Central

Maguire, David R; Gerak, Lisa R; France, Charles P

2015-01-01

Opioid abusers discount delayed reinforcers more rapidly than non-users; however, it is unclear whether chronic drug administration or its discontinuation impact discounting. This study examined daily morphine administration and its discontinuation on delay discounting of food in rhesus monkeys. Responding on one lever delivered 1 food pellet immediately; responding on another lever delivered 2 food pellets either immediately or after a delay (30–120 sec) that increased within the session. Monkeys (n=3) responded for the large reinforcer when both reinforcers were delivered immediately and more for the smaller, immediately available reinforcer as delay to delivery of the large reinforcer increased. When administered acutely, morphine (0.032–5.6 mg/kg) increased trial omissions and had variable effects on choice, with small doses decreasing and large doses increasing choice of the large delayed reinforcer. Chronic morphine administration (0.1 mg/kg/day to 3.2 mg/kg twice daily) reduced choice of the large delayed reinforcer in two monkeys while increasing choice in a third monkey. Despite the development of tolerance to some effects (i.e., rightward shifts in dose-effect curves for the number of trials omitted) and evidence of mild opioid dependence (e.g., decrease in the number of trials completed as well as body weight), discontinuation of treatment did not appear to systematically impact discounting. Overall, these results suggest that repeated opioid administration causes persistent effects on choice under a delay discounting procedure; however, differences in the direction of effect among individuals suggest factors other than, or in addition to, changes in discounting might play a role. PMID:26397762

Verbal learning in the context of background music: no influence of vocals and instrumentals on verbal learning

PubMed Central

2014-01-01

Background Whether listening to background music enhances verbal learning performance is still a matter of dispute. In this study we investigated the influence of vocal and instrumental background music on verbal learning. Methods 226 subjects were randomly assigned to one of five groups (one control group and 4 experimental groups). All participants were exposed to a verbal learning task. One group served as control group while the 4 further groups served as experimental groups. The control group learned without background music while the 4 experimental groups were exposed to vocal or instrumental musical pieces during learning with different subjective intensity and valence. Thus, we employed 4 music listening conditions (vocal music with high intensity: VOC_HIGH, vocal music with low intensity: VOC_LOW, instrumental music with high intensity: INST_HIGH, instrumental music with low intensity: INST_LOW) and one control condition (CONT) during which the subjects learned the word lists. Since it turned out that the high and low intensity groups did not differ in terms of the rated intensity during the main experiment these groups were lumped together. Thus, we worked with 3 groups: one control group and two groups, which were exposed to background music (vocal and instrumental) during verbal learning. As dependent variable, the number of learned words was used. Here we measured immediate recall during five learning sessions (recall 1 – recall 5) and delayed recall for 15 minutes (recall 6) and 14 days (recall 7) after the last learning session. Results Verbal learning improved during the first 5 recall sessions without any strong difference between the control and experimental groups. Also the delayed recalls were similar for the three groups. There was only a trend for attenuated verbal learning for the group passively listened to vocals. This learning attenuation diminished during the following learning sessions. Conclusions The exposure to vocal or instrumental background music during encoding did not influence verbal learning. We suggest that the participants are easily able to cope with this background stimulation by ignoring this information channel in order to focus on the verbal learning task. PMID:24670048

Acquisition of choice in concurrent chains: Assessing the cumulative decision model.

PubMed

Grace, Randolph C

2016-05-01

Concurrent chains is widely used to study pigeons' choice between terminal links that can vary in delay, magnitude, or probability of reinforcement. We review research on the acquisition of choice in this procedure. Acquisition has been studied with a variety of research designs, and some studies have incorporated no-food trials to allow for timing and choice to be observed concurrently. Results show that: Choice can be acquired rapidly within sessions when terminal links change unpredictably; under steady-state conditions, acquisition depends on both initial- and terminal-link schedules; and initial-link responding is mediated by learning about the terminal-link stimulus-reinforcer relations. The cumulative decision model (CDM) proposed by Christensen and Grace (2010) and Grace and McLean (2006, 2015) provides a good description of within-session acquisition, and correctly predicts the effects of initial and terminal-link schedules in steady-state designs (Grace, 2002a). Questions for future research include how abrupt shifts in preference within individual sessions and temporal control of terminal-link responding can be modeled. Copyright © 2016 Elsevier B.V. All rights reserved.

Draft Registration Implementation. Report Together with Dissenting Individual, Additional, and Separate Views. House of Representatives, Committee on Education and Labor, Ninety-eighth Congress, First Session.

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. House Committee on Education and Labor.

A report on a bill to delay the effective date for the denial of federal aid to students who have failed to comply with draft registration requirements is presented. The bill also directs the Comptroller General to conduct an ongoing study of the effectiveness of the Department of Defense Authorization Act of 1983 (Solomon/Hayakawa amendment) in…

Reduction of Clinical Culture Contamination in an Inpatient Medical Unit by Revisiting Microbiology Education.

PubMed

Yoon, Bona; Irmler, Monica; Faselis, Charles; Liappis, Angelike P

2016-10-01

Clinical culture contaminations delay the correct diagnosis, result in repeat testing, and may extend the length of a hospital stay. A simple educational session reminding providers of the ubiquitous presence of bacteria on the skin and in our environment, led to a significant decrease in contaminated cultures (16.9% versus 10.9%, p = 0.03). J Contin Educ Nurs. 2016;47(10):446-448. Copyright 2016, SLACK Incorporated.

"Pussy Cat, Pussy Cat, Where Have You Been?" An Account of Intensive Psychotherapy with a Seven-Year-Old Boy in a Special School

ERIC Educational Resources Information Center

Robertson, Kate

2008-01-01

This paper gives an account of the developments in the intensive psychotherapy of a seven-year-old boy with global development delay. It also describes the adaptations to technique and the changes in the setting that were required to support the work, which was undertaken in a special school. The importance of the regularity of sessions in helping…

Army Training Study: Training Effectiveness Analysis (TEA) Summary.

DTIC Science & Technology

1978-08-08

eliminated and new means computed. The disadvantage of this approach is the loss of some responses from the data base . In view of the improved ... improve over the 3 week training period. Exercises were of two basic types: meeting engagements (N = 33) and attack/defense (delay) (N = 26). The...posttest exercises were counter- balanced across units. A feedback session, the format and context of which were being pilot-tested in the effort

Repeatability of short-duration transient visual evoked potentials in normal subjects.

PubMed

Tello, Celso; De Moraes, Carlos Gustavo V; Prata, Tiago S; Derr, Peter; Patel, Jayson; Siegfried, John; Liebmann, Jeffrey M; Ritch, Robert

2010-06-01

To evaluate the within-session and inter-session repeatability of a new, short-duration transient visual evoked potential (SD-tVEP) device on normal individuals, we tested 30 normal subjects (20/20 visual acuity, normal 24-2 SITA Standard VF) with SD-tVEP. Ten of these subjects had their tests repeated within 1-2 months from the initial visit. Synchronized single-channel EEG was recorded using a modified Diopsys Enfant System (Diopsys, Inc., Pine Brook, New Jersey, USA). A checkerboard stimulus was modulated at two reversals per second. Two different contrasts of checkerboard reversal patterns were used: 85% Michelson contrast with a mean luminance of 66.25 cd/m(2) and 10% Michelson contrast with a mean luminance of 112 cd/m(2). Each test lasted 20 s. Both eyes, independently and together, were tested 10 times (5 times at each contrast level). The following information was identified from the filtered N75-P100-N135 complex: N75 amplitude, N75 latency, P100 amplitude, P100 latency, and Delta Amplitude (N75-P100). The median values for each eye's five SD-tVEP parameters were calculated and grouped into two data sets based on contrast level. Mean age was 27.3 +/- 5.2 years. For OD only, the median (95% confidence intervals) of Delta Amplitude (N75-P100) amplitudes at 10% and 85% contrast were 4.6 uV (4.1-5.9) and 7.1 uV (5.15-9.31). The median P100 latencies were 115.2 ms (112.0-117.7) and 104.0 ms (99.9-106.0). There was little within-session variability for any of these parameters. Intraclass correlation coefficients ranged between 0.64 and 0.98, and within subject coefficients of variation were 3-5% (P100 latency) and 15-30% (Delta Amplitude (N75-P100) amplitude). Bland-Altman plots showed good agreement between the first and fifth test sessions (85% contrast Delta Amplitude (N75-P100) delta amplitude, mean difference, 0.48 mV, 95% CI, -0.18-1.12; 85% contrast P100 latency delay, -0.82 ms, 95% CI, -3.12-1.46; 10% contrast Delta Amplitude (N75-P100) amplitude, 0.58 mV, 95% CI, -0.27-1.45; 10% contrast P100 latency delay, -2.05 mV, 95% CI, -5.12-1.01). The inter-eye correlation and agreement were significant for both SD-tVEP amplitude and P100 latency measurements. For the subset of eyes in which the inter-session repeatability was tested, the intraclass correlation coefficients ranged between 0.71 and 0.86 with good agreement shown on Bland-Altman plots. Short-duration transient VEP technology showed good within-session, inter-session repeatability, and good inter-eye correlation and agreement.

Classifier transfer with data selection strategies for online support vector machine classification with class imbalance

NASA Astrophysics Data System (ADS)

Krell, Mario Michael; Wilshusen, Nils; Seeland, Anett; Kim, Su Kyoung

2017-04-01

Objective. Classifier transfers usually come with dataset shifts. To overcome dataset shifts in practical applications, we consider the limitations in computational resources in this paper for the adaptation of batch learning algorithms, like the support vector machine (SVM). Approach. We focus on data selection strategies which limit the size of the stored training data by different inclusion, exclusion, and further dataset manipulation criteria like handling class imbalance with two new approaches. We provide a comparison of the strategies with linear SVMs on several synthetic datasets with different data shifts as well as on different transfer settings with electroencephalographic (EEG) data. Main results. For the synthetic data, adding only misclassified samples performed astoundingly well. Here, balancing criteria were very important when the other criteria were not well chosen. For the transfer setups, the results show that the best strategy depends on the intensity of the drift during the transfer. Adding all and removing the oldest samples results in the best performance, whereas for smaller drifts, it can be sufficient to only add samples near the decision boundary of the SVM which reduces processing resources. Significance. For brain-computer interfaces based on EEG data, models trained on data from a calibration session, a previous recording session, or even from a recording session with another subject are used. We show, that by using the right combination of data selection criteria, it is possible to adapt the SVM classifier to overcome the performance drop from the transfer.

Ultra-fast movies of thin-film laser ablation

NASA Astrophysics Data System (ADS)

Domke, Matthias; Rapp, Stephan; Schmidt, Michael; Huber, Heinz P.

2012-11-01

Ultra-short-pulse laser irradiation of thin molybdenum films from the glass substrate side initiates an intact Mo disk lift off free from thermal effects. For the investigation of the underlying physical effects, ultra-fast pump-probe microscopy is used to produce stop-motion movies of the single-pulse ablation process, initiated by a 660-fs laser pulse. The ultra-fast dynamics in the femtosecond and picosecond ranges are captured by stroboscopic illumination of the sample with an optically delayed probe pulse of 510-fs duration. The nanosecond and microsecond delay ranges of the probe pulse are covered by an electronically triggered 600-ps laser. Thus, the setup enables an observation of general laser ablation processes from the femtosecond delay range up to the final state. A comparison of time- and space-resolved observations of film and glass substrate side irradiation of a 470-nm molybdenum layer reveals the driving mechanisms of the Mo disk lift off initiated by glass-side irradiation. Observations suggest that a phase explosion generates a liquid-gas mixture in the molybdenum/glass interface about 10 ps after the impact of the pump laser pulse. Then, a shock wave and gas expansion cause the molybdenum layer to bulge, while the enclosed liquid-gas mixture cools and condenses at delay times in the 100-ps range. The bulging continues for approximately 20 ns, when an intact Mo disk shears and lifts off at a velocity of above 70 m/s. As a result, the remaining hole is free from thermal effects.

β-delayed p-decay of proton-rich nuclei ^23Al and ^31Cl and explosive H-burning in novae

NASA Astrophysics Data System (ADS)

Trache, L.; Banu, A.; Hardy, J. C.; McCleskey, M.; Simmons, E.; Tabacaru, G.; Tribble, R. E.; Aysto, J.; Jokinen, A.; Saastamoinen, A.; Davinson, T.; Woods, P. J.; Achouri, L.; Roeder, B.

2008-10-01

We developed a technique to measure β-delayed proton-decay of proton-rich nuclei produced and separated with MARS at TAMU. In particular, we studied the decay of ^23Al and ^31Cl, both important for understanding explosive H-burning in novae. We have pulsed the beam, implanting the source nuclei moving at about 40 MeV/u in a thin Si strip detector, and then measured β-p and β-γ coincidences simultaneously. The states populated above the proton threshold in ^23Mg and ^31S, respectively, may proton decay. They are resonances in the reaction ^22Na(p,γ)^23Mg (crucial for the depletion of ^22Na in ONe novae) and in ^30P(p,γ)^31S (critical point in explosive H-burning in novae), but the protons emitted have very low energies, starting at about 200 keV, an experimental challenge. The setup and the results are described. The β-decay schemes were established for both nuclei, and IAS identified. The technique has shown a remarkable selectivity to β-delayed charged particle emission and shown to work even at radioactive beam rates of a few pps, for rare isotopes with lifetimes as low as 10s msec.

A Kindergarten Number-Sense Intervention With Contrasting Practice Conditions for Low-Achieving Children

PubMed Central

Dyson, Nancy; Jordan, Nancy C.; Beliakoff, Amber; Hassinger-Das, Brenna

2015-01-01

The efficacy of a research-based number-sense intervention for low-achieving kinder-gartners was examined. Children (N = 126) were randomly assigned to 1 of 3 conditions: a number-sense intervention followed by a number-fact practice session, an identical number-sense intervention followed by a number-list practice session, or a business-as-usual control group. The interventions were delivered in a small-group setting over 24 half-hour lessons. Both intervention groups performed better than controls on measures of number sense, arithmetic fluency, and general mathematics calculation achievement at immediate posttest. However, the number-fact practice condition gave children an additional advantage over the number-list practice condition on the outcomes at delayed posttest 8 weeks later. The number-fact practice condition was especially effective for producing gains in English learners. PMID:26388651

Gating Out Misinformation: Can Young Children Follow Instructions to Ignore False Information?

PubMed

Schaaf, Jennifer M; Bederian-Gardner, Daniel; Goodman, Gail S

2015-08-01

The current study investigated the effects of misinformation on children's memory reports after practice with the logic-of-opposition instruction at time of test. Four- and 6-year-old children participated in a play event in Session 1. During a two-week delay, parents presented their children with either misinformation or correct information about the play event. Prior to a memory interview in Session 2, some misled children were given a developmentally appropriate logic-of-opposition instruction to not report information provided by their parents. Results indicated that children were misled by the incorrect information, but that the logic-of-opposition instruction aided in the children's retrieval of the original memory, particularly for the 6-year-olds. Implications of the results for memory malleability and social demand effects in children are discussed. Copyright © 2015 John Wiley & Sons, Ltd.

A prototype gas exchange monitor for exercise stress testing aboard NASA Space Station

NASA Technical Reports Server (NTRS)

Orr, Joseph A.; Westenskow, Dwayne R.; Bauer, Anne

1989-01-01

This paper describes an easy-to-use monitor developed to track the weightlessness deconditioning aboard the NASA Space Station, together with the results of testing of a prototype instrument. The monitor measures the O2 uptake and CO2 production, and calculates the maximum O2 uptake and anaerobic threshold during an exercise stress test. The system uses two flowmeters in series to achieve a completely automatic calibration, and uses breath-by-breath compensation for sample line-transport delay. The monitor was evaluated using two laboratory methods and was shown to be accurate. The system's block diagram and the bench test setup diagram are included.

Performance improvement in remote manipulation with time delay by means of a learning system.

NASA Technical Reports Server (NTRS)

Freedy, A.; Weltman, G.

1973-01-01

A teleoperating system is presented that involves shared control between a human operator and a general-purpose computer-based learning machine. This setup features a trainable control network termed the autonomous control subsystem (ACS) which is able to observe the operator's control actions, learn the task at hand, and take appropriate control actions. A working ACS system is described that has been put in operation for the purpose of exploring the uses of a remote intelligence of this type. The expansion of the present system into a multifunctional learning machine capable of a greater degree of autonomy is also discussed.

Experimental model of the device for detection of nuclear cycle materials by photoneutron technology

NASA Astrophysics Data System (ADS)

Bakalyarov, A. M.; Karetnikov, M. D.; Kozlov, K. N.; Lebedev, V. I.; Meleshko, E. A.; Obinyakov, B. A.; Ostashev, I. E.; Tupikin, N. A.; Yakovlev, G. V.

2007-08-01

The inherent complexity of sea container control makes them potentially dangerous for smuggling nuclear materials. The experts believe that only active technologies based on recording the products of induced radiation from sensitive materials might solve the problem. The paper reports on the experimental model of the device on the basis of the electron LINAC U-28 for detection of nuclear materials by photonuclear technology. The preliminary numerical optimization of output units (converter, filter, collimator) for shaping the bremsstrahlung was carried out. The setup of experimental device and initial results of recording the prompt and delayed fission products are discussed.

Comparative Shock-Tube Study of Autoignition and Plasma-Assisted Ignition of C2-Hydrocarbons

NASA Astrophysics Data System (ADS)

Kosarev, Ilya; Kindysheva, Svetlana; Plastinin, Eugeny; Aleksandrov, Nikolay; Starikovskiy, Andrey

2015-09-01

The dynamics of pulsed picosecond and nanosecond discharge development in liquid water, ethanol and hexane Using a shock tube with a discharge cell, ignition delay time was measured in a lean (φ = 0.5) C2H6:O2:Ar mixture and in lean (φ = 0.5) and stoichiometric C2H4:O2:Ar mixtures with a high-voltage nanosecond discharge and without it. The measured results were compared with the measurements made previously with the same setup for C2H6-, C2H5OH- and C2H2-containing mixtures. It was shown that the effect of plasma on ignition is almost the same for C2H6, C2H4 and C2H5OH. The reduction in time is smaller for C2H2, the fuel that is well ignited even without the discharge. Autoignition delay time was independent of the stoichiometric ratio for C2H6 and C2H4, whereas this time in stoichiometric C2H2- and C2H5OH-containing mixtures was noticeably shorter than that in the lean mixtures. Ignition after the discharge was not affected by a change in the stoichiometric ratio for C2H2 and C2H4, whereas the plasma-assisted ignition delay time for C2H6 and C2H5OH decreased as the equivalence ratio changed from 1 to 0.5. Ignition delay time was calculated in C2-hydrocarbon-containing mixtures under study by simulating separately discharge and ignition processes. Good agreement was obtained between new measurements and calculated ignition delay times.

Time‐of‐flight secondary ion mass spectrometry imaging of biological samples with delayed extraction for high mass and high spatial resolutions

PubMed Central

Vanbellingen, Quentin P.; Elie, Nicolas; Eller, Michael J.; Della‐Negra, Serge; Touboul, David

2015-01-01

Rationale In Time‐of‐Flight Secondary Ion Mass Spectrometry (TOF‐SIMS), pulsed and focused primary ion beams enable mass spectrometry imaging, a method which is particularly useful to map various small molecules such as lipids at the surface of biological samples. When using TOF‐SIMS instruments, the focusing modes of the primary ion beam delivered by liquid metal ion guns can provide either a mass resolution of several thousand or a sub‐µm lateral resolution, but the combination of both is generally not possible. Methods With a TOF‐SIMS setup, a delayed extraction applied to secondary ions has been studied extensively on rat cerebellum sections in order to compensate for the effect of long primary ion bunches. Results The use of a delayed extraction has been proven to be an efficient solution leading to unique features, i.e. a mass resolution up to 10000 at m/z 385.4 combined with a lateral resolution of about 400 nm. Simulations of ion trajectories confirm the experimental determination of optimal delayed extraction and allow understanding of the behavior of ions as a function of their mass‐to‐charge ratio. Conclusions Although the use of a delayed extraction has been well known for many years and is very popular in MALDI, it is much less used in TOF‐SIMS. Its full characterization now enables secondary ion images to be recorded in a single run with a submicron spatial resolution and with a mass resolution of several thousand. This improvement is very useful when analyzing lipids on tissue sections, or rare, precious, or very small size samples. © 2015 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons Ltd. PMID:26395603

On-Board Imaging Validation of Optically Guided Stereotactic Radiosurgery Positioning System for Conventionally Fractionated Radiotherapy for Paranasal Sinus and Skull Base Cancer

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

Maxim, Peter G.; Loo, Billy W.; Murphy, James D.

2011-11-15

Purpose: To evaluate the positioning accuracy of an optical positioning system for stereotactic radiosurgery in a pilot experience of optically guided, conventionally fractionated, radiotherapy for paranasal sinus and skull base tumors. Methods and Materials: Before each daily radiotherapy session, the positioning of 28 patients was set up using an optical positioning system. After this initial setup, the patients underwent standard on-board imaging that included daily orthogonal kilovoltage images and weekly cone beam computed tomography scans. Daily translational shifts were made after comparing the on-board images with the treatment planning computed tomography scans. These daily translational shifts represented the daily positionalmore » error in the optical tracking system and were recorded during the treatment course. For 13 patients treated with smaller fields, a three-degree of freedom (3DOF) head positioner was used for more accurate setup. Results: The mean positional error for the optically guided system in patients with and without the 3DOF head positioner was 1.4 {+-} 1.1 mm and 3.9 {+-} 1.6 mm, respectively (p <.0001). The mean positional error drifted 0.11 mm/wk upward during the treatment course for patients using the 3DOF head positioner (p = .057). No positional drift was observed in the patients without the 3DOF head positioner. Conclusion: Our initial clinical experience with optically guided head-and-neck fractionated radiotherapy was promising and demonstrated clinical feasibility. The optically guided setup was especially useful when used in conjunction with the 3DOF head positioner and when it was recalibrated to the shifts using the weekly portal images.« less

Target coverage in image-guided stereotactic body radiotherapy of liver tumors.

PubMed

Wunderink, Wouter; Méndez Romero, Alejandra; Vásquez Osorio, Eliana M; de Boer, Hans C J; Brandwijk, René P; Levendag, Peter C; Heijmen, Ben J M

2007-05-01

To determine the effect of image-guided procedures (with computed tomography [CT] and electronic portal images before each treatment fraction) on target coverage in stereotactic body radiotherapy for liver patients using a stereotactic body frame (SBF) and abdominal compression. CT guidance was used to correct for day-to-day variations in the tumor's mean position in the SBF. By retrospectively evaluating 57 treatment sessions, tumor coverage, as obtained with the clinically applied CT-guided protocol, was compared with that of alternative procedures. The internal target volume-plus (ITV(+)) was introduced to explicitly include uncertainties in tumor delineations resulting from CT-imaging artifacts caused by residual respiratory motion. Tumor coverage was defined as the volume overlap of the ITV(+), derived from a tumor delineated in a treatment CT scan, and the planning target volume. Patient stability in the SBF, after acquisition of the treatment CT scan, was evaluated by measuring the displacement of the bony anatomy in the electronic portal images relative to CT. Application of our clinical protocol (with setup corrections following from manual measurements of the distances between the contours of the planning target volume and the daily clinical target volume in three orthogonal planes, multiple two-dimensional) increased the frequency of nearly full (> or = 99%) ITV(+) coverage to 77% compared with 63% without setup correction. An automated three-dimensional method further improved the frequency to 96%. Patient displacements in the SBF were generally small (< or = 2 mm, 1 standard deviation), but large craniocaudal displacements (maximal 7.2 mm) were occasionally observed. Daily, CT-assisted patient setup may substantially improve tumor coverage, especially with the automated three-dimensional procedure. In the present treatment design, patient stability in the SBF should be verified with portal imaging.

Accuracy and Consistency of Respiratory Gating in Abdominal Cancer Patients

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

Ge, Jiajia; Santanam, Lakshmi; Yang, Deshan

2013-03-01

Purpose: To evaluate respiratory gating accuracy and intrafractional consistency for abdominal cancer patients treated with respiratory gated treatment on a regular linear accelerator system. Methods and Materials: Twelve abdominal patients implanted with fiducials were treated with amplitude-based respiratory-gated radiation therapy. On the basis of daily orthogonal fluoroscopy, the operator readjusted the couch position and gating window such that the fiducial was within a setup margin (fiducial-planning target volume [f-PTV]) when RPM indicated “beam-ON.” Fifty-five pre- and post-treatment fluoroscopic movie pairs with synchronized respiratory gating signal were recorded. Fiducial motion traces were extracted from the fluoroscopic movies using a template matchingmore » algorithm and correlated with f-PTV by registering the digitally reconstructed radiographs with the fluoroscopic movies. Treatment was determined to be “accurate” if 50% of the fiducial area stayed within f-PTV while beam-ON. For movie pairs that lost gating accuracy, a MATLAB program was used to assess whether the gating window was optimized, the external-internal correlation (EIC) changed, or the patient moved between movies. A series of safety margins from 0.5 mm to 3 mm was added to f-PTV for reassessing gating accuracy. Results: A decrease in gating accuracy was observed in 44% of movie pairs from daily fluoroscopic movies of 12 abdominal patients. Three main causes for inaccurate gating were identified as change of global EIC over time (∼43%), suboptimal gating setup (∼37%), and imperfect EIC within movie (∼13%). Conclusions: Inconsistent respiratory gating accuracy may occur within 1 treatment session even with a daily adjusted gating window. To improve or maintain gating accuracy during treatment, we suggest using at least a 2.5-mm safety margin to account for gating and setup uncertainties.« less

A multiple camera tongue switch for a child with severe spastic quadriplegic cerebral palsy.

PubMed

Leung, Brian; Chau, Tom

2010-01-01

The present study proposed a video-based access technology that facilitated a non-contact tongue protrusion access modality for a 7-year-old boy with severe spastic quadriplegic cerebral palsy (GMFCS level 5). The proposed system featured a centre camera and two peripheral cameras to extend coverage of the frontal face view of this user for longer durations. The child participated in a descriptive case study. The participant underwent 3 months of tongue protrusion training while the multiple camera tongue switch prototype was being prepared. Later, the participant was brought back for five experiment sessions where he worked on a single-switch picture matching activity, using the multiple camera tongue switch prototype in a controlled environment. The multiple camera tongue switch achieved an average sensitivity of 82% and specificity of 80%. In three of the experiment sessions, the peripheral cameras were associated with most of the true positive switch activations. These activations would have been missed by a centre-camera-only setup. The study demonstrated proof-of-concept of a non-contact tongue access modality implemented by a video-based system involving three cameras and colour video processing.

Volumetric Modulated Arc (Radio) Therapy in Pets Treatment: The “La Cittadina Fondazione” Experience

PubMed Central

Dolera, Mario; Malfassi, Luca; Carrara, Nancy; Finesso, Sara; Marcarini, Silvia; Mazza, Giovanni; Pavesi, Simone; Sala, Massimo; Urso, Gaetano

2018-01-01

Volumetric Modulated Arc Therapy (VMAT) is a modern technique, widely used in human radiotherapy, which allows a high dose to be delivered to tumor volumes and low doses to the surrounding organs at risk (OAR). Veterinary clinics takes advantage of this feature due to the small target volumes and distances between the target and the OAR. Sparing the OAR permits dose escalation, and hypofractionation regimens reduce the number of treatment sessions with a simpler manageability in the veterinary field. Multimodal volumes definition is mandatory for the small volumes involved and a positioning device precisely reproducible with a setup confirmation is needed before each session for avoiding missing the target. Additionally, the elaborate treatment plan must pursue hard constraints and objectives, and its feasibility must be evaluated with a per patient quality control. The aim of this work is to report results with regard to brain meningiomas and gliomas, trigeminal nerve tumors, brachial plexus tumors, adrenal tumors with vascular invasion and rabbit thymomas, in comparison with literature to determine if VMAT is a safe and viable alternative to surgery or chemotherapy alone, or as an adjuvant therapy in pets. PMID:29364837

Improved Walking Claudication Distance with Transcutaneous Electrical Nerve Stimulation: An Old Treatment with a New Indication in Patients with Peripheral Artery Disease.

PubMed

Labrunée, Marc; Boned, Anne; Granger, Richard; Bousquet, Marc; Jordan, Christian; Richard, Lisa; Garrigues, Damien; Gremeaux, Vincent; Sénard, Jean-Michel; Pathak, Atul; Guiraud, Thibaut

2015-11-01

The aim of this study was to determine whether 45 mins of transcutaneous electrical nerve stimulation before exercise could delay pain onset and increase walking distance in peripheral artery disease patients. After a baseline assessment of the walking velocity that led to pain after 300 m, 15 peripheral artery disease patients underwent four exercise sessions in a random order. The patients had a 45-min transcutaneous electrical nerve stimulation session with different experimental conditions: 80 Hz, 10 Hz, sham (presence of electrodes without stimulation), or control with no electrodes, immediately followed by five walking bouts on a treadmill until pain occurred. The patients were allowed to rest for 10 mins between each bout and had no feedback concerning the walking distance achieved. Total walking distance was significantly different between T10, T80, sham, and control (P < 0.0003). No difference was observed between T10 and T80, but T10 was different from sham and control. Sham, T10, and T80 were all different from control (P < 0.001). There was no difference between each condition for heart rate and blood pressure. Transcutaneous electrical nerve stimulation immediately before walking can delay pain onset and increase walking distance in patients with class II peripheral artery disease, with transcutaneous electrical nerve stimulation of 10 Hz being the most effective.

Auditory memory in monkeys: costs and benefits of proactive interference.

PubMed

Bigelow, James; Poremba, Amy

2013-05-01

Proactive interference (PI) has traditionally been understood as an adverse consequence of stimulus repetition during memory tasks. Herein, we present data that emphasize costs as well as benefits of PI for monkeys performing an auditory delayed matching-to-sample (DMTS) task. The animals made same/different judgments for a variety of simple and complex sounds separated by a 5-s memory delay. Each session used a stimulus set that included eight sounds; thus, each sound was repeated multiple times per session for match trials and for nonmatch trials as the sample (Cue 1) or test (Cue 2) stimulus. For nonmatch trials, performance was substantially diminished when the test stimulus had been previously presented on a recent trial. However, when the sample stimulus had been recently presented, performance was significantly improved. We also observed a marginal performance benefit when stimuli for match trials had been recently presented. The costs of PI for nonmatch test stimuli were greater than the combined benefits of PI for nonmatch sample stimuli and match trials, indicating that the net influence of PI is detrimental. For all three manifestations of PI, the effects are shown to extend beyond the immediately subsequent trial. Our data suggest that PI in auditory DMTS is best understood as an enduring influence that can be both detrimental and beneficial to memory-task performance. © 2012 Wiley Periodicals, Inc.

Pomegranate Supplementation Accelerates Recovery of Muscle Damage and Soreness and Inflammatory Markers after a Weightlifting Training Session

PubMed Central

Ammar, Achraf; Turki, Mouna; Chtourou, Hamdi; Hammouda, Omar; Trabelsi, Khaled; Kallel, Choumous; Abdelkarim, Osama; Hoekelmann, Anita; Bouaziz, Mohamed; Ayadi, Fatma; Driss, Tarak; Souissi, Nizar

2016-01-01

Purpose The aim of this study was to investigate the effect of natural Pomegranate juice supplementation on performance and acute and delayed responses of muscle soreness and biomarkers of muscle damage after a weightlifting training session. Methods Nine elite weightlifters (21±0.5 years) performed two Olympic-Weightlifting-sessions after either placebo (PLA) or natural pomegranate juice (POMj) supplementations. Heart rate, blood pressure and blood samples (hematological parameters, muscle damage and C-reactive protein (CRP)) were collected at rest, 3min and 48h after each session. Weightlifting performance, RPE, and DOMS were also assessed after each training session. Results T-test showed higher performance (+8.30%) and lower RPE values (-4.37%) using POMj supplementation (p<0.05) in comparison with PLA. For the DOMS values, a significant improvement (13.4%) was shown only for the knee extensors (p<0.01) using the POMj. Compared to PLA condition, POMj attenuated the acute (i.e., 3min) increase of systolic blood pressure (SBP), HR, CK and LDH (p<0.05; -4.46%, -1.81%, -8.75%, -1.64%, respectively) and blunted the significant increase of ASAT, PAL and CRP (p>0.05). Additionally, during the 48h following the training session, POMj improved the recovery kinetic of SBP (p<0.01, 7.97%), CK (p<0.001, 11.34%), LDH (p<0.05, 7.30%) and ASAT (p<0.05, 6.77%). Indeed, the present study showed that 48h of recovery associated to natural POMj supplementation was sufficient to reach the resting values of the selected muscle damage markers after intensive training session. Conclusion Natural POMj seems to ameliorate the capacity to adhere to an intensive training program. Therefore, elite weightlifters are advised to use natural POMj during intensive training program and competition to accelerate muscle recovery. Trial Registration ClinicalTrials.gov NCT02697903 PMID:27764091

Pomegranate Supplementation Accelerates Recovery of Muscle Damage and Soreness and Inflammatory Markers after a Weightlifting Training Session.

PubMed

Ammar, Achraf; Turki, Mouna; Chtourou, Hamdi; Hammouda, Omar; Trabelsi, Khaled; Kallel, Choumous; Abdelkarim, Osama; Hoekelmann, Anita; Bouaziz, Mohamed; Ayadi, Fatma; Driss, Tarak; Souissi, Nizar

2016-01-01

The aim of this study was to investigate the effect of natural Pomegranate juice supplementation on performance and acute and delayed responses of muscle soreness and biomarkers of muscle damage after a weightlifting training session. Nine elite weightlifters (21±0.5 years) performed two Olympic-Weightlifting-sessions after either placebo (PLA) or natural pomegranate juice (POMj) supplementations. Heart rate, blood pressure and blood samples (hematological parameters, muscle damage and C-reactive protein (CRP)) were collected at rest, 3min and 48h after each session. Weightlifting performance, RPE, and DOMS were also assessed after each training session. T-test showed higher performance (+8.30%) and lower RPE values (-4.37%) using POMj supplementation (p<0.05) in comparison with PLA. For the DOMS values, a significant improvement (13.4%) was shown only for the knee extensors (p<0.01) using the POMj. Compared to PLA condition, POMj attenuated the acute (i.e., 3min) increase of systolic blood pressure (SBP), HR, CK and LDH (p<0.05; -4.46%, -1.81%, -8.75%, -1.64%, respectively) and blunted the significant increase of ASAT, PAL and CRP (p>0.05). Additionally, during the 48h following the training session, POMj improved the recovery kinetic of SBP (p<0.01, 7.97%), CK (p<0.001, 11.34%), LDH (p<0.05, 7.30%) and ASAT (p<0.05, 6.77%). Indeed, the present study showed that 48h of recovery associated to natural POMj supplementation was sufficient to reach the resting values of the selected muscle damage markers after intensive training session. Natural POMj seems to ameliorate the capacity to adhere to an intensive training program. Therefore, elite weightlifters are advised to use natural POMj during intensive training program and competition to accelerate muscle recovery. ClinicalTrials.gov NCT02697903.

Exercise, Manual Therapy, and Booster Sessions in Knee Osteoarthritis: Cost-Effectiveness Analysis From a Multicenter Randomized Controlled Trial.

PubMed

Bove, Allyn M; Smith, Kenneth J; Bise, Christopher G; Fritz, Julie M; Childs, John; Brennan, Gerard P; Abbott, J Haxby; Fitzgerald, G Kelley

2018-01-01

Limited information exists regarding the cost-effectiveness of rehabilitation strategies for individuals with knee osteoarthritis (OA). The study objective was to compare the cost-effectiveness of 4 different combinations of exercise, manual therapy, and booster sessions for individuals with knee OA. This economic evaluation involved a cost-effectiveness analysis performed alongside a multicenter randomized controlled trial. The study took place in Pittsburgh, Pennsylvania; Salt Lake City, Utah; and San Antonio, Texas. The study participants were 300 individuals taking part in a randomized controlled trial investigating various physical therapy strategies for knee OA. Participants were randomized into 4 treatment groups: exercise only (EX), exercise plus booster sessions (EX+B), exercise plus manual therapy (EX+MT), and exercise plus manual therapy and booster sessions (EX+MT+B). For the 2-year base case scenario, a Markov model was constructed using the United States societal perspective and a 3% discount rate for costs and quality-adjusted life years (QALYs). Incremental cost-effectiveness ratios were calculated to compare differences in cost per QALY gained among the 4 treatment strategies. In the 2-year analysis, booster strategies (EX+MT+B and EX+B) dominated no-booster strategies, with both lower health care costs and greater effectiveness. EX+MT+B had the lowest total health care costs. EX+B cost ${\\$}$1061 more and gained 0.082 more QALYs than EX+MT+B, for an incremental cost-effectiveness ratio of ${\\$}$12,900/QALY gained. The small number of total knee arthroplasty surgeries received by individuals in this study made the assessment of whether any particular strategy was more successful at delaying or preventing surgery in individuals with knee OA difficult. Spacing exercise-based physical therapy sessions over 12 months using periodic booster sessions was less costly and more effective over 2 years than strategies not containing booster sessions for individuals with knee OA. © 2017 American Physical Therapy Association

Comparative Investigation of Shared Filesystems for the LHCb Online Cluster

NASA Astrophysics Data System (ADS)

Vijay Kartik, S.; Neufeld, Niko

2012-12-01

This paper describes the investigative study undertaken to evaluate shared filesystem performance and suitability in the LHCb Online environment. Particular focus is given to the measurements and field tests designed and performed on an in-house OpenAFS setup; related comparisons with NFSv4 and GPFS (a clustered filesystem from IBM) are presented. The motivation for the investigation and the test setup arises from the need to serve common user-space like home directories, experiment software and control areas, and clustered log areas. Since the operational requirements on such user-space are stringent in terms of read-write operations (in frequency and access speed) and unobtrusive data relocation, test results are presented with emphasis on file-level performance, stability and “high-availability” of the shared filesystems. Use cases specific to the experiment operation in LHCb, including the specific handling of shared filesystems served to a cluster of 1500 diskless nodes, are described. Issues of prematurely expiring authenticated sessions are explicitly addressed, keeping in mind long-running analysis jobs on the Online cluster. In addition, quantitative test results are also presented with alternatives including NFSv4. Comparative measurements of filesystem performance benchmarks are presented, which are seen to be used as reference for decisions on potential migration of the current storage solution deployed in the LHCb online cluster.

Application of ray-traced tropospheric slant delays to geodetic VLBI analysis

NASA Astrophysics Data System (ADS)

Hofmeister, Armin; Böhm, Johannes

2017-08-01

The correction of tropospheric influences via so-called path delays is critical for the analysis of observations from space geodetic techniques like the very long baseline interferometry (VLBI). In standard VLBI analysis, the a priori slant path delays are determined using the concept of zenith delays, mapping functions and gradients. The a priori use of ray-traced delays, i.e., tropospheric slant path delays determined with the technique of ray-tracing through the meteorological data of numerical weather models (NWM), serves as an alternative way of correcting the influences of the troposphere on the VLBI observations within the analysis. In the presented research, the application of ray-traced delays to the VLBI analysis of sessions in a time span of 16.5 years is investigated. Ray-traced delays have been determined with program RADIATE (see Hofmeister in Ph.D. thesis, Department of Geodesy and Geophysics, Faculty of Mathematics and Geoinformation, Technische Universität Wien. http://resolver.obvsg.at/urn:nbn:at:at-ubtuw:1-3444, 2016) utilizing meteorological data provided by NWM of the European Centre for Medium-Range Weather Forecasts (ECMWF). In comparison with a standard VLBI analysis, which includes the tropospheric gradient estimation, the application of the ray-traced delays to an analysis, which uses the same parameterization except for the a priori slant path delay handling and the used wet mapping factors for the zenith wet delay (ZWD) estimation, improves the baseline length repeatability (BLR) at 55.9% of the baselines at sub-mm level. If no tropospheric gradients are estimated within the compared analyses, 90.6% of all baselines benefit from the application of the ray-traced delays, which leads to an average improvement of the BLR of 1 mm. The effects of the ray-traced delays on the terrestrial reference frame are also investigated. A separate assessment of the RADIATE ray-traced delays is carried out by comparison to the ray-traced delays from the National Aeronautics and Space Administration Goddard Space Flight Center (NASA GSFC) (Eriksson and MacMillan in http://lacerta.gsfc.nasa.gov/tropodelays, 2016) with respect to the analysis performances in terms of BLR results. If tropospheric gradient estimation is included in the analysis, 51.3% of the baselines benefit from the RADIATE ray-traced delays at sub-mm difference level. If no tropospheric gradients are estimated within the analysis, the RADIATE ray-traced delays deliver a better BLR at 63% of the baselines compared to the NASA GSFC ray-traced delays.

Modulating Memory Performance in Healthy Subjects with Transcranial Direct Current Stimulation Over the Right Dorsolateral Prefrontal Cortex.

PubMed

Smirni, Daniela; Turriziani, Patrizia; Mangano, Giuseppa Renata; Cipolotti, Lisa; Oliveri, Massimiliano

2015-01-01

The role of the Dorsolateral Prefrontal Cortex (DLPFC) in recognition memory has been well documented in lesion, neuroimaging and repetitive Transcranial Magnetic Stimulation (rTMS) studies. The aim of the present study was to investigate the effects of transcranial Direct Current Stimulation (tDCS) over the left and the right DLPFC during the delay interval of a non-verbal recognition memory task. 36 right-handed young healthy subjects participated in the study. The experimental task was an Italian version of Recognition Memory Test for unknown faces. Study included two experiments: in a first experiment, each subject underwent one session of sham tDCS and one session of left or right cathodal tDCS; in a second experiment each subject underwent one session of sham tDCS and one session of left or right anodal tDCS. Cathodal tDCS over the right DLPFC significantly improved non verbal recognition memory performance, while cathodal tDCS over the left DLPFC had no effect. Anodal tDCS of both the left and right DLPFC did not modify non verbal recognition memory performance. Complementing the majority of previous studies, reporting long term memory facilitations following left prefrontal anodal tDCS, the present findings show that cathodal tDCS of the right DLPFC can also improve recognition memory in healthy subjects.

Effects of MDMA on olfactory memory and reversal learning in rats

PubMed Central

Hawkey, Andrew; April, L. Brooke; Galizio, Mark

2014-01-01

The effects of acute and sub-chronic MDMA were assessed using a procedure designed to test rodent working memory capacity: the odor span task (OST). Rats were trained to select an odor that they had not previously encountered within the current session, and the number of odors to remember was incremented up to 24 during the course of each session. In order to separate drug effects on the OST from more general performance impairment, a simple olfactory discrimination was also assessed in each session. In Experiment 1, acute doses of MDMA were administered prior to select sessions. MDMA impaired memory span in a dose-dependent fashion, but impairment was seen only at doses (1.8 and 3.0 mg/kg) that also increased response omissions on both the simple discrimination and the OST. In Experiment 2, a sub-chronic regimen of MDMA (10.0 mg/kg, twice daily over four days) was administered after OST training. There was no evidence of reduced memory span following sub-chronic MDMA, but a temporary increase in omission errors on the OST was observed. In addition, rats exposed to sub-chronic MDMA showed delayed learning when the simple discrimination was reversed. Overall, the disruptive effects of both acute and sub-chronic MDMA appeared to be due to non-mnemonic processes, rather than effects on specific memory functions. PMID:25017644

Similar Comparative Low and High Doses of Deltamethrin and Acetamiprid Differently Impair the Retrieval of the Proboscis Extension Reflex in the Forager Honey Bee (Apis mellifera).

PubMed

Thany, Steeve H; Bourdin, Céline M; Graton, Jérôme; Laurent, Adèle D; Mathé-Allainmat, Monique; Lebreton, Jacques; Questel, Jean-Yves le

2015-09-28

In the present study, the effects of low (10 ng/bee) and high (100 ng/bee) doses of acetamiprid and deltamethrin insecticides on multi-trial learning and retrieval were evaluated in the honey bee Apis mellifera. After oral application, acetamiprid and deltamethrin at the concentrations used were not able to impair learning sessions. When the retention tests were performed 1 h, 6 h, and 24 h after learning, we found a significant difference between bees after learning sessions when drugs were applied 24 h before learning. Deltamethrin-treated bees were found to be more sensitive at 10 ng/bee and 100 ng/bee doses compared to acetamiprid-treated bees, only with amounts of 100 ng/bee and at 6 h and 24 h delays. When insecticides were applied during learning sessions, none of the tested insecticides was able to impair learning performance at 10 ng/bee or 100 ng/bee but retention performance was altered 24 h after learning sessions. Acetamiprid was the only one to impair retrieval at 10 ng/bee, whereas at 100 ng/bee an impairment of retrieval was found with both insecticides. The present results therefore suggest that acetamiprid and deltamethrin are able to impair retrieval performance in the honey bee Apis mellifera.

Time-Dependent Effects of Prazosin on the Development of Methamphetamine Conditioned Hyperactivity and Context-Specific Sensitization in Mice

PubMed Central

White, André O.; Rauhut, Anthony S.

2014-01-01

The present experiments examined the effects of prazosin, a selective α1-adrenergic receptor antagonist, on the development of methamphetamine conditioned hyperactivity and context-specific sensitization. Mice received an injection of vehicle (distilled water) or prazosin (0.5, 1.0 or 2.0 mg/kg) 30 minutes prior to a second injection of vehicle (saline) or methamphetamine (1.0 mg/kg) during the conditioning sessions (Experiment 1). Following the conditioning sessions, mice were tested for conditioned hyperactivity and then tested for context-specific sensitization. In subsequent experiments, mice received an injection of vehicle (distilled water) or prazosin (2.0 mg/kg) immediately (Experiment 2) or 24 hours (Experiment 3) after the conditioning sessions and then tested for conditioned hyperactivity and context-specific sensitization. Prazosin dose-dependently blocked the development of methamphetamine conditioned hyperactivity and context-specific sensitization when administered prior to the methamphetamine during the conditioning phase; however nonspecific motor impairments also were observed (Experiment 1). Immediate (Experiment 2), but not the 24-hour delay (Experiment 3), post-session administration of prazosin attenuated the development of methamphetamine conditioned hyperactivity and context-specific sensitization. Nonspecific motor impairments were not observed in these latter experiments. Collectively, these results suggest that the α1-adrenergic receptor mediates the development of methamphetamine-conditioned hyperactivity and context-specific sensitization, perhaps by altering memory consolidation and/or reconsolidation processes. PMID:24487011

Aging and solid shape recognition: Vision and haptics.

PubMed

Norman, J Farley; Cheeseman, Jacob R; Adkins, Olivia C; Cox, Andrea G; Rogers, Connor E; Dowell, Catherine J; Baxter, Michael W; Norman, Hideko F; Reyes, Cecia M

2015-10-01

The ability of 114 younger and older adults to recognize naturally-shaped objects was evaluated in three experiments. The participants viewed or haptically explored six randomly-chosen bell peppers (Capsicum annuum) in a study session and were later required to judge whether each of twelve bell peppers was "old" (previously presented during the study session) or "new" (not presented during the study session). When recognition memory was tested immediately after study, the younger adults' (Experiment 1) performance for vision and haptics was identical when the individual study objects were presented once. Vision became superior to haptics, however, when the individual study objects were presented multiple times. When 10- and 20-min delays (Experiment 2) were inserted in between study and test sessions, no significant differences occurred between vision and haptics: recognition performance in both modalities was comparable. When the recognition performance of older adults was evaluated (Experiment 3), a negative effect of age was found for visual shape recognition (younger adults' overall recognition performance was 60% higher). There was no age effect, however, for haptic shape recognition. The results of the present experiments indicate that the visual recognition of natural object shape is different from haptic recognition in multiple ways: visual shape recognition can be superior to that of haptics and is affected by aging, while haptic shape recognition is less accurate and unaffected by aging. Copyright © 2015 Elsevier Ltd. All rights reserved.

Accelerometer-based automatic voice onset detection in speech mapping with navigated repetitive transcranial magnetic stimulation.

PubMed

Vitikainen, Anne-Mari; Mäkelä, Elina; Lioumis, Pantelis; Jousmäki, Veikko; Mäkelä, Jyrki P

2015-09-30

The use of navigated repetitive transcranial magnetic stimulation (rTMS) in mapping of speech-related brain areas has recently shown to be useful in preoperative workflow of epilepsy and tumor patients. However, substantial inter- and intraobserver variability and non-optimal replicability of the rTMS results have been reported, and a need for additional development of the methodology is recognized. In TMS motor cortex mappings the evoked responses can be quantitatively monitored by electromyographic recordings; however, no such easily available setup exists for speech mappings. We present an accelerometer-based setup for detection of vocalization-related larynx vibrations combined with an automatic routine for voice onset detection for rTMS speech mapping applying naming. The results produced by the automatic routine were compared with the manually reviewed video-recordings. The new method was applied in the routine navigated rTMS speech mapping for 12 consecutive patients during preoperative workup for epilepsy or tumor surgery. The automatic routine correctly detected 96% of the voice onsets, resulting in 96% sensitivity and 71% specificity. Majority (63%) of the misdetections were related to visible throat movements, extra voices before the response, or delayed naming of the previous stimuli. The no-response errors were correctly detected in 88% of events. The proposed setup for automatic detection of voice onsets provides quantitative additional data for analysis of the rTMS-induced speech response modifications. The objectively defined speech response latencies increase the repeatability, reliability and stratification of the rTMS results. Copyright © 2015 Elsevier B.V. All rights reserved.

Reliability measures of functional magnetic resonance imaging in a longitudinal evaluation of mild cognitive impairment.

PubMed

Zanto, Theodore P; Pa, Judy; Gazzaley, Adam

2014-01-01

As the aging population grows, it has become increasingly important to carefully characterize amnestic mild cognitive impairment (aMCI), a preclinical stage of Alzheimer's disease (AD). Functional magnetic resonance imaging (fMRI) is a valuable tool for monitoring disease progression in selectively vulnerable brain regions associated with AD neuropathology. However, the reliability of fMRI data in longitudinal studies of older adults with aMCI is largely unexplored. To address this, aMCI participants completed two visual working tasks, a Delayed-Recognition task and a One-Back task, on three separate scanning sessions over a three-month period. Test-retest reliability of the fMRI blood oxygen level dependent (BOLD) activity was assessed using an intraclass correlation (ICC) analysis approach. Results indicated that brain regions engaged during the task displayed greater reliability across sessions compared to regions that were not utilized by the task. During task-engagement, differential reliability scores were observed across the brain such that the frontal lobe, medial temporal lobe, and subcortical structures exhibited fair to moderate reliability (ICC=0.3-0.6), while temporal, parietal, and occipital regions exhibited moderate to good reliability (ICC=0.4-0.7). Additionally, reliability across brain regions was more stable when three fMRI sessions were used in the ICC calculation relative to two fMRI sessions. In conclusion, the fMRI BOLD signal is reliable across scanning sessions in this population and thus a useful tool for tracking longitudinal change in observational and interventional studies in aMCI. © 2013.

The ERP old-new effect: A useful indicator in studying the effects of sleep on memory retrieval processes.

PubMed

Mograss, Melodee; Godbout, Roger; Guillem, F

2006-11-01

To verify that the classic "Old/New" memory effect can be detected after a long delay, and to investigate the differential influence of declarative memory processes after normal sleep and daytime wake. The protocol is a variation of a more traditional study-recognition test used in event-related potential (ERP) studies in which sleep or wake is inserted between the learning and recognition session in order to verify the existence of the Old/New effect (ie, positive shift that occurs when stimuli are repeated). ERPs were recorded during the recognition-test session. The protocol was based on early work that compared the effect of sleep on memory without recording sleep. Data collection occurred in the outpatient sleep laboratory. Results from 13 subjects (6 men) aged between 21 and 39 years. The subjects performed the recognition memory test after sleep and daytime wake periods. More-accurate performance for the old (studied) stimuli occurred after the sleep session. Analysis of variance on correctly answered reaction times revealed a significant effect of condition (old/new) with no difference across session. A repeated-measure analysis revealed differences in "Old/New" effect, whereby the amplitude difference between the old and new items was larger after sleep than after wake. This effect of sleep was found in early frontal and later posterior ERP components, processes that represent strategic, contextual processing and facilitation of episodic memory. Memory representation was not different across sessions. These findings suggest that sleep and wake facilitate 2 components of memory unequally, ie, episodic recognition and memory representation functioning.

4D laser camera for accurate patient positioning, collision avoidance, image fusion and adaptive approaches during diagnostic and therapeutic procedures.

PubMed

Brahme, Anders; Nyman, Peter; Skatt, Björn

2008-05-01

A four-dimensional (4D) laser camera (LC) has been developed for accurate patient imaging in diagnostic and therapeutic radiology. A complementary metal-oxide semiconductor camera images the intersection of a scanned fan shaped laser beam with the surface of the patient and allows real time recording of movements in a three-dimensional (3D) or four-dimensional (4D) format (3D +time). The LC system was first designed as an accurate patient setup tool during diagnostic and therapeutic applications but was found to be of much wider applicability as a general 4D photon "tag" for the surface of the patient in different clinical procedures. It is presently used as a 3D or 4D optical benchmark or tag for accurate delineation of the patient surface as demonstrated for patient auto setup, breathing and heart motion detection. Furthermore, its future potential applications in gating, adaptive therapy, 3D or 4D image fusion between most imaging modalities and image processing are discussed. It is shown that the LC system has a geometrical resolution of about 0, 1 mm and that the rigid body repositioning accuracy is about 0, 5 mm below 20 mm displacements, 1 mm below 40 mm and better than 2 mm at 70 mm. This indicates a slight need for repeated repositioning when the initial error is larger than about 50 mm. The positioning accuracy with standard patient setup procedures for prostate cancer at Karolinska was found to be about 5-6 mm when independently measured using the LC system. The system was found valuable for positron emission tomography-computed tomography (PET-CT) in vivo tumor and dose delivery imaging where it potentially may allow effective correction for breathing artifacts in 4D PET-CT and image fusion with lymph node atlases for accurate target volume definition in oncology. With a LC system in all imaging and radiation therapy rooms, auto setup during repeated diagnostic and therapeutic procedures may save around 5 min per session, increase accuracy and allow efficient image fusion between all imaging modalities employed.

Digital Synchronizer without Metastability

NASA Technical Reports Server (NTRS)

Simle, Robert M.; Cavazos, Jose A.

2009-01-01

A proposed design for a digital synchronizing circuit would eliminate metastability that plagues flip-flop circuits in digital input/output interfaces. This metastability is associated with sampling, by use of flip-flops, of an external signal that is asynchronous with a clock signal that drives the flip-flops: it is a temporary flip-flop failure that can occur when a rising or falling edge of an asynchronous signal occurs during the setup and/or hold time of a flip-flop. The proposed design calls for (1) use of a clock frequency greater than the frequency of the asynchronous signal, (2) use of flip-flop asynchronous preset or clear signals for the asynchronous input, (3) use of a clock asynchronous recovery delay with pulse width discriminator, and (4) tying the data inputs to constant logic levels to obtain (5) two half-rate synchronous partial signals - one for the falling and one for the rising edge. Inasmuch as the flip-flop data inputs would be permanently tied to constant logic levels, setup and hold times would not be violated. The half-rate partial signals would be recombined to construct a signal that would replicate the original asynchronous signal at its original rate but would be synchronous with the clock signal.

A new device for monitoring individual activity rhythms of honey bees reveals critical effects of the social environment on behavior.

PubMed

Beer, Katharina; Steffan-Dewenter, Ingolf; Härtel, Stephan; Helfrich-Förster, Charlotte

2016-08-01

Chronobiological studies of individual activity rhythms in social insects can be constrained by the artificial isolation of individuals from their social context. We present a new experimental set-up that simultaneously measures the temperature rhythm in a queen-less but brood raising mini colony and the walking activity rhythms of singly kept honey bees that have indirect social contact with it. Our approach enables monitoring of individual bees in the social context of a mini colony under controlled laboratory conditions. In a pilot experiment, we show that social contact with the mini colony improves the survival of monitored young individuals and affects locomotor activity patterns of young and old bees. When exposed to conflicting Zeitgebers consisting of a light-dark (LD) cycle that is phase-delayed with respect to the mini colony rhythm, rhythms of young and old bees are socially synchronized with the mini colony rhythm, whereas isolated bees synchronize to the LD cycle. We conclude that the social environment is a stronger Zeitgeber than the LD cycle and that our new experimental set-up is well suited for studying the mechanisms of social entrainment in honey bees.

Design and evaluation of bilayered buccal film preparations for local administration of lidocaine hydrochloride.

PubMed

Preis, Maren; Woertz, Christina; Schneider, Katharina; Kukawka, Jennifer; Broscheit, Jens; Roewer, Norbert; Breitkreutz, Jörg

2014-04-01

Bilayered oromucosal film preparations (buccal films) offer a promising way to enable drug administration via the oral cavity. Adding a non-soluble or slowly eroding/dissolving backing layer to a mucoadhesive drug-loaded layer enables unidirectional drug delivery. The aim of this study was to investigate different approaches to the manufacture of bilayered films and to examine their properties by applying different characterization methods including an optimized experimental setup for the study of drug release from bilayered films. A solvent suitability study was performed screening over 15 polymers with respect to their feasibility for viscous film formation for film preparation by solvent casting method. Two methods (double-casting and pasting) were found as suitable methods for bilayered film manufacturing. Results from drug release experiments indicated that slowly eroding hypromellose backing layer films revealed the best shielding of the drug-loaded layer to enable unidirectional drug release. In summary, manufacturing of bilayered films using the described methods was feasible. Furthermore, the use of an optimized experimental setup for drug dissolution studies enabled monitoring of drug release without delays in sampling. Copyright © 2014 Elsevier B.V. All rights reserved.

Intake-dependent effects of cocaine self-administration on impulsive choice in a delay discounting task

PubMed Central

Mitchell, Marci R.; Weiss, Virginia G.; Ouimet, Dominique J.; Fuchs, Rita A.; Morgan, Drake; Setlow, Barry

2014-01-01

Cocaine use is associated with high levels of impulsive choice (greater discounting of delayed rewards) in humans, but the cause/effect relationships between cocaine use and impulsive choice are not fully understood. In previous work, we found that both experimenter- and self-administration of fixed quantities of cocaine caused lasting increases in impulsive choice in rats. The present study extended these findings by taking into account baseline impulsive choice prior to self-administration, and by allowing rats free access to cocaine. Male Long-Evans rats were trained in a delay discounting task in which they made discrete-trial choices between small immediate and large delayed food rewards. Half of the rats were then implanted with intravenous catheters and, following recovery, allowed to self-administer cocaine HCl (1.0 mg/kg/infusion) in 6 hour sessions over 14 days. Control rats orally self-administered a sucrose solution under similar conditions. Upon completion of self-administration training, rats remained abstinent for 3 weeks before retesting in the delay discounting task. Cocaine and control groups did not differ prior to self-administration, but afterward, the cocaine group showed greater impulsive choice (fewer choices of large, delayed rewards) than controls. Additional analyses revealed that the effects of cocaine on impulsive choice were intake-dependent; rats classified as “low intake” did not differ from controls, whereas rats classified as “high intake” were significantly more impulsive than both controls and their pre-cocaine baseline. These findings are consistent with the idea that cocaine-induced, pharmacologically based neural adaptations promote the development of impulsive decision making. PMID:24841739

VGOS Operations and Geodetic Results

NASA Astrophysics Data System (ADS)

Niell, Arthur E.; Beaudoin, Christopher J.; Bolotin, Sergei; Cappallo, Roger J.; Corey, Brian E.; Gipson, John; Gordon, David; McWhirter, Russell; Ruszczyk, Chester A.; SooHoo, Jason

2014-12-01

Over the past two years the first VGOS geodetic results were obtained using the GGAO12M and Westford broadband systems that have been developed under NASA sponsorship and funding. These observations demonstrated full broadband operation, from data acquisition through correlation, delay extraction, and baseline estimation. The May 2013 24-hour session proceeded almost without human intervention in anticipation of the goal of unattended operation. A recent test observation successfully demonstrated the use of what is expected to be the operational version of the RDBE digital back end and the Mark 6 system on which the outputs of four RDBEs, each processing one RF band, were recorded on a single module at eight gigabits per second. The complex-sample VDIF data from GGAO12M and Westford were cross-correlated on the Haystack DiFX software correlator, and the instrumental delay was calculated from all of the phase calibration tones in each channel. A minimum redundancy frequency sequence (1, 2, 4, 6, 9, 13, 14, 15) was utilized to minimize the first sidelobes of the multiband delay resolution function.

Test-retest reliability and practice effects of a rapid screen of mild traumatic brain injury.

PubMed

De Monte, Veronica Eileen; Geffen, Gina Malke; Kwapil, Karleigh

2005-07-01

Test-retest reliabilities and practice effects of measures from the Rapid Screen of Concussion (RSC), in addition to the Digit Symbol Substitution Test (Digit Symbol), were examined. Twenty five male participants were tested three times; each testing session scheduled a week apart. The test-retest reliability estimates for most measures were reasonably good, ranging from .79 to .97. An exception was the delayed word recall test, which has had a reliability estimate of .66 for the first retest, and .59 for the second retest. Practice effects were evident from Times 1 to 2 on the sentence comprehension and delayed recall subtests of the RSC, Digit Symbol and a composite score. There was also a practice effect of the same magnitude found from Time 2 to Time 3 on Digit Symbol, delayed recall and the composite score. Statistics on measures for both the first and second retest intervals, with associated practice effects, are presented to enable the calculation of reliable change indices (RCI). The RCI may be used to assess any improvement in cognitive functioning after mild Traumatic Brain Injury.

Short-term family-centered workshop for children with developmental delays enhances family functioning and satisfaction: A prospective clinical trial.

PubMed

Hsieh, Ru-Lan; Hsieh, Wen-Huei; Lee, Wen-Chung

2016-08-01

We investigated the clinical efficacy on family functioning and parental satisfaction of a short-term family-centered workshop for children with developmental delays.A total of 32 children with developmental delays and their parents participated in 2-hour weekly group therapy sessions over 6 weeks. The workshop was conducted by rehabilitation professionals and teachers using a family-centered multidisciplinary approach. Both before and after the 6-week workshop, the parents were administered the Pediatric Quality of Life Inventory (PedsQL) Family Impact Module, the PedsQL Healthcare Satisfaction Module, the Hospital Anxiety and Depression Scale, and the World Health Organization Quality of Life brief assessment instrument. Overall satisfaction with the workshop was also evaluated.Significant improvements were noted in physical aspect (P = 0.03), communication (P = 0.002), and daily activities (P = 0.04) in the PedsQL Family Impact Module, and in communication (P = 0.03) and technical skills (P = 0.05) in the PedsQL Healthcare Satisfaction Module. Overall satisfaction with the workshop was rated as very high. There was no significant effect on psychological distress or quality of life.Short-term family-centered workshops for children with developmental delays improved family functioning and the parental perception of satisfaction, including health care satisfaction.

Tropospheric Parameters Determined by VLBI Within the IVS

NASA Astrophysics Data System (ADS)

Schuh, H.; Boehm, J.

2003-12-01

In April 2002 the IVS (International VLBI Service for Geodesy and Astrometry) set up the Pilot Project - Tropospheric Parameters, and the Institute of Geodesy and Geophysics (IGG), Vienna, was put in charge of coordinating the project. Seven IVS Analysis Centers have joined the project and regularly submitted their estimates of tropospheric parameters (wet and total zenith delays, horizontal gradients) for all IVS-R1 and IVS-R4 sessions since January 1st, 2002. The individual submissions are combined by a two-step procedure to obtain stable, robust and highly accurate tropospheric parameter time series with one hour resolution. The internal accuracy of the combined wet zenith delays is between 2 and 4 mm. The zenith delays derived by VLBI are compared with those provided by the International GPS Service (IGS). At sites with co-located VLBI and GPS antennas the short-term variabilities of the GPS and VLBI derived zenith delays generally show a good agreement but biases are found between the results of the two techniques. Possible reasons for these biases are discussed. Since July 1st, 2003, within the IVS the tropospheric parameters are determined as operational products. The presentation also includes the VLBI CONT02 campaign of 15 days of continuous observing in the second half of October 2002.

Immediate extinction causes a less durable loss of performance than delayed extinction following either fear or appetitive conditioning.

PubMed

Woods, Amanda M; Bouton, Mark E

2008-12-01

Five experiments with rat subjects compared the effects of immediate and delayed extinction on the durability of extinction learning. Three experiments examined extinction of fear conditioning (using the conditioned emotional response method), and two experiments examined extinction of appetitive conditioning (using the food-cup entry method). In all experiments, conditioning and extinction were accomplished in single sessions, and retention testing took place 24 h after extinction. In both fear and appetitive conditioning, immediate extinction (beginning 10 min after conditioning) caused a faster loss of responding than delayed extinction (beginning 24 h after conditioning). However, immediate extinction was less durable than delayed extinction: There was stronger spontaneous recovery during the final retention test. There was also substantial renewal of responding when the physical context was changed between immediate extinction and testing (Experiment 1). The results suggest that, in these two widely used conditioning preparations, immediate extinction does not erase or depotentiate the original learning, and instead creates a less permanent reduction in conditioned responding. Results did not support the possibility that the strong recovery after immediate extinction was due to a mismatch in the recent "context" provided by the presence or absence of a recent conditioning experience. Several other accounts are considered.

The use of EMDR in positive verbal material: results from a patient study

PubMed Central

Matthijssen, Suzy Johanna Martina Adriana; van den Hout, Marcel

2016-01-01

Background According to the working memory (WM) theory of eye movement desensitisation and reprocessing (EMDR), dual tasks that tax WM during memory recall reduce image vividness and emotionality of memory during future recalls when no dual task is carried out. There is some evidence that WM taxing also reduces vividness and emotionality of auditory or verbal imagery. Objective The present study tests the effect of eye movements (EM) on positive verbal material (verbal imagery), which is used in different parts of the EMDR protocol. In the Dutch version of the standard EMDR protocol, a procedure “Positive Closure” (PC) is performed, which uses verbal imagery under dual task condition (EM). The value of EM in this procedure has not been established and according to the WM account would be counterproductive. Two earlier studies with undergraduates, with a set-up comparable to the present one, showed no additive value of the EM in the procedure, but no counterproductive effect either. Method Thirty-six patients rated the belief in possessing two positive personality traits and emotionality of the traits. They then had an EMDR session targeting a negative memory and recalled and re-rated the belief and emotionality of the traits afterward. Subsequently, they recalled one trait while dual tasking (EM) and the other trait without dual tasking. Afterward, they re-rated the belief and emotionality. Results EM did not affect the belief in possessing the trait or the emotionality. Secondary analysis shows an effective EMDR session itself enhances the belief in the traits, compared to a less or non-effective EMDR session. Conclusions EM are not effective in enhancing the belief in possessing a personality trait or the emotionality. If replicated by other patient studies, this suggests elimination of the PC procedure. Highlights of the article In this study the additive value of EM on verbal material (in the procedure Positive Closure) is not found. No effect of the procedure Positive Closure on the Belief in a personality trait nor the emotional intensity of the trait was found. An effective EMDR session (large reduction of the SUD during the session) was effective in changing the Belief in personality traits. PMID:27387844

Physical exercises on a bicycle-ergometer and running track to prevent hypodynamia in workers of intellectual labor

NASA Technical Reports Server (NTRS)

Vasilyeva, V. V.; Korableva, Y. N.; Trunin, V. V.

1980-01-01

A program of exercises was developed and tested, consisting of a 12 minute session on a variable load bicycle ergometer and a 10-11 min. run with brief stretching and resting sessions between. Physical performance capacity was measured before, during, and after the period of the experiment and physical exams conducted. After a 4 month test period involving 30 men, aged 25-35, the program was found to be successful in increasing physical performance capacity. The PWC170 increased an average of 22 percent and maximum oxygen consumption 14 percent. Arterial pressure dropped (120/75 to 114/68), vital capacity of lungs increased by 6 percent, strength of respiratory muscles by 8.8 percent, duration of respiratory delay by 18 percent. Duration of cardiac cycles increased, stress index decreased. Cardiac contraction rate 2 minutes after work on the ergometer decreased from 118 to 102 bt/min.

Quadriplegia due to lead-contaminated opium--case report.

PubMed

Beigmohammadi, Mohammad Taghi; Aghdashi, Moosa; Najafi, Atabak; Mojtahedzadeh, Mojtaba; Karvandian, Kassra

2008-10-01

Utilization of lead-contaminated opium may lead to severe motor neuron impairment and quadriplegia. Forty years oriented old male, opium addict, was admitted to the ICU, with headache, nausea and abdominal pain, and weakness in his lower and upper extremities without definitive diagnosis. The past medical and occupational history was negative. Laboratory investigation showed; anemia (Hb 7.7 g/dl), slightly elevated liver function tests, elevated total bilirubin, and ESR. Abdominal sonography and brain CT scan were normal. EMG and NCV results and neurologic examination were suggestive for Guillain-Barre. He underwent five sessions of plasmapheresis. Blood lead level was > 200 microg/dl. He received dimercaprol (BAL) and calcium disodium edetate (CaEDTA) for two five days session. Upon discharge from ICU all laboratory tests were normal and blood lead level was reduced, but he was quadriplegic. The delayed treatment of lead poisoning may lead to irreversible motor neuron defect.

Terrestrial reference frame solution with the Vienna VLBI Software VieVS and implication of tropospheric gradient estimation

NASA Astrophysics Data System (ADS)

Spicakova, H.; Plank, L.; Nilsson, T.; Böhm, J.; Schuh, H.

2011-07-01

The Vienna VLBI Software (VieVS) has been developed at the Institute of Geodesy and Geophysics at TU Vienna since 2008. In this presentation, we present the module Vie_glob which is the part of VieVS that allows the parameter estimation from multiple VLBI sessions in a so-called global solution. We focus on the determination of the terrestrial reference frame (TRF) using all suitable VLBI sessions since 1984. We compare different analysis options like the choice of loading corrections or of one of the models for the tropospheric delays. The effect of atmosphere loading corrections on station heights if neglected at observation level will be shown. Time series of station positions (using a previously determined TRF as a priori values) are presented and compared to other estimates of site positions from individual IVS (International VLBI Service for Geodesy and Astrometry) Analysis Centers.

D.C. Public School 1997 Repair Program and Facilities Master Plan. Hearing before the Subcommittee on the District of Columbia of the Committee on Government Reform and Oversight. House of Representatives. One Hundred Fifth Congress, Second Session.

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. House Committee on Government Reform and Oversight.

A Congressional hearing dealt with issues related to the repair program and facilities master plan of the District of Columbia Public Schools (DCPS). Opening remarks by Representative Thomas M. Davis outlined his concern over the delayed opening of the DCPS in the fall of 1997 because of uncompleted roof repairs, and the results from a performance…

Haystack Observatory VLBI Correlator

NASA Technical Reports Server (NTRS)

Titus, Mike; Cappallo, Roger; Corey, Brian; Dudevoir, Kevin; Niell, Arthur; Whitney, Alan

2013-01-01

This report summarizes the activities of the Haystack Correlator during 2012. Highlights include finding a solution to the DiFX InfiniBand timeout problem and other DiFX software development, conducting a DBE comparison test following the First International VLBI Technology Workshop, conducting a Mark IV and DiFX correlator comparison, more broadband delay experiments, more u- VLBI Galactic Center observations, and conversion of RDV session processing to the Mark IV/HOPS path. Non-real-time e-VLBI transfers and engineering support of other correlators continued.

Copyright and Technological Change. Hearings before the Subcommittee on Courts, Civil Liberties, and the Administration of Justice of the Committee on the Judiciary. House of Representatives, Ninety-Eighth Congress, First Session on Copyright and Technological Change (July 20 and 21, 1983).

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. House Committee on the Judiciary.

This hearing addressed three major issues: How should copyright law respond to technological change? Should copyright law accommodate changes initiated outside the law, or attempt to delay change by preserving existing rights? and How should the legal dividing lines be drawn between the sometimes competing demands of consumer and proprietor?…

Delayed onset and prolonged interictal delirium following electroconvulsive therapy.

PubMed

Selvaraj, Arun G; Praharaj, Samir Kumar

2012-09-01

Electroconvulsive therapy is safe and effective in the treatment of depression in older individuals. Minor cognitive side effects of electroconvulsive therapy include acute postictal confusion and reversible short-term memory deficits. However, interictal delirium is uncommon in absence of risk factors. Herein, we report the case a depressed male patient without any known risk factors who developed interictal delirium 2 days after his sixth electroconvulsive therapy session. Interictal delirium improved with treatment within 1 week. © 2012 The Authors. Psychogeriatrics © 2012 Japanese Psychogeriatric Society.

National Institute for Occupational Safety and Health Oversight: OMB Involvement in VDT Study. Hearing before the Subcommittee on Health and Safety of the Committee on Education and Labor. House of Representatives, Ninety-Ninth Congress, Second Session (June 4, 1986).

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. House Committee on Education and Labor.

This hearing addressed the issue of whether the delays in producing a proposed National Institute for Occupational and Safety Health (NIOSH) study on the possible health hazards associated with video display terminals (VDTs) are due to concerns about scientific methodology or unwarranted interference by the Office of Management and Budget (OMB).…

Multiple-Frequency Ultrasonic Pulse-Echo Display System.

DTIC Science & Technology

1982-09-28

will sweep across some time interval. Adjust the ramp rate potentiometer to set this interval to exactly 10 ps. Ramp Delay None Set time base to 1.0 lis...the function keys. The table is a printout which results F.irectly from exercising Program KEE, listed in Appendix C-I. Note that "(ESC)B" refers to...flag +21 ŕ" = one-time flag (nessage is presented prior to full plot once per session) +22 time- base duration code +23 (High order digit) +24 * +25

Effects of formaldehyde-enriched mists on Pseudotsuga menziesii (Mirbel) Franco and Lobaria pulmonaria (L.) Hoffm.

PubMed

Muir, P S; Shirazi, A M

1996-01-01

The atmosphere in some areas is polluted with formaldehyde (HCHO); however, little is known about effects of HCHO on plants at concentrations resembling those in polluted areas. The effects of simulated fogwater enriched with HCHO on seedlings of Pseudotsuga menziesii (Mirbel) Franco (Douglas fir) and pendants of Lobaria pulmonaria (L.) Hoffm. were assessed. Plants were treated with HCHO-enriched fog (target concentrations of 100, 500, and 1000 microm) during five 4-night mist sessions. Growth and nitrogenase activity (acetylene reduction rate) for lichens and growth and timing of bud-break for Douglas fir were monitored. Nitrogenase activity was lowest in lichens treated at the highest HCHO concentration after all but the first mist session, and it declined significantly with increasing HCHO concentration after the final mist session (R(2) = 0.60, p = 0.02). However, differences in nitrogenase activity among treatments were generally not statistically significant (most p values from ANOVAs were >/= 0.20). Formaldehyde did not affect growth of the lichens. Budbreak of Douglas firs was slightly delayed and height growth was slightly depressed with increasing HCHO concentration, although effects were not statistically significant.

Effects of self-administered cocaine in adolescent and adult male rats on orbitofrontal cortex-related neurocognitive functioning

PubMed Central

Harvey, Roxann C.; Dembro, Kimberly A.; Rajagopalan, Kiran; Mutebi, Michael M.; Kantak, Kathleen M.

2010-01-01

Rationale Deficits in amygdala-related stimulus-reward learning are produced following 18 drug-free days of cocaine self-administration or its passive delivery in rats exposed during adulthood. No deficits in stimulus-reward learning are produced by cocaine exposure initiated during adolescence. Objectives To determine if age of initiating cocaine exposure differentially affects behavioral functioning of an additional memory system linked to cocaine addiction, the orbitofrontal cortex. Materials and methods A yoked-triad design (n=8) was used. One rat controlled cocaine delivery and the other two passively received cocaine or saline. Rats controlling drug delivery (1.0 mg/kg) self-administered cocaine from either P37–P59 or P77–P99, and then underwent 18 drug-free days (P60–P77 vs. P100–P117). Rats next were tested for acquisition of odor-delayed win-shift behavior conducted over 15 sessions (P78–P96 vs. P118–P136). Results Cocaine self-administration did not differ between adults and adolescents. During the test phase of the odor-delayed win-shift task (relatively difficult task demands), rats from both drug-onset ages showed learning deficits. Rats with cocaine self-administration experience committed more errors and had longer session latencies compared to rats passively receiving saline or cocaine. Rats with adolescent-onset cocaine self-administration experience showed an additional learning deficit by requiring more sessions to reach criterion levels for task acquisition compared to same-aged passive saline controls or rats with adult-onset cocaine self-administration experience. Rats passively receiving cocaine did not differ from the passive saline control from either age group. Conclusions Rats with adolescent-onset cocaine self-administration experience were more impaired in an orbitofrontal cortex-related learning task than rats with adult-onset cocaine self-administration experience. PMID:19513699

Extinction of Conditioned Fear is Better Learned and Recalled in the Morning than in the Evening

PubMed Central

Pace-Schott, Edward F.; Spencer, Rebecca M.C.; Vijayakumar, Shilpa; Ahmed, Nafis; Verga, Patrick W.; Orr, Scott P.; Pitman, Roger K.; Milad, Mohammed R.

2013-01-01

Sleep helps emotional memories consolidate and may promote generalization of fear extinction memory. We examined whether extinction learning and memory might differ in the morning and evening due, potentially, to circadian and/or sleep-homeostatic factors. Healthy men (N=109) in 6 groups completed a 2-session protocol. In Session 1, fear conditioning was followed by extinction learning. Partial reinforcement with mild electric shock produced conditioned skin conductance responses (SCR) to 2 differently colored lamps (CS+), but not a third color (CS−), within the computer image of a room (conditioning context). One CS+ (CS+E) but not the other (CS+U) was immediately extinguished by un-reinforced presentations in a different room (extinction context). Delay durations of 3 hr (within AM or PM), 12 hr (morning-to-evening or evening-to-morning) or 24 hr (morning-to-morning or evening-to-evening) followed. In Session 2, extinction recall and contextual fear renewal were tested. We observed no significant effects of the delay interval on extinction memory but did observe an effect of time-of-day. Fear extinction was significantly better if learned in the morning (p=.002). Collapsing across CS+ type, there was smaller morning differential SCR at both extinction recall (p=.003) and fear renewal (p=.005). Morning extinction recall showed better generalization from the CS+E to CS+U with the response to the CS+U significantly larger than to the CS+E only in the evening (p=.028). Thus, extinction is learned faster and its memory is better generalized in the morning. Cortisol and testosterone showed the expected greater salivary levels in the morning when higher testosterone/cortisol ratio also predicting better extinction learning. Circadian factors may promote morning extinction. Alternatively, evening homeostatic sleep pressure may impede extinction and favor recall of conditioned fear. PMID:23992769

Extinction of conditioned fear is better learned and recalled in the morning than in the evening.

PubMed

Pace-Schott, Edward F; Spencer, Rebecca M C; Vijayakumar, Shilpa; Ahmed, Nafis A K; Verga, Patrick W; Orr, Scott P; Pitman, Roger K; Milad, Mohammed R

2013-11-01

Sleep helps emotional memories consolidate and may promote generalization of fear extinction memory. We examined whether extinction learning and memory might differ in the morning and evening due, potentially, to circadian and/or sleep-homeostatic factors. Healthy men (N = 109) in 6 groups completed a 2-session protocol. In Session 1, fear conditioning was followed by extinction learning. Partial reinforcement with mild electric shock produced conditioned skin conductance responses (SCRs) to 2 differently colored lamps (CS+), but not a third color (CS-), within the computer image of a room (conditioning context). One CS+ (CS + E) but not the other (CS + U) was immediately extinguished by un-reinforced presentations in a different room (extinction context). Delay durations of 3 h (within AM or PM), 12 h (morning-to-evening or evening-to-morning) or 24 h (morning-to-morning or evening-to-evening) followed. In Session 2, extinction recall and contextual fear renewal were tested. We observed no significant effects of the delay interval on extinction memory but did observe an effect of time-of-day. Fear extinction was significantly better if learned in the morning (p = .002). Collapsing across CS + type, there was smaller morning differential SCR at both extinction recall (p = .003) and fear renewal (p = .005). Morning extinction recall showed better generalization from the CS + E to CS + U with the response to the CS + U significantly larger than to the CS + E only in the evening (p = .028). Thus, extinction is learned faster and its memory is better generalized in the morning. Cortisol and testosterone showed the expected greater salivary levels in the morning when higher testosterone/cortisol ratio also predicted better extinction learning. Circadian factors may promote morning extinction. Alternatively, evening homeostatic sleep pressure may impede extinction and favor recall of conditioned fear. Copyright © 2013 Elsevier Ltd. All rights reserved.

Remifentanil maintains lower initial delayed nonmatching-to-sample accuracy compared to food pellets in male rhesus monkeys.

PubMed

Hutsell, Blake A; Banks, Matthew L

2017-12-01

Emerging human laboratory and preclinical drug self-administration data suggest that a history of contingent abused drug exposure impairs performance in operant discrimination procedures, such as delayed nonmatching-to-sample (DNMTS), that are hypothesized to assess components of executive function. However, these preclinical discrimination studies have exclusively used food as the reinforcer and the effects of drugs as reinforcers in these operant procedures are unknown. The present study determined effects of contingent intravenous remifentanil injections on DNMTS performance hypothesized to assess 1 aspect of executive function, working memory. Daily behavioral sessions consisted of 2 components with sequential intravenous remifentanil (0, 0.01-1.0 μg/kg/injection) or food (0, 1-10 pellets) availability in nonopioid dependent male rhesus monkeys (n = 3). Remifentanil functioned as a reinforcer in the DNMTS procedure. Similar delay-dependent DNMTS accuracy was observed under both remifentanil- and food-maintained components, such that higher accuracies were maintained at shorter (0.1-1.0 s) delays and lower accuracies approaching chance performance were maintained at longer (10-32 s) delays. Remifentanil maintained significantly lower initial DNMTS accuracy compared to food. Reinforcer magnitude was not an important determinant of DNMTS accuracy for either remifentanil or food. These results extend the range of experimental procedures under which drugs function as reinforcers. Furthermore, the selective remifentanil-induced decrease in initial DNMTS accuracy is consistent with a selective impairment of attentional, but not memorial, processes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

SPICODYN: A Toolbox for the Analysis of Neuronal Network Dynamics and Connectivity from Multi-Site Spike Signal Recordings.

PubMed

Pastore, Vito Paolo; Godjoski, Aleksandar; Martinoia, Sergio; Massobrio, Paolo

2018-01-01

We implemented an automated and efficient open-source software for the analysis of multi-site neuronal spike signals. The software package, named SPICODYN, has been developed as a standalone windows GUI application, using C# programming language with Microsoft Visual Studio based on .NET framework 4.5 development environment. Accepted input data formats are HDF5, level 5 MAT and text files, containing recorded or generated time series spike signals data. SPICODYN processes such electrophysiological signals focusing on: spiking and bursting dynamics and functional-effective connectivity analysis. In particular, for inferring network connectivity, a new implementation of the transfer entropy method is presented dealing with multiple time delays (temporal extension) and with multiple binary patterns (high order extension). SPICODYN is specifically tailored to process data coming from different Multi-Electrode Arrays setups, guarantying, in those specific cases, automated processing. The optimized implementation of the Delayed Transfer Entropy and the High-Order Transfer Entropy algorithms, allows performing accurate and rapid analysis on multiple spike trains from thousands of electrodes.

Charge dynamics in aluminum oxide thin film studied by ultrafast scanning electron microscopy.

PubMed

Zani, Maurizio; Sala, Vittorio; Irde, Gabriele; Pietralunga, Silvia Maria; Manzoni, Cristian; Cerullo, Giulio; Lanzani, Guglielmo; Tagliaferri, Alberto

2018-04-01

The excitation dynamics of defects in insulators plays a central role in a variety of fields from Electronics and Photonics to Quantum computing. We report here a time-resolved measurement of electron dynamics in 100 nm film of aluminum oxide on silicon by Ultrafast Scanning Electron Microscopy (USEM). In our pump-probe setup, an UV femtosecond laser excitation pulse and a delayed picosecond electron probe pulse are spatially overlapped on the sample, triggering Secondary Electrons (SE) emission to the detector. The zero of the pump-probe delay and the time resolution were determined by measuring the dynamics of laser-induced SE contrast on silicon. We observed fast dynamics with components ranging from tens of picoseconds to few nanoseconds, that fits within the timescales typical of the UV color center evolution. The surface sensitivity of SE detection gives to the USEM the potential of applying pump-probe investigations to charge dynamics at surfaces and interfaces of current nano-devices. The present work demonstrates this approach on large gap insulator surfaces. Copyright © 2018 Elsevier B.V. All rights reserved.

Control of the coherence behavior in a SFG interferometer through the multipump phases command.

PubMed

Darré, P; Lehmann, L; Grossard, L; Delage, L; Reynaud, F

2018-03-19

In this paper, we report on a novel method to control the coherence behavior in a sum frequency generation interferometer powered by two independent pump lines. At the output of the interferometer, the two incoherent fringe patterns must be superimposed to maximize the contrast. The first step consists in canceling the differential group delay. The second one uses the phase control on one pump to synchronize the fringe patterns. This innovative method is experimentally demonstrated with a setup involving a 1544 nm signal and two pump lines around 1064 nm leading to a converted signal around 630 nm. It can be easily extended to a greater number of pump lines.

Superluminal propagation in a poly-chromatically driven gain assisted four-level N-type atomic system

NASA Astrophysics Data System (ADS)

Amin Bacha, Bakht; Ahmad, Iftikhar; Ullah, Arif; Ali, Hazrat

2013-10-01

We investigate the behavior of light propagation in an N-type four-level gain assisted model (Agarwal and Dasgupta 2004 Phys. Rev. A 70 023802) under poly-chromatic pump fields. The system exhibits interesting results of multiple controllable pairs of the gain doublet profile with changes in the intensity of the control field. We observe multiple anomalous dispersive regions for superluminal propagation in the medium. A negative group velocity of -37.50 m s-1 with a negative time delay of -8 ms is observed between each gain doublet in anomalous dispersive regions. This generalized model and its predictions can be tested with existing experimental setups.

Control of Tollmien-Schlichting instabilities by finite distributed wall actuation

NASA Astrophysics Data System (ADS)

Losse, Nikolas R.; King, Rudibert; Zengl, Marcus; Rist, Ulrich; Noack, Bernd R.

2011-06-01

Tollmien-Schlichting waves are one of the key mechanisms triggering the laminar-turbulent transition in a flat-plate boundary-layer flow. By damping these waves and thus delaying transition, skin friction drag can be significantly decreased. In this simulation study, a wall segment is actuated according to a control scheme based on a POD-Galerkin model driven extended Kalman filter for state estimation and a model predictive controller to dampen TS waves by negative superposition based on this information. The setup of the simulation is chosen to resemble actuation with a driven compliant wall, such as a membrane actuator. Most importantly, a method is proposed to integrate such a localized wall actuation into a Galerkin model.

Enhancing signal detection and completely eliminating scattering using quasi-phase-cycling in 2D IR experiments.

PubMed

Bloem, Robbert; Garrett-Roe, Sean; Strzalka, Halina; Hamm, Peter; Donaldson, Paul

2010-12-20

We demonstrate how quasi-phase-cycling achieved by sub-cycle delay modulation can be used to replace optical chopping in a box-CARS 2D IR experiment in order to enhance the signal size, and, at the same time, completely eliminate any scattering contamination. Two optical devices are described that can be used for this purpose, a wobbling Brewster window and a photoelastic modulator. They are simple to construct, easy to incorporate into any existing 2D IR setup, and have attractive features such as a high optical throughput and a fast modulation frequency needed to phase cycle on a shot-to-shot basis.

A comparison of recording modalities of P300 event-related potentials (ERP) for brain-computer interface (BCI) paradigm.

PubMed

Mayaud, L; Congedo, M; Van Laghenhove, A; Orlikowski, D; Figère, M; Azabou, E; Cheliout-Heraut, F

2013-10-01

A brain-computer interface aims at restoring communication and control in severely disabled people by identification and classification of EEG features such as event-related potentials (ERPs). The aim of this study is to compare different modalities of EEG recording for extraction of ERPs. The first comparison evaluates the performance of six disc electrodes with that of the EMOTIV headset, while the second evaluates three different electrode types (disc, needle, and large squared electrode). Ten healthy volunteers gave informed consent and were randomized to try the traditional EEG system (six disc electrodes with gel and skin preparation) or the EMOTIV Headset first. Together with the six disc electrodes, a needle and a square electrode of larger surface were simultaneously recording near lead Cz. Each modality was evaluated over three sessions of auditory P300 separated by one hour. No statically significant effect was found for the electrode type, nor was the interaction between electrode type and session number. There was no statistically significant difference of performance between the EMOTIV and the six traditional EEG disc electrodes, although there was a trend showing worse performance of the EMOTIV headset. However, the modality-session interaction was highly significant (P<0.001) showing that, while the performance of the six disc electrodes stay constant over sessions, the performance of the EMOTIV headset drops dramatically between 2 and 3h of use. Finally, the evaluation of comfort by participants revealed an increasing discomfort with the EMOTIV headset starting with the second hour of use. Our study does not recommend the use of one modality over another based on performance but suggests the choice should be made on more practical considerations such as the expected length of use, the availability of skilled labor for system setup and above all, the patient comfort. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

A method to assess how interactive water simulation tools influence transdisciplinary decision-making processes in water management

NASA Astrophysics Data System (ADS)

Leskens, Johannes

2015-04-01

In modern water management, often transdisciplinary work sessions are organized in which various stakeholders participate to jointly define problems, choose measures and divide responsibilities to take actions. Involved stakeholders are for example policy analysts or decision-makers from municipalities, water boards or provinces, representatives of pressure groups and researchers from knowledge institutes. Parallel to this increasing attention for transdisciplinary work sessions, we see a growing availability of interactive IT-tools that can be applied during these sessions. For example, dynamic flood risk maps have become recently available that allow users during a work sessions to instantaneously assess the impact of storm surges or dam breaches, displayed on digital maps. Other examples are serious games, realistic visualizations and participatory simulations. However, the question is if and how these interactive IT-tools contribute to better decision-making. To assess this, we take the process of knowledge construction during a work session as a measure for the quality of decision-making. Knowledge construction can be defined as the process in which ideas, perspectives and opinions of different stakeholders, all having their own expertise and experience, are confronted with each other and new shared meanings towards water management issues are created. We present an assessment method to monitor the process of knowledge construction during work sessions in water management in which interactive IT tools are being used. The assessment method is based on a literature review, focusing on studies in which knowledge construction was monitored in other contexts that water management. To test the applicability of the assessment method, we applied it during a multi-stakeholder work session in Westland, located in the southwest of the Netherlands. The discussions during the work session were observed by camera. All statements, expressed by the various members of a stakeholder session, were classified according to our assessment method. We can draw the following preliminary conclusions. First, the case study showed that the method was useful to show the knowledge construction process over time, in terms of content and cognitive level of statements and interaction, attention and response between stakeholders. It was observed that the various aspects of knowledge construction all were influenced by the use of the 3Di model. The model focused discussions on technical issues of flood risk management, non-flood specialists were able to participate in discussions and in suggesting solutions and more topics could be evaluated in respect to non-interactive flood maps. Second, the method is considered useful as a benchmark for different interactive IT tools. The method is also considered useful to gain insight in how to optimally set-up multi-stakeholder meetings in which interactive IT-tools are being used. Further, the method can provide model developers insight in how to better meet the technical requirements of interactive IT tools to support the knowledge construction process during multi-stakeholder meeting

Human phase response curve to intermittent blue light using a commercially available device

PubMed Central

Revell, Victoria L; Molina, Thomas A; Eastman, Charmane I

2012-01-01

Light shifts the timing of the circadian clock according to a phase response curve (PRC). To date, all human light PRCs have been to long durations of bright white light. However, melanopsin, the primary photopigment for the circadian system, is most sensitive to short wavelength blue light. Therefore, to optimise light treatment it is important to generate a blue light PRC. We used a small, commercially available blue LED light box, screen size 11.2 × 6.6 cm at ∼50 cm, ∼200 μW cm−2, ∼185 lux. Subjects participated in two 5 day laboratory sessions 1 week apart. Each session consisted of circadian phase assessments to obtain melatonin profiles before and after 3 days of free-running through an ultradian light–dark cycle (2.5 h wake in dim light, 1.5 h sleep in the dark), forced desynchrony protocol. During one session subjects received intermittent blue light (three 30 min pulses over 2 h) once a day for the 3 days of free-running, and in the other session (control) they remained in dim room light, counterbalanced. The time of blue light was varied among subjects to cover the entire 24 h day. For each individual, the phase shift to blue light was corrected for the free-run determined during the control session. The blue light PRC had a broad advance region starting in the morning and extending through the afternoon. The delay region started a few hours before bedtime and extended through the night. This is the first PRC to be constructed to blue light and to a stimulus that could be used in the real world. PMID:22753544

The repeated bout effect of typical lower body strength training sessions on sub-maximal running performance and hormonal response.

PubMed

Doma, Kenji; Schumann, Moritz; Sinclair, Wade H; Leicht, Anthony S; Deakin, Glen B; Häkkinen, Keijo

2015-08-01

This study examined the effects of two typical strength training sessions performed 1 week apart (i.e. repeated bout effect) on sub-maximal running performance and hormonal. Fourteen resistance-untrained men (age 24.0 ± 3.9 years; height 1.83 ± 0.11 m; body mass 77.4 ± 14.0 kg; VOpeak 48.1 ± 6.1 M kg(-1) min(-1)) undertook two bouts of high-intensity strength training sessions (i.e. six-repetition maximum). Creatine kinase (CK), delayed-onset muscle soreness (DOMS), counter-movement jump (CMJ) as well as concentrations of serum testosterone, cortisol and testosterone/cortisol ratio (T/C) were examined prior to and immediately post, 24 (T24) and 48 (T48) h post each strength training bout. Sub-maximal running performance was also conducted at T24 and T48 of each bout. When measures were compared between bouts at T48, the degree of elevation in CK (-58.4 ± 55.6 %) and DOMS (-31.43 ± 42.9 %) and acute reduction in CMJ measures (4.1 ± 5.4 %) were attenuated (p < 0.05) following the second bout. Cortisol was increased until T24 (p < 0.05) although there were no differences between bouts and no differences were found for testosterone and T/C ratio (p > 0.05). Sub-maximal running performance was impaired until T24, although changes were not attenuated following the second bout. The initial bout appeared to provide protection against a number of muscle damage indicators suggesting a greater need for recovery following the initial session of typical lower body resistance exercises in resistance-untrained men although sub-maximal running should be avoided following the first two sessions.

Human phase response curve to intermittent blue light using a commercially available device.

PubMed

Revell, Victoria L; Molina, Thomas A; Eastman, Charmane I

2012-10-01

Light shifts the timing of the circadian clock according to a phase response curve (PRC). To date, all human light PRCs have been to long durations of bright white light. However, melanopsin, the primary photopigment for the circadian system, is most sensitive to short wavelength blue light. Therefore, to optimise light treatment it is important to generate a blue light PRC.We used a small, commercially available blue LED light box, screen size 11.2 × 6.6 cm at ∼50 cm, ∼200 μW cm(−2), ∼185 lux. Subjects participated in two 5 day laboratory sessions 1 week apart. Each session consisted of circadian phase assessments to obtain melatonin profiles before and after 3 days of free-running through an ultradian light–dark cycle (2.5 h wake in dim light, 1.5 h sleep in the dark), forced desynchrony protocol. During one session subjects received intermittent blue light (three 30 min pulses over 2 h) once a day for the 3 days of free-running, and in the other session (control) they remained in dim room light, counterbalanced. The time of blue light was varied among subjects to cover the entire 24 h day. For each individual, the phase shift to blue light was corrected for the free-run determined during the control session. The blue light PRC had a broad advance region starting in the morning and extending through the afternoon. The delay region started a few hours before bedtime and extended through the night. This is the first PRC to be constructed to blue light and to a stimulus that could be used in the real world.

Using recovery modalities between training sessions in elite athletes: does it help?

PubMed

Barnett, Anthony

2006-01-01

Achieving an appropriate balance between training and competition stresses and recovery is important in maximising the performance of athletes. A wide range of recovery modalities are now used as integral parts of the training programmes of elite athletes to help attain this balance. This review examined the evidence available as to the efficacy of these recovery modalities in enhancing between-training session recovery in elite athletes. Recovery modalities have largely been investigated with regard to their ability to enhance the rate of blood lactate removal following high-intensity exercise or to reduce the severity and duration of exercise-induced muscle injury and delayed onset muscle soreness (DOMS). Neither of these reflects the circumstances of between-training session recovery in elite athletes. After high-intensity exercise, rest alone will return blood lactate to baseline levels well within the normal time period between the training sessions of athletes. The majority of studies examining exercise-induced muscle injury and DOMS have used untrained subjects undertaking large amounts of unfamiliar eccentric exercise. This model is unlikely to closely reflect the circumstances of elite athletes. Even without considering the above limitations, there is no substantial scientific evidence to support the use of the recovery modalities reviewed to enhance the between-training session recovery of elite athletes. Modalities reviewed were massage, active recovery, cryotherapy, contrast temperature water immersion therapy, hyperbaric oxygen therapy, nonsteroidal anti-inflammatory drugs, compression garments, stretching, electromyostimulation and combination modalities. Experimental models designed to reflect the circumstances of elite athletes are needed to further investigate the efficacy of various recovery modalities for elite athletes. Other potentially important factors associated with recovery, such as the rate of post-exercise glycogen synthesis and the role of inflammation in the recovery and adaptation process, also need to be considered in this future assessment.

Ethanol induces impulsive-like responding in a delay-of-reward operant choice procedure: impulsivity predicts autoshaping.

PubMed

Tomie, A; Aguado, A S; Pohorecky, L A; Benjamin, D

1998-10-01

Autoshaping conditioned responses (CRs) are reflexive and targeted motor responses expressed as a result of experience with reward. To evaluate the hypothesis that autoshaping may be a form of impulsive responding, within-subjects correlations between performance on autoshaping and impulsivity tasks were assessed in 15 Long-Evans hooded rats. Autoshaping procedures [insertion of retractable lever conditioned stimulus (CS) followed by the response-independent delivery of food (US)] were followed by testing for impulsive-like responding in a two-choice lever-press operant delay-of-reward procedure (immediate small food reward versus delayed large food reward). Delay-of-reward functions revealed two distinct subject populations. Subjects in the Sensitive group (n=7) were more impulsive-like, increasing immediate reward choices at longer delays for large reward, while those in the Insensitive group (n=8) responded predominantly on only one lever. During the prior autoshaping phase, the Sensitive group had performed more autoshaping CRs, and correlations revealed that impulsive subjects acquired the autoshaping CR in fewer trials. In the Sensitive group, acute injections of ethanol (0, 0.25, 0.50, 1.00, 1.50 g/kg) given immediately before delay-of-reward sessions yielded an inverted U-shaped dose-response curve with increased impulsivity induced by the 0.25, 0.50, and 1.00 g/kg doses of ethanol, while choice strategy of the Insensitive group was not influenced by ethanol dose. Ethanol induced impulsive-like responding only in rats that were flexible in their response strategy (Sensitive group), and this group also performed more autoshaping CRs. Data support the hypothesis that autoshaping and impulsivity are linked.

Mixed-Effects Modeling of Neurofeedback Self-Regulation Performance: Moderators for Learning in Children with ADHD.

PubMed

Zuberer, Agnieszka; Minder, Franziska; Brandeis, Daniel; Drechsler, Renate

2018-01-01

Neurofeedback (NF) has gained increasing popularity as a training method for children and adults with attention deficit hyperactivity disorder (ADHD). However, it is unclear to what extent children learn to regulate their brain activity and in what way NF learning may be affected by subject- and treatment-related factors. In total, 48 subjects with ADHD (age 8.5-16.5 years; 16 subjects on methylphenidate (MPH)) underwent 15 double training sessions of NF in either a clinical or a school setting. Four mixed-effects models were employed to analyze learning: training within-sessions, across-sessions, with continuous feedback, and with transfer in which performance feedback is delayed. Age and MPH affected the NF performance in all models. Cross-session learning in the feedback condition was mainly moderated by age and MPH, whereas NF learning in the transfer condition was mainly boosted by MPH. Apart from IQ and task types, other subject-related or treatment-related effects were unrelated to NF learning. This first study analyzing moderators of NF learning in ADHD with a mixed-effects modeling approach shows that NF performance is moderated differentially by effects of age and MPH depending on the training task and time window. Future studies may benefit from using this approach to analyze NF learning and NF specificity. The trial name Neurofeedback and Computerized Cognitive Training in Different Settings for Children and Adolescents With ADHD is registered with NCT02358941.

Rest Interval Required for Power Training With Power Load in the Bench Press Throw Exercise.

PubMed

Hernández Davó, Jose L; Solana, Rafael Sabido; Sarabia Marín, Jose M; Fernández Fernández, Jaime; Moya Ramón, Manuel

2016-05-01

This study aimed to test the influence of various rest interval (RI) durations used between sets on power output performance and physiological and perceptual variables during a strength training session using 40% of the 1 repetition maximum (1RM) in the bench press throw exercise. Thirty-one college students (18 males and 13 females) took part in the study. The experimental protocol consists of 5 sets of 8 repetitions of the bench press throw exercise with a load representing 40% of 1RM. Subjects performed the experimental protocol on 3 different occasions, differing by the RI between sets (1, 2, or 3 minutes). During the sessions, power data (mean power and peak power), physiological (lactate concentration [La]) and perceptual (rating of perceived exertion) variables were measured. In addition, delayed onset muscular soreness was reported 24 and 48 hours after the training session. One-way repeated-measures analysis of variance showed that 1-minute RI entailed higher power decreases and greater increases in values of physiological and perceptual variables compared with both 2- and 3-minute RIs. Nevertheless, no differences were found between 2- and 3-minute RIs. Therefore, this study showed that, when training with 40% of 1RM in the bench press throw exercise, a 2-minute RI between sets can be enough to avoid significant decreases in power output. Consequently, training sessions' duration could be reduced without causing excessive fatigue, allowing additional time to focus on other conditioning priorities.

Time-dependent effects of prazosin on the development of methamphetamine conditioned hyperactivity and context-specific sensitization in mice.

PubMed

White, André O; Rauhut, Anthony S

2014-04-15

The present experiments examined the effects of prazosin, a selective α₁-adrenergic receptor antagonist, on the development of methamphetamine conditioned hyperactivity and context-specific sensitization. Mice received an injection of vehicle (distilled water) or prazosin (0.5, 1.0 or 2.0 mg/kg) 30 min prior to a second injection of vehicle (saline) or methamphetamine (1.0 mg/kg) during the conditioning sessions (Experiment 1). Following the conditioning sessions, mice were tested for conditioned hyperactivity and then tested for context-specific sensitization. In subsequent experiments, mice received an injection of vehicle (distilled water) or prazosin (2.0 mg/kg) immediately (Experiment 2) or 24 h (Experiment 3) after the conditioning sessions and then tested for conditioned hyperactivity and context-specific sensitization. Prazosin dose-dependently blocked the development of methamphetamine conditioned hyperactivity and context-specific sensitization when administered prior to the methamphetamine during the conditioning phase; however nonspecific motor impairments also were observed (Experiment 1). Immediate (Experiment 2), but not the 24-h delay (Experiment 3), post-session administration of prazosin attenuated the development of methamphetamine conditioned hyperactivity and context-specific sensitization. Nonspecific motor impairments were not observed in these latter experiments. Collectively, these results suggest that the α₁-adrenergic receptor mediates the development of methamphetamine-conditioned hyperactivity and context-specific sensitization, perhaps by altering memory consolidation and/or reconsolidation processes. Copyright © 2014 Elsevier B.V. All rights reserved.

Individual Differences in Behavioural Despair Predict Brain GSK-3beta Expression in Mice: The Power of a Modified Swim Test

PubMed Central

Markova, Nataliia; Shevtsova, Elena; Bakhmet, Anastassia; Steinbusch, Harry M.

2016-01-01

While deficient brain plasticity is a well-established pathophysiologic feature of depression, little is known about disorder-associated enhanced cognitive processing. Here, we studied a novel mouse paradigm that potentially models augmented learning of adverse memories during development of a depressive-like state. We used a modification of the classic two-day protocol of a mouse Porsolt test with an additional session occurring on Day 5 following the initial exposure. Unexpectedly, floating behaviour and brain glycogen synthase kinase-3 beta (GSK-3beta) mRNA levels, a factor of synaptic plasticity as well as a marker of distress and depression, were increased during the additional swimming session that was prevented by imipramine. Observed increases of GSK-3beta mRNA in prefrontal cortex during delayed testing session correlated with individual parameters of behavioural despair that was not found in the classic Porsolt test. Repeated swim exposure was accompanied by a lower pGSK-3beta/GSK-3beta ratio. A replacement of the second or the final swim sessions with exposure to the context of testing resulted in increased GSK-3beta mRNA level similar to the effects of swimming, while exclusion of the second testing prevented these changes. Together, our findings implicate the activation of brain GSK-3beta expression in enhanced contextual conditioning of adverse memories, which is associated with an individual susceptibility to a depressive syndrome. PMID:27478647

Individual Differences in Behavioural Despair Predict Brain GSK-3beta Expression in Mice: The Power of a Modified Swim Test.

PubMed

Strekalova, Tatyana; Markova, Nataliia; Shevtsova, Elena; Zubareva, Olga; Bakhmet, Anastassia; Steinbusch, Harry M; Bachurin, Sergey; Lesch, Klaus-Peter

2016-01-01

While deficient brain plasticity is a well-established pathophysiologic feature of depression, little is known about disorder-associated enhanced cognitive processing. Here, we studied a novel mouse paradigm that potentially models augmented learning of adverse memories during development of a depressive-like state. We used a modification of the classic two-day protocol of a mouse Porsolt test with an additional session occurring on Day 5 following the initial exposure. Unexpectedly, floating behaviour and brain glycogen synthase kinase-3 beta (GSK-3beta) mRNA levels, a factor of synaptic plasticity as well as a marker of distress and depression, were increased during the additional swimming session that was prevented by imipramine. Observed increases of GSK-3beta mRNA in prefrontal cortex during delayed testing session correlated with individual parameters of behavioural despair that was not found in the classic Porsolt test. Repeated swim exposure was accompanied by a lower pGSK-3beta/GSK-3beta ratio. A replacement of the second or the final swim sessions with exposure to the context of testing resulted in increased GSK-3beta mRNA level similar to the effects of swimming, while exclusion of the second testing prevented these changes. Together, our findings implicate the activation of brain GSK-3beta expression in enhanced contextual conditioning of adverse memories, which is associated with an individual susceptibility to a depressive syndrome.

TU-A-BRB-03: Panel Member

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

Winey, B.

2016-06-15

Brain stereotactic radiosurgery (SRS) and spine stereotactic body radiation therapy (SBRT) are commonly treated by a multidisciplinary team of neurosurgeons, radiation oncologists, and medical physicists. However the treatment objectives, constraints, and technical considerations involved can be quite different between the two techniques. In this interactive session an expert panel of speakers will present clinical brain SRS and spine SBRT cases in order to demonstrate real-world considerations for ensuring safe and accurate treatment delivery and to highlight the significant differences in approach for each treatment site. The session will include discussion of topic such as clinical indications, immobilization, target definition, normalmore » tissue tolerance limits, and beam arrangements. Learning Objectives: Understand the differences in indications and dose/fractionation strategies for intracranial SRS and spine SBRT. Describe the different treatment modalities which can be used to deliver intracranial SRS and spine SBRT. Cite the major differences in treatment setup and delivery principles between intracranial and spine treatments. Identify key critical structures and clinical dosimetric tolerance levels for spine SBRT and intracranial SRS. Understand areas of ongoing work to standardize intracranial SRS and spine SBRT procedures. Schlesinger: Research support: Elekta Instruments, AB; D. Schlesinger, Elekta Instruments, AB - research support; B. Winey, No relevant external funding for this subject.« less

TU-A-BRB-02: Panel Member

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

Ma, L.

2016-06-15

Brain stereotactic radiosurgery (SRS) and spine stereotactic body radiation therapy (SBRT) are commonly treated by a multidisciplinary team of neurosurgeons, radiation oncologists, and medical physicists. However the treatment objectives, constraints, and technical considerations involved can be quite different between the two techniques. In this interactive session an expert panel of speakers will present clinical brain SRS and spine SBRT cases in order to demonstrate real-world considerations for ensuring safe and accurate treatment delivery and to highlight the significant differences in approach for each treatment site. The session will include discussion of topic such as clinical indications, immobilization, target definition, normalmore » tissue tolerance limits, and beam arrangements. Learning Objectives: Understand the differences in indications and dose/fractionation strategies for intracranial SRS and spine SBRT. Describe the different treatment modalities which can be used to deliver intracranial SRS and spine SBRT. Cite the major differences in treatment setup and delivery principles between intracranial and spine treatments. Identify key critical structures and clinical dosimetric tolerance levels for spine SBRT and intracranial SRS. Understand areas of ongoing work to standardize intracranial SRS and spine SBRT procedures. Schlesinger: Research support: Elekta Instruments, AB; D. Schlesinger, Elekta Instruments, AB - research support; B. Winey, No relevant external funding for this subject.« less

TU-A-BRB-01: Panel Member

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

Schlesinger, D.

2016-06-15

Brain stereotactic radiosurgery (SRS) and spine stereotactic body radiation therapy (SBRT) are commonly treated by a multidisciplinary team of neurosurgeons, radiation oncologists, and medical physicists. However the treatment objectives, constraints, and technical considerations involved can be quite different between the two techniques. In this interactive session an expert panel of speakers will present clinical brain SRS and spine SBRT cases in order to demonstrate real-world considerations for ensuring safe and accurate treatment delivery and to highlight the significant differences in approach for each treatment site. The session will include discussion of topic such as clinical indications, immobilization, target definition, normalmore » tissue tolerance limits, and beam arrangements. Learning Objectives: Understand the differences in indications and dose/fractionation strategies for intracranial SRS and spine SBRT. Describe the different treatment modalities which can be used to deliver intracranial SRS and spine SBRT. Cite the major differences in treatment setup and delivery principles between intracranial and spine treatments. Identify key critical structures and clinical dosimetric tolerance levels for spine SBRT and intracranial SRS. Understand areas of ongoing work to standardize intracranial SRS and spine SBRT procedures. Schlesinger: Research support: Elekta Instruments, AB; D. Schlesinger, Elekta Instruments, AB - research support; B. Winey, No relevant external funding for this subject.« less

The Aircraft Simulation Role in Improving Flight Safety Through Control Room Training

NASA Technical Reports Server (NTRS)

Shy, Karla S.; Hageman, Jacob J.; Le, Jeanette H.; Sitz, Joel (Technical Monitor)

2002-01-01

NASA Dryden Flight Research Center uses its six-degrees-of-freedom (6-DOF) fixed-base simulations for mission control room training to improve flight safety and operations. This concept is applied to numerous flight projects such as the F-18 High Alpha Research Vehicle (HARV), the F-15 Intelligent Flight Control System (IFCS), the X-38 Actuator Control Test (XACT), and X-43A (Hyper-X). The Dryden 6-DOF simulations are typically used through various stages of a project, from design to ground tests. The roles of these simulations have expanded to support control room training, reinforcing flight safety by building control room staff proficiency. Real-time telemetry, radar, and video data are generated from flight vehicle simulation models. These data are used to drive the control room displays. Nominal static values are used to complete information where appropriate. Audio communication is also an integral part of training sessions. This simulation capability is used to train control room personnel and flight crew for nominal missions and emergency situations. Such training sessions are also opportunities to refine flight cards and control room display pages, exercise emergency procedures, and practice control room setup for the day of flight. This paper describes this technology as it is used in the X-43A and F-15 IFCS and XACT projects.

TU-A-BRB-00: PANEL DISCUSSION: SBRT/SRS Case Studies - Brain and Spine

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

NONE

Brain stereotactic radiosurgery (SRS) and spine stereotactic body radiation therapy (SBRT) are commonly treated by a multidisciplinary team of neurosurgeons, radiation oncologists, and medical physicists. However the treatment objectives, constraints, and technical considerations involved can be quite different between the two techniques. In this interactive session an expert panel of speakers will present clinical brain SRS and spine SBRT cases in order to demonstrate real-world considerations for ensuring safe and accurate treatment delivery and to highlight the significant differences in approach for each treatment site. The session will include discussion of topic such as clinical indications, immobilization, target definition, normalmore » tissue tolerance limits, and beam arrangements. Learning Objectives: Understand the differences in indications and dose/fractionation strategies for intracranial SRS and spine SBRT. Describe the different treatment modalities which can be used to deliver intracranial SRS and spine SBRT. Cite the major differences in treatment setup and delivery principles between intracranial and spine treatments. Identify key critical structures and clinical dosimetric tolerance levels for spine SBRT and intracranial SRS. Understand areas of ongoing work to standardize intracranial SRS and spine SBRT procedures. Schlesinger: Research support: Elekta Instruments, AB; D. Schlesinger, Elekta Instruments, AB - research support; B. Winey, No relevant external funding for this subject.« less

Investigation of a novel approach for the cross-linking characterization of SU-8 photoresist materials by means of optical dispersion measurements

NASA Astrophysics Data System (ADS)

Taudt, Ch.; Baselt, T.; Koch, E.; Hartmann, P.

2014-03-01

The increase in efficiency and precision in the production of semiconductor structures under the use of polymeric materials like SU-8 is crucial in securing the technological innovation within this industry. The manufacturing of structures on wafers demands a high quality of materials, tools and production processes. In particular, deviations in the materials' parameters (e.g. cross-linking state, density or mechanical properties) could lead to subsequent problems such as a reduced lifetime of structures and systems. In particular problems during the soft and post-exposure bake process can lead to an inhomogeneous distribution of material properties. This paper describes a novel approach for the characterization of SU-8 material properties in relation to a second epoxy-based material of different cross-linking by the measurement of optical dispersion within the material. A white-light interferometer was used. In particular the setup consisted of a white-light source, a Michelson-type interferometer and a spectrometer. The investigation of the dispersion characteristics was carried out by the detection of the equalization wavelength for different positions of the reference arm in a range from 400 to 900 nm. The measured time delay due to dispersion ranges from 850 to 1050 ps/m. For evaluation purposes a 200μm SU-8 sample was characterized in the described setup regarding its dispersion characteristics in relation to bulk epoxy material. The novel measurement approach allowed a fast and high-resolution material characterization for SU-8 micro structures which was suitable for integration in production lines. The outlook takes modifications of the experimental setup regarding on-wafer measurements into account.

Interrelationships between Marijuana Demand and Discounting of Delayed Rewards: Convergence in Behavioral Economic Methods

PubMed Central

Aston, Elizabeth R.; Metrik, Jane; Amlung, Michael; Kahler, Christopher W.; MacKillop, James

2016-01-01

Background Distinct behavioral economic domains, including high perceived drug value (demand) and delay discounting (DD), have been implicated in the initiation of drug use and the progression to dependence. However, it is unclear whether frequent marijuana users conform to a “reinforcer pathology” addiction model wherein marijuana demand and DD jointly increase risk for problematic marijuana use and cannabis dependence (CD). Methods Participants (n=88, 34% female, 14% cannabis dependent) completed a marijuana purchase task at baseline. A delay discounting task was completed following placebo marijuana cigarette (0% THC) administration during a separate experimental session. Results Marijuana demand and DD were quantified using area under the curve (AUC). In multiple regression models, demand uniquely predicted frequency of marijuana use while DD did not. In contrast, DD uniquely predicted CD symptom count while demand did not. There were no significant interactions between demand and DD in either model. Conclusions These findings suggest that frequent marijuana users exhibit key constituents of the reinforcer pathology model: high marijuana demand and steep discounting of delayed rewards. However, demand and DD appear to be independent rather than synergistic risk factors for elevated marijuana use and risk for progression to CD. Findings also provide support for using AUC as a singular marijuana demand metric, particularly when also examining other behavioral economic constructs that apply similar statistical approaches, such as DD, to support analytic methodological convergence. PMID:27810657

Cocaine cues drive opposing context-dependent shifts in reward processing and emotional state.

PubMed

Wheeler, Robert A; Aragona, Brandon J; Fuhrmann, Katherine A; Jones, Joshua L; Day, Jeremy J; Cacciapaglia, Fabio; Wightman, R Mark; Carelli, Regina M

2011-06-01

Prominent neurobiological theories of addiction posit a central role for aberrant mesolimbic dopamine release but disagree as to whether repeated drug experience blunts or enhances this system. Although drug withdrawal diminishes dopamine release, drug sensitization augments mesolimbic function, and both processes have been linked to drug seeking. One possibility is that the dopamine system can rapidly switch from dampened to enhanced release depending on the specific drug-predictive environment. To test this, we examined dopamine release when cues signaled delayed cocaine delivery versus imminent cocaine self-administration. Fast-scan cyclic voltammetry was used to examine real-time dopamine release while simultaneously monitoring behavioral indexes of aversion as rats experienced a sweet taste cue that predicted delayed cocaine availability and during self-administration. Furthermore, the impact of cues signaling delayed drug availability on intracranial self-stimulation, a broad measure of reward function, was assessed. We observed decreased mesolimbic dopamine concentrations, decreased reward sensitivity, and negative affect in response to the cocaine-predictive taste cue that signaled delayed cocaine availability. Importantly, dopamine concentration rapidly switched to elevated levels to cues signaling imminent cocaine delivery in the subsequent self-administration session. These findings show rapid, bivalent contextual control over brain reward processing, affect, and motivated behavior and have implications for mechanisms mediating substance abuse. Copyright © 2011 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Effects of edaravone on a rat model of punch-drunk syndrome.

PubMed

Nomoto, Jun; Kuroki, Takao; Nemoto, Masaaki; Kondo, Kosuke; Harada, Naoyuki; Nagao, Takeki

2011-01-01

Punch-drunk syndrome (PDS) refers to a pathological condition in which higher brain dysfunction occurs in a delayed fashion in boxers who have suffered repeated blows to the head. However, the underlying mechanisms remain unknown. This study attempted to elucidate the mechanism of higher brain dysfunction observed following skull vibration in two experiments involving a rat model of PDS. Experiment 1 evaluated the effects of edaravone on histological changes in the rat brain tissue after skull vibration (frequency 20 Hz, amplitude 4 mm, duration 60 minutes). The amount of free radicals formed in response to skull vibration was very small, and edaravone administration reduced the number of glial fibrillary acidic protein and advanced glycation end product-positive cells. Experiment 2 examined the time course of change in learning ability following skull vibration in Tokai High Avoider rats. The learning ability of individual rats was evaluated by the Sidman-type electric shock avoidance test 5 days after the last session of skull vibration or final anesthesia and once a month for 9 consecutive months. Delayed learning disability was not observed in rats administered edaravone immediately after skull vibration. These results suggest that free radical-induced astrocyte activation and subsequent glial scar formation contribute to the occurrence of delayed learning disabilities. Edaravone administration after skull vibration suppressed glial scar formation, thereby inhibiting the occurrence of delayed learning disabilities.

Adaptive Phase Delay Generator

NASA Technical Reports Server (NTRS)

Greer, Lawrence

2013-01-01

There are several experimental setups involving rotating machinery that require some form of synchronization. The adaptive phase delay generator (APDG) the Bencic-1000 is a flexible instrument that allows the user to generate pulses synchronized to the rising edge of a tachometer signal from any piece of rotating machinery. These synchronized pulses can vary by the delay angle, pulse width, number of pulses per period, number of skipped pulses, and total number of pulses. Due to the design of the pulse generator, any and all of these parameters can be changed independently, yielding an unparalleled level of versatility. There are two user interfaces to the APDG. The first is a LabVIEW program that has the advantage of displaying all of the pulse parameters and input signal data within one neatly organized window on the PC monitor. Furthermore, the LabVIEW interface plots the rpm of the two input signal channels in real time. The second user interface is a handheld portable device that goes anywhere a computer is not accessible. It consists of a liquid-crystal display and keypad, which enable the user to control the unit by scrolling through a host of command menus and parameter listings. The APDG combines all of the desired synchronization control into one unit. The experimenter can adjust the delay, pulse width, pulse count, number of skipped pulses, and produce a specified number of pulses per revolution. Each of these parameters can be changed independently, providing an unparalleled level of versatility when synchronizing hardware to a host of rotating machinery. The APDG allows experimenters to set up quickly and generate a host of synchronizing configurations using a simple user interface, which hopefully leads to faster results.

The Sense of Agency Is More Sensitive to Manipulations of Outcome than Movement-Related Feedback Irrespective of Sensory Modality

PubMed Central

David, Nicole; Skoruppa, Stefan; Gulberti, Alessandro

2016-01-01

The sense of agency describes the ability to experience oneself as the agent of one's own actions. Previous studies of the sense of agency manipulated the predicted sensory feedback related either to movement execution or to the movement’s outcome, for example by delaying the movement of a virtual hand or the onset of a tone that resulted from a button press. Such temporal sensorimotor discrepancies reduce the sense of agency. It remains unclear whether movement-related feedback is processed differently than outcome-related feedback in terms of agency experience, especially if these types of feedback differ with respect to sensory modality. We employed a mixed-reality setup, in which participants tracked their finger movements by means of a virtual hand. They performed a single tap, which elicited a sound. The temporal contingency between the participants’ finger movements and (i) the movement of the virtual hand or (ii) the expected auditory outcome was systematically varied. In a visual control experiment, the tap elicited a visual outcome. For each feedback type and participant, changes in the sense of agency were quantified using a forced-choice paradigm and the Method of Constant Stimuli. Participants were more sensitive to delays of outcome than to delays of movement execution. This effect was very similar for visual or auditory outcome delays. Our results indicate different contributions of movement- versus outcome-related sensory feedback to the sense of agency, irrespective of the modality of the outcome. We propose that this differential sensitivity reflects the behavioral importance of assessing authorship of the outcome of an action. PMID:27536948

Development of Pointing Gestures in Children With Typical and Delayed Language Acquisition.

PubMed

Lüke, Carina; Ritterfeld, Ute; Grimminger, Angela; Liszkowski, Ulf; Rohlfing, Katharina J

2017-11-09

This longitudinal study compared the development of hand and index-finger pointing in children with typical language development (TD) and children with language delay (LD). First, we examined whether the number and the form of pointing gestures during the second year of life are potential indicators of later LD. Second, we analyzed the influence of caregivers' gestural and verbal input on children's communicative development. Thirty children with TD and 10 children with LD were observed together with their primary caregivers in a seminatural setting in 5 sessions between the ages of 12 and 21 months. Language skills were assessed at 24 months. Compared with children with TD, children with LD used fewer index-finger points at 12 and 14 months but more pointing gestures in total at 21 months. There were no significant differences in verbal or gestural input between caregivers of children with or without LD. Using more index-finger points at the beginning of the second year of life is associated with TD, whereas using more pointing gestures at the end of the second year of life is associated with delayed acquisition. Neither the verbal nor gestural input of caregivers accounted for differences in children's skills.

A Progress Report on the Reforms in D.C. Public Schools. Hearing before the Subcommittee on Oversight of Government Management, Restructuring, and the District of Columbia of the Committee on Governmental Affairs. United States Senate, One Hundred Fifth Congress, First Session (September 8, 1997).

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. Senate Committee on Governmental Affairs.

A hearing before the oversight committee for the District of Columbia (D.C.) public schools provided the opportunity for several senators and educators to comment on the progress of educational reform in the District's public schools. The hearing was held at a time when the opening of the city's public schools was delayed because of their many…

Methylphenidate does not improve interference control during a working memory task in young patients with attention-deficit hyperactivity disorder.

PubMed

Prehn-Kristensen, Alexander; Krauel, Kerstin; Hinrichs, Hermann; Fischer, Jochen; Malecki, Ulrike; Schuetze, Hartmut; Wolff, Stephan; Jansen, Olav; Duezel, Emrah; Baving, Lioba

2011-05-04

Patients with attention-deficit/hyperactivity disorder (ADHD) show deficits in working memory (WM) which may be related to prefrontal dysfunction. Methylphenidate (MPH) can restore WM deficits in ADHD by enhancing prefrontal activity. At the same time, changes in striatal activation could cause ADHD patients to be more interference-sensitive during working memory tasks. However, it is unclear whether MPH reduces WM distractibility in ADHD. In this fMRI study, 12 ADHD patients and 12 healthy controls participated on two separate days in a delayed-match-to-sample test. During the delay interval, a distractor stimulus was presented in half of the trials. Children and adolescents with ADHD received MPH only on one of the two sessions. Behavioral data analyses revealed that MPH normalized WM in ADHD. However, MPH did not improve WM performance when a distractor was presented during the delay interval. Functional images showed that MPH enhanced prefrontal activity during the delay in ADHD patients when no distractor was present. If the delay was interrupted by a distractor, only healthy controls showed activation of the caudate. In patients with ADHD, however, in line with behavioral data, MPH did not enhance caudate activity. In healthy youth, caudate activity is involved in interference control allowing the successful maintenance of information in working memory even in the presence of distraction. Our findings suggest that interference control, linked to caudate activity, is not adequately enhanced by MPH in ADHD. Copyright © 2011 Elsevier B.V. All rights reserved.

Electromyography as a recording system for eyeblink conditioning with functional magnetic resonance imaging.

PubMed

Knuttinen, M-G; Parrish, T B; Weiss, C; LaBar, K S; Gitelman, D R; Power, J M; Mesulam, M-M; Disterhoft, J F

2002-10-01

This study was designed to develop a suitable method of recording eyeblink responses while conducting functional magnetic resonance imaging (fMRI). Given the complexity of this behavioral setup outside of the magnet, this study sought to adapt and further optimize an approach to eyeblink conditioning that would be suitable for conducting event-related fMRI experiments. This method involved the acquisition of electromyographic (EMG) signals from the orbicularis oculi of the right eye, which were subsequently amplified and converted into an optical signal outside of the head coil. This optical signal was converted back into an electrical signal once outside the magnet room. Electromyography (EMG)-detected eyeblinks were used to measure responses in a delay eyeblink conditioning paradigm. Our results indicate that: (1) electromyography is a sensitive method for the detection of eyeblinks during fMRI; (2) minimal interactions or artifacts of the EMG signal were created from the magnetic resonance pulse sequence; and (3) no electromyography-related artifacts were detected in the magnetic resonance images. Furthermore, an analysis of the functional data showed areas of activation that have previously been shown in positron emission tomography studies of human eyeblink conditioning. Our results support the strength of this behavioral setup as a suitable method to be used in association with fMRI.

Summaries from the Eleventh Annual Houston Conference on AIDS in America.

PubMed

1999-07-01

A number of significant papers from the Eleventh Annual Houston Conference on AIDS in America are summarized. Topics include the current concepts in pathogenesis of HIV infection, the use of anti-HIV therapies, and drug interactions in HIV treatment. A session on HIV disease in children focused on the epidemiology and prevention of vertical transmission with Zidovudine, when to initiate therapy, and options for children who have failed current therapies. Studies using immune-based therapy have shown promise in treating HIV disease. New data from a study with sargramostim, an investigational agent for opportunistic infection prophylaxis, shows that the drug reduces viral loads and delays time to treatment failure. Pentafuside (T-20), the first of a new class of HIV drugs, fusion inhibitors, has been found to be safe and effective against HIV, although drug resistance may be associated with its use. Other sessions summarized progress in clearing HIV from viral reservoirs, the ethics of HIV research support from the drug industry and drug marketing, and a review of immune reconstitution studies among people on antiretroviral therapy. Sam Avrett of the AIDS Vaccine Advocacy Coalition (AVAC) summarized in his session the characteristics of a successful HIV vaccine and the need to have more people involved in vaccine advocacy as a means to ending the epidemic. Contact information is provided.

They saw a movie: long-term memory for an extended audiovisual narrative.

PubMed

Furman, Orit; Dorfman, Nimrod; Hasson, Uri; Davachi, Lila; Dudai, Yadin

2007-06-01

We measured long-term memory for a narrative film. During the study session, participants watched a 27-min movie episode, without instructions to remember it. During the test session, administered at a delay ranging from 3 h to 9 mo after the study session, long-term memory for the movie was probed using a computerized questionnaire that assessed cued recall, recognition, and metamemory of movie events sampled approximately 20 sec apart. The performance of each group of participants was measured at a single time point only. The participants remembered many events in the movie even months after watching it. Analysis of performance, using multiple measures, indicates differences between recent (weeks) and remote (months) memory. While high-confidence recognition performance was a reliable index of memory throughout the measured time span, cued recall accuracy was higher for relatively recent information. Analysis of different content elements in the movie revealed differential memory performance profiles according to time since encoding. We also used the data to propose lower limits on the capacity of long-term memory. This experimental paradigm is useful not only for the analysis of behavioral performance that results from encoding episodes in a continuous real-life-like situation, but is also suitable for studying brain substrates and processes of real-life memory using functional brain imaging.

They saw a movie: Long-term memory for an extended audiovisual narrative

PubMed Central

Furman, Orit; Dorfman, Nimrod; Hasson, Uri; Davachi, Lila; Dudai, Yadin

2007-01-01

We measured long-term memory for a narrative film. During the study session, participants watched a 27-min movie episode, without instructions to remember it. During the test session, administered at a delay ranging from 3 h to 9 mo after the study session, long-term memory for the movie was probed using a computerized questionnaire that assessed cued recall, recognition, and metamemory of movie events sampled ∼20 sec apart. The performance of each group of participants was measured at a single time point only. The participants remembered many events in the movie even months after watching it. Analysis of performance, using multiple measures, indicates differences between recent (weeks) and remote (months) memory. While high-confidence recognition performance was a reliable index of memory throughout the measured time span, cued recall accuracy was higher for relatively recent information. Analysis of different content elements in the movie revealed differential memory performance profiles according to time since encoding. We also used the data to propose lower limits on the capacity of long-term memory. This experimental paradigm is useful not only for the analysis of behavioral performance that results from encoding episodes in a continuous real-life-like situation, but is also suitable for studying brain substrates and processes of real-life memory using functional brain imaging. PMID:17562897

Femtosecond noncollinear SFG dynamics in autocorrelator setup at low level of photons

NASA Astrophysics Data System (ADS)

Tenishev, Vladimir P.; Persson, A.; Larsson, J.

2004-06-01

We report here the characteristics of noncollinear sum frequency generation in nonlinear KDP crystals by ultrashort (80 fsec) IR pulses irradiated by the intense Ti:Sapphire laser and their behavior in single shot auto-crosscorrelator (ACC) configuration. In particular we study the case where one of the beams is very weak. Our aim is to develop a procedure to provide delay time signal between light pulses for time resolved pump probe experiments based on the extraction of the phase-matched SHG spatial distribution by means of pulse shape analysis technique. We intend to apply these results to synchronize a weak short-pulse source and an intense Ti:Sapphire laser and to measure the pulse time jitter between them.

Dynamic MTF, an innovative test bench for detector characterization

NASA Astrophysics Data System (ADS)

Emmanuel, Rossi; Raphaël, Lardière; Delmonte, Stephane

2017-11-01

PLEIADES HR are High Resolution satellites for Earth observation. Placed at 695km they reach a 0.7m spatial resolution. To allow such performances, the detectors are working in a TDI mode (Time and Delay Integration) which consists in a continuous charge transfer from one line to the consecutive one while the image is passing on the detector. The spatial resolution, one of the most important parameter to test, is characterized by the MTF (Modulation Transfer Function). Usually, detectors are tested in a staring mode. For a higher level of performances assessment, a dedicated bench has been set-up, allowing detectors' MTF characterization in the TDI mode. Accuracy and reproducibility are impressive, opening the door to new perspectives in term of HR imaging systems testing.

Mode coupling at connectors in mode-division multiplexed transmission over few-mode fiber.

PubMed

Vuong, Jordi; Ramantanis, Petros; Frignac, Yann; Salsi, Massimiliano; Genevaux, Philippe; Bendimerad, Djalal F; Charlet, Gabriel

2015-01-26

In mode-division multiplexed (MDM) transmission systems, mode coupling is responsible for inter-modal crosstalk. We consider the transmission of modulated signals over a few-mode fiber (FMF) having low mode coupling and large differential mode group delay in the presence of a non-ideal fiber connection responsible for extra mode coupling. In this context, we first analytically derive the coupling matrix of the multimode connector and we numerically study the dependence of the matrix coefficients as a function of the butt-joint connection characteristics. The numerical results are then validated through an experiment with a five-mode setup. Finally, through numerical simulations, we assess the impact of the connector on the signal quality investigating different receiver digital signal processing (DSP) schemes.

Position control of an electro-pneumatic system based on PWM technique and FLC.

PubMed

Najjari, Behrouz; Barakati, S Masoud; Mohammadi, Ali; Futohi, Muhammad J; Bostanian, Muhammad

2014-03-01

In this paper, modeling and PWM based control of an electro-pneumatic system, including the four 2-2 valves and a double acting cylinder are studied. Dynamic nonlinear behavior of the system, containing fast switching solenoid valves and a pneumatic cylinder, as well as electrical, magnetic, mechanical, and fluid subsystems are modeled. A DC-DC power converter is employed to improve solenoid valve performance and suppress system delay. Among different position control methods, a proportional integrator derivative (PID) controller and fuzzy logic controller (FLC) are evaluated. An experimental setup, using an AVR microcontroller is implemented. Simulation and experimental results verify the effectiveness of the proposed control strategies. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Components of day-to-day variability of cerebral perfusion measurements - Analysis of phase contrast mapping magnetic resonance imaging measurements in healthy volunteers.

PubMed

Ismaili, Abd R A; Vestergaard, Mark B; Hansen, Adam E; Larsson, Henrik B W; Johannesen, Helle H; Law, Ian; Henriksen, Otto M

2018-01-01

The aim of the study was to investigate the components of day-to-day variability of repeated phase contrast mapping (PCM) magnetic resonance imaging measurements of global cerebral blood flow (gCBF). Two dataset were analyzed. In Dataset 1 duplicated PCM measurements of total brain flow were performed in 11 healthy young volunteers on two separate days applying a strictly standardized setup. For comparison PCM measurements obtained from a previously published study (Dataset 2) were analyzed in order to assess long-term variability in an aged population in a less strictly controlled setup. Global CBF was calculated by normalizing total brain flow to brain volume. On each day measurements of hemoglobin, caffeine and glucose were obtained. Linear mixed models were applied to estimate coefficients of variation (CV) of total (CVt), between-subject (CVb), within-subject day-to-day (CVw), and intra-session residual variability (CVr). In Dataset 1 CVt, CVb, CVw and CVr were estimated to be 11%, 9.4%, 4% and 4.2%, respectively, and to 8.8%, 7.2%, 2.7% and 4.3%, respectively, when adjusting for hemoglobin and plasma caffeine. In Dataset 2 CVt, CVb and CVw were estimated to be 25.4%, 19.2%, and 15.0%, respectively, and decreased to 16.6%, 8.2% and 12.5%, respectively, when adjusting for the same covariates. Our results suggest that short-term day-to-day variability of gCBF is relatively low compared to between-subject variability when studied in standardized conditions, whereas long-term variability in an aged population appears to be much larger when studied in less a standardized setup. The results further showed that from 20% to 35% of the total variability in gCBF can be attributed to the effects of hemoglobin and caffeine.

Craniocaudal Safety Margin Calculation Based on Interfractional Changes in Tumor Motion in Lung SBRT Assessed With an EPID in Cine Mode

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

Ueda, Yoshihiro, E-mail: ueda-yo@mc.pref.osaka.jp; Miyazaki, Masayoshi; Nishiyama, Kinji

2012-07-01

Purpose: To evaluate setup error and interfractional changes in tumor motion magnitude using an electric portal imaging device in cine mode (EPID cine) during the course of stereotactic body radiation therapy (SBRT) for non-small-cell lung cancer (NSCLC) and to calculate margins to compensate for these variations. Materials and Methods: Subjects were 28 patients with Stage I NSCLC who underwent SBRT. Respiratory-correlated four-dimensional computed tomography (4D-CT) at simulation was binned into 10 respiratory phases, which provided average intensity projection CT data sets (AIP). On 4D-CT, peak-to-peak motion of the tumor (M-4DCT) in the craniocaudal direction was assessed and the tumor centermore » (mean tumor position [MTP]) of the AIP (MTP-4DCT) was determined. At treatment, the tumor on cone beam CT was registered to that on AIP for patient setup. During three sessions of irradiation, peak-to-peak motion of the tumor (M-cine) and the mean tumor position (MTP-cine) were obtained using EPID cine and in-house software. Based on changes in tumor motion magnitude ( Increment M) and patient setup error ( Increment MTP), defined as differences between M-4DCT and M-cine and between MTP-4DCT and MTP-cine, a margin to compensate for these variations was calculated with Stroom's formula. Results: The means ({+-}standard deviation: SD) of M-4DCT and M-cine were 3.1 ({+-}3.4) and 4.0 ({+-}3.6) mm, respectively. The means ({+-}SD) of Increment M and Increment MTP were 0.9 ({+-}1.3) and 0.2 ({+-}2.4) mm, respectively. Internal target volume-planning target volume (ITV-PTV) margins to compensate for Increment M, Increment MTP, and both combined were 3.7, 5.2, and 6.4 mm, respectively. Conclusion: EPID cine is a useful modality for assessing interfractional variations of tumor motion. The ITV-PTV margins to compensate for these variations can be calculated.« less

Optimal marker placement in hadrontherapy: intelligent optimization strategies with augmented Lagrangian pattern search.

PubMed

Altomare, Cristina; Guglielmann, Raffaella; Riboldi, Marco; Bellazzi, Riccardo; Baroni, Guido

2015-02-01

In high precision photon radiotherapy and in hadrontherapy, it is crucial to minimize the occurrence of geometrical deviations with respect to the treatment plan in each treatment session. To this end, point-based infrared (IR) optical tracking for patient set-up quality assessment is performed. Such tracking depends on external fiducial points placement. The main purpose of our work is to propose a new algorithm based on simulated annealing and augmented Lagrangian pattern search (SAPS), which is able to take into account prior knowledge, such as spatial constraints, during the optimization process. The SAPS algorithm was tested on data related to head and neck and pelvic cancer patients, and that were fitted with external surface markers for IR optical tracking applied for patient set-up preliminary correction. The integrated algorithm was tested considering optimality measures obtained with Computed Tomography (CT) images (i.e. the ratio between the so-called target registration error and fiducial registration error, TRE/FRE) and assessing the marker spatial distribution. Comparison has been performed with randomly selected marker configuration and with the GETS algorithm (Genetic Evolutionary Taboo Search), also taking into account the presence of organs at risk. The results obtained with SAPS highlight improvements with respect to the other approaches: (i) TRE/FRE ratio decreases; (ii) marker distribution satisfies both marker visibility and spatial constraints. We have also investigated how the TRE/FRE ratio is influenced by the number of markers, obtaining significant TRE/FRE reduction with respect to the random configurations, when a high number of markers is used. The SAPS algorithm is a valuable strategy for fiducial configuration optimization in IR optical tracking applied for patient set-up error detection and correction in radiation therapy, showing that taking into account prior knowledge is valuable in this optimization process. Further work will be focused on the computational optimization of the SAPS algorithm toward fast point-of-care applications. Copyright © 2014 Elsevier Inc. All rights reserved.

Validity of the Catapult ClearSky T6 Local Positioning System for Team Sports Specific Drills, in Indoor Conditions

PubMed Central

Luteberget, Live S.; Spencer, Matt; Gilgien, Matthias

2018-01-01

Aim: The aim of the present study was to determine the validity of position, distance traveled and instantaneous speed of team sport players as measured by a commercially available local positioning system (LPS) during indoor use. In addition, the study investigated how the placement of the field of play relative to the anchor nodes and walls of the building affected the validity of the system. Method: The LPS (Catapult ClearSky T6, Catapult Sports, Australia) and the reference system [Qualisys Oqus, Qualisys AB, Sweden, (infra-red camera system)] were installed around the field of play to capture the athletes' motion. Athletes completed five tasks, all designed to imitate team-sports movements. The same protocol was completed in two sessions, one with an assumed optimal geometrical setup of the LPS (optimal condition), and once with a sub-optimal geometrical setup of the LPS (sub-optimal condition). Raw two-dimensional position data were extracted from both the LPS and the reference system for accuracy assessment. Position, distance and speed were compared. Results: The mean difference between the LPS and reference system for all position estimations was 0.21 ± 0.13 m (n = 30,166) in the optimal setup, and 1.79 ± 7.61 m (n = 22,799) in the sub-optimal setup. The average difference in distance was below 2% for all tasks in the optimal condition, while it was below 30% in the sub-optimal condition. Instantaneous speed showed the largest differences between the LPS and reference system of all variables, both in the optimal (≥35%) and sub-optimal condition (≥74%). The differences between the LPS and reference system in instantaneous speed were speed dependent, showing increased differences with increasing speed. Discussion: Measures of position, distance, and average speed from the LPS show low errors, and can be used confidently in time-motion analyses for indoor team sports. The calculation of instantaneous speed from LPS raw data is not valid. To enhance instantaneous speed calculation the application of appropriate filtering techniques to enhance the validity of such data should be investigated. For all measures, the placement of anchor nodes and the field of play relative to the walls of the building influence LPS output to a large degree. PMID:29670530

The effects of huperzine A and IDRA 21 on visual recognition memory in young macaques

PubMed Central

Malkova, Ludise; Kozikowski, Alan P.; Gale, Karen

2011-01-01

Nootropic agents or cognitive enhancers are purported to improve mental functions such as cognition, memory, or attention. The aim of our study was to determine the effects of two possible cognitive enhancers, huperzine A and IDRA 21, in normal young adult monkeys performing a visual memory task of varying degrees of difficulty. Huperzine A is a reversible acetylcholinesterase (AChE) inhibitor, its administration results in regionally specific increases in acetylcholine levels in the brain. In human clinical trials, Huperzine A resulted in cognitive improvement in patients with mild to moderate form of Alzheimer's disease (AD) showing its potential as a palliative agent in the treatment of AD. IDRA 21 is a positive allosteric modulator of glutamate AMPA receptors. It increases excitatory synaptic strength by attenuating rapid desensitization of AMPA receptors and may thus have beneficial therapeutic effects to ameliorate memory deficits in patients with cognitive impairments, including AD. The present study evaluated the effects of the two drugs in normal, intact, young adult monkeys to determine whether they can result in cognitive enhancement in a system that is presumably functioning optimally. Six young pigtail macaques (Macaca nemestrina) were trained on delayed non-matching-to-sample task, a measure of visual recognition memory, up to criterion of 90% correct responses on each of the four delays (10s, 30s, 60s, and 90s). They were then tested on two versions of the task: Task 1 included the four delays intermixed within a session and the monkeys performed it with the accuracy of 90%. Task 2 included, in each of 24 trials, a list of six objects presented in succession. Two objects from the list were then presented for choice paired with novel objects and following two of the four delays intermixed within a session. This task with a higher mnemonic demand yielded an average performance of 64% correct. Oral administration of huperzine A did not significantly affect the monkeys' performance on either task. However, a significant negative correlation was found between the baseline performance on each delay and the change in performance under huperzine A, suggesting that under conditions in which the subjects were performing poorly (55 – 69%), the drug resulted in improved performance, whereas no improvement was obtained when the baseline was close to 90%. In fact, when the subjects were performing very well, huperzine A tended to reduce the performance accuracy, indicating that in a system that functions optimally, the increased availability of acetylcholine does not improve performance or memory, especially when the animals are close to the maximum performance. In contrast, oral administration of IDRA 21 significantly improved performance on Task 2, especially on the longest delay. This finding supports the potential use of this drug in treatment of cognitive and memory disorders. PMID:21185313

Measurement of rabbit eardrum vibration through stroboscopic digital holography

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

De Greef, Daniël; Dirckx, Joris J. J.

In this work, we present a setup for high-power single shot stroboscopic digital holography and demonstrate it in an application on rabbit eardrum vibration measurement. The setup is able to make full-field time-resolved measurements of vibrating surfaces with a precision in the nanometer range in a broad frequency range. The height displacement of the measured object is visualized over the entire surface as a function of time. Vibration magnitude and phase maps can be extracted from these data, the latter proving to be very useful to reveal phase delays across the surface. Such deviations from modal motion indicate energy lossesmore » due to internal damping, in contrast to purely elastic mechanics. This is of great interest in middle ear mechanics and finite element modelling. In our setup, short laser pulses are fired at selected instants within the surface vibration period and are recorded by a CCD camera. The timing of the pulses and the exposure of the camera are synchronized to the vibration phase by a microprocessor. The high-power frequency-doubled Nd:YAG laser produces pulses containing up to 5 mJ of energy, which is amply sufficient to record single-shot holograms. As the laser pulse length is 8 ns and the smallest time step of the trigger electronics is 1 μs, vibration measurements of frequencies up to 250 kHz are achievable through this method, provided that the maximum vibration amplitude exceeds a few nanometers. In our application, middle ear mechanics, measuring frequencies extend from 5 Hz to 20 kHz. The experimental setup will be presented, as well as results of measurements on a stretched circular rubber membrane and a rabbit's eardrum. Two of the challenges when measuring biological tissues, such as the eardrum, are low reflectivity and fast dehydration. To increase reflectivity, a coating is applied and to counteract the undesirable effects of tissue dehydration, the measurement setup and software have been optimized for speed without compromising on the quality. Results of a repeatability test will be presented as well. Since the method measures the membrane motion as a function of time in small time steps, we do not only measure vibration amplitude like in time-average holography, but we can also measure non-linear elastic and transient behaviour. In conclusion, the combination of good spatial, depth and time resolution with the fast data acquisition and very wide frequency range make our technique applicable in a number of fields, including biological tissue vibrations.« less

A number sense intervention for low-income kindergartners at risk for mathematics difficulties.

PubMed

Dyson, Nancy I; Jordan, Nancy C; Glutting, Joseph

2013-01-01

Early number sense is a strong predictor of later success in school mathematics. A disproportionate number of children from low-income families come to first grade with weak number competencies, leaving them at risk for a cycle of failure. The present study examined the effects of an 8-week number sense intervention to develop number competencies of low-income kindergartners (N = 121). The intervention purposefully targeted whole number concepts related to counting, comparing, and manipulating sets. Children were randomly assigned to either a number sense intervention or a business as usual contrast group. The intervention was carried out in small-group, 30-min sessions, 3 days per week, for a total of 24 sessions. Controlling for number sense at pretest, the intervention group made meaningful gains relative to the control group at immediate as well delayed posttest on a measure of early numeracy. Intervention children also performed better than controls on a standardized test of mathematics calculation at immediate posttest.

Single session treatment for bleeding hemorrhoids

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

Weinstein, S.J.; Rypins, E.B.; Houck, J.

1987-12-01

Fifty consecutive outpatients with bleeding internal hemorrhoids were prospectively treated with a single application of rubber band ligation or infrared coagulation. Complete follow-up observation was obtained in 48 patients (23 underwent rubber band ligation and 25 underwent infrared coagulation). At one month after treatment, 22 patients who underwent rubber band ligation and 16 who underwent infrared coagulation, were symptomatically improved (p less than 0.05). At six months, 15 patients who had undergone rubber band ligation and ten who had infrared coagulation treatment, remained improved (p less than 0.05). There was no statistical difference in the discomfort experienced by either groupmore » during or after the procedure as determined by a self-assessment scale. Two patients who underwent rubber band ligation experienced complications--a thrombosed external hemorrhoid developed in one patient and another had delayed rectal bleeding. Although associated with occasional complications after treatment, rubber band ligation is more effective than in infrared coagulation for single session treatment of bleeding internal hemorrhoids.« less

A Number Sense Intervention for Low-Income Kindergartners at Risk for Mathematics Difficulties

PubMed Central

Dyson, Nancy I.; Jordan, Nancy C.; Glutting, Joseph

2012-01-01

Early number sense is a strong predictor of later success in school mathematics. A disproportionate number of children from low-income families come to first grade with weak number competencies, leaving them at-risk for a cycle of failure. The present study examined the effects of an 8-week number sense intervention to develop number competencies of low-income kindergartners (n = 121). The intervention purposefully targeted whole number concepts related to counting, comparing, and manipulating sets. Children were randomly assigned either to a number sense intervention or a business as usual contrast group. The intervention was carried out in small group, 30-minute sessions, 3 days per week for a total of 24 sessions. Controlling for number sense at pretest, the intervention group made meaningful gains relative to the control group at immediate as well delayed posttest on a measure of early numeracy. Intervention children also performed better than controls on a standardized test of mathematics calculation at immediate posttest. PMID:21685346

Determinants of Motion Sickness in Tilting Trains: Coriolis/Cross-Coupling Stimuli and Tilt Delay

PubMed Central

Bertolini, Giovanni; Durmaz, Meek Angela; Ferrari, Kim; Küffer, Alexander; Lambert, Charlotte; Straumann, Dominik

2017-01-01

Faster trains require tilting of the cars to counterbalance the centrifugal forces during curves. Motion sensitive passengers, however, complain of discomfort and overt motion sickness. A recent study comparing different control systems in a tilting train, suggested that the delay of car tilts relative to the curve of the track contributes to motion sickness. Other aspects of the motion stimuli, like the lateral accelerations and the car jitters, differed between the tested conditions and prevented a final conclusion on the role of tilt delay. Nineteen subjects were tested on a motorized 3D turntable that simulated the roll tilts during yaw rotations experienced on a tilting train, isolating them from other motion components. Each session was composed of two consecutive series of 12 ideal curves that were defined on the bases of recordings during an actual train ride. The simulated car tilts started either at the beginning of the curve acceleration phase (no-delay condition) or with 3 s of delay (delay condition). Motion sickness was self-assessed by each subject at the end of each series using an analog motion sickness scale. All subjects were tested in both conditions. Significant increases of motion sickness occurred after the first sequence of 12 curves in the delay condition, but not in the no-delay condition. This increase correlated with the sensitivity of motion sickness, which was self-assessed by each subject before the experiment. The second sequence of curve did not lead to a significant further increase of motion sickness in any condition. Our results demonstrate that, even if the speed and amplitude are as low as those experienced on tilting trains, a series of roll tilts with a delay relative to the horizontal rotations, isolated from other motion stimuli occurring during a travel, generate Coriolis/cross-coupling stimulations sufficient to rapidly induce motion sickness in sensitive individuals. The strength and the rapid onset of the motion sickness reported confirm that, even if the angular velocity involved are low, the Coriolis/cross-coupling resulting from the delay is a major factor in causing sickness that can be resolved by improving the tilt timing relative to the horizontal rotation originating from the curve. PMID:28555125

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

Fradkin, D.B.; Hull, L.M.; Laabs, G.W.

The results of dynamic sled track performance testing of advanced tandem configuration shaped-charge warheads against multiple-reactive-element tank armors are presented. Tandem configurations utilizing both currently fielded and experimental shaped-charge warheads were tested. Sled velocities used were between 400 and 1100 ft/s (Mach number 0.35 to 0.95), typical of the terminal approach velocity of TOW-type antitank missiles. High-speed motion pictures (5000 frames/s) of the sled in operation and a typical mock missile'' warhead package approaching the target are shown. Details of the sled design and fabrication and of the warhead package design and fabrication are presented. Sled track instrumentation is discussed.more » This instrumentation includes foil make/break switches and associated time interval meters (TIM) and digital delay units (DDU), magnetic Hall-effect transistors for measuring sled trajectory, and flash x-rays (FXR). Methods for timing the x-rays are presented. Schematic functional diagrams of the experimental setups are also given. Evidence of the ability to accurately time the delay between precursor and main warheads for even very long time delays are presented. FXR pictures illustrate the dynamics of the interaction of the jets with various target elements. The interaction dynamics of the jets is discussed in relation to the overall penetration performance of the tandem warhead. The use of x-ray fluorescence spectroscopy to help diagnose interaction dynamics is illustrated. The results of a test utilizing the missile propulsion rocket motor as a blast shield is presented in this paper. 2 refs., 22 figs.« less

Donepezil improves episodic memory in young individuals vulnerable to the effects of sleep deprivation.

PubMed

Chuah, Lisa Y M; Chong, Delise L; Chen, Annette K; Rekshan, William R; Tan, Jiat-Chow; Zheng, Hui; Chee, Michael W L

2009-08-01

We investigated if donepezil, a long-acting orally administered cholinesterase inhibitor, would reduce episodic memory deficits associated with 24 h of sleep deprivation. Double-blind, placebo-controlled, crossover study involving 7 laboratory visits over 2 months. Participants underwent 4 functional MRI scans; 2 sessions (donepezil or placebo) followed a normal night's sleep, and 2 sessions followed a night of sleep deprivation. The study took place in a research laboratory. 26 young, healthy volunteers with no history of any sleep, psychiatric, or neurologic disorders. 5 mg of donepezil was taken once daily for approximately 17 days. Subjects were scanned while performing a semantic judgment task and tested for word recognition outside the scanner 45 minutes later. Sleep deprivation increased the frequency of non-responses at encoding and impaired delayed recognition. No benefit of donepezil was evident when participants were well rested. When sleep deprived, individuals who showed greater performance decline improved with donepezil, whereas more resistant individuals did not benefit. Accompanying these behavioral effects, there was corresponding modulation of task-related activation in functionally relevant brain regions. Brain regions identified in relation to donepezil-induced alteration in non-response rates could be distinguished from regions relating to improved recognition memory. This suggests that donepezil can improve delayed recognition in sleep-deprived persons by improving attention as well as enhancing memory encoding. Donepezil reduced decline in recognition performance in individuals vulnerable to the effects of sleep deprivation. Additionally, our findings demonstrate the utility of combined fMRI-behavior evaluation in psychopharmacological studies.

Effect of N-Acetylcysteine Pretreatment of Deceased Organ Donors on Renal Allograft Function: A Randomized Controlled Trial

PubMed Central

Orban, Jean-Christophe; Quintard, Hervé; Cassuto, Elisabeth; Jambou, Patrick; Samat-Long, Corine; Ichai, Carole

2015-01-01

Background Antioxidant donor pretreatment is one of the pharmacologic strategy proposed to prevent renal ischemia-reperfusion injuries and delayed graft function (DGF). The aim of the study was to investigate whether a donor pretreatment with N-acetylcysteine (NAC) reduces the incidence of DGF in adult human kidney transplant recipients. Methods In this randomized, open-label, monocenter trial, 160 deceased heart-beating donors were allowed to perform 236 renal transplantations from September 2005 to December 2010. Donors were randomized to receive, in a single-blind controlled fashion, 600 mg of intravenous NAC 1 hr before and 2 hr after cerebral angiography performed to confirm brain death. Primary endpoint was DGF defined by the need for at least one dialysis session within the first week or a serum creatinine level greater than 200 μmol/L at day 7 after kidney transplantation. Results The incidence of DGF was similar between donors pretreated with or without NAC (39/118; 33% vs. 30/118; 25.4%; P = 0.19). Requirement for at least one dialysis session was not different between the NAC and No NAC groups (17/118; 14.4% vs. 14/118; 11.8%, P = 0.56). The two groups had comparable serum creatinine levels, estimated glomerular filtration rates, and daily urine output at days 1, 7, 15, and 30 after kidney transplantation as well as at hospital discharge. No difference in recipient mortality nor in 1-year kidney graft survival was observed. Conclusion Donor pretreatment with NAC does not improve delayed graft function after kidney transplantation. PMID:25250647

A three pulse phase response curve to three milligrams of melatonin in humans

PubMed Central

Burgess, Helen J; Revell, Victoria L; Eastman, Charmane I

2008-01-01

Exogenous melatonin is increasingly used for its phase shifting and soporific effects. We generated a three pulse phase response curve (PRC) to exogenous melatonin (3 mg) by administering it to free-running subjects. Young healthy subjects (n = 27) participated in two 5 day laboratory sessions, each preceded by at least a week of habitual, but fixed sleep. Each 5 day laboratory session started and ended with a phase assessment to measure the circadian rhythm of endogenous melatonin in dim light using 30 min saliva samples. In between were three days in an ultradian dim light (< 150 lux)–dark cycle (LD 2.5 : 1.5) during which each subject took one pill per day at the same clock time (3 mg melatonin or placebo, double blind, counterbalanced). Each individual's phase shift to exogenous melatonin was corrected by subtracting their phase shift to placebo (a free-run). The resulting PRC has a phase advance portion peaking about 5 h before the dim light melatonin onset, in the afternoon. The phase delay portion peaks about 11 h after the dim light melatonin onset, shortly after the usual time of morning awakening. A dead zone of minimal phase shifts occurred around the first half of habitual sleep. The fitted maximum advance and delay shifts were 1.8 h and 1.3 h, respectively. This new PRC will aid in determining the optimal time to administer exogenous melatonin to achieve desired phase shifts and demonstrates that using exogenous melatonin as a sleep aid at night has minimal phase shifting effects. PMID:18006583

Training Rapid Stepping Responses in an Individual With Stroke

PubMed Central

Inness, Elizabeth L.; Komar, Janice; Biasin, Louis; Brunton, Karen; Lakhani, Bimal; McIlroy, William E.

2011-01-01

Background and Purpose Compensatory stepping reactions are important responses to prevent a fall following a postural perturbation. People with hemiparesis following a stroke show delayed initiation and execution of stepping reactions and often are found to be unable to initiate these steps with the more-affected limb. This case report describes a targeted training program involving repeated postural perturbations to improve control of compensatory stepping in an individual with stroke. Case Description Compensatory stepping reactions of a 68-year-old man were examined 52 days after left hemorrhagic stroke. He required assistance to prevent a fall in all trials administered during his initial examination because he showed weight-bearing asymmetry (with more weight borne on the more-affected right side), was unable to initiate stepping with the right leg (despite blocking of the left leg in some trials), and demonstrated delayed response times. The patient completed 6 perturbation training sessions (30–60 minutes per session) that aimed to improve preperturbation weight-bearing symmetry, to encourage stepping with the right limb, and to reduce step initiation and completion times. Outcomes Improved efficacy of compensatory stepping reactions with training and reduced reliance on assistance to prevent falling were observed. Improvements were noted in preperturbation asymmetry and step timing. Blocking the left foot was effective in encouraging stepping with the more-affected right foot. Discussion This case report demonstrates potential short-term adaptations in compensatory stepping reactions following perturbation training in an individual with stroke. Future work should investigate the links between improved compensatory step characteristics and fall risk in this vulnerable population. PMID:21511992

Individual variables related to craving reduction in cue exposure treatment.

PubMed

Pericot-Valverde, Irene; García-Rodríguez, Olaya; Gutiérrez-Maldonado, José; Secades-Villa, Roberto

2015-10-01

Although extensive research has demonstrated that cigarette craving can be effectively attenuated, very few studies have explored associations between individual variables and craving reduction. This study explored whether individual characteristics predict craving decreases during virtual reality cue exposure treatment (VR-CET). Participants were 41 treatment-seeking smokers (73% women) with a mean age of 39.4 (SD=13.2), who had been smoking 15.0 (SD=7.1) cigarettes per day for 20.0 (SD=10.7) years. Their mean score on the Fagerström Test of Nicotine Dependence (FTND) was 4.8 (SD=2.3). Participants completed five cue exposure sessions using virtual reality for smoking cessation over a five-week period. The percentage of reduction in craving was calculated by comparing self-reported craving after the first and last exposure sessions. Sociodemographic characteristics (gender, age, years of education and marital status), tobacco-related [duration of daily smoking, cigarettes per day, FTND and Nicotine Dependence Syndrome Scale (NDSS)] and psychological characteristics [depressive symptoms (Beck's Depression Inventory-Second Edition, BDI-II), impulsiveness (delay discounting) and anxiety (State-Trait Anxiety Inventory, STAI)] were examined as possible predictors for craving reductions. Multiple regression revealed that greater decreases in craving were associated with younger age (β=-.30, p=.043), cigarettes smoked per day (β=.30, p=.042), higher values on delay discounting (β=.34, p=.020) and higher BDI-II scores (β=.30, p=.035). These findings suggest that smokers with certain individual characteristics may benefit most from interventions aimed at reducing craving through VR-CET. Copyright © 2015 Elsevier Ltd. All rights reserved.

An arousing, musically enhanced bird song stimulus mediates circadian rhythm phase advances in dim light.

PubMed

Goel, Namni

2006-09-01

A musically enhanced bird song stimulus presented in the early subjective night phase delays human circadian rhythms. This study determined the phase-shifting effects of the same stimulus in the early subjective day. Eleven subjects (ages 18-63 yr; mean +/- SD: 28.0 +/- 16.6 yr) completed two 4-day laboratory sessions in constant dim light (<20 lux). They received two consecutive presentations of either a 2-h musically enhanced bird song or control stimulus from 0600 to 0800 on the second and third mornings while awake. The 4-day sessions employing either the stimulus or control were counterbalanced. Core body temperature (CBT) was collected throughout the study, and salivary melatonin was obtained every 30 min from 1900 to 2330 on the baseline and poststimulus/postcontrol nights. Dim light melatonin onset and CBT minimum circadian phase before and after stimulus or control presentation was assessed. The musically enhanced bird song stimulus produced significantly larger phase advances of the circadian melatonin (mean +/- SD: 0.87 +/- 0.36 vs. 0.24 +/- 0.22 h) and CBT (1.08 +/- 0.50 vs. 0.43 +/- 0.37 h) rhythms than the control. The stimulus also decreased fatigue and total mood disturbance, suggesting arousing effects. This study shows that a musically enhanced bird song stimulus presented during the early subjective day phase advances circadian rhythms. However, it remains unclear whether the phase shifts are due directly to effects of the stimulus on the clock or are arousal- or dim light-mediated effects. This nonphotic stimulus mediates circadian resynchronization in either the phase advance or delay direction.

Do we perform surgical programming well? How can we improve it?

PubMed

Albareda, J; Clavel, D; Mahulea, C; Blanco, N; Ezquerra, L; Gómez, J; Silva, J M

The objective is to establish the duration of our interventions, intermediate times and surgical performance. This will create a virtual waiting list to apply a mathematical programme that performs programming with maximum performance. Retrospective review of 49 surgical sessions obtaining the delay in start time, intermediate time and surgical performance. Retrospective review of 4,045 interventions performed in the last 3 years to obtain the average duration of each type of surgery. Creation of a virtual waiting list of 700 patients in order to perform virtual programming through the MIQCP-P until achieving optimal performance. Our surgical performance with manual programming was 75.9%, ending 22.4% later than 3pm. The performance in the days without suspensions was 78.4%. The delay at start time was 9.7min. The optimum performance was 77.5% with a confidence of finishing before 15h of 80.6%. The waiting list has been scheduled in 254 sessions. Our manual surgical performance without suspensions (78.4%) was superior to the optimal (77.5%), generating days finished later than 3pm and suspensions. The possibilities for improvement are to achieve punctuality at the start time and adjust the schedule to the ideal performance. The virtual programming has allowed us to obtain our ideal performance and to establish the number of operating rooms necessary to solve the waiting list created. The data obtained in virtual mathematical programming are reliable enough to implement this model with guarantees. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

Excitotoxic lesions of the medial striatum delay extinction of a reinforcement color discrimination operant task in domestic chicks; a functional role of reward anticipation.

PubMed

Ichikawa, Yoko; Izawa, Ei-Ichi; Matsushima, Toshiya

2004-12-01

To reveal the functional roles of the striatum, we examined the effects of excitotoxic lesions to the bilateral medial striatum (mSt) and nucleus accumbens (Ac) in a food reinforcement color discrimination operant task. With a food reward as reinforcement, 1-week-old domestic chicks were trained to peck selectively at red and yellow beads (S+) and not to peck at a blue bead (S-). Those chicks then received either lesions or sham operations and were tested in extinction training sessions, during which yellow turned out to be nonrewarding (S-), whereas red and blue remained unchanged. To further examine the effects on postoperant noninstrumental aspects of behavior, we also measured the "waiting time", during which chicks stayed at the empty feeder after pecking at yellow. Although the lesioned chicks showed significantly higher error rates in the nonrewarding yellow trials, their postoperant waiting time gradually decreased similarly to the sham controls. Furthermore, the lesioned chicks waited significantly longer than the controls, even from the first extinction block. In the blue trials, both lesioned and sham chicks consistently refrained from pecking, indicating that the delayed extinction was not due to a general disinhibition of pecking. Similarly, no effects were found in the novel training sessions, suggesting that the lesions had selective effects on the extinction of a learned operant. These results suggest that a neural representation of memory-based reward anticipation in the mSt/Ac could contribute to the anticipation error required for extinction.

Pavlovian conditioning to food reward as a function of eating disorder risk.

PubMed

Astur, Robert S; Palmisano, Alexandra N; Hudd, Ellie C; Carew, Andrew W; Deaton, Bonnie E; Kuhney, Franchesca S; Niezrecki, Rachel N; Santos, Melissa

2015-09-15

The aim of this experiment was to examine the extent to which eating disorder risk affects the strength of food-reward conditioning. Eighty food-restricted undergraduates were placed into a VR environment consisting of two visually distinct rooms. Participants underwent multiple pairing sessions in which they were confined into one of the two rooms and explored a VR environment. Room A was paired with real-life M&Ms for three sessions, and Room B was paired with no food for three sessions. After a short delay, a test session was administered, and participants were given free access to the entire VR environment for 5 min. Participants also completed the Eating Attitudes Test (EAT-26; [11]), which is a standard screening tool of eating disorder risk. Participants displayed a significant conditioned place preference for the VR room previously paired with food, and they displayed a significant explicit preference for the M&M-paired room in a forced-choice test. There was a significant positive correlation between place preference strength and scores on the dieting subscale of the EAT-26. Additionally, ratings of the no-food room were significantly lower as dieting scores increased. This suggests that components of eating disorder risk can influence basic conditioning strength to places associated with food reward. For both males and females, additional correlations between eating disorder risk subscales and conditioning variables are discussed, and implications for future research are proposed in hopes of understanding how conditioning paradigms can provide insight into treating and preventing eating disorders. Copyright © 2015 Elsevier B.V. All rights reserved.

Interrelationships between marijuana demand and discounting of delayed rewards: Convergence in behavioral economic methods.

PubMed

Aston, Elizabeth R; Metrik, Jane; Amlung, Michael; Kahler, Christopher W; MacKillop, James

2016-12-01

Distinct behavioral economic domains, including high perceived drug value (demand) and delay discounting (DD), have been implicated in the initiation of drug use and the progression to dependence. However, it is unclear whether frequent marijuana users conform to a "reinforcer pathology" addiction model wherein marijuana demand and DD jointly increase risk for problematic marijuana use and cannabis dependence (CD). Participants (n=88, 34% female, 14% cannabis dependent) completed a marijuana purchase task at baseline. A delay discounting task was completed following placebo marijuana cigarette (0% THC) administration during a separate experimental session. Marijuana demand and DD were quantified using area under the curve (AUC). In multiple regression models, demand uniquely predicted frequency of marijuana use while DD did not. In contrast, DD uniquely predicted CD symptom count while demand did not. There were no significant interactions between demand and DD in either model. These findings suggest that frequent marijuana users exhibit key constituents of the reinforcer pathology model: high marijuana demand and steep discounting of delayed rewards. However, demand and DD appear to be independent rather than synergistic risk factors for elevated marijuana use and risk for progression to CD. Findings also provide support for using AUC as a singular marijuana demand metric, particularly when also examining other behavioral economic constructs that apply similar statistical approaches, such as DD, to support analytic methodological convergence. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Canal switch and re-entry phenomenon in benign paroxysmal positional vertigo: difference between immediate and delayed occurrence.

PubMed

Dispenza, F; DE Stefano, A; Costantino, C; Rando, D; Giglione, M; Stagno, R; Bennici, E

2015-04-01

This prospective study was designed to evaluate the differences between immediate and delayed canal re-entry of otoliths after therapeutic manoeuvres in patients with benign paroxysmal positional vertigo (BPPV). A total of 196 patients with BPPV were visited and 127 matched our inclusion criteria. The mean age was 54.74 years. The horizontal semicircular canal (HSC) was involved in 30 cases and the posterior semicircular canal (PSC) in 97 patients. Patients with hearing loss in the ear affected by BPPV have a more recurrent form, compared to those with normal hearing. An immediate canal re-entry was recorded in 3 patients with HSC BPPV, all with geotropic nystagmus. In 7 patients with PSC BPPV, the immediate canal re-entry was detected and the delayed form was noted in 5 patients. The patients with the delayed canal re-entry underwent more than 2 previous manoeuvres. The canal re-entry was not related to the manoeuvre performed. The timing of the Dix-Hallpike test to verify the resolution of the BPPV had a significant role in immediate canal re-entry. A recurrence in the follow-up at least one month after treatment was recorded in 20 patients and was more frequent in patients that had canal re-entry. The canal re-entry or canal switch is a clinical entity that should be kept in mind of the neurotologist when approaching BPPV patients. It is important to distinguish it from recurrence when delayed and from manoeuvre failure when immediate. The timing of manoeuvre performing, in particular the final verification test after therapeutic sessions, is important to prevent the immediate reflux of particles into canals.

The Impact of Short-Term Video Games on Performance among Children with Developmental Delays: A Randomized Controlled Trial

PubMed Central

Hsieh, Ru-Lan; Lee, Wen-Chung; Lin, Jui-Hsiang

2016-01-01

This prospective, randomized controlled study investigated the effects of short-term interactive video game playing among children with developmental delays participating in traditional rehabilitation treatment at a rehabilitation clinic. One hundred and one boys and 46 girls with a mean age of 5.8 years (range: 3 to 12 years) were enrolled in this study. All patients were confirmed to suffer from developmental delays, and were participating in traditional rehabilitation treatment. Children participated in two periods of 4 weeks each, group A being offered intervention of eight 30-minute sessions of interactive video games in the first period, and group B in the second, in addition to the traditional rehabilitation treatment. The physical, psychosocial, and total health of the children was periodically assessed using the parent-reported Pediatric Quality of Life Inventory-Generic Core Scales (PedsQL); and the children’s upper extremity and physical function, transfer and basic mobility, sports and physical functioning, and global functioning were assessed using the Pediatric Outcomes Data Collection Instrument. Parental impact was evaluated using the PedsQL-Family Impact Module for family function, PedsQL-Health Satisfaction questionnaire for parents’ satisfaction with their children’s care and World Health Organization-Quality of Life-Brief Version for quality of life. Compared with the baseline, significant improvements of physical function were observed in both groups (5.6 ± 19.5, p = 0.013; 4.7 ± 13.8, p = 0.009) during the intervention periods. No significant improvement of psychosocial health, functional performance, or family impact was observed in children with developmental delays. Short-term interactive video game play in conjunction with traditional rehabilitation treatment improved the physical health of children with developmental delays. Trial Registration: ClinicalTrials.gov NCT02184715 PMID:26983099

The Impact of Short-Term Video Games on Performance among Children with Developmental Delays: A Randomized Controlled Trial.

PubMed

Hsieh, Ru-Lan; Lee, Wen-Chung; Lin, Jui-Hsiang

2016-01-01

This prospective, randomized controlled study investigated the effects of short-term interactive video game playing among children with developmental delays participating in traditional rehabilitation treatment at a rehabilitation clinic. One hundred and one boys and 46 girls with a mean age of 5.8 years (range: 3 to 12 years) were enrolled in this study. All patients were confirmed to suffer from developmental delays, and were participating in traditional rehabilitation treatment. Children participated in two periods of 4 weeks each, group A being offered intervention of eight 30-minute sessions of interactive video games in the first period, and group B in the second, in addition to the traditional rehabilitation treatment. The physical, psychosocial, and total health of the children was periodically assessed using the parent-reported Pediatric Quality of Life Inventory-Generic Core Scales (PedsQL); and the children's upper extremity and physical function, transfer and basic mobility, sports and physical functioning, and global functioning were assessed using the Pediatric Outcomes Data Collection Instrument. Parental impact was evaluated using the PedsQL-Family Impact Module for family function, PedsQL-Health Satisfaction questionnaire for parents' satisfaction with their children's care and World Health Organization-Quality of Life-Brief Version for quality of life. Compared with the baseline, significant improvements of physical function were observed in both groups (5.6 ± 19.5, p = 0.013; 4.7 ± 13.8, p = 0.009) during the intervention periods. No significant improvement of psychosocial health, functional performance, or family impact was observed in children with developmental delays. Short-term interactive video game play in conjunction with traditional rehabilitation treatment improved the physical health of children with developmental delays. ClinicalTrials.gov NCT02184715.

Security-Enhanced Push Button Configuration for Home Smart Control.

PubMed

Han, Junghee; Park, Taejoon

2017-06-08

With the emergence of smart and converged home services, the need for the secure and easy interplay of various devices has been increased. Push Button Configuration (PBC) is one of the technologies proposed for easy set-up of a secure session between IT and consumer devices. Although the Wi-Fi Direct specification explicitly states that all devices must support the PBC method, its applicability is very limited. This is because the security vulnerability of PBC can be maliciously exploited so that attackers can make illegitimate sessions with consumer devices. To address this problem, this paper proposes a novel Security-enhanced PBC (SePBC) scheme with which we can uncover suspicious or malicious devices. The proposed mechanism has several unique features. First, we develop a secure handshake distance measurement protocol by preventing an adversary sitting outside the region from maliciously manipulating its distance to be fake. Second, it is compatible with the original Wi-Fi PBC without introducing a brand-new methodology. Finally, SePBC uses lightweight operations without CPU-intensive cryptography computation and employs inexpensive H/W. Moreover, it needs to incur little overhead when there is no attack. This paper also designs and implements the proposed SePBC in the real world. Our experimental results and analysis show that the proposed SePBC scheme effectively defeats attacks on PBC while minimizing the modification of the original PBC equipment.

Security-Enhanced Push Button Configuration for Home Smart Control †

PubMed Central

Han, Junghee; Park, Taejoon

2017-01-01

With the emergence of smart and converged home services, the need for the secure and easy interplay of various devices has been increased. Push Button Configuration (PBC) is one of the technologies proposed for easy set-up of a secure session between IT and consumer devices. Although the Wi-Fi Direct specification explicitly states that all devices must support the PBC method, its applicability is very limited. This is because the security vulnerability of PBC can be maliciously exploited so that attackers can make illegitimate sessions with consumer devices. To address this problem, this paper proposes a novel Security-enhanced PBC (SePBC) scheme with which we can uncover suspicious or malicious devices. The proposed mechanism has several unique features. First, we develop a secure handshake distance measurement protocol by preventing an adversary sitting outside the region from maliciously manipulating its distance to be fake. Second, it is compatible with the original Wi-Fi PBC without introducing a brand-new methodology. Finally, SePBC uses lightweight operations without CPU-intensive cryptography computation and employs inexpensive H/W. Moreover, it needs to incur little overhead when there is no attack. This paper also designs and implements the proposed SePBC in the real world. Our experimental results and analysis show that the proposed SePBC scheme effectively defeats attacks on PBC while minimizing the modification of the original PBC equipment. PMID:28594370

Comparison of Sensor Selection Mechanisms for an ERP-Based Brain-Computer Interface

PubMed Central

Metzen, Jan H.

2013-01-01

A major barrier for a broad applicability of brain-computer interfaces (BCIs) based on electroencephalography (EEG) is the large number of EEG sensor electrodes typically used. The necessity for this results from the fact that the relevant information for the BCI is often spread over the scalp in complex patterns that differ depending on subjects and application scenarios. Recently, a number of methods have been proposed to determine an individual optimal sensor selection. These methods have, however, rarely been compared against each other or against any type of baseline. In this paper, we review several selection approaches and propose one additional selection criterion based on the evaluation of the performance of a BCI system using a reduced set of sensors. We evaluate the methods in the context of a passive BCI system that is designed to detect a P300 event-related potential and compare the performance of the methods against randomly generated sensor constellations. For a realistic estimation of the reduced system's performance we transfer sensor constellations found on one experimental session to a different session for evaluation. We identified notable (and unanticipated) differences among the methods and could demonstrate that the best method in our setup is able to reduce the required number of sensors considerably. Though our application focuses on EEG data, all presented algorithms and evaluation schemes can be transferred to any binary classification task on sensor arrays. PMID:23844021

An automated psychoacoustic testing apparatus for use in cats.

PubMed

Benovitski, Yuri B; Blamey, Peter J; Rathbone, Graeme D; Fallon, James B

2014-03-01

Animal behavioral studies make a significant contribution to hearing research and provide vital information which is not available from human subjects. Animal psychoacoustics is usually extremely time consuming and labor intensive; in addition, animals may become stressed, especially if restraints or negative reinforcers such as electric shocks are used. We present a novel behavioral experimental system that was developed to allow efficient animal training in response to acoustic stimuli. Cats were required to perform a relatively simple task of moving toward and away from the device depending on whether the members of a tone pair were different or the same in frequency (go/no-go task). The experimental setup proved to be effective, with all animals (N = 7) performing at above 90% correct on an easy task. Animals were trained within 2-4 weeks and then generated a total of 150-200 trials per day, distributed within approximately 8 self initiated sessions. Data collected using this system were stable over 1 week and repeatable over long test periods (14 weeks). Measured frequency discrimination thresholds from 3 animals at 3 different reference frequencies were comparable with previously published results. The main advantages of the system are: relatively simple setup; large amounts of data can be generated without the need of researcher supervision; multiple animals can be tested simultaneously without removal from home pens; and no electric shocks or restraints are required. Copyright © 2013 Elsevier B.V. All rights reserved.

Systems, Subjects, Sessions: To What Extent Do These Factors Influence EEG Data?

PubMed

Melnik, Andrew; Legkov, Petr; Izdebski, Krzysztof; Kärcher, Silke M; Hairston, W David; Ferris, Daniel P; König, Peter

2017-01-01

Lab-based electroencephalography (EEG) techniques have matured over decades of research and can produce high-quality scientific data. It is often assumed that the specific choice of EEG system has limited impact on the data and does not add variance to the results. However, many low cost and mobile EEG systems are now available, and there is some doubt as to the how EEG data vary across these newer systems. We sought to determine how variance across systems compares to variance across subjects or repeated sessions. We tested four EEG systems: two standard research-grade systems, one system designed for mobile use with dry electrodes, and an affordable mobile system with a lower channel count. We recorded four subjects three times with each of the four EEG systems. This setup allowed us to assess the influence of all three factors on the variance of data. Subjects performed a battery of six short standard EEG paradigms based on event-related potentials (ERPs) and steady-state visually evoked potential (SSVEP). Results demonstrated that subjects account for 32% of the variance, systems for 9% of the variance, and repeated sessions for each subject-system combination for 1% of the variance. In most lab-based EEG research, the number of subjects per study typically ranges from 10 to 20, and error of uncertainty in estimates of the mean (like ERP) will improve by the square root of the number of subjects. As a result, the variance due to EEG system (9%) is of the same order of magnitude as variance due to subjects (32%/sqrt(16) = 8%) with a pool of 16 subjects. The two standard research-grade EEG systems had no significantly different means from each other across all paradigms. However, the two other EEG systems demonstrated different mean values from one or both of the two standard research-grade EEG systems in at least half of the paradigms. In addition to providing specific estimates of the variability across EEG systems, subjects, and repeated sessions, we also propose a benchmark to evaluate new mobile EEG systems by means of ERP responses.

Impact of a parenting program in a high-risk, multi-ethnic community: the PALS trial.

PubMed

Scott, Stephen; O'Connor, Thomas G; Futh, Annabel; Matias, Carla; Price, Jenny; Doolan, Moira

2010-12-01

Parenting programs have been shown to work when delivered to motivated ethnic majority parents in demonstration projects, but comparatively little is known about their impact when delivered to high-risk, multi-ethnic populations by routine local services. The Primary Age Learning Skills (PALS) trial was a randomized controlled trial of an evidence-based parenting-group program that targeted the parent-child relationship and child literacy. Parents of 174 children were selected from a population of 672 5- and 6-year-olds attending four primary schools in a high-risk, ethnically diverse, inner-city area. Eighty-eight children were allocated to the Incredible Years preventive program plus a shortened six-week version of the SPOKES literacy program, delivered by local services; 86 to usual community services; 152/174 (87%) of families were successfully followed up. Parent-child relationship quality and child behavior were measured using direct observation and parent interview; child reading was assessed psychometrically. Two-thirds (58/89) of those offered the parenting program attended at least one session, with similar enrollment rates across the Black African, African-Caribbean, White-British and Other ethnic groups. Mean attendance was four relationship-building sessions and one literacy-development session. Satisfaction questionnaires were completed by 43/58 starters; 93% said they were well or extremely satisfied, with equally high rates across ethnic groups. At follow-up after one year, those allocated to the intervention showed significant improvements in the parent-child relationship on observation and at interview compared to controls; effects were similar across all ethnic groups. However, child behavior problems and reading did not improve. The cost was £1,343 ($2,100) per child. Programs can be organized to be engaging and effective in improving parenting among high-risk, multi-ethnic communities, which is of considerable value. To also be cost-effective in achieving child changes may require a set-up that enables parents to attend more sessions and/or an exclusive focus on children with clinically significant behavior problems. © 2010 The Authors. Journal of Child Psychology and Psychiatry. © 2010 Association for Child and Adolescent Mental Health.

Systems, Subjects, Sessions: To What Extent Do These Factors Influence EEG Data?

PubMed Central

Melnik, Andrew; Legkov, Petr; Izdebski, Krzysztof; Kärcher, Silke M.; Hairston, W. David; Ferris, Daniel P.; König, Peter

2017-01-01

Lab-based electroencephalography (EEG) techniques have matured over decades of research and can produce high-quality scientific data. It is often assumed that the specific choice of EEG system has limited impact on the data and does not add variance to the results. However, many low cost and mobile EEG systems are now available, and there is some doubt as to the how EEG data vary across these newer systems. We sought to determine how variance across systems compares to variance across subjects or repeated sessions. We tested four EEG systems: two standard research-grade systems, one system designed for mobile use with dry electrodes, and an affordable mobile system with a lower channel count. We recorded four subjects three times with each of the four EEG systems. This setup allowed us to assess the influence of all three factors on the variance of data. Subjects performed a battery of six short standard EEG paradigms based on event-related potentials (ERPs) and steady-state visually evoked potential (SSVEP). Results demonstrated that subjects account for 32% of the variance, systems for 9% of the variance, and repeated sessions for each subject-system combination for 1% of the variance. In most lab-based EEG research, the number of subjects per study typically ranges from 10 to 20, and error of uncertainty in estimates of the mean (like ERP) will improve by the square root of the number of subjects. As a result, the variance due to EEG system (9%) is of the same order of magnitude as variance due to subjects (32%/sqrt(16) = 8%) with a pool of 16 subjects. The two standard research-grade EEG systems had no significantly different means from each other across all paradigms. However, the two other EEG systems demonstrated different mean values from one or both of the two standard research-grade EEG systems in at least half of the paradigms. In addition to providing specific estimates of the variability across EEG systems, subjects, and repeated sessions, we also propose a benchmark to evaluate new mobile EEG systems by means of ERP responses. PMID:28424600

SU-F-E-17: A Dedicated Teaching and Research Linac as a Stepping Stone to Introduce Medical Physics to Students

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

Beaulieu, L; Archambault, L; Universite Laval, Quebec, Quebec

Purpose: This work describes how a non-clinical, research and teaching Linac is used as an extremely motivating and exciting way to introduce students to medical physics. Methods: The dedicated facility was inaugurated in 2014. The facility is composed of a fully equipped and functional state-of-the-art Varian TrueBeam Linac and a complete set of physics instruments and QA phantoms for the Linac and onboard imaging. The Linac bunker and treatment console are oversized such that a class of 12–15 can comfortably fit, seated if needed for longer sessions. A 3cr undergraduate laboratory course that includes medical imaging, x-ray source characterization (mAs,more » kVp, and filtering) and many others including an introductory Linac laboratory was created. The latter is composed of one general 4-hours session and a weekly 4-hours session for teams of two students. The general session includes a hands-on presentation of the Linac, its environment and a formal safety and radiation protection course (with an exam). Results: Since the winter of 2015, senior undergraduate (total of 15) pursuing either the medical physics or the biomedical engineering tracks can register. At the Linac, the students are allowed full control of the experiments, including set-up and irradiation. Supervisor intervention is limited to safety concerns for students or equipment. Measurements of output factors using two chambers (regular and small field) for various field sizes (1×1 to 30×30 cm{sup 2}) and of detailed depth-dose curves for 6 MV, 6 and 12 MeV beams are to be performed and discussed in a formal report. Conclusion: Full access to, and control of, a Linac is the high point of this course. It provides a glimpse of medical physics and generates an experimental background for those continuing to CAMPEP programs. This dedicated, non-clinical facility further enable enhance CAMPEP graduate teaching and research activities not possible with a clinical device.« less

Associative learning rapidly establishes neuronal representations of upcoming behavioral choices in crows

PubMed Central

Veit, Lena; Pidpruzhnykova, Galyna; Nieder, Andreas

2015-01-01

The ability to form associations between behaviorally relevant sensory stimuli is fundamental for goal-directed behaviors. We investigated neuronal activity in the telencephalic area nidopallium caudolaterale (NCL) while two crows (Corvus corone) performed a delayed association task. Whereas some paired associates were familiar to the crows, novel associations had to be learned and mapped to the same target stimuli within a single session. We found neurons that prospectively encoded the chosen test item during the delay for both familiar and newly learned associations. These neurons increased their selectivity during learning in parallel with the crows' increased behavioral performance. Thus, sustained activity in the NCL actively processes information for the upcoming behavioral choice. These data provide new insights into memory representations of behaviorally meaningful stimuli in birds, and how such representations are formed during learning. The findings suggest that the NCL plays a role in learning arbitrary associations, a cornerstone of corvids’ remarkable behavioral flexibility and adaptability. PMID:26598669

The Costs and Benefits of Testing and Guessing on Recognition Memory

PubMed Central

Huff, Mark J.; Balota, David A.; Hutchison, Keith A.

2016-01-01

We examined whether two types of interpolated tasks (i.e., retrieval-practice via free recall or guessing a missing critical item) improved final recognition for related and unrelated word lists relative to restudying or completing a filler task. Both retrieval-practice and guessing tasks improved correct recognition relative to restudy and filler tasks, particularly when study lists were semantically related. However, both retrieval practice and guessing also generally inflated false recognition for the non-presented critical words. These patterns were found when final recognition was completed during a short delay within the same experimental session (Experiment 1) and following a 24-hr delay (Experiment 2). In Experiment 3, task instructions were presented randomly after each list to determine whether retrieval-practice and guessing effects were influenced by task-expectancy processes. In contrast to Experiments 1 and 2, final recognition following retrieval practice and guessing was equivalent to restudy, suggesting that the observed retrieval-practice and guessing advantages were in part due to preparatory task-based processing during study. PMID:26950490

No Evidence for Inhibitory Deficits or Altered Reward Processing in ADHD: Data From a New Integrated Monetary Incentive Delay Go/No-Go Task.

PubMed

Demurie, Ellen; Roeyers, Herbert; Wiersema, Jan R; Sonuga-Barke, Edmund

2016-04-01

Cognitive and motivational factors differentially affect individuals with mental health problems such as ADHD. Here we introduce a new task to disentangle the relative contribution of inhibitory control and reward anticipation on task performance in children with ADHD and/or autism spectrum disorders (ASD). Typically developing children, children with ADHD,  ASD, or both disorders worked during separate sessions for monetary or social rewards in go/no-go tasks with varying inhibitory load levels. Participants also completed a monetary temporal discounting (TD) task. As predicted, task performance was sensitive to both the effects of anticipated reward amount and inhibitory load. Reward amount had different effects depending on inhibitory load level. TD correlated with inhibitory control in the ADHD group. The integration of the monetary incentive delay and go/no-go paradigms was successful. Surprisingly, there was no evidence of inhibitory control deficits or altered reward anticipation in the clinical groups. © The Author(s) 2013.

Using aberrant behaviors as reinforcers for autistic children.

PubMed Central

Charlop, M H; Kurtz, P F; Casey, F G

1990-01-01

In a series of experiments, we assessed the efficacy of using autistic children's aberrant behaviors as reinforcers to increase their correct task responding. In Experiment 1, reinforcer conditions of stereotypy, food, and varied (food or stereotypy) were compared. In Experiment 2, the conditions were delayed echolalia, food, and varied (food or delayed echolalia), and in Experiment 3, perseverative behavior was compared with stereotypy and food as potential reinforcers. A multielement design was used for all comparisons, and side-effect measures were recorded during and after teaching sessions as well as at home. Results indicated that, in general, task performance was highest when brief opportunities to engage in aberrant behaviors were provided as reinforcers. Edibles were associated with the lowest performance. Furthermore, no negative side effects (e.g., an increase in aberrant behaviors) occurred. The results are discussed in terms of suggesting a more pragmatic treatment approach by addressing the contingent use of autistic children's aberrant behaviors as reinforcers. PMID:2373653

Delay discounting moderates the effect of food reinforcement on energy intake among non-obese women☆

PubMed Central

Rollins, Brandi Y.; Dearing, Kelly K.; Epstein, Leonard H.

2011-01-01

Recent theoretical approaches to food intake hypothesize that eating represents a balance between reward-driven motivation to eat versus inhibitory executive function processes, however this hypothesis remains to be tested. The objective of the current study was to test the hypothesis that the motivation to eat, operationalized by the relative reinforcing value (RRV) of food, and inhibitory processes, assessed by delay discounting (DD), interact to influence energy intake in an ad libitum eating task. Female subjects (n = 24) completed a DD of money procedure, RRV task, and an ad libitum eating task in counterbalanced sessions. RRV of food predicted total energy intake, however the effect of the RRV of food on energy intake was moderated by DD. Women higher in DD and RRV of food consumed greater total energy, whereas women higher in RRV of food but lower in DD consumed less total energy. Our findings support the hypothesis that reinforcing value and executive function mediated processes interactively influence food consumption. PMID:20678532

Effects of a group rational-emotive behavior therapy program on the Type A behavior pattern.

PubMed

Möller, A T; Botha, H C

1996-06-01

A sample of 44 male Type A insurance representatives, selected by means of the Videotaped Structured Interview, were randomly assigned to a treatment (n = 22) and a delayed treatment control group (n = 22). The treatment group participated in 9 weekly sessions of group Rational-Emotive Behavior Therapy and were followed up after 10 weeks. After the control period, the delayed treatment control group received the same treatment program. Repeated measurements were obtained by means of the Videotaped Structured Interview, Jenkins Activity Survey, Cook-Medley Hostility Scale, and Type A Cognitive Questionnaire. Self and spouse/friend ratings of Type A behavior were obtained by means of the Bortner Rating Scale. Analysis indicated that, compared to the control condition, the therapy significantly reduced the intensity of Type A behavior and its time urgency component. These improvements were maintained at follow-up and were accompanied by self-reports of significant positive changes in Type A behavior and irrational beliefs.

Music Improves Subjective Feelings Leading to Cardiac Autonomic Nervous Modulation: A Pilot Study

PubMed Central

Kume, Satoshi; Nishimura, Yukako; Mizuno, Kei; Sakimoto, Nae; Hori, Hiroshi; Tamura, Yasuhisa; Yamato, Masanori; Mitsuhashi, Rika; Akiba, Keigo; Koizumi, Jun-ichi; Watanabe, Yasuyoshi; Kataoka, Yosky

2017-01-01

It is widely accepted that listening to music improves subjective feelings and reduces fatigue sensations, and different kinds of music lead to different activations of these feelings. Recently, cardiac autonomic nervous modulation has been proposed as a useful objective indicator of fatigue. However, scientific considerations of the relation between feelings of fatigue and cardiac autonomic nervous modulation while listening to music are still lacking. In this study, we examined which subjective feelings of fatigue are related to participants' cardiac autonomic nervous function while they listen to music. We used an album of comfortable and relaxing environmental music, with blended sounds from a piano and violin as well as natural sound sources. We performed a crossover trial of environmental music and silent sessions for 20 healthy subjects, 12 females, and 8 males, after their daily work shift. We measured changes in eight types of subjective feelings, including healing, fatigue, sleepiness, relaxation, and refreshment, using the KOKORO scale, a subjective mood measurement system for self-reported feelings. Further, we obtained measures of cardiac autonomic nervous function on the basis of heart rate variability before and after the sessions. During the music session, subjective feelings significantly shifted toward healing and a secure/relaxed feeling and these changes were greater than those in the silent session. Heart rates (ΔHR) in the music session significantly decreased compared with those in the silent session. Other cardiac autonomic parameters such as high-frequency (HF) component and the ratio of low-frequency (LF) and HF components (LF/HF) were similar in the two sessions. In the linear regression analysis of the feelings with ΔHR and changes in LF/HF (ΔLF/HF), increases and decreases in ΔHR were correlated to the feeling axes of Fatigue-Healing and Anxiety/Tension–Security/Relaxation, whereas those in ΔLF/HF were related to the feeling axes of Sleepiness–Wakefulness and Gloomy–Refreshed. This indicated that listening to music improved the participants' feelings of fatigue and decreased their heart rates. However, it did not reduce the cardiac LF/HF, suggesting that cardiac LF/HF might show a delayed response to fatigue. Thus, we demonstrated changes in cardiac autonomic nervous functions based on feelings of fatigue. PMID:28344545

Music Improves Subjective Feelings Leading to Cardiac Autonomic Nervous Modulation: A Pilot Study.

PubMed

Kume, Satoshi; Nishimura, Yukako; Mizuno, Kei; Sakimoto, Nae; Hori, Hiroshi; Tamura, Yasuhisa; Yamato, Masanori; Mitsuhashi, Rika; Akiba, Keigo; Koizumi, Jun-Ichi; Watanabe, Yasuyoshi; Kataoka, Yosky

2017-01-01

It is widely accepted that listening to music improves subjective feelings and reduces fatigue sensations, and different kinds of music lead to different activations of these feelings. Recently, cardiac autonomic nervous modulation has been proposed as a useful objective indicator of fatigue. However, scientific considerations of the relation between feelings of fatigue and cardiac autonomic nervous modulation while listening to music are still lacking. In this study, we examined which subjective feelings of fatigue are related to participants' cardiac autonomic nervous function while they listen to music. We used an album of comfortable and relaxing environmental music, with blended sounds from a piano and violin as well as natural sound sources. We performed a crossover trial of environmental music and silent sessions for 20 healthy subjects, 12 females, and 8 males, after their daily work shift. We measured changes in eight types of subjective feelings, including healing, fatigue, sleepiness, relaxation, and refreshment, using the KOKORO scale, a subjective mood measurement system for self-reported feelings. Further, we obtained measures of cardiac autonomic nervous function on the basis of heart rate variability before and after the sessions. During the music session, subjective feelings significantly shifted toward healing and a secure/relaxed feeling and these changes were greater than those in the silent session. Heart rates (ΔHR) in the music session significantly decreased compared with those in the silent session. Other cardiac autonomic parameters such as high-frequency (HF) component and the ratio of low-frequency (LF) and HF components (LF/HF) were similar in the two sessions. In the linear regression analysis of the feelings with ΔHR and changes in LF/HF (ΔLF/HF), increases and decreases in ΔHR were correlated to the feeling axes of Fatigue-Healing and Anxiety/Tension-Security/Relaxation, whereas those in ΔLF/HF were related to the feeling axes of Sleepiness-Wakefulness and Gloomy-Refreshed. This indicated that listening to music improved the participants' feelings of fatigue and decreased their heart rates. However, it did not reduce the cardiac LF/HF, suggesting that cardiac LF/HF might show a delayed response to fatigue. Thus, we demonstrated changes in cardiac autonomic nervous functions based on feelings of fatigue.

A wearable biofeedback control system based body area network for freestyle swimming.

PubMed

Rui Li; Zibo Cai; WeeSit Lee; Lai, Daniel T H

2016-08-01

Wearable posture measurement units are capable of enabling real-time performance evaluation and providing feedback to end users. This paper presents a wearable feedback prototype designed for freestyle swimming with focus on trunk rotation measurement. The system consists of a nine-degree-of-freedom inertial sensor, which is built in a central data collection and processing unit, and two vibration motors for delivering real-time feedback. Theses devices form a fundamental body area network (BAN). In the experiment setup, four recreational swimmers were asked to do two sets of 4 x 25m freestyle swimming without and with feedback provided respectively. Results showed that real-time biofeedback mechanism improves swimmers kinematic performance by an average of 4.5% reduction in session time. Swimmers can gradually adapt to feedback signals, and the biofeedback control system can be employed in swimmers daily training for fitness maintenance.

Portable conduction velocity experiments using earthworms for the college and high school neuroscience teaching laboratory

PubMed Central

Shannon, Kyle M.; Gage, Gregory J.; Jankovic, Aleksandra; Wilson, W. Jeffrey

2014-01-01

The earthworm is ideal for studying action potential conduction velocity in a classroom setting, as its simple linear anatomy allows easy axon length measurements and the worm's sparse coding allows single action potentials to be easily identified. The earthworm has two giant fiber systems (lateral and medial) with different conduction velocities that can be easily measured by manipulating electrode placement and the tactile stimulus. Here, we present a portable and robust experimental setup that allows students to perform conduction velocity measurements within a 30-min to 1-h laboratory session. Our improvement over this well-known preparation is the combination of behaviorally relevant tactile stimuli (avoiding electrical stimulation) with the invention of minimal, low-cost, and portable equipment. We tested these experiments during workshops in both a high school and college classroom environment and found positive learning outcomes when we compared pre- and posttests taken by the students. PMID:24585472

Learning to teach optics through experiments and demonstrations

NASA Astrophysics Data System (ADS)

Lancis, Jesús; Fernández-Alonso, Mercedes; Martínez-León, Lluis; Tajahuerce-Romera, Enrique; Mínguez-Vega, Gladis

2014-07-01

We have applied an active methodology to pre-service teacher training courses and to active teacher workshops on Optics. As a practical resource, a set of demonstrations has been used to learn how to perform classroom demonstrations. The set includes experiments about polarization and birefringence, optical information transmission, diffraction, fluorescence or scattering. It had been prepared for Science popularization activities and has been employed in several settings with a variety of audiences. In the teacher training sessions, simple but clarifying experiments have been performed by all the participants. Moreover, in these workshops, devices or basic set-ups, like the ones included in our demonstration set, have been built. The practical approach has allowed the enthusiastic sharing of teaching and learning experiences among the workshop participants. We believe that such an active orientation in teacher training courses promotes the active and collaborative teaching and learning of Optics in different levels of Education.

[Home Daily Hemodialysis with NxStage System One: monocentric italian casistic results].

PubMed

Brunati, Chiara; Cassaro, Franca; Cretti, Laura; Izzo, Michela; Pegoraro, Marisa; Negri, Daniela; Gervasi, Francesca; Colussi, Giacomo

2017-09-28

NxStage System One is a new dialytic technology based on easy setup, simplicity of use and reduced dimensions, which is increasingly in use worldwide for home hemodialysis treatments. The system utilizes a low amount of dialysate, usually 15-30 liters according to anthropometric patients' values. The dialysate is supplied at very low flux, generally about 1/3 of blood flow, in order to obtain an elevated saturation of dialysate for solutes. In these conditions the clearance of urea will be almost equal to dialysate flow rate. In order to achieve an obptimal weekly clearance evaluated by Std Kt/V the dialysis sessions are repeated six times a week. In this way a good control of blood voleme can be reached. In this paper we report our experience of treatment with NxStage System One in 12 patients from May 2011 to Dicember 2016. Copyright by Società Italiana di Nefrologia SIN, Rome, Italy.

Hemodialysis without Systemic Anticoagulation: A Prospective Randomized Trial to Evaluate 3 Strategies in Patients at Risk of Bleeding

PubMed Central

Guéry, Bruno; Alberti, Corinne; Servais, Aude; Harrami, Elarbi; Bererhi, Lynda; Zins, Brigitte; Touam, Malik; Joly, Dominique

2014-01-01

Objective In this clinical trial, we aimed to compare three means of performing chronic hemodialysis in patients with contra-indication to systemic heparinization. Methods This open-label monocentric randomized « n-of-one » trial, conducted in a single tertiary care center, recruited chronic hemodialysis patients with a contra-indication to systemic heparinization for at least 3 consecutive sessions. All patients underwent hemodialysis with an AN69ST dialyzer, and were administered three alternative dialysis procedures in a random sequence: intermittent saline flushes, constant saline infusion, or pre-dialysis heparin coating of the membrane. The primary outcome was the need to interrupt the dialysis session because of clotting events due to either (i) a complete coagulation of the circuit; (ii) a partial coagulation of the circuit; (iii) a>50% rise over baseline in the venous pressure. Results At the end of the inclusion period (May, 2007 to December, 2008), the number of patients to include (n = 75) was not reached: only 46 patients were included and underwent randomization. The study was terminated, and statistical analysis took into account 224 hemodialysis sessions performed in 44 patients with analyzable data. Heparin adsorption was associated with a significant reduction of the need to interrupt the dialysis session because of clotting events: odds ratio 0.3 (CI 95% 0.2 to 0.6; p<0.001, versus intermittent saline flushes). Heparin adsorption was also associated with higher odds for performing >3 h dialysis sessions and for having complete blood restitution. There were no significant effects of the dialysis procedure on weight loss, online ionic dialysance, and adverse events. Conclusion Heparin-coated AN69ST dialysis membrane is a safe and effective method to avoid or delay per-dialytic clotting events in patients with contra-indication to systemic anticoagulation. However, results are not generalizable safely to patients with active bleeding, since weak heparinemia, not assessed in this study, may occur. Trial Registration ClinicalTrials.gov NCT00473109. PMID:24825343

Ethanol does not delay muscle recovery but decreases testosterone/cortisol ratio.

PubMed

Haugvad, Anders; Haugvad, Lars; Hamarsland, Håvard; Paulsen, Gøran

2014-11-01

This study investigated the effects of ethanol consumption on recovery from traditional resistance exercise in recreationally trained individuals. Nine recreationally trained volunteers (eight males and one female, 26 ± 4 yr, 81 ± 4 kg) conducted four resistance exercise sessions and consumed a low (0.6 (females) and 0.7 (males) g · kg(-1) body mass) or a high dose (1.2 or 1.4 g · kg(-1) body mass) of ethanol 1-2.5 h after exercise on two occasions. The first session was for familiarization with the tests and exercises and was performed without ethanol consumption. As a control trial, alcohol-free drinks were consumed after the exercise session. The sequence of trials, with low and high ethanol doses and alcohol-free drinks (control), was randomized. Maximal voluntary contractions (MVC) (knee extension), electrically stimulated contractions (knee extension), squat jumps, and hand grip strength were assessed 10-15 min and 12 and 24 h after the ethanol/placebo drinks. In addition to a baseline sample, blood was collected 1, 12, and 24 h after the ethanol/placebo drinks. The exercise session comprised 4 × 8 repetition maximum of squats, leg presses, and knee extensions. MVC were reduced by 13%-15% immediately after the exercise sessions (P < 0.01). MVC, electrically stimulated force, and squat jump performance were recovered 24 h after ethanol drinks. MVC was not fully recovered at 24 h in the control trial. Compared with those in the control, cortisol increased and the free testosterone/cortisol ratio were reduced after the high ethanol dose (P < 0.01). Neither a low nor a high dose of ethanol adversely affected recovery of muscle function after resistance exercise in recreationally strength-trained individuals. However, the increased cortisol levels and reduced testosterone/cortisol ratio after the high ethanol dose could translate into long-term negative effects.

Nonreciprocal wave scattering on nonlinear string-coupled oscillators

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

Lepri, Stefano, E-mail: stefano.lepri@isc.cnr.it; Istituto Nazionale di Fisica Nucleare, Sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino; Pikovsky, Arkady

2014-12-01

We study scattering of a periodic wave in a string on two lumped oscillators attached to it. The equations can be represented as a driven (by the incident wave) dissipative (due to radiation losses) system of delay differential equations of neutral type. Nonlinearity of oscillators makes the scattering non-reciprocal: The same wave is transmitted differently in two directions. Periodic regimes of scattering are analyzed approximately, using amplitude equation approach. We show that this setup can act as a nonreciprocal modulator via Hopf bifurcations of the steady solutions. Numerical simulations of the full system reveal nontrivial regimes of quasiperiodic and chaoticmore » scattering. Moreover, a regime of a “chaotic diode,” where transmission is periodic in one direction and chaotic in the opposite one, is reported.« less

Moving image analysis to the cloud: A case study with a genome-scale tomographic study

NASA Astrophysics Data System (ADS)

Mader, Kevin; Stampanoni, Marco

2016-01-01

Over the last decade, the time required to measure a terabyte of microscopic imaging data has gone from years to minutes. This shift has moved many of the challenges away from experimental design and measurement to scalable storage, organization, and analysis. As many scientists and scientific institutions lack training and competencies in these areas, major bottlenecks have arisen and led to substantial delays and gaps between measurement, understanding, and dissemination. We present in this paper a framework for analyzing large 3D datasets using cloud-based computational and storage resources. We demonstrate its applicability by showing the setup and costs associated with the analysis of a genome-scale study of bone microstructure. We then evaluate the relative advantages and disadvantages associated with local versus cloud infrastructures.

Temporal measurement on and using pulses from spectrally narrowed emission in styrylpyridinium cyanine dye

NASA Astrophysics Data System (ADS)

Dharmadhikari, Aditya K.; Bhowmik, Achintya K.; Ahyi, Ayayi C.; Thakur, Mrinal

2001-11-01

Highly efficient spectrally narrowed emission (SNE) was observed in the solution of strylpyridinium cyanine dye (SPCD) pumped by fundamental and second harmonic of a picosecond Nd:YAG laser in two separate arrangements. A highly directional emission was observed in both the pumping arrangements without incorporating any mirrors. The pulse duration of the SNE was measured by background free SHG intensity autocorrelation technique. The measured duration of the pulses was 40 ps. These pulses, having a spectral linewidth of 10 nm (full width at half maximum), were used as a probe to measure the transient changes in the transmission in SPCD solution using a pump-probe setup. The transient optical transmission indicated a gain at the overlap and no gain was observed beyond a delay of 40 ps.

Evaluation of a randomized intervention to delay sexual initiation among fifth-graders followed through the sixth grade

PubMed Central

Koo, Helen P.; Rose, Allison; El-Khorazaty, M. Nabil; Yao, Qing; Jenkins, Renee R.; Anderson, Karen M.; Davis, Maurice; Walker, Leslie R.

2011-01-01

US adolescents initiate sex at increasingly younger ages, yet few pregnancy prevention interventions for children as young as 10–12 years old have been evaluated. Sixteen Washington, DC schools were randomly assigned to intervention versus control conditions. Beginning in 2001/02 with fifth-grade students and continuing during the sixth grade, students completed pre-intervention and post-intervention surveys each school year. Each year, the intervention included 10–13 classroom sessions related to delaying sexual initiation. Linear hierarchical models compared outcome changes between intervention and control groups by gender over time. Results show the intervention significantly decreased a rise over time in the anticipation of having sex in the next 12 months among intervention boys versus control boys, but it had no other outcome effects. Among girls, the intervention had no significant outcome effects. One exception is that for both genders, compared with control students, intervention students increased their pubertal knowledge. In conclusion, a school-based curriculum to delay sexual involvement among fifth-grade and sixth-grade high-risk youths had limited impact. Additional research is necessary to outline effective interventions, and more intensive, comprehensive interventions may be required to counteract adverse circumstances in students’ lives and pervasive influences toward early sex. ClinicalTrials. gov identifier: NCT00341471 PMID:21857793

Single baseline GLONASS observations with VLBI: data processing and first results

NASA Astrophysics Data System (ADS)

Tornatore, V.; Haas, R.; Duev, D.; Pogrebenko, S.; Casey, S.; Molera Calvés, G.; Keimpema, A.

2011-07-01

Several tests to observe signals transmitted by GLONASS (GLObal NAvigation Satellite System) satellites have been performed using the geodetic VLBI (Very Long Baseline Interferometry) technique. The radio telescopes involved in these experiments were Medicina (Italy) and Onsala (Sweden), both equipped with L-band receivers. Observations at the stations were performed using the standard Mark4 VLBI data acquisition rack and Mark5A disk-based recorders. The goals of the observations were to develop and test the scheduling, signal acquisition and processing routines to verify the full tracking pipeline, foreseeing the cross-correlation of the recorded data on the baseline Onsala-Medicina. The natural radio source 3c286 was used as a calibrator before the starting of the satellite observation sessions. Delay models, including the tropospheric and ionospheric corrections, which are consistent for both far- and near-field sources are under development. Correlation of the calibrator signal has been performed using the DiFX software, while the satellite signals have been processed using the narrow band approach with the Metsaehovi software and analysed with a near-field delay model. Delay models both for the calibrator signals and the satellites signals, using the same geometrical, tropospheric and ionospheric models, are under investigation to make a correlation of the satellite signals possible.

Patients Awaiting Surgical Repair for Large Abdominal Aortic Aneurysms Can Exercise at Moderate to Hard Intensities with a Low Risk of Adverse Events

PubMed Central

Weston, Matthew; Batterham, Alan M.; Tew, Garry A.; Kothmann, Elke; Kerr, Karen; Nawaz, Shah; Yates, David; Danjoux, Gerard

2017-01-01

Purpose: Intervention fidelity refers to the extent an experimental manipulation has been implemented as intended. Our aim was to evaluate the fidelity of high-intensity interval training (HIT) in patients awaiting repair of large abdominal aortic aneurysms. Methods: Following a baseline cardiopulmonary exercise test, 27 participants performed a hospital-based, supervised HIT intervention in the 4 weeks preceding surgery. The intervention was performed thrice weekly on a cycle ergometer and involved either 8 × 2-min intervals, each interspersed by 2-min recovery periods, or 4 × 4-min intervals interspersed with 4-min recovery periods. When surgery was delayed, participants undertook one maintenance HIT session per week until surgery. Session one power output was set to baseline anaerobic threshold power output and then increased on subsequent sessions until ratings of perceived exertion (RPE; Borg CR-10) for the legs (RPE-L) and sense of breathlessness/ chest (RPE-C) were hard (5) to very hard (7) at the end of each interval. For safety, power output was maintained or reduced if systolic blood pressure exceeded 180 mm Hg or heart rate exceeded 95% of maximum. Results: Overall session attendance across the 4-week HIT intervention was 74%. Seventeen participants met our compliance criteria of ≥75% of intervention sessions and all maintenance sessions. When compared to non-compliance, compliant participants had higher fitness, performed more HIT sessions and were able to exercise at higher exercise intensities with a lower proportion of exercise safety breaches. In the 17 compliant participants, the proportion of repetitions meeting the HIT criterion was 30% (RPE-L) and 16% (RPE-C). Mean repetition intensity was 4.1 ± 2.0 Arbitrary Units [AU] (RPE-L) and 3.5 ± 1.9 AU (RPE-C) with a within-subject variability of ±1.4 AU and ±1.6 AU, respectively. We observed higher RPE scores (~0.5 AU) following 2-min intervals when compared to 4-min intervals and exercise power output increased 23% across the 4-week HIT intervention. One participant experienced an adverse event but were still able to complete their remaining exercise sessions. Conclusions: Despite an inconsistent and lower than prescribed intensity, it is possible to exercise this high-risk patient population at moderate to hard intensities with a low risk of adverse events. Clinical Trial Registration: http://www.isrctn.com/, registration number ISRCTN09433624. PMID:28119627

Comparison of between-training-sessions recovery strategies for world-class BMX pilots.

PubMed

Marquet, Laurie-Anne; Hausswirth, Christophe; Hays, Arnaud; Vettoretti, Fabrice; Brisswalter, Jeanick

2015-03-01

To assess the impact of between-training-sessions recovery strategies (passive [PAS], active [ACT], cold-water immersion [CWI], and ingestion of a recovery drink [NUTR]) on maximal cycling performance, perceptions of delayed-onset muscle soreness (DOMS), and fatigue in world-class BMX riders. Eleven elite BMX athletes, members of the French national team (top country in the 2011 international ranking, 4 medals at the 2012 World Championships, top European country), participated in the study, which involved standardized training periods. Athletes performed 3 maximal-sprint power tests: the first day of the week before the training session and before and after training on the third day of the week (D3). The recovery strategy was randomly assigned to each participant on day 2 immediately after the last training period of the day. Perceptions of DOMS and general fatigue were recorded on D3. After training on D3, the decrease in maximal-sprint power (Pmax) was significantly greater for PAS than with CWI (P=.02) and NUTR (P=.018). Similar results were found with ACT (vs CWI P=.044, and vs NUTR P=.042). Self-reported DOMS and fatigue were significantly greater after PAS than after other strategies. For elite BMX riders, between training days, nutritional and/or CWI recovery strategies appear to be best for reducing muscle fatigue and increasing the capacity to withstand the training schedule.

High-Intensity Intermittent Exercise and Autonomic Modulation: Effects of Different Volume Sessions.

PubMed

Castrillón, Carlos Iván Mesa; Miranda, Rodolfo Augusto Travagin; Cabral-Santos, Carolina; Vanzella, Lais Manata; Rodrigues, Bruno; Vanderlei, Luiz Carlos Marques; Lira, Fábio Santos; Campos, Eduardo Zapaterra

2017-06-01

The aim of this study was to compare heart rate variability (HRV) recovery after 2 sessions of high-intensity intermittent exercise at different volumes (1.25 km [HIIE 1.25 ] and 2.5 km [HIIE 2.5 ]). 13 participants determined their maximal aerobic speed (MAS) and completed 2 HIIE (1:1 at 100% MAS) trials. The heart rate was recorded before and after each session. HRV indicators were calculated according to time (RMSSD and SDNN) and frequency (LF, HF and LF/HF ratio) domains. SDNN and RMSSD presented effect of test (F=20.97; p<0.01 and F=21.00; p<0.01, respectively) and moment (F=6.76; p<0.01 and F=12.30; p<0.01, respectively), without interaction. Even though we did not find an interaction effect for any HRV variables, the HIIE 2.5 presented a delay of only 5 min in HRV recovery, when compared to HIIE 1.25 . However, the effects of the test (SDNN, RMSSD, LF-log, and HF-log) indicate higher autonomic stress during the entire recovery period. These findings may indicate that exercise volume interferes with HRV recovery. If so, physically active subjects may choose a lower volume exercise (i. e., HIIE 1.25 ) in order to promote similar physical fitness adaptations with lower loading on autonomic modulation. © Georg Thieme Verlag KG Stuttgart · New York.

Cardiac Autonomic and Blood Pressure Responses to an Acute Foam Rolling Session.

PubMed

Lastova, Kevin; Nordvall, Michael; Walters-Edwards, Michelle; Allnutt, Amy; Wong, Alexei

2018-03-22

Foam Rolling (FR) is a self-myofascial release method that has become extremely popular among athletes and fitness enthusiasts for its ability to improve flexibility and range of motion and alleviate delayed onset muscle soreness. However, the cardiac autonomic modulation and blood pressure (BP) responses induced by an acute FR session are currently unknown. The present study evaluated the effects of an acute session of FR exercise on heart rate variability (HRV) and BP responses in healthy individuals. Fifteen (M=8, F=7) healthy subjects completed either a FR or non-exercise control trial in randomized order. HRV and BP measurements were collected at baseline, 10 and 30 min after each trial. There were significant increases (P < 0.01) in markers of vagal tone (nHF) for 30 min after the FR trial, while no changes from baseline were observed following control. There were also significant decreases (P < 0.05) in markers of sympathetic activity (nLF), sympathovagal balance (nLF/nHF), systolic BP and diastolic BP at 10 and 30 min after the trial KB trial while no changes from baseline were observed after the control trial. Our findings indicate that FR decreases sympathovagal balance for 30 min post-intervention which is concurrent with an important hypotensive effect. Further research is warranted to evaluate the potential cardiovascular protective effects of FR in diverse populations.