The effects of time delay in man-machine control systems: Implications for design of flight simulator Visual-Display-Delay compensation

NASA Technical Reports Server (NTRS)

Crane, D. F.

1984-01-01

When human operators are performing precision tracking tasks, their dynamic response can often be modeled by quasilinear describing functions. That fact permits analysis of the effects of delay in certain man machine control systems using linear control system analysis techniques. The analysis indicates that a reduction in system stability is the immediate effect of additional control system delay, and that system characteristics moderate or exaggerate the importance of the delay. A selection of data (simulator and flight test) consistent with the analysis is reviewed. Flight simulator visual-display delay compensation, designed to restore pilot aircraft system stability, was evaluated in several studies which are reviewed here. The studies range from single-axis, tracking-task experiments (with sufficient subjects and trials to establish the statistical significance of the results) to a brief evaluation of compensation of a computer generated imagery (CGI) visual display system in a full six degree of freedom simulation. The compensation was effective, improvements in pilot performance and workload or aircraft handling qualities rating (HQR) were observed. Results from recent aircraft handling qualities research literature, which support the compensation design approach, are also reviewed.

Assessment of simulation fidelity using measurements of piloting technique in flight. II

NASA Technical Reports Server (NTRS)

Ferguson, S. W.; Clement, W. F.; Hoh, R. H.; Cleveland, W. B.

1985-01-01

Two components of the Vertical Motion Simulator (presently being used to assess the fidelity of UH-60A simulation) are evaluated: (1) the dash/quickstop Nap-of-the-earth (NOE) piloting task, and (2) the bop-up task. Data from these two flight test experiments are presented which provide information on the effect of reduced visual field of view, variation in scene content and texture, and the affect of pure time delay in the closed-loop pilot response. In comparison with task performance results obtained in flight tests, the results from the simulation indicate that the pilot's NOE task performance in the simulator is significantly degraded.

Piloted simulator study of allowable time delay in pitch flight control system of a transport airplane with negative static stability

NASA Technical Reports Server (NTRS)

Grantham, William D.; Smith, Paul M.; Person, Lee H., Jr.; Meyer, Robert T.; Tingas, Stephen A.

1987-01-01

A piloted simulation study was conducted to determine the permissible time delay in the flight control system of a 10-percent statically unstable transport airplane during cruise flight conditions. The math model used for the simulation was a derivative Lockheed L-1011 wide-body jet transport. Data were collected and analyzed from a total of 137 cruising flights in both calm- and turbulent-air conditions. Results of this piloted simulation study verify previous findings that show present military specifications for allowable control-system time delay may be too stringent when applied to transport-size airplanes. Also, the degree of handling-qualities degradation due to time delay is shown to be strongly dependent on the source of the time delay in an advanced flight control system. Maximum allowable time delay for each source of time delay in the control system, in addition to a less stringent overall maximum level of time delay, should be considered for large aircraft. Preliminary results also suggest that adverse effects of control-system time delay may be at least partially offset by variations in control gearing. It is recommended that the data base include different airplane baselines, control systems, and piloting tasks with many pilots participating, so that a reasonable set of limits for control-system time delay can be established to replace the military specification limits currently being used.

Piloted simulator study of allowable time delays in large-airplane response

NASA Technical Reports Server (NTRS)

Grantham, William D.; Bert T.?aetingas, Stephen A.dings with ran; Bert T.?aetingas, Stephen A.dings with ran

1987-01-01

A piloted simulation was performed to determine the permissible time delay and phase shift in the flight control system of a specific large transport-type airplane. The study was conducted with a six degree of freedom ground-based simulator and a math model similar to an advanced wide-body jet transport. Time delays in discrete and lagged form were incorporated into the longitudinal, lateral, and directional control systems of the airplane. Three experienced pilots flew simulated approaches and landings with random localizer and glide slope offsets during instrument tracking as their principal evaluation task. Results of the present study suggest a level 1 (satisfactory) handling qualities limit for the effective time delay of 0.15 sec in both the pitch and roll axes, as opposed to a 0.10-sec limit of the present specification (MIL-F-8785C) for both axes. Also, the present results suggest a level 2 (acceptable but unsatisfactory) handling qualities limit for an effective time delay of 0.82 sec and 0.57 sec for the pitch and roll axes, respectively, as opposed to 0.20 sec of the present specifications for both axes. In the area of phase shift between cockpit input and control surface deflection,the results of this study, flown in turbulent air, suggest less severe phase shift limitations for the approach and landing task-approximately 50 deg. in pitch and 40 deg. in roll - as opposed to 15 deg. of the present specifications for both axes.

The effect of visual-motion time delays on pilot performance in a pursuit tracking task

NASA Technical Reports Server (NTRS)

Miller, G. K., Jr.; Riley, D. R.

1976-01-01

A study has been made to determine the effect of visual-motion time delays on pilot performance of a simulated pursuit tracking task. Three interrelated major effects have been identified: task difficulty, motion cues, and time delays. As task difficulty, as determined by airplane handling qualities or target frequency, increases, the amount of acceptable time delay decreases. However, when relatively complete motion cues are included in the simulation, the pilot can maintain his performance for considerably longer time delays. In addition, the number of degrees of freedom of motion employed is a significant factor.

Timing and teamwork--an observational pilot study of patients referred to a Rapid Response Team with the aim of identifying factors amenable to re-design of a Rapid Response System.

PubMed

Peebles, Emma; Subbe, Christian P; Hughes, Paul; Gemmell, Les

2012-06-01

Rapid Response Teams aim to accelerate recognition and treatment of acutely unwell patients. Delays in delivery might undermine efficiency of the intervention. Our understanding of the causes of these delays is, as yet, incomplete. To identify modifiable causes of delays in the treatment of critically ill patients outside intensive care with a focus on factors amenable to system design. Review of care records and direct observation with process mapping of care delivered to 17 acutely unwell patients attended by a Rapid Response Team in a District General Hospital in the United Kingdom. Delays were defined as processes with no added value for patient care. Essential diagnostic and therapeutic procedures accounted for only 31% of time of care processes. Causes for delays could be classified into themes as (1) delays in call-out of the Rapid Response Team, (2) problems with team cohesion including poor communication and team efficiency and (3) lack of resources including lack of first line antibiotics, essential equipment, experienced staff and critical care beds. We identified a number of potentially modifiable causes for delays in care of acutely ill patients. Improved process design could include automated call-outs, a dedicated kit for emergency treatment in relevant clinical areas, increased usage of standard operating procedures and staff training using crew resource management techniques. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Summary of the effects of engine throttle response on airplane formation-flying qualities

NASA Technical Reports Server (NTRS)

Walsh, Kevin R.

1992-01-01

A flight evaluation as conducted to determine the effect of engine throttle response characteristics on precision formation-flying qualities. A variable electronic throttle control system was developed and flight-tested on a TF-104G airplane with a J79-11B engine at the NASA Dryden Flight Research Facility. Ten research flights were flown to evaluate the effects of throttle gain, time delay, and fuel control rate limiting on engine handling qualities during a demanding precision wing formation task. Handling quality effects of lag filters and lead compensation time delays were also evaluated. Data from pilot ratings and comments indicate that throttle control system time delays and rate limits cause significant degradations in handling qualities. Threshold values for satisfactory (level 1) and adequate (level 2) handling qualities of these key variables are presented.

Comparison of flying qualities derived from in-flight and ground-based simulators for a jet-transport airplane for the approach and landing pilot tasks

NASA Technical Reports Server (NTRS)

Grantham, William D.

1989-01-01

The primary objective was to provide information to the flight controls/flying qualities engineer that will assist him in determining the incremental flying qualities and/or pilot-performance differences that may be expected between results obtained via ground-based simulation (and, in particular, the six-degree-of-freedom Langley Visual/Motion Simulator (VMS)) and flight tests. Pilot opinion and performance parameters derived from a ground-based simulator and an in-flight simulator are compared for a jet-transport airplane having 32 different longitudinal dynamic response characteristics. The primary pilot tasks were the approach and landing tasks with emphasis on the landing-flare task. The results indicate that, in general, flying qualities results obtained from the ground-based simulator may be considered conservative-especially when the pilot task requires tight pilot control as during the landing flare. The one exception to this, according to the present study, was that the pilots were more tolerant of large time delays in the airplane response on the ground-based simulator. The results also indicated that the ground-based simulator (particularly the Langley VMS) is not adequate for assessing pilot/vehicle performance capabilities (i.e., the sink rate performance for the landing-flare task when the pilot has little depth/height perception from the outside scene presentation).

Handling Qualities of a Large Civil Tiltrotor in Hover using Translational Rate Command

NASA Technical Reports Server (NTRS)

Malpica, Carlos A.; Theodore, Colin R.; Lawrence, Ben; Lindsey, James; Blanken, Chris

2012-01-01

A Translational Rate Command (TRC) control law has been developed to enable low speed maneuvering of a large civil tiltrotor with minimal pitch changes by means of automatic nacelle angle deflections for longitudinal velocity control. The nacelle actuator bandwidth required to achieve Level 1 handling qualities in hover and the feasibility of additional longitudinal cyclic control to augment low bandwidth nacelle actuation were investigated. A frequency-domain handling qualities criterion characterizing TRC response in terms of bandwidth and phase delay was proposed and validated against a piloted simulation conducted on the NASA-Ames Vertical Motion Simulator. Seven experimental test pilots completed evaluations in the ADS-33E-PRF Hover Mission Task Element (MTE) for a matrix of nacelle actuator bandwidths, equivalent rise times and control response sensitivities, and longitudinal cyclic control allocations. Evaluated against this task, longitudinal phase delay shows the Level 1 boundary is around 0.4 0.5 s. Accordingly, Level 1 handling qualities were achieved either with a nacelle actuator bandwidth greater than 4 rad/s, or by employing longitudinal cyclic control to augment low bandwidth nacelle actuation.

Measurement properties and classification accuracy of two spanish parent surveys of language development for preschool-age children.

PubMed

Guiberson, Mark; Rodríguez, Barbara L

2010-08-01

To describe the concurrent validity and classification accuracy of 2 Spanish parent surveys of language development, the Spanish Ages and Stages Questionnaire (ASQ; Squires, Potter, & Bricker, 1999) and the Pilot Inventario-III (Pilot INV-III; Guiberson, 2008a). Forty-eight Spanish-speaking parents of preschool-age children participated. Twenty-two children had expressive language delays, and 26 had typical language development. The parents completed the Spanish ASQ and the Pilot INV-III at home, and the Preschool Language Scale, Fourth Edition: Spanish Edition (PLS-4 Spanish; Zimmerman, Steiner, & Pond, 2002) was administered to the children at preschool centers. The Spanish ASQ and Pilot INV-III were significantly correlated with the PLS-4 Spanish, establishing concurrent validity. On both surveys, children with expressive language delays scored significantly lower than children with typical development. The Spanish ASQ demonstrated unacceptably low sensitivity (59%) and good specificity (92%), while the Pilot INV-III demonstrated fair sensitivity (82%) and specificity (81%). Likelihood ratios and posttest probability revealed that the Pilot INV-III may assist in detection of expressive language delays, but viewed alone it is insufficient to make an unconditional screening determination. Results suggest that Spanish parent surveys hold promise for screening language delay in Spanish-speaking preschool children; however, further refinement of these tools is needed.

Cockpit displayed traffic information and distributed management in air traffic control

NASA Technical Reports Server (NTRS)

Kreifeldt, J. G.

1980-01-01

A graphical display of information (such as surrounding aircraft and navigation routes) in the cockpit on a cathode ray tube has been proposed for improving the safety, orderliness, and expeditiousness of the air traffic control system. An investigation of this method at NASA-Ames indicated a large reduction in controller verbal work load without increasing pilot verbal load; the visual work may be increased. The cockpit displayed traffic and navigation information system reduced response delays permitting pilots to maintain their spacing more closely and precisely than when depending entirely on controller-issued radar vectors and speed command.

A Control Allocation Technique to Recover From Pilot-Induced Oscillations (CAPIO) Due to Actuator Rate Limiting

NASA Technical Reports Server (NTRS)

Yildiz, Yildiray; Kolmanovsky, Ilya V.

2010-01-01

This paper proposes a control allocation technique that can help pilots recover from pilot induced oscillations (PIO). When actuators are rate-saturated due to aggressive pilot commands, high gain flight control systems or some anomaly in the system, the effective delay in the control loop may increase depending on the nature of the cause. This effective delay increase manifests itself as a phase shift between the commanded and actual system signals and can instigate PIOs. The proposed control allocator reduces the effective time delay by minimizing the phase shift between the commanded and the actual attitude accelerations. Simulation results are reported, which demonstrate phase shift minimization and recovery from PIOs. Conversion of the objective function to be minimized and constraints to a form that is suitable for implementation is given.

Parent Training with High-Risk Immigrant Chinese Families: A Pilot Group Randomized Trial Yielding Practice-Based Evidence

ERIC Educational Resources Information Center

Lau, Anna S.; Fung, Joey J.; Ho, Lorinda Y.; Liu, Lisa L.; Gudino, Omar G.

2011-01-01

We studied the efficacy and implementation outcomes of a culturally responsive parent training (PT) program. Fifty-four Chinese American parents participated in a wait-list controlled group randomized trial (32 immediate treatment, 22 delayed treatment) of a 14-week intervention designed to address the needs of high-risk immigrant families.…

Electroencephalographic Response to Sodium Nitrite May Predict Delayed Cerebral Ischemia After Severe Subarachnoid Hemorrhage.

PubMed

Garry, Payashi S; Rowland, Matthew J; Ezra, Martyn; Herigstad, Mari; Hayen, Anja; Sleigh, Jamie W; Westbrook, Jon; Warnaby, Catherine E; Pattinson, Kyle T S

2016-11-01

Aneurysmal subarachnoid hemorrhage often leads to death and poor clinical outcome. Injury occurring during the first 72 hours is termed "early brain injury," with disruption of the nitric oxide pathway playing an important pathophysiologic role in its development. Quantitative electroencephalographic variables, such as α/δ frequency ratio, are surrogate markers of cerebral ischemia. This study assessed the quantitative electroencephalographic response to a cerebral nitric oxide donor (intravenous sodium nitrite) to explore whether this correlates with the eventual development of delayed cerebral ischemia. Unblinded pilot study testing response to drug intervention. Neuroscience ICU, John Radcliffe Hospital, Oxford, United Kingdom. Fourteen World Federation of Neurosurgeons grades 3, 4, and 5 patients (mean age, 52.8 yr [range, 41-69 yr]; 11 women). IV sodium nitrite (10 μg/kg/min) for 1 hour. Continuous electroencephalographic recording for 2 hours. The alpha/delta frequency ratio was measured before and during IV sodium nitrite infusion. Seven of 14 patients developed delayed cerebral ischemia. There was a +30% to +118% (range) increase in the alpha/delta frequency ratio in patients who did not develop delayed cerebral ischemia (p < 0.0001) but an overall decrease in the alpha/delta frequency ratio in those patients who did develop delayed cerebral ischemia (range, +11% to -31%) (p = 0.006, multivariate analysis accounting for major confounds). Administration of sodium nitrite after severe subarachnoid hemorrhage differentially influences quantitative electroencephalographic variables depending on the patient's susceptibility to development of delayed cerebral ischemia. With further validation in a larger sample size, this response may be developed as a tool for risk stratification after aneurysmal subarachnoid hemorrhage.

The implementation and operation of a variable-response electronic throttle control system for a TF-104G aircraft

NASA Technical Reports Server (NTRS)

Neal, Bradford; Sengupta, Upal

1989-01-01

During some flight programs, researchers have encountered problems in the throttle response characteristics of high-performance aircraft. To study and to help solve these problems, the National Aeronautics and Space Administration Ames Research Center's Dryden Flight Research Facility (Ames-Dryden) conducted a study using a TF-104G airplane modified with a variable-response electronic throttle control system. Ames-Dryden investigated the effects of different variables on engine response and handling qualities. The system provided transport delay, lead and lag filters, second-order lags, command rate and position limits, and variable gain between the pilot's throttle command and the engine fuel controller. These variables could be tested individually or in combination. Ten research flights were flown to gather data on engine response and to obtain pilot ratings of the various system configurations. The results should provide design criteria for engine-response characteristics. The variable-response throttle components and how they were installed in the TF-104G aircraft are described. How the variable-response throttle was used in flight and some of the results of using this system are discussed.

Modified superposition: A simple time series approach to closed-loop manual controller identification

NASA Technical Reports Server (NTRS)

Biezad, D. J.; Schmidt, D. K.; Leban, F.; Mashiko, S.

1986-01-01

Single-channel pilot manual control output in closed-tracking tasks is modeled in terms of linear discrete transfer functions which are parsimonious and guaranteed stable. The transfer functions are found by applying a modified super-position time series generation technique. A Levinson-Durbin algorithm is used to determine the filter which prewhitens the input and a projective (least squares) fit of pulse response estimates is used to guarantee identified model stability. Results from two case studies are compared to previous findings, where the source of data are relatively short data records, approximately 25 seconds long. Time delay effects and pilot seasonalities are discussed and analyzed. It is concluded that single-channel time series controller modeling is feasible on short records, and that it is important for the analyst to determine a criterion for best time domain fit which allows association of model parameter values, such as pure time delay, with actual physical and physiological constraints. The purpose of the modeling is thus paramount.

An optimal control model approach to the design of compensators for simulator delay

NASA Technical Reports Server (NTRS)

Baron, S.; Lancraft, R.; Caglayan, A.

1982-01-01

The effects of display delay on pilot performance and workload and of the design of the filters to ameliorate these effects were investigated. The optimal control model for pilot/vehicle analysis was used both to determine the potential delay effects and to design the compensators. The model was applied to a simple roll tracking task and to a complex hover task. The results confirm that even small delays can degrade performance and impose a workload penalty. A time-domain compensator designed by using the optimal control model directly appears capable of providing extensive compensation for these effects even in multi-input, multi-output problems.

Fixed-base simulator study of the effect of time delays in visual cues on pilot tracking performance

NASA Technical Reports Server (NTRS)

Queijo, M. J.; Riley, D. R.

1975-01-01

Factors were examined which determine the amount of time delay acceptable in the visual feedback loop in flight simulators. Acceptable time delays are defined as delays which significantly affect neither the results nor the manner in which the subject 'flies' the simulator. The subject tracked a target aircraft as it oscillated sinusoidally in a vertical plane only. The pursuing aircraft was permitted five degrees of freedom. Time delays of from 0.047 to 0.297 second were inserted in the visual feedback loop. A side task was employed to maintain the workload constant and to insure that the pilot was fully occupied during the experiment. Tracking results were obtained for 17 aircraft configurations having different longitudinal short-period characteristics. Results show a positive correlation between improved handling qualities and a longer acceptable time delay.

Flying-qualities criteria for wings-level-turn maneuvering during an air-to-ground weapon delivery task

NASA Technical Reports Server (NTRS)

Sammonds, R. I.; Bunnell, J. W.

1981-01-01

A moving base simulator experiment demonstrated that a wings-level-turn control mode improved flying qualities for air to ground weapon delivery compared with those of a conventionally controlled aircraft. Evaluations of criteria for dynamic response for this system have shown that pilot ratings correlate well on the basis of equivalent time constant of the initial response. Ranges of this time constant, as well as digital system transport delays and lateral acceleration control authorities that encompassed level 1 through 3 handling qualities, were determined.

Criteria for Side-Force Control in Air-to-Ground Target Acquisition and Tracking

NASA Technical Reports Server (NTRS)

Sammonds, Robert I.; McNeill, Walter E.; Bunnell, John W.

1982-01-01

A moving-base simulator experiment conducted at Ames Research Center demonstrated that a wings-level-turn control mode improved flying qualities for air-to-ground weapons delivery compared with those of a conventional aircraft. Evaluations of criteria for dynamic response for this system have shown that pilot ratings correlate well with equivalent time constant of the initial response and with system bandwidth. Ranges of this time constant, as well as digital-system transport delays and lateral-acceleration control authorities that encompassed level 1 through level 3 handling qualities, were determined.

Structural dynamic model obtained from flight use with piloted simulation and handling qualities analysis

NASA Technical Reports Server (NTRS)

Powers, Bruce G.

1996-01-01

The ability to use flight data to determine an aircraft model with structural dynamic effects suitable for piloted simulation. and handling qualities analysis has been developed. This technique was demonstrated using SR-71 flight test data. For the SR-71 aircraft, the most significant structural response is the longitudinal first-bending mode. This mode was modeled as a second-order system, and the other higher order modes were modeled as a time delay. The distribution of the modal response at various fuselage locations was developed using a uniform beam solution, which can be calibrated using flight data. This approach was compared to the mode shape obtained from the ground vibration test, and the general form of the uniform beam solution was found to be a good representation of the mode shape in the areas of interest. To calibrate the solution, pitch-rate and normal-acceleration instrumentation is required for at least two locations. With the resulting structural model incorporated into the simulation, a good representation of the flight characteristics was provided for handling qualities analysis and piloted simulation.

A Control Allocation System for Automatic Detection and Compensation of Phase Shift Due to Actuator Rate Limiting

NASA Technical Reports Server (NTRS)

Yildiz, Yidiray; Kolmanovsky, Ilya V.; Acosta, Diana

2011-01-01

This paper proposes a control allocation system that can detect and compensate the phase shift between the desired and the actual total control effort due to rate limiting of the actuators. Phase shifting is an important problem in control system applications since it effectively introduces a time delay which may destabilize the closed loop dynamics. A relevant example comes from flight control where aggressive pilot commands, high gain of the flight control system or some anomaly in the system may cause actuator rate limiting and effective time delay introduction. This time delay can instigate Pilot Induced Oscillations (PIO), which is an abnormal coupling between the pilot and the aircraft resulting in unintentional and undesired oscillations. The proposed control allocation system reduces the effective time delay by first detecting the phase shift and then minimizing it using constrained optimization techniques. Flight control simulation results for an unstable aircraft with inertial cross coupling are reported, which demonstrate phase shift minimization and recovery from a PIO event.

Simulator study of the effect of visual-motion time delays on pilot tracking performance with an audio side task

NASA Technical Reports Server (NTRS)

Riley, D. R.; Miller, G. K., Jr.

1978-01-01

The effect of time delay was determined in the visual and motion cues in a flight simulator on pilot performance in tracking a target aircraft that was oscillating sinusoidally in altitude only. An audio side task was used to assure the subject was fully occupied at all times. The results indicate that, within the test grid employed, about the same acceptable time delay (250 msec) was obtained for a single aircraft (fighter type) by each of two subjects for both fixed-base and motion-base conditions. Acceptable time delay is defined as the largest amount of delay that can be inserted simultaneously into the visual and motion cues before performance degradation occurs. A statistical analysis of the data was made to establish this value of time delay. Audio side task provided quantitative data that documented the subject's work level.

Demonstration of frequency-sweep testing technique using a Bell 214-ST helicopter

NASA Technical Reports Server (NTRS)

Tischler, Mark B.; Fletcher, Jay W.; Diekmann, Vernon L.; Williams, Robert A.; Cason, Randall W.

1987-01-01

A demonstration of frequency-sweep testing using a Bell-214ST single-rotor helicopter was completed in support of the Army's development of an updated MIL-H-8501A, and an LHX (ADS-33) handling-qualities specification. Hover and level-flight (V sub a = 0 knots and V sub a = 90 knots) tests were conducted in 3 flight hours by Army test pilots at the Army Aviation Engineering Flight Activity (AEFA) at Edwards AFB, Calif. Bandwidth and phase-delay parameters were determined from the flight-extracted frequency responses as required by the proposed specifications. Transfer function modeling and verification demonstrates the validity of the frequency-response concept for characterizing closed-loop flight dynamics of single-rotor helicopters -- even in hover. This report documents the frequency-sweep flight-testing technique and data-analysis procedures. Special emphasis is given to piloting and analysis considerations which are important for demonstrating frequency-domain specification compliance.

Interaction of feel system and flight control system dynamics on lateral flying qualities

NASA Technical Reports Server (NTRS)

Bailey, Randall E.; Powers, Bruce G.; Shafer, Mary F.

1988-01-01

An investigation of feel system and flight control system dynamics on lateral flying qualities was conducted using the variable stability USAF NT-33 aircraft. Experimental variations in feel system natural frequency, force-deflection gradient, control system command architecture type, flight control system filter frequency, and control system delay were made. The experiment data include pilot ratings using the Cooper-Harper (1969) rating scale, pilot comments, and tracking performance statistic. Three test pilots served as evaluators. The data indicate that as the feel system natural frequency is reduced lateral flying qualities degrade. At the slowest feel system frequency, the closed-loop response becomes nonlinear with a 'bobweight' effect apparent in the feel system. Feel system influences were essentially independent of the control system architecture. The flying qualities influence due to the feel system was different than when the identical dynamic systenm was used as a flight control system element.

Stability Properties and Cross Coupling Performance of the Control Allocation Scheme CAPIO

NASA Technical Reports Server (NTRS)

Yildiz, Yildiray; Kolmanovsky, Ilya V.

2010-01-01

This paper presents a stability analysis and an application of a recently developed Control Allocator for recovery from Pilot Induced Oscillations (CAPIO). When actuators are rate-saturated due to either aggressive pilot commands, high gain ight control systems or some anomaly in the system, the effective delay in the control loop may increase. This effective delay increase manifests itself as a phase shift between the commanded and actual system signals and can instigate Pilot induced Oscillations (PIO). CAPIO reduces the e ective time delay by minimizing the phase shift between the commanded and the actual attitude accelerations. We present a stability analysis of CAPIO for a scalar system. In addition, we present simulation results for aircraft with cross-coupling which demonstrates the potential of CAPIO serving as an effective PIO handler in adverse conditions.

Pilot/vehicle model analysis of visually guided flight

NASA Technical Reports Server (NTRS)

Zacharias, Greg L.

1991-01-01

Information is given in graphical and outline form on a pilot/vehicle model description, control of altitude with simple terrain clues, simulated flight with visual scene delays, model-based in-cockpit display design, and some thoughts on the role of pilot/vehicle modeling.

Delay-based signal shapers and acfa 2020 blended wing body flight control system

NASA Astrophysics Data System (ADS)

Kucera, V.; Hromčík, M.

2013-12-01

The purpose of this paper is twofold. First: results related to application of signal shapers, imposed on pilot's commands, in cooperation with feedback flight control system (FCS) are reported for the case of ACFA2020 (Active Control for Flexible 2020 Aircraft) blended-wingbody (BWB) design. The results suggest that signal shapers can cooperate nicely both with FCS focused on the rigid-body dynamics only, as well as with an implemented and properly working active damping system. In both cases, the amount of vibrations due to pilot's inputs (manoeuvres) can be substantially reduced. Second: combination of signal shapers and rate-limiters is discussed in detail. Rate-limiters, representing finite achievable rates of servos for control surfaces, deteriorate considerably performance of the delay-based shapers. Configuration proposes only open-loop response of the free aircraft (without controller) for shaped reference respect to nonlinearities at action surface. Standard versions of the shapers cannot be therefore directly applied, especially for higher control surfaces deflections. Instead, two efficient alternatives can be used, suggested in the paper, that take the rate limitations into account at the design stage already.

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

Visual-motor response of crewmen during a simulated 90-day space mission as measured by the critical task battery

NASA Technical Reports Server (NTRS)

Allen, R. W.; Jex, H. R.

1973-01-01

In order to test various components of a regenerative life support system and to obtain data on the physiological and psychological effects of long duration exposure to confinement in a space station atmosphere, four carefully screened young men were sealed in a space station simulator for 90 days and administered a tracking test battery. The battery included a clinical test (Critical Instability Task) designed to measure a subject's dynamic time delay, and a more conventional steady tracking task, during which dynamic response (describing functions) and performance measures were obtained. Good correlation was noted between the clinical critical instability scores and more detailed tracking parameters such as dynamic time delay and gain-crossover frequency. The levels of each parameter span the range observed with professional pilots and astronaut candidates tested previously. The chamber environment caused no significant decrement on the average crewman's dynamic response behavior, and the subjects continued to improve slightly in their tracking skills during the 90-day confinement period.

Flying-qualities criteria for wings-level-turn maneuvering during an air-to-ground weapon delivery task

NASA Technical Reports Server (NTRS)

Sammonds, R. I.; Bunnell, J. W., Jr.

1980-01-01

A moving-base simulator experiment conducted at Ames Research Center demonstrated that a wings-level-turn control mode improved flying qualities for air-to-ground weapons delivery compared with those of a conventional aircraft. Evaluations of criteria for dynamic response for this system have shown that pilot ratings correlate well on the basis of equivalent time constant of the initial response. Ranges of this time constant, as well as digital-system transport delays and lateral-acceleration control authorities that encompassed Level I through Level III handling qualities, were determined.

78 FR 8675 - Self-Regulatory Organizations; International Securities Exchange, LLC; Notice of Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-06

... Proposed Rule Change to Amend ISE Rule 2102 to Extend the Market-Wide Circuit Breaker Pilot Program January...- wide circuit breaker on a pilot basis for a period that corresponds to the pilot period for the LULD... delay the operative date of the market-wide circuit breaker pilot to April 8, 2013 in order for the...

14 CFR 29.143 - Controllability and maneuverability.

Code of Federal Regulations, 2010 CFR

2010-01-01

... occurs with maximum continuous power and critical weight. No corrective action time delay for any... pilot reaction time (whichever is greater); and (ii) For any other condition, normal pilot reaction time...

A simulator investigation of the use of digital data link for pilot/ATC communications in a single pilot operation

NASA Technical Reports Server (NTRS)

Hinton, David A.; Lohr, Gary W.

1988-01-01

Studies have shown that radio communications between pilots and air traffic control contribute to high pilot workload and are subject to various errors. These errors result from congestion on the voice radio channel, and missed and misunderstood messages. The use of digital data link has been proposed as a means of reducing this workload and error rate. A critical factor, however, in determining the potential benefit of data link will be the interface between future data link systems and the operator of those systems, both in the air and on the ground. The purpose of this effort was to evaluate the pilot interface with various levels of data link capability, in simulated general aviation, single-pilot instrument flight rule operations. Results show that the data link reduced demands on pilots' short-term memory, reduced the number of communication transmissions, and permitted the pilots to more easily allocate time to critical cockpit tasks while receiving air traffic control messages. The pilots who participated unanimously indicated a preference for data link communications over voice-only communications. There were, however, situations in which the pilot preferred the use of voice communications, and the ability for pilots to delay processing the data link messages, during high workload events, caused delays in the acknowledgement of messages to air traffic control.

Developmental delays and dental caries in low-income preschoolers in the USA: a pilot cross-sectional study and preliminary explanatory model

PubMed Central

2013-01-01

Background Anecdotal evidence suggests that low-income preschoolers with developmental delays are at increased risk for dental caries and poor oral health, but there are no published studies based on empirical data. The purpose of this pilot study was two-fold: to examine the relationship between developmental delays and dental caries in low-income preschoolers and to present a preliminary explanatory model on the determinants of caries for enrollees in Head Start, a U.S. school readiness program for low-income preschool-aged children. Methods Data were collected on preschoolers ages 3–5 years at two Head Start centers in Washington, USA (N = 115). The predictor variable was developmental delay status (no/yes). The outcome variable was the prevalence of decayed, missing, and filled surfaces (dmfs) on primary teeth. We used multiple variable Poisson regression models to test the hypothesis that within a population of low-income preschoolers, those with developmental delays would have increased dmfs prevalence than those without developmental delays. Results Seventeen percent of preschoolers had a developmental delay and 51.3% of preschoolers had ≥1 dmfs. Preschoolers with developmental delays had a dmfs prevalence ratio that was 1.26 times as high as preschoolers without developmental delays (95% CI: 1.01, 1.58; P < .04). Other factors associated with increased dmfs prevalence ratios included: not having a dental home (P = .01); low caregiver education (P < .001); and living in a non-fluoridated community (P < .001). Conclusions Our pilot data suggest that developmental delays among low-income preschoolers are associated with increased primary tooth dmfs. Additional research is needed to further examine this relationship. Future interventions and policies should focus on caries prevention strategies within settings like Head Start classrooms that serve low-income preschool-aged children with additional targeted home- and community-based interventions for those with developmental delays. PMID:24119240

Loss-of-Control-Inhibitor Systems for Aircraft

NASA Technical Reports Server (NTRS)

AHarrah, Ralph C.

2007-01-01

Systems to provide improved tactile feedback to aircraft pilots are being developed to help the pilots maintain harmony between their control actions and the positions of aircraft control surfaces, thereby helping to prevent loss of control. A system of this type, denoted a loss-of-control-inhibitor system (LOCIS) can be implemented as a relatively simple addition to almost any pre-existing flight-control system. The LOCIS concept offers at least a partial solution to the problem of (1) keeping a pilot aware of the state of the control system and the aircraft and (2) maintaining sufficient control under conditions that, as described below, have been known to lead to loss of control. Current commercial aircraft exhibit uneven responses of primary flight-control surfaces to aggressive pilot control commands, leading to deterioration of pilots ability to control their aircraft. In severe cases, this phenomenon can result in loss of control and consequent loss of aircraft. For an older aircraft equipped with a purely mechanical control system, the loss of harmony between a pilot s command action and the control- surface response can be attributed to compliance in the control system (caused, for example, by stretching of control cables, flexing of push rods, or servo-valve distortion). In a newer aircraft equipped with a fly-by-wire control system, the major contributions to loss of harmony between the pilot and the control surfaces are delays attributable to computer cycle time, control shaping, filtering, aliasing, servo-valve distortion, and actuator rate limiting. In addition, a fly-by-wire control system provides no tactile feedback that would enable the pilot to sense such features of the control state as surface flutter, surface jam, position limiting, actuator rate limiting, and control limiting imposed by the aircraft operational envelope. Hence, for example, when a pilot is involved in aggressive closed-loop maneuvering, as when encountering a wake-vortex upset on final landing approach, the control-surface delay can lead to loss of control. Aggressive piloting can be triggered and exacerbated by control-system anomalies, which the pilot cannot diagnose because of the lack of symptoms caused by the absence of feedback through the controls. The purpose served by a LOCIS is to counteract these adverse effects by providing real-time feedback that notifies the pilot that the aircraft is tending to lag the pilot s commands. A LOCIS (see figure) includes cockpit control input-position sensors, control-surface output-position sensors, variable dampers (for example, shock absorbers containing magneto-rheological fluids such that the damping forces can be varied within times of the order of milliseconds by varying applied magnetic fields) attached to the cockpit control levers, electromagnet coils to apply the magnetic fields, and feedback control circuits to drive the electromagnet coils. The feedback control gains are chosen so that the current applied to each electromagnet coil results in a damping force that increases in a suitable nonlinear manner (e.g., exponentially) with the difference between the actual and commanded positions of the affected control surface. The increasing damping force both alerts the pilot to the onset of a potentially dangerous situation and resists the pilot s effort to command a control surface to change position at an excessive rate

14 CFR 27.143 - Controllability and maneuverability.

Code of Federal Regulations, 2010 CFR

2010-01-01

... failure occurs with maximum continuous power and critical weight. No corrective action time delay for any... pilot reaction time (whichever is greater); and (ii) For any other condition, normal pilot reaction time...

Delayed flap approach procedures for noise abatement and fuel conservation

NASA Technical Reports Server (NTRS)

Edwards, F. G.; Bull, J. S.; Foster, J. D.; Hegarty, D. M.; Drinkwater, F. J., III

1976-01-01

The NASA/Ames Research Center is currently investigating the delayed flap approach during which pilot actions are determined and prescribed by an onboard digital computer. The onboard digital computer determines the proper timing for the deployment of the landing gear and flaps based on the existing winds and airplane gross weight. Advisory commands are displayed to the pilot. The approach is flown along the conventional ILS glide slope but is initiated at a higher airspeed and in a clean aircraft configuration that allows for low thrust and results in reduced noise and fuel consumption. Topics discussed include operational procedures, pilot acceptability of these procedures, and fuel/noise benefits resulting from flight tests and simulation.

Pilot tests of a seat belt gearshift delay on the belt use of commercial fleet drivers.

DOT National Transportation Integrated Search

2009-12-01

the seat belt was buckled. Participants, commercial drivers from the United States and Canada who did not consistently wear their seat belts, could avoid the delay by fastening their seat belts. Unbelted participants experienced a delay of either a c...

Pilot/vehicle model analysis of visual and motion cue requirements in flight simulation. [helicopter hovering

NASA Technical Reports Server (NTRS)

Baron, S.; Lancraft, R.; Zacharias, G.

1980-01-01

The optimal control model (OCM) of the human operator is used to predict the effect of simulator characteristics on pilot performance and workload. The piloting task studied is helicopter hover. Among the simulator characteristics considered were (computer generated) visual display resolution, field of view and time delay.

Cancellation of scheduled procedures as a mechanism to generate hospital bed surge capacity-a pilot study.

PubMed

Soremekun, Olan A; Zane, Richard D; Walls, Andrew; Allen, Matthew B; Seefeld, Kimberly J; Pallin, Daniel J

2011-06-01

The ability to generate hospital beds in response to a mass-casualty incident is an essential component of public health preparedness. Although many acute care hospitals' emergency response plans include some provision for delaying or cancelling elective procedures in the event of an inpatient surge, no standardized method for implementing and quantifying the impact of this strategy exists in the literature. The aim of this study was to develop a methodology to prospectively emergency plan for implementing a strategy of delaying procedures and quantifying the potential impact of this strategy on creating hospital bed capacity. This is a pilot study. A categorization methodology was devised and applied retrospectively to all scheduled procedures during four one-week periods chosen by convenience. The categorization scheme grouped procedures into four categories: (A) procedures with no impact on inpatient capacity; (B) procedures that could be delayed indefinitely; (C) procedures that could be delayed by one week; and (D) procedures that could not be delayed. The categorization scheme was applied by two research assistants and an emergency medicine resident. All three raters categorized the first 100 cases to allow for calculation of inter-rater reliability. Maximal hospital bed capacity was defined as the 95th percentile weekday occupancy, as this is more representative of functional bed capacity than is the number of licensed beds. The main outcome was the number of hospital beds that could be created by postponing procedures in categories B and C. Maximal hospital bed capacity was 816 beds. Mean occupancy during weekdays was 759 versus 694 on weekends. By postponing Group B and C procedures, a mean of 60 beds (51 general medical/surgical and nine intensive care unit (ICU)) could be created on weekdays, and four beds (three general medical/surgical and one ICU) on weekends. This represents 7.3% and 0.49% of maximal hospital bed capacity and ICU capacity, respectively. In the event that sustained surge is needed, delaying all category B and C procedures for one week would lead to the generation of 1,235 hospital-bed days. Inter-rater reliability was high (kappa = 0.74) indicating good agreement between all three raters. For the institution studied, the strategy of delaying scheduled procedures could generate inpatient capacity with maximal impact during weekdays and little impact on weekends. Future research is needed to validate the categorization scheme and increase the ability to predict inpatient surge capacity across various hospital types and sizes.

Planned Variation in Preanalytical Conditions to Evaluate Biospecimen Stability in the National Children’s Study (NCS)

PubMed Central

Mechanic, Leah; Mendez, Armando; Merrill, Lori; Rogers, John; Layton, Marnie; Todd, Deborah; Varanasi, Arti; O’Brien, Barbara; Meyer, William A.; Zhang, Ming; Schleicher, Rosemary L.; Moye, Jack

2014-01-01

BACKGROUND Preanalytical conditions encountered during collection, processing, and storage of biospecimens may influence laboratory results. The National Children’s Study (NCS) is a planned prospective cohort study of 100,000 families to examine the influence of a wide variety of exposures on child health. In developing biospecimen collection, processing, and storage procedures for the NCS, we identified several analytes of different biochemical categories for which it was unclear to what extent deviations from NCS procedures could influence measurement results. METHODS A pilot study was performed to examine effects of preanalytic sample handling conditions (delays in centrifugation, freezing delays, delays in separation from cells, additive delay, and tube type) on concentrations of eight different analytes. 2,825 measurements were made to assess 15 unique combinations of analyte and handling conditions in blood collected from 151 women of childbearing age (≥20 individuals per handling condition). RESULTS The majority of analytes were stable under the conditions evaluated. However, levels of plasma interleukin-6 and serum insulin were decreased in response to sample centrifugation delays of up to 5.5 hours post collection (P<0.0001). In addition, delays in freezing centrifuged plasma samples (comparing 24, 48 and 72 hours to immediate freezing) resulted in increased levels of adrenocorticotropic hormone (P=0.0014). CONCLUSIONS Determining stability of proposed analytes in response to preanalytical conditions and handling helps to ensure high-quality specimens for study now and in the future. The results inform development of procedures, plans for measurement of analytes, and interpretation of laboratory results. PMID:23924524

Effects of simulator motion and visual characteristics on rotorcraft handling qualities evaluations

NASA Technical Reports Server (NTRS)

Mitchell, David G.; Hart, Daniel C.

1993-01-01

The pilot's perceptions of aircraft handling qualities are influenced by a combination of the aircraft dynamics, the task, and the environment under which the evaluation is performed. When the evaluation is performed in a groundbased simulator, the characteristics of the simulation facility also come into play. Two studies were conducted on NASA Ames Research Center's Vertical Motion Simulator to determine the effects of simulator characteristics on perceived handling qualities. Most evaluations were conducted with a baseline set of rotorcraft dynamics, using a simple transfer-function model of an uncoupled helicopter, under different conditions of visual time delays and motion command washout filters. Differences in pilot opinion were found as the visual and motion parameters were changed, reflecting a change in the pilots' perceptions of handling qualities, rather than changes in the aircraft model itself. The results indicate a need for tailoring the motion washout dynamics to suit the task. Visual-delay data are inconclusive but suggest that it may be better to allow some time delay in the visual path to minimize the mismatch between visual and motion, rather than eliminate the visual delay entirely through lead compensation.

Primary display latency criteria based on flying qualities and performance data

NASA Technical Reports Server (NTRS)

Funk, John D., Jr.; Beck, Corin P.; Johns, John B.

1993-01-01

With a pilots' increasing use of visual cue augmentation, much requiring extensive pre-processing, there is a need to establish criteria for new avionics/display design. The timeliness and synchronization of the augmented cues is vital to ensure the performance quality required for precision mission task elements (MTEs) where augmented cues are the primary source of information to the pilot. Processing delays incurred while transforming sensor-supplied flight information into visual cues are unavoidable. Relationships between maximum control system delays and associated flying qualities levels are documented in MIL-F-83300 and MIL-F-8785. While cues representing aircraft status may be just as vital to the pilot as prompt control response for operations in instrument meteorological conditions, presently, there are no specification requirements on avionics system latency. To produce data relating avionics system latency to degradations in flying qualities, the Navy conducted two simulation investigations. During the investigations, flying qualities and performance data were recorded as simulated avionics system latency was varied. Correlated results of the investigation indicates that there is a detrimental impact of latency on flying qualities. Analysis of these results and consideration of key factors influencing their application indicate that: (1) Task performance degrades and pilot workload increases as latency is increased. Inconsistency in task performance increases as latency increases. (2) Latency reduces the probability of achieving Level 1 handling qualities with avionics system latency as low as 70 ms. (3) The data suggest that the achievement of desired performance will be ensured only at display latency values below 120 ms. (4) These data also suggest that avoidance of inadequate performance will be ensured only at display latency values below 150 ms.

Advanced techniques for mitigating the effects of temporal distortions in human in the loop control systems

NASA Astrophysics Data System (ADS)

Guo, Liwen

The desire to create more complex visual scenes in modern flight simulators outpaces recent increases in processor speed. As a result, the simulation transport delay remains a problem. Because of the limitations shown in the three prominent existing delay compensators---the lead/lag filter, the McFarland compensator and the Sobiski/Cardullo predictor---new approaches of compensating the transport delay in a flight simulator have been developed. The first novel compensator is the adaptive predictor making use of the Kalman filter algorithm in a unique manner so that the predictor can provide accurately the desired amount of prediction, significantly reducing the large spikes caused by the McFarland predictor. Among several simplified online adaptive predictors it illustrates mathematically why the stochastic approximation algorithm achieves the best compensation results. A second novel approach employed a reference aircraft dynamics model to implement a state space predictor on a flight simulator. The practical implementation formed the filter state vector from the operator's control input and the aircraft states. The relationship between the reference model and the compensator performance was investigated in great detail, and the best performing reference model was selected for implementation in the final tests. Piloted simulation tests were conducted for assessing the effectiveness of the two novel compensators in comparison to the McFarland predictor and no compensation. Thirteen pilots with heterogeneous flight experience executed straight-in and offset approaches, at various delay configurations, on a flight simulator where different predictors were applied to compensate for transport delay. Four metrics---the glide slope and touchdown errors, power spectral density of the pilot control inputs, NASA Task Load Index, and Cooper-Harper rating on the handling qualities---were employed for the analyses. The overall analyses show that while the adaptive predictor results in slightly poorer compensation for short added delay (up to 48 ms) and better compensation for long added delay (up to 192 ms) than the McFarland compensator, the state space predictor is fairly superior for short delay and significantly superior for long delay to the McFarland compensator. The state space predictor also achieves better compensation than the adaptive predictor. The results of the evaluation on the effectiveness of these predictors in the piloted tests agree with those in the theoretical offline tests conducted with the recorded simulation aircraft states.

Standard- or high-dose oxytocin for nulliparous women with confirmed delay in labour: quantitative and qualitative results from a pilot randomised controlled trial.

PubMed

Kenyon, S; Armstrong, N; Johnston, T; Walkinshaw, S; Petrou, S; Howman, A; Cheed, V; Markham, C; McNicol, S; Willars, J; Waugh, J

2013-10-01

Evidence suggests that a high dose of oxytocin for nulliparous women at 37-42 weeks of gestation with confirmed delay in labour increases spontaneous vaginal birth. We undertook a pilot study to test the feasibility of this treatment. Pilot double-blind randomised controlled trial. Three teaching hospitals in the UK. A total of 94 consenting nulliparous women at term with confirmed delay in labour were recruited, and 18 were interviewed. Women were assigned to either a standard (2 mU/min, increasing every 30 minutes to 32 mU/minute) or a high-dose regimen (4 mU/minute, increasing every 30 minutes to 64 mU/minutes) oxytocin by computer-generated randomisation. Simple descriptive statistics were used, as the sample size was insufficient to evaluate clinical outcomes. The constant comparative method was used to analyse the interviews. The main outcome measures: number of women eligible; maternal and neonatal birth; safety; maternal psychological outcomes and experiences; health-related quality of life outcomes using validated tools and data on health service resource use; incidence of suspected delay of labour (cervical dilatation of <2 cm after 4 hours, once labour is established); and incidence of confirmed delay of labour (progress of <1 cm on repeat vaginal examination after a period of 2 hours). We successfully developed systems to recruit eligible women in labour and to collect data. Rates of spontaneous vaginal birth (10/47 versus 12/47, RR 1.2, 95% CI 0.6-2.5) and caesarean section (15/47 versus 17/47, RR 1.1, 95% CI 0.6-2.0) were increased, and rates of instrumental birth were reduced (21/47 versus 17/47, RR 0.8, 95% CI 0.5-1.3). No evidence of increased harm for either mother or baby was found. The incidences of suspected delay (14%) and confirmed delay (11%) in labour were less than anticipated. Of those who did not go on to have delayed labour confirmed, all except one woman gave birth vaginally. A pilot trial assessing the efficacy of high-dose oxytocin was feasible, but uncertainty remains, highlighting the need for a large definitive trial. The implementation of national guidance of suspected and confirmed delay in labour is likely to reduce intervention. © 2013 RCOG.

Modeling to predict pilot performance during CDTI-based in-trail following experiments

NASA Technical Reports Server (NTRS)

Sorensen, J. A.; Goka, T.

1984-01-01

A mathematical model was developed of the flight system with the pilot using a cockpit display of traffic information (CDTI) to establish and maintain in-trail spacing behind a lead aircraft during approach. Both in-trail and vertical dynamics were included. The nominal spacing was based on one of three criteria (Constant Time Predictor; Constant Time Delay; or Acceleration Cue). This model was used to simulate digitally the dynamics of a string of multiple following aircraft, including response to initial position errors. The simulation was used to predict the outcome of a series of in-trail following experiments, including pilot performance in maintaining correct longitudinal spacing and vertical position. The experiments were run in the NASA Ames Research Center multi-cab cockpit simulator facility. The experimental results were then used to evaluate the model and its prediction accuracy. Model parameters were adjusted, so that modeled performance matched experimental results. Lessons learned in this modeling and prediction study are summarized.

In-flight investigation of the effects of pilot location and control system design on airplane flying qualities for approach and landing

NASA Technical Reports Server (NTRS)

Weingarten, N. C.; Chalk, C. R.

1982-01-01

The handling qualities of large airplanes in the approach and landing flight phase were studied. The primary variables were relative pilot position with respect to center of rotation, command path time delays and phase shifts, augmentation schemes and levels of augmentation. It is indicated that the approach and landing task with large airplanes is a low bandwidth task. Low equivalent short period frequencies and relatively long time delays are tolerated only when the pilot is located at considerable distance forward of the center of rotation. The control problem experienced by the pilots, when seated behind the center of rotation, tended to occur at low altitude when they were using visual cues of rate of sink and altitude. A direct lift controller improved final flight path control of the shuttle like configurations.

Air Traffic Control: Economics of Flight

NASA Technical Reports Server (NTRS)

Murphy, James R.

2004-01-01

Contents include the following: 1. Commercial flight is a partnership. Airlines. Pilots. Air traffic control. 2. Airline schedules and weather problems can cause delays at the airport. Delays are inevitable in de-regulated industry due to simple economics. 3.Delays can be mitigated. Build more runways/technology. Increase airspace supply. 4. Cost/benefit analysis determine justification.

Motion/visual cueing requirements for vortex encounters during simulated transport visual approach and landing

NASA Technical Reports Server (NTRS)

Parrish, R. V.; Bowles, R. L.

1983-01-01

This paper addresses the issues of motion/visual cueing fidelity requirements for vortex encounters during simulated transport visual approaches and landings. Four simulator configurations were utilized to provide objective performance measures during simulated vortex penetrations, and subjective comments from pilots were collected. The configurations used were as follows: fixed base with visual degradation (delay), fixed base with no visual degradation, moving base with visual degradation (delay), and moving base with no visual degradation. The statistical comparisons of the objective measures and the subjective pilot opinions indicated that although both minimum visual delay and motion cueing are recommended for the vortex penetration task, the visual-scene delay characteristics were not as significant a fidelity factor as was the presence of motion cues. However, this indication was applicable to a restricted task, and to transport aircraft. Although they were statistically significant, the effects of visual delay and motion cueing on the touchdown-related measures were considered to be of no practical consequence.

Human performance evaluation of a pathway HMD

NASA Astrophysics Data System (ADS)

Lorenz, Bernd; Tobben, Helmut; Schmerwitz, Sven

2005-05-01

Head-up displays (HUD) and helmet (or head)-mounted displays (HMD) aim at reducing the pilot's visual scanning cost in support of concurrent monitoring of both instrument information (near domain) and the outside environment (far domain). An HMD used in combination with a head tracker enables the assessment of the pilot"s head direction in real time allowing symbologies to remain spatially linked to elements of the outside environment. The paper examines the potential added benefits of improved flight path tracking to be expected by displaying symbologies of a virtual 3D perspective pathway plus predictor information on an HMD. Results of a high-fidelity flight-simulation experiment are reported that involved a series of curved approaches supported with such a pathway HMD. The study used a monocular retinal-scanning HMD and involved 18 pilots. Dependent human performance data were derived from flight path tracking measures, subjective measures of mental workload and situation awareness and pilot reactions in response to an unexpected rare event in the outside scene (intruding aircraft on the active runway for the intended landing). Comparison with a standard head-down ILS baseline condition revealed a mix of performance costs and benefits, which is consistent with most of the human factors literature on the general use of HUDs and of HUDs used in combination with pathway guidance: The pathway HMD promoted substantially better flight path tracking but caused also a delayed response to the unexpected event. This effect points to some disadvantages of HUDs referred to as 'attention capture', which may become exaggerated by the additional use of pathway guidance symbology.

Novel Estimation of Pilot Performance Characteristics

NASA Technical Reports Server (NTRS)

Bachelder, Edward N.; Aponso, Bimal

2017-01-01

Two mechanisms internal to the pilot that affect performance during a tracking task are: 1) Pilot equalization (i.e. lead/lag); and 2) Pilot gain (i.e. sensitivity to the error signal). For some applications McRuer's Crossover Model can be used to anticipate what equalization will be employed to control a vehicle's dynamics. McRuer also established approximate time delays associated with different types of equalization - the more cognitive processing that is required due to equalization difficulty, the larger the time delay. However, the Crossover Model does not predict what the pilot gain will be. A nonlinear pilot control technique, observed and coined by the authors as 'amplitude clipping', is shown to improve stability, performance, and reduce workload when employed with vehicle dynamics that require high lead compensation by the pilot. Combining linear and nonlinear methods a novel approach is used to measure the pilot control parameters when amplitude clipping is present, allowing precise measurement in real time of key pilot control parameters. Based on the results of an experiment which was designed to probe workload primary drivers, a method is developed that estimates pilot spare capacity from readily observable measures and is tested for generality using multi-axis flight data. This paper documents the initial steps to developing a novel, simple objective metric for assessing pilot workload and its variation over time across a wide variety of tasks. Additionally, it offers a tangible, easily implementable methodology for anticipating a pilot's operating parameters and workload, and an effective design tool. The model shows promise in being able to precisely predict the actual pilot settings and workload, and observed tolerance of pilot parameter variation over the course of operation. Finally, an approach is proposed for generating Cooper-Harper ratings based on the workload and parameter estimation methodology.

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.

Defeathering of broiler carcasses subjected to delayed scalding 1, 2, 4, and 8 hours after slaughter

USDA-ARS?s Scientific Manuscript database

With implementation of farm slaughter, scalding and defeathering could be delayed for a minimum of 2 to 4 h. This research evaluated the potential for delaying scalding and defeathering up to 8 h after slaughter. Following 12 h feed withdrawal broilers were cooped and transported to the pilot plan...

78 FR 8666 - Self-Regulatory Organizations; The NASDAQ Stock Market LLC; Notice of Filing and Immediate...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-06

... adopted the proposed changes to the market-wide circuit breakers on a pilot basis for a period that... to April 8, 2013. The proposal would delay the operative date of the market-wide circuit breaker pilot to April 8, 2013 in order for the implementation date for the market-wide circuit breaker pilot...

A pilot investigation in constructing crisis communications: what leads to best practice?

PubMed

Firestone, Rachel M; Everly, George S

2013-01-01

Crisis communications can play an important role in mitigating, or exacerbating, the psychological and behavioral reactions to critical incidents and disasters. Effective crisis communications can serve to mitigate anxiogenesis and direct rapid and focused rescue, recovery, and rehabilitative operations. Ambiguous and/or deceptive communications can serve to worsen mental health reactions and delay operational response and recovery (Everly, Strouse, & Everly, 2010). It seems, therefore, that inquiry into the content of acute crisis communications would be warranted Said more simply, given limited time, cryptic messaging in social media, and the "sound bite" mentality that seems to govern news dissemination, it is important to identify the most important content to convey in the wake of critical incidents and disasters. This paper reports on a pilot investigation into "best practices" for the construction of acute crisis communications.

Realizable optimal control for a remotely piloted research vehicle. [stability augmentation

NASA Technical Reports Server (NTRS)

Dunn, H. J.

1980-01-01

The design of a control system using the linear-quadratic regulator (LQR) control law theory for time invariant systems in conjunction with an incremental gradient procedure is presented. The incremental gradient technique reduces the full-state feedback controller design, generated by the LQR algorithm, to a realizable design. With a realizable controller, the feedback gains are based only on the available system outputs instead of being based on the full-state outputs. The design is for a remotely piloted research vehicle (RPRV) stability augmentation system. The design includes methods for accounting for noisy measurements, discrete controls with zero-order-hold outputs, and computational delay errors. Results from simulation studies of the response of the RPRV to a step in the elevator and frequency analysis techniques are included to illustrate these abnormalities and their influence on the controller design.

Delay in disclosure of non-parental child sexual abuse in the context of emotional and physical maltreatment: A pilot study.

PubMed

Tashjian, Sarah M; Goldfarb, Deborah; Goodman, Gail S; Quas, Jodi A; Edelstein, Robin

2016-08-01

The present pilot study sought to identify predictors of delays in child sexual abuse (CSA) disclosure, specifically whether emotional and physical abuse by a parental figure contributes to predicting delays over and above other important victim factors. Alleged CSA victims (N=79), whose parental figures were not the purported sexual abuse perpetrators, were interviewed and their case files reviewed, across two waves of a longitudinal study. Regression analyses indicated that experiencing both emotional and physical abuse by a parental figure was uniquely predictive of longer delays in disclosure of CSA perpetrated by someone other than a parental figure. Victim-CSA perpetrator relationship type and sexual abuse duration also significantly predicted CSA disclosure delay, whereas victim age at the time of the police report, victim gender, and victims' feelings of complicity were not significant unique predictors. Child abuse victims' expectations of lack of parental support may underlie these findings. Parent-child relationships are likely crucial to timely disclosure of CSA, even when a parent is not the CSA perpetrator. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Method for Measuring the Effective Throughput Time Delay in Simulated Displays Involving Manual Control

NASA Technical Reports Server (NTRS)

Jewell, W. F.; Clement, W. F.

1984-01-01

The advent and widespread use of the computer-generated image (CGI) device to simulate visual cues has a mixed impact on the realism and fidelity of flight simulators. On the plus side, CGIs provide greater flexibility in scene content than terrain boards and closed circuit television based visual systems, and they have the potential for a greater field of view. However, on the minus side, CGIs introduce into the visual simulation relatively long time delays. In many CGIs, this delay is as much as 200 ms, which is comparable to the inherent delay time of the pilot. Because most GCIs use multiloop processing and smoothing algorithms and are linked to a multiloop host computer, it is seldom possible to identify a unique throughput time delay, and it is therefore difficult to quantify the performance of the closed loop pilot simulator system relative to the real world task. A method to address these issues using the critical task tester is described. Some empirical results from applying the method are presented, and a novel technique for improving the performance of GCIs is discussed.

Hypoxia symptoms reported during helicopter operations below 10,000 ft: a retrospective survey.

PubMed

Smith, Adrian

2005-08-01

During routine aviation medicine training, rotary-wing aircrew are instructed that the impact of hypoxia on them from flying in unpressurized cabins up to 10,000 ft (3048 m) above mean sea level (AMSL) is relatively small and has few implications for aviation safety. Such reassurance is based on data derived from experiments conducted on resting subjects and may not reflect the true impact of hypoxia in aircrew engaged in operational tasks. A survey listing common symptoms of hypoxia was distributed to Australian Army helicopter aircrew who had operated at altitudes up to 10,000 ft AMSL. There were 53 surveys that were returned (71% response), representing 25 loadmasters, 23 pilots, and 5 aircrewman technicians. All respondents were Australian Army aircrew. One or more symptoms consistent with hypoxia were reported by 86.6% of non-pilot aircrew and 60.9% of pilots. 60% of non-pilot aircrew reported four or more symptoms, compared with only 17% of pilots. The most commonly reported symptoms were difficulty with calculations (45%), feeling light-headed (38%), delayed reaction time (38%), and mental confusion (36%). Loadmasters reported more symptoms (mean 5.4) than pilots (mean 2.2) (p < 0.001). From the narratives provided (n = 21), aircrew experienced potentially operationally significant symptoms at a mean altitude of 8462 ft (2579 m). The helicopter aircrew surveyed reported symptoms consistent with hypoxia at altitudes within the so-called physiological zone; loadmasters reported more effects than pilots. It may be inappropriate to emphasize the benign nature of the physiological zone during aviation medicine training of a non-resting population such as helicopter aircrew.

Delayed but successful response to noninvasive ventilation in COPD patients with acute hypercapnic respiratory failure.

PubMed

Lemyze, Malcolm; Bury, Quentin; Guiot, Aurélie; Jonard, Marie; Mohammad, Usman; Van Grunderbeeck, Nicolas; Gasan, Gaelle; Thevenin, Didier; Mallat, Jihad

2017-01-01

We evaluated a new noninvasive ventilation (NIV) protocol that allows the pursuit of NIV in the case of persistent severe respiratory acidosis despite a first NIV challenge in COPD patients with acute hypercapnic respiratory failure (AHRF). A prospective observational multicentric pilot study was conducted in three tertiary hospitals over a 12-month study period. A total of 155 consecutive COPD patients who were admitted for AHRF and treated by NIV were enrolled. Delayed response to NIV was defined as a significant clinical improvement in the first 48 h following NIV initiation despite a persistent severe respiratory acidosis (pH <7.30) after the first 2 h of NIV trial. NIV failed in only 10 patients (6.5%). Delayed responders to NIV (n=83, 53%) exhibited similar nutritional status, comorbidities, functional status, frailty score, dyspnea score, and severity score at admission, compared with early responders (n=62, 40%). Only age (66 vs 70 years in early responders; P =0.03) and encephalopathy score (3 [2-4] vs 3 [2-4] in early responders; P =0.015) were different among the responders. Inhospital mortality did not differ between responders to NIV (n=10, 12% for delayed responders vs n=10, 16% for early responders, P =0.49). A second episode of AHRF occurred in 20 responders (14%), equally distributed among early and delayed responders to NIV (n=9, 14.5% in early responders vs n=11, 13% in delayed responders; P =0.83), with a poor survival rate (n=1, 5%). Most of the COPD patients with AHRF have a successful outcome when NIV is pursued despite a persistent severe respiratory acidosis after the first NIV trial. The outcome of delayed responders is similar to the one of the early responders. On the contrary, the second episode of AHRF during the hospital stay carries a poor prognosis.

Design and Flight Tests of an Adaptive Control System Employing Normal-Acceleration Command

NASA Technical Reports Server (NTRS)

McNeill, Water E.; McLean, John D.; Hegarty, Daniel M.; Heinle, Donovan R.

1961-01-01

An adaptive control system employing normal-acceleration command has been designed with the aid of an analog computer and has been flight tested. The design of the system was based on the concept of using a mathematical model in combination with a high gain and a limiter. The study was undertaken to investigate the application of a system of this type to the task of maintaining nearly constant dynamic longitudinal response of a piloted airplane over the flight envelope without relying on air data measurements for gain adjustment. The range of flight conditions investigated was between Mach numbers of 0.36 and 1.15 and altitudes of 10,000 and 40,000 feet. The final adaptive system configuration was derived from analog computer tests, in which the physical airplane control system and much of the control circuitry were included in the loop. The method employed to generate the feedback signals resulted in a model whose characteristics varied somewhat with changes in flight condition. Flight results showed that the system limited the variation in longitudinal natural frequency of the adaptive airplane to about half that of the basic airplane and that, for the subsonic cases, the damping ratio was maintained between 0.56 and 0.69. The system also automatically compensated for the transonic trim change. Objectionable features of the system were an exaggerated sensitivity of pitch attitude to gust disturbances, abnormally large pitch attitude response for a given pilot input at low speeds, and an initial delay in normal-acceleration response to pilot control at all flight conditions. The adaptive system chatter of +/-0.05 to +/-0.10 of elevon at about 9 cycles per second (resulting in a maximum airplane normal-acceleration response of from +/-0.025 g to +/- 0.035 g) was considered by the pilots to be mildly objectionable but tolerable.

Effects of Spatio-Temporal Aliasing on Pilot Performance in Active Control Tasks

NASA Technical Reports Server (NTRS)

Zaal, Peter; Sweet, Barbara

2010-01-01

Spatio-temporal aliasing affects pilot performance and control behavior. For increasing refresh rates: 1) Significant change in control behavior: a) Increase in visual gain and neuromuscular frequency. b) Decrease in visual time delay. 2) Increase in tracking performance: a) Decrease in RMSe. b) Increase in crossover frequency.

Channel Acquisition for Massive MIMO-OFDM With Adjustable Phase Shift Pilots

NASA Astrophysics Data System (ADS)

You, Li; Gao, Xiqi; Swindlehurst, A. Lee; Zhong, Wen

2016-03-01

We propose adjustable phase shift pilots (APSPs) for channel acquisition in wideband massive multiple-input multiple-output (MIMO) systems employing orthogonal frequency division multiplexing (OFDM) to reduce the pilot overhead. Based on a physically motivated channel model, we first establish a relationship between channel space-frequency correlations and the channel power angle-delay spectrum in the massive antenna array regime, which reveals the channel sparsity in massive MIMO-OFDM. With this channel model, we then investigate channel acquisition, including channel estimation and channel prediction, for massive MIMO-OFDM with APSPs. We show that channel acquisition performance in terms of sum mean square error can be minimized if the user terminals' channel power distributions in the angle-delay domain can be made non-overlapping with proper phase shift scheduling. A simplified pilot phase shift scheduling algorithm is developed based on this optimal channel acquisition condition. The performance of APSPs is investigated for both one symbol and multiple symbol data models. Simulations demonstrate that the proposed APSP approach can provide substantial performance gains in terms of achievable spectral efficiency over the conventional phase shift orthogonal pilot approach in typical mobility scenarios.

Pursuit tracking and higher levels of skill development in the human pilot

NASA Technical Reports Server (NTRS)

Hess, R. A.

1981-01-01

A model of the human pilot is offered for pursuit tracking tasks; the model encompasses an existing model for compensatory tracking. The central hypothesis in the development of this model states that those primary structural elements in the compensatory model responsible for the pilot's equalization capabilities remain intact in the pursuit model. In this latter case, effective low-frequency inversion of the controlled-element dynamics occurs by feeding-forward derived input rate through the equalization dynamics, with low-frequency phase droop minimized. The sharp reduction in low-frequency phase lag beyond that associated with the disappearance of phase droop is seen to accompany relatively low-gain feedback of vehicle output. The results of some recent motion cue research are discussed and interpreted in terms of the compensatory-pursuit display dichotomy. Tracking with input preview is discussed in a qualitative way. In terms of the model, preview is shown to demand no fundamental changes in structure or equalization and to allow the pilot to eliminate the effective time delays that accrue in the inversion of the controlled-element dynamics. Precognitive behavior is discussed, and a model that encompasses all the levels of skill development outlined in the successive organizations of perception theory is finally proposed.

Pilot Non-Conformance to Alerting System Commands During Closely Spaced Parallel Approaches

NASA Technical Reports Server (NTRS)

Pritchett, Amy Ruth; Hansman, R. John; Corker, Kevin (Technical Monitor)

1997-01-01

Cockpit alerting systems monitor potentially hazardous situations, both inside and outside the aircraft. When a hazard is projected to occur, the alerting system displays alerts and/or command decisions to the pilot. However, pilots have been observed to not conform to alerting system commands by delaying their response or by not following the automatic commands exactly. This non-conformance to the automatic alerting system can reduce its benefit. Therefore, a need exists to understand the causes and effects of pilot non-conformance in order to develop automatic alerting systems whose commands the pilots are more likely to follow. These considerations were examined through flight simulator evaluations of the collision avoidance task during closely spaced parallel approaches. This task provided a useful case-study because the effects of non-conformance can be significant, given the time-critical nature of the task. A preliminary evaluation of alerting systems identified non-conformance in over 40% of the cases and a corresponding drop in collision avoidance performance. A follow-on experiment found subjects' alerting and maneuver selection criteria were consistent with different strategies than those used by automatic systems, indicating the pilot may potentially disagree with the alerting system if the pilot attempts to verify automatic alerts and commanded avoidance maneuvers. A final experiment found supporting automatic alerts with the explicit display of its underlying criteria resulted in more consistent subject reactions. In light of these experimental results, a general discussion of pilot non-conformance is provided. Contributing factors in pilot non-conformance include a lack of confidence in the automatic system and mismatches between the alerting system's commands and the pilots' own decisions based on the information available to them. The effects of non-conformance on system performance are discussed. Possible methods of reconciling mismatches are given, and design considerations for alerting systems which alleviate the problem of non-conformance are provided.

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).

The Effects of Sensory Processing and Behavior of Toddlers on Parent Participation: A Pilot Study

ERIC Educational Resources Information Center

DaLomba, Elaina; Baxter, Mary Frances; Fingerhut, Patricia; O'Donnell, Anne

2017-01-01

Occupational therapists treat children with sensory processing and behavioral concerns, however, little information exists on how these issues affect parent participation. This pilot study examined the sensory processing and behaviors of toddlers with developmental delays and correlated these with parents' perceived ability to participate in…

Determinants of hospital-to-nursing home placement delays: a pilot study.

PubMed Central

Weissert, W G; Cready, C M

1988-01-01

Estimates of hospital-to-nursing home placement delays have always been varied, and given Medicare's new Prospective Payment System (PPS) based on diagnosis-related groups (DRGs), they are likely to have changed again. Theory and previous research suggest that four patient characteristics are the main causes of delays: Medicaid as the patient's nursing home payer source; need for heavy care due to major physical or mental problems; admission to the hospital from a nursing home; and lack of social support. A pilot study of all 1,016 elderly awaiting nursing home placement in two admission cohorts (pre- and post-PPS) from the three largest hospitals in the county surrounding Charlotte, North Carolina--where nursing home beds are in short supply--indicates that other factors are more important. While most placements were delayed, delays were short. Multiple regression results show that Medicaid patients' delays were only about a day longer than those of private-pay patients. Of the many heavy-care conditions studied, only three were associated with delay. Patients without social support and patients admitted from a nursing home, discharged to a hospital-affiliated facility, or placed after PPS had shorter delays. Long delays were found among patients who had applied for Medicaid coverage but had not yet been certified as financially eligible. Nonwhites and males were also delayed. These findings, if replicated in other areas with perceived nursing home bed shortages, appear to have important implications not only for the usefulness of nursing home case-mix reimbursement and subacute levels of nursing home care, but for nursing home bed-need estimates, too, as well as for Medicaid eligibility determination practices and civil rights law enforcement. PMID:3060449

Insulin Secretion Improves in Cystic Fibrosis Following Ivacaftor Correction of CFTR: A Small Pilot Study

PubMed Central

Bellin, Melena D.; Laguna, Theresa; Leschyshyn, Janice; Regelmann, Warren; Dunitz, Jordan; Billings, JoAnne; Moran, Antoinette

2013-01-01

Objective To determine whether the cystic fibrosis transmembrane conductance regulator (CFTR) is involved in human insulin secretion by assessing the metabolic impact of the new CFTR corrector, ivacaftor. Methods This open-label pilot study was conducted in CF patients with the G551D mutation given new prescriptions for ivacaftor. At baseline and 4 weeks after daily ivacaftor therapy, intravenous (IVGTT) and oral glucose (OGTT) tolerance tests were performed. Results Five patients age 6–52 were studied. After 1 month on ivacaftor, the insulin response to oral glucose improved by 66–178% in all subjects except one with long-standing diabetes. OGTT glucose levels were not lower in the two individuals with diabetes or the two with normal glucose tolerance (NGT), but the glucose tolerance category in the subject with impaired glucose tolerance (IGT) improved to NGT after treatment. In response to intravenous glucose, the only patient whose acute insulin secretion did not improve had newly diagnosed, untreated CFRD. The others improved by 51–346%. Acute insulin secretion was partially restored in two subjects with no measurable acute insulin response at baseline, including the one with IGT and the one with long-standing diabetes. Conclusions This small pilot study suggests there is a direct role of CFTR in human insulin secretion. Larger, long-term longitudinal studies are necessary to determine whether early initiation of CFTR correction, particularly in young children with CF who have not yet lost considerable beta-cell mass, will delay or prevent development of diabetes in this high risk population. PMID:23952705

Activity In Children With ADHD During Waiting Situations In The Classroom: A Pilot Study

ERIC Educational Resources Information Center

Antrop, Inge; Buysse, Ann; Roeyers, Herbert; Van Oost, Paulette

2005-01-01

Background: According to the optimal stimulation theory and the delay aversion hypothesis, children with attention deficit hyperactivity disorder (ADHD) experience difficulties when they are confronted with low levels of stimulation and delay, respectively. Aim: This study investigated the activity level of children with ADHD during waiting…

Ex-vivo sensitivity profiling to guide clinical decision making in acute myeloid leukemia: A pilot study.

PubMed

Swords, Ronan T; Azzam, Diana; Al-Ali, Hassan; Lohse, Ines; Volmar, Claude-Henry; Watts, Justin M; Perez, Aymee; Rodriguez, Ana; Vargas, Fernando; Elias, Roy; Vega, Francisco; Zelent, Arthur; Brothers, Shaun P; Abbasi, Taher; Trent, Jonathan; Rangwala, Shaukat; Deutsch, Yehuda; Conneally, Eibhlin; Drusbosky, Leylah; Cogle, Christopher R; Wahlestedt, Claes

2018-01-01

A precision medicine approach is appealing for use in AML due to ease of access to tumor samples and the significant variability in the patients' response to treatment. Attempts to establish a precision medicine platform for AML, however, have been unsuccessful, at least in part due to the use of small compound panels and having relatively slow turn over rates, which restricts the scope of treatment and delays its onset. For this pilot study, we evaluated a cohort of 12 patients with refractory AML using an ex vivo drug sensitivity testing (DST) platform. Purified AML blasts were screened with a panel of 215 FDA-approved compounds and treatment response was evaluated after 72h of exposure. Drug sensitivity scoring was reported to the treating physician, and patients were then treated with either DST- or non-DST guided therapy. We observed survival benefit of DST-guided therapy as compared to the survival of patients treated according to physician recommendation. Three out of four DST-treated patients displayed treatment response, while all of the non-DST-guided patients progressed during treatment. DST rapidly and effectively provides personalized treatment recommendations for patients with refractory AML. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

A Pilot Study Examining the Test-Retest and Internal Consistency Reliability of the ABLLS-R

ERIC Educational Resources Information Center

Partington, James W.; Bailey, Autumn; Partington, Scott W.

2018-01-01

The literature contains a variety of assessment tools for measuring the skills of individuals with autism or other developmental delays, but most lack adequate empirical evidence supporting their reliability and validity. The current pilot study sought to examine the reliability of scores obtained from the Assessment of Basic Language and Learning…

Results of the "In Control: No Alcohol!" Pilot Study

ERIC Educational Resources Information Center

Mares, Suzanne H. W.; van der Vorst, Haske; Vermeulen-Smit, Evelien; Lichtwarck-Aschoff, Anna; Verdurmen, Jacqueline E. E.; Engels, Rutger C. M. E.

2012-01-01

More than 50% of Dutch 12-year olds already started drinking. Since it is known that delaying the onset of alcohol use results in a lower risk of alcohol-related problems, the recently developed "In control: No alcohol!" prevention program is targeted at elementary school children and their mothers. In this pilot study, the success of…

TAILSIM Users Guide

NASA Technical Reports Server (NTRS)

Hiltner, Dale W.

2000-01-01

The TAILSIM program uses a 4th order Runge-Kutta method to integrate the standard aircraft equations-of-motion (EOM). The EOM determine three translational and three rotational accelerations about the aircraft's body axis reference system. The forces and moments that drive the EOM are determined from aerodynamic coefficients, dynamic derivatives, and control inputs. Values for these terms are determined from linear interpolation of tables that are a function of parameters such as angle-of-attack and surface deflections. Buildup equations combine these terms and dimensionalize them to generate the driving total forces and moments. Features that make TAILSIM applicable to studies of tailplane stall include modeling of the reversible control System, modeling of the pilot performing a load factor and/or airspeed command task, and modeling of vertical gusts. The reversible control system dynamics can be described as two hinged masses connected by a spring. resulting in a fifth order system. The pilot model is a standard form of lead-lag with a time delay applied to an integrated pitch rate and/or airspeed error feedback. The time delay is implemented by a Pade approximation, while the commanded pitch rate is determined by a commanded load factor. Vertical gust inputs include a single 1-cosine gust and a continuous NASA Dryden gust model. These dynamic models. coupled with the use of a nonlinear database, allow the tailplane stall characteristics, elevator response, and resulting aircraft response, to be modeled. A useful output capability of the TAILSIM program is the ability to display multiple post-run plot pages to allow a quick assessment of the time history response. There are 16 plot pages currently available to the user. Each plot page displays 9 parameters. Each parameter can also be displayed individually. on a one plot-per-page format. For a more refined display of the results the program can also create files of tabulated data. which can then be used by other plotting programs. The TAILSIM program was written straightforwardly assuming the user would want to change the database tables, the buildup equations, the output parameters. and the pilot model parameters. A separate database file and input file are automatically read in by the program. The use of an include file to set up all common blocks facilitates easy changing of parameter names and array sizes.

Stereotactic body radiation therapy with concurrent full-dose gemcitabine for locally advanced pancreatic cancer: a pilot trial demonstrating safety

PubMed Central

2013-01-01

Background Concurrent chemoradiation is a standard option for locally advanced pancreatic cancer (LAPC). Concurrent conventional radiation with full-dose gemcitabine has significant toxicity. Stereotactic body radiation therapy (SBRT) may provide the opportunity to administer radiation in a shorter time frame with similar efficacy and reduced toxicity. This Pilot study assessed the safety of concurrent full-dose gemcitabine with SBRT for LAPC. Methods Patients received gemcitabine, 1000 mg/m2 for 6 cycles. During week 4 of cycle 1, patients received SBRT (25 Gy delivered in five consecutive daily fractions of 5 Gy prescribed to the 75-83% isodose line). Acute and late toxicities were assessed using NIH CTCAE v3. Tumor response was assessed by RECIST. Patients underwent an esophagogastroduodenoscopy at baseline, 2, and 6 months to assess the duodenal mucosa. Quality of life (QoL) data was collected before and after treatment using the QLQ-C30 and QLQ-PAN26 questionnaires. Results Between September 2009 and February 2011, 11 patients enrolled with one withdrawal during radiation therapy. Patients had grade 1 to 2 gastrointestinal toxicity from the start of SBRT to 2 weeks after treatment. There were no grade 3 or greater radiation-related toxicities or delays for cycle 2 of gemcitabine. On endoscopy, there were no grade 2 or higher mucosal toxicities. Two patients had a partial response. The median progression free and overall survival were 6.8 and 12.2 months, respectively. Global QoL did not change between baseline and immediately after radiation treatment. Conclusions SBRT with concurrent full dose gemcitabine is safe when administered to patients with LAPC. There is no delay in administration of radiation or chemotherapy, and radiation is completed with minimal toxicity. PMID:23452509

Prevention in Poland: health care system reform.

PubMed Central

Sheahan, M D

1995-01-01

Despite the political and economic reforms that have swept Eastern Europe in the past 5 years, there has been little change in Poland's health care system. The Ministry of Health and Social Welfare has targeted preventive care as a priority, yet the enactment of legislation to meet this goal has been slow. The process of reform has been hindered by political stagnation, economic crisis, and a lack of delineation of responsibility for implementing the reforms. Despite the delays in reform, recent developments indicate that a realistic, sustainable restructuring of the health care system is possible, with a focus on preventive services. Recent proposals for change have centered on applying national goals to limited geographic areas, with both local and international support. Regional pilot projects to restructure health care delivery at a community level, local health education and disease prevention initiatives, and a national training program for primary care and family physicians and nurses are being planned. Through regionalization, an increase in responsibility for both the physician and the patient, and redefinition of primary health care and the role of family physicians, isolated local movements and pilot projects have shown promise in achieving these goals, even under the current budgetary constraints. PMID:7610217

Prevention in Poland: health care system reform.

PubMed

Sheahan, M D

1995-01-01

Despite the political and economic reforms that have swept Eastern Europe in the past 5 years, there has been little change in Poland's health care system. The Ministry of Health and Social Welfare has targeted preventive care as a priority, yet the enactment of legislation to meet this goal has been slow. The process of reform has been hindered by political stagnation, economic crisis, and a lack of delineation of responsibility for implementing the reforms. Despite the delays in reform, recent developments indicate that a realistic, sustainable restructuring of the health care system is possible, with a focus on preventive services. Recent proposals for change have centered on applying national goals to limited geographic areas, with both local and international support. Regional pilot projects to restructure health care delivery at a community level, local health education and disease prevention initiatives, and a national training program for primary care and family physicians and nurses are being planned. Through regionalization, an increase in responsibility for both the physician and the patient, and redefinition of primary health care and the role of family physicians, isolated local movements and pilot projects have shown promise in achieving these goals, even under the current budgetary constraints.

First-Order-hold interpolation digital-to-analog converter with application to aircraft simulation

NASA Technical Reports Server (NTRS)

Cleveland, W. B.

1976-01-01

Those who design piloted aircraft simulations must contend with the finite size and speed of the available digital computer and the requirement for simulation reality. With a fixed computational plant, the more complex the model, the more computing cycle time is required. While increasing the cycle time may not degrade the fidelity of the simulated aircraft dynamics, the larger steps in the pilot cue feedback variables (such as the visual scene cues), may be disconcerting to the pilot. The first-order-hold interpolation (FOHI) digital-to-analog converter (DAC) is presented as a device which offers smooth output, regardless of cycle time. The Laplace transforms of these three conversion types are developed and their frequency response characteristics and output smoothness are compared. The FOHI DAC exhibits a pure one-cycle delay. Whenever the FOHI DAC input comes from a second-order (or higher) system, a simple computer software technique can be used to compensate for the DAC phase lag. When so compensated, the FOHI DAC has (1) an output signal that is very smooth, (2) a flat frequency response in frequency ranges of interest, and (3) no phase error. When the input comes from a first-order system, software compensation may cause the FOHI DAC to perform as an FOHE DAC, which, although its output is not as smooth as that of the FOHI DAC, has a smoother output than that of the ZOH DAC.

Cockpit resources management and the theory of the situation

NASA Technical Reports Server (NTRS)

Bolman, L.

1984-01-01

The cockpit resource management (CRM) and hypothetical cockpit situations are discussed. Four different conditions which influence pilot action are outlined: (1) wrong assumptions about a situation; (2) stress and workload; (3) frustration and delays to cause risk taking; and (4) ambigious incomplete or contradicting information. Human factors and behavior, and pilot communication and management in the simulator are outlined.

Evaluating the Feasibility, Effectiveness and Acceptability of an Active Play Intervention for Disadvantaged Preschool Children: A Pilot Study

ERIC Educational Resources Information Center

Stagnitti, Karen; Malakellis, Mary; Kershaw, Beth; Hoare, Majella; Kenna, Rachel; de Silva-Sanigorski, Andrea

2011-01-01

Australian children from disadvantaged families are at increased risk of delays in acquiring fundamental movement skills, with physical inactivity and increased risk of the potential consequences of obesity. The aims of this pilot study were to: 1) assess the fundamental movement skills of disadvantaged children; 2) evaluate the feasibility and…

78 FR 8638 - Self-Regulatory Organizations; National Stock Exchange, Inc.; Notice of Filing and Immediate...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-06

... Change To Delay the Operative Date of Rule 11.20A Regarding Market-Wide Circuit Breakers Due to... the market- wide circuit breakers on a pilot basis for a period scheduled to start on February 4, 2013... changed to April 8, 2013. The proposal would delay the operative date of the market-wide circuit breaker...

The Results of a Simulator Study to Determine the Effects on Pilot Performance of Two Different Motion Cueing Algorithms and Various Delays, Compensated and Uncompensated

NASA Technical Reports Server (NTRS)

Guo, Li-Wen; Cardullo, Frank M.; Telban, Robert J.; Houck, Jacob A.; Kelly, Lon C.

2003-01-01

A study was conducted employing the Visual Motion Simulator (VMS) at the NASA Langley Research Center, Hampton, Virginia. This study compared two motion cueing algorithms, the NASA adaptive algorithm and a new optimal control based algorithm. Also, the study included the effects of transport delays and the compensation thereof. The delay compensation algorithm employed is one developed by Richard McFarland at NASA Ames Research Center. This paper reports on the analyses of the results of analyzing the experimental data collected from preliminary simulation tests. This series of tests was conducted to evaluate the protocols and the methodology of data analysis in preparation for more comprehensive tests which will be conducted during the spring of 2003. Therefore only three pilots were used. Nevertheless some useful results were obtained. The experimental conditions involved three maneuvers; a straight-in approach with a rotating wind vector, an offset approach with turbulence and gust, and a takeoff with and without an engine failure shortly after liftoff. For each of the maneuvers the two motion conditions were combined with four delay conditions (0, 50, 100 & 200ms), with and without compensation.

Non-invasive electromechanical activation imaging as a tool to study left ventricular dyssynchronous patients: Implication for CRT therapy.

PubMed

Dawoud, Fady; Spragg, David D; Berger, Ronald D; Cheng, Alan; Horáček, B Milan; Halperin, Henry R; Lardo, Albert C

2016-01-01

Electromechanical de-coupling is hypothesized to explain non-response of dyssynchrony patient to cardiac resynchronization therapy (CRT). In this pilot study, we investigated regional electromechanical uncoupling in 10 patients referred for CRT using two non-invasive electrical and mechanical imaging techniques (CMR tissue tracking and ECGI). Reconstructed regional electrical and mechanical activation captured delayed LBBB propagation direction from septal to anterior/inferior and finally to lateral walls as well as from LV apical to basal. All 5 responders demonstrated significantly delayed mechanical and electrical activation on the lateral LV wall at baseline compared to the non-responders (P<.05). On follow-up ECGI, baseline electrical activation patterns were preserved in native rhythm and global LV activation time was reduced with biventricular pacing. The combination of novel imaging techniques of ECGI and CMR tissue tracking can be used to assess spatial concordance of LV electrical and mechanical activation to gain insight into electromechanical coupling. Copyright © 2016 Elsevier Inc. All rights reserved.

New Predictive Filters for Compensating the Transport Delay on a Flight Simulator

NASA Technical Reports Server (NTRS)

Guo, Liwen; Cardullo, Frank M.; Houck, Jacob A.; Kelly, Lon C.; Wolters, Thomas E.

2004-01-01

The problems of transport delay in a flight simulator, such as its sources and effects, are reviewed. Then their effects on a pilot-in-the-loop control system are investigated with simulations. Three current prominent delay compensators the lead/lag filter, McFarland filter, and the Sobiski/Cardullo filter were analyzed and compared. This paper introduces two novel delay compensation techniques an adaptive predictor using the Kalman estimator and a state space predictive filter using a reference aerodynamic model. Applications of these two new compensators on recorded data from the NASA Langley Research Center Visual Motion Simulator show that they achieve better compensation over the current ones.

The combustion properties analysis of various liquid fuels based on crude oil and renewables

NASA Astrophysics Data System (ADS)

Grab-Rogalinski, K.; Szwaja, S.

2016-09-01

The paper presents results of investigation on combustion properties analysis of hydrocarbon based liquid fuels commonly used in the CI engine. The analysis was performed with aid of the CRU (Combustion Research Unit). CRU is the machine consisted of a constant volume combustion chamber equipped with one or two fuel injectors and a pressure sensor. Fuel can be injected under various both injection pressure and injection duration, also with two injector versions two stage combustion with pilot injection can be simulated, that makes it possible to introduce and modify additional parameter which is injection delay (defined as the time between pilot and main injection). On a basis of this investigation such combustion parameters as pressure increase, rate of heat release, ignition delay and combustion duration can be determined. The research was performed for the four fuels as follows: LFO, HFO, Biofuel from rape seeds and Glycerol under various injection parameters as well as combustion chamber thermodynamic conditions. Under these tests the change in such injection parameters as injection pressure, use of pilot injection, injection delay and injection duration, for main injection, were made. Moreover, fuels were tested under different conditions of load, what was determined by initial conditions (pressure and temperature) in the combustion chamber. Stored data from research allows to compare combustion parameters for fuels applied to tests and show this comparison in diagrams.

An Ad-Hoc Adaptive Pilot Model for Pitch Axis Gross Acquisition Tasks

NASA Technical Reports Server (NTRS)

Hanson, Curtis E.

2012-01-01

An ad-hoc algorithm is presented for real-time adaptation of the well-known crossover pilot model and applied to pitch axis gross acquisition tasks in a generic fighter aircraft. Off-line tuning of the crossover model to human pilot data gathered in a fixed-based high fidelity simulation is first accomplished for a series of changes in aircraft dynamics to provide expected values for model parameters. It is shown that in most cases, for this application, the traditional crossover model can be reduced to a gain and a time delay. The ad-hoc adaptive pilot gain algorithm is shown to have desirable convergence properties for most types of changes in aircraft dynamics.

A Comprehensive Study of Three Delay Compensation Algorithms for Flight Simulators

NASA Technical Reports Server (NTRS)

Guo, Liwen; Cardullo, Frank M.; Houck, Jacob A.; Kelly, Lon C.; Wolters, Thomas E.

2005-01-01

This paper summarizes a comprehensive study of three predictors used for compensating the transport delay in a flight simulator; The McFarland, Adaptive and State Space Predictors. The paper presents proof that the stochastic approximation algorithm can achieve the best compensation among all four adaptive predictors, and intensively investigates the relationship between the state space predictor s compensation quality and its reference model. Piloted simulation tests show that the adaptive predictor and state space predictor can achieve better compensation of transport delay than the McFarland predictor.

Pilot-model analysis and simulation study of effect of control task desired control response

NASA Technical Reports Server (NTRS)

Adams, J. J.; Gera, J.; Jaudon, J. B.

1978-01-01

A pilot model analysis was performed that relates pilot control compensation, pilot aircraft system response, and aircraft response characteristics for longitudinal control. The results show that a higher aircraft short period frequency is required to achieve superior pilot aircraft system response in an altitude control task than is required in an attitude control task. These results were confirmed by a simulation study of target tracking. It was concluded that the pilot model analysis provides a theoretical basis for determining the effect of control task on pilot opinions.

Lessons Learned From a Pilot RCT of Simultaneous Versus Delayed Initiation of Continuous Glucose Monitoring in Children and Adolescents With Type 1 Diabetes Starting Insulin Pump Therapy

PubMed Central

Olivier, Patricia; Huot, Celine; Richardson, Christine; Nakhla, Meranda; Romain, Judette

2014-01-01

Uncertainty remains about effectiveness of continuous glucose monitoring (CGM) in pediatric type 1 diabetes (T1D). Success with CGM is related to CGM adherence, which may relate to readiness to make the behavior changes required for effective use. We hypothesize that readiness for change will be greater at initiation of insulin pump therapy than in established pump users, and that this will predict CGM adherence. Our objective was to evaluate the feasibility of a randomized controlled trial (RCT) in children with established T1D comparing simultaneous pump and CGM initiation to standard pump therapy with delayed CGM initiation. We randomized participants to simultaneous pump and CGM initiation or to standard pump therapy with the option of adding CGM 4 months later. CGM adherence was tracked via web-based download and readiness for change assessed with the SOCRATES questionnaire. Of 41 eligible children, 20 agreed to participate; 15 subjects completed the study (7 males; baseline age 11.8 ± 4.0 years; T1D duration 2.7 ± 2.7 years; mean A1C 8.2 ± 0.8%). Six of 8 simultaneous group subjects used CGM > 60% of the time for 4 months compared to 1 of 7 delayed group subjects (P = .02). Using SOCRATES, we could assign 87-100% of subjects to a single motivation stage at baseline and 4 months. This pilot study demonstrates the feasibility of randomizing pump naïve children and adolescents with established T1D to simultaneous pump and CGM initiation versus standard pump therapy with delayed CGM initiation. Lessons from this pilot study were used to inform development of a full-scale multicenter RCT. PMID:24876616

Delayed mirror visual feedback presented using a novel mirror therapy system enhances cortical activation in healthy adults.

PubMed

Lee, Hsin-Min; Li, Ping-Chia; Fan, Shih-Chen

2015-07-11

Mirror visual feedback (MVF) generated in mirror therapy (MT) with a physical mirror promotes the recovery of hemiparetic limbs in patients with stroke, but is limited in that it cannot provide an asymmetric mode for bimanual coordination training. Here, we developed a novel MT system that can manipulate the MVF to resolve this issue. The aims of this pilot study were to examine the feasibility of delayed MVF on MT and to establish its effects on cortical activation in order to understand how it can be used for clinical applications in the future. Three conditions (no MVF, MVF, and 2-s delayed MVF) presented via our digital MT system were evaluated for their time-course effects on cortical activity by event-related desynchronization (ERD) of mu rhythm electroencephalography (EEG) during button presses in 18 healthy adults. Phasic ERD areas, defined as the areas of the relative ERD curve that were below the reference level and within -2-0 s (P0), 0-2 s (P1), and 2-4 s (P2) of the button press, were used. The overall (P0 to P2) and phasic ERD areas were higher when MVF was provided compared to when MVF was not provided for all EEG channels (C3, Cz, and C4). Phasic ERD areas in the P2 phase only increased during the delayed-MVF condition. Significant enhancement of cortical activation in the mirror neuron system and an increase in attention to the unseen limb may play major roles in the response to MVF during MT. In comparison to the no MVF condition, the higher phasic ERD areas that were observed during the P1 phase in the delayed-MVF condition indicate that the image of the still hand may have enhanced the cortical activation that occurred in response to the button press. This study is the first to achieve delayed MVF for upper-limb MT. Our approach confirms previous findings regarding the effects of MVF on cortical activation and contributes additional evidence supporting the use of this method in the future for upper-limb motor training in patients with stroke.

Helicopter pilots' views of air traffic controller responsibilities: a mismatch.

PubMed

Martin, Daniel; Nixon, Jim

2018-02-21

Controllers and pilots must work together to ensure safe and efficient helicopter flight within the London control zone. Subjective ratings of pilot perception of controller responsibility for five key flight tasks were obtained from thirty helicopter pilots. Three types of airspace were investigated. Results indicate that there is variation in pilot understanding of controller responsibility compared to the formal regulations that define controller responsibility. Significant differences in the perception of controller responsibility were found for the task of aircraft separation in class D airspace and along helicopter routes. Analysis of the patterns of response suggests that task type rather than the airspace type may be the key factor. Results are framed using the concept of a shared mental model. This research demonstrates that pilots flying in complex London airspace have an expectation of controller responsibility for certain flight tasks, in certain airspace types that is not supported by aviation regulation. Practitioner Summary: The responsibility for tasks during flight varies according to the flight rules used and airspace type. Helicopter pilots may attribute responsibility to controllers for tasks when controllers have no responsibility as defined by regulation. This variation between pilot perceptions of controller responsibility could affect safety within the London control zone.

Theoretical Prediction of Microgravity Ignition Delay of Polymeric Fuels in Low Velocity Flows

NASA Technical Reports Server (NTRS)

Fernandez-Pello, A. C.; Torero, J. L.; Zhou, Y. Y.; Walther, D.; Ross, H. D.

2001-01-01

A new flammability apparatus and protocol, FIST (Forced Flow Ignition and Flame Spread Test), is under development. Based on the LIFT (Lateral Ignition and Flame Spread Test) protocol, FIST better reflects the environments expected in spacebased facilities. The final objective of the FIST research is to provide NASA with a test methodology that complements the existing protocol and provides a more comprehensive assessment of material flammability of practical materials for space applications. Theoretical modeling, an extensive normal gravity data bank and a few validation space experiments will support the testing methodology. The objective of the work presented here is to predict the ignition delay and critical heat flux for ignition of solid fuels in microgravity at airflow velocities below those induced in normal gravity. This is achieved through the application of a numerical model previously developed of piloted ignition of solid polymeric materials exposed to an external radiant heat flux. The model predictions will provide quantitative results about ignition of practical materials in the limiting conditions expected in space facilities. Experimental data of surface temperature histories and ignition delay obtained in the KC-135 aircraft are used to determine the critical pyrolysate mass flux for ignition and this value is subsequently used to predict the ignition delay and the critical heat flux for ignition of the material. Surface temperature and piloted ignition delay calculations for Polymethylmethacrylate (PMMA) and a Polypropylene/Fiberglass (PP/GL) composite were conducted under both reduced and normal gravity conditions. It was found that ignition delay times are significantly shorter at velocities below those induced by natural convection.

Investigation of interactions between limb-manipulator dynamics and effective vehicle roll control characteristics

NASA Technical Reports Server (NTRS)

Johnston, D. E.; Mcruer, D. T.

1986-01-01

A fixed-base simulation was performed to identify and quantify interactions between the pilot's hand/arm neuromuscular subsystem and such features of typical modern fighter aircraft roll rate command control system mechanization as: (1) force sensing side-stick type manipulator; (2) vehicle effective role time constant; and (3) flight control system effective time delay. The simulation results provide insight to high frequency pilot induced oscillations (PIO) (roll ratchet), low frequency PIO, and roll-to-right control and handling problems previously observed in experimental and production fly-by-wire control systems. The simulation configurations encompass and/or duplicate actual flight situations, reproduce control problems observed in flight, and validate the concept that the high frequency nuisance mode known as roll ratchet derives primarily from the pilot's neuromuscular subsystem. The simulations show that force-sensing side-stick manipulator force/displacement/command gradients, command prefilters, and flight control system time delays need to be carefully adjusted to minimize neuromuscular mode amplitude peaking (roll ratchet tendency) without restricting roll control bandwidth (with resulting sluggish or PIO prone control).

A failure effects simulation of a low authority flight control augmentation system on a UH-1H helicopter

NASA Technical Reports Server (NTRS)

Corliss, L. D.; Talbot, P. D.

1977-01-01

A two-pilot moving base simulator experiment was conducted to assess the effects of servo failures of a flight control system on the transient dynamics of a Bell UH-1H helicopter. The flight control hardware considered was part of the V/STOLAND system built with control authorities of from 20-40%. Servo hardover and oscillatory failures were simulated in each control axis. Measurements were made to determine the adequacy of the failure monitoring system time delay and the servo center and lock time constant, the pilot reaction times, and the altitude and attitude excursions of the helicopter at hover and 60 knots. Safe recoveries were made from all failures under VFR conditions. Pilot reaction times were from 0.5 to 0.75 sec. Reduction of monitor delay times below these values resulted in significantly reduced excursion envelopes. A subsequent flight test was conducted on a UH-1H helicopter with the V/STOLAND system installed. Series servo hardovers were introduced in hover and at 60 knots straight and level. Data from these tests are included for comparison.

Flight test experience with pilot-induced-oscillation suppressor filters

NASA Technical Reports Server (NTRS)

Shafer, M. F.; Smith, R. E.; Stewart, J. F.; Bailey, R. E.

1983-01-01

Digital flight control systems are popular for their flexibility, reliability, and power; however, their use sometimes results in deficient handling qualities, including pilot-induced oscillation (PIO), which can require extensive redesign of the control system. When redesign is not immediately possible, temporary solutions, such as the PIO suppression (PIOS) filter developed for the Space Shuttle, have been proposed. To determine the effectiveness of such PIOS filters on more conventional, high-performance aircraft, three experiments were performed using the NASA F-8 digital fly-by-wire and USAF/Calspan NT-33 variable-stability aircraft. Two types of PIOS filters were evaluated, using high-gain, precision tasks (close formation, probe-and-drogue refueling, and precision touch-and-go landing) with a time delay or a first-order lag added to make the aircraft prone to PIO. Various configurations of the PIOS filter were evaluated in the flight programs, and most of the PIOS filter configurations reduced the occurrence of PIOs and improved the handling qualities of the PIO-prone aircraft. These experiments also confirmed the influence of high-gain tasks and excessive control system time delay in evoking pilot-induced oscillations.

Flight test experience with pilot-induced-oscillation suppression filters

NASA Technical Reports Server (NTRS)

Shafer, M. F.; Smith, R. E.; Stewart, J. F.; Bailey, R. E.

1984-01-01

Digital flight control systems are popular for their flexibility, reliability, and power; however, their use sometimes results in deficient handling qualities, including pilot-induced oscillation (PIO), which can require extensive redesign of the control system. When redesign is not immediately possible, temporary solutions, such as the PIO suppression (PIOS) filter developed for the Space Shuttle, have been proposed. To determine the effectiveness of such PIOS filters on more conventional, high-performance aircraft, three experiments were performed using the NASA F-8 digital fly-by-wire and USAF/Calspan NT-33 variable-stability aircraft. Two types of PIOS filters were evaluated, using high-gain, precision tasks (close formation, probe-and-drogue refueling, and precision touch-and-go landing) with a time delay or a first-order lag added to make the aircraft prone to PIO. Various configurations of the PIOS filter were evaluated in the flight programs, and most of the PIOS filter configurations reduced the occurrence of PIOs and improved the handling qualities of the PIO-prone aircraft. These experiments also confirmed the influence of high-gain tasks and excessive control system time delay in evoking pilot-induced oscillations.

Increasing the response rate of text messaging data collection: a delayed randomized controlled trial

PubMed Central

Li, Ye; Wang, Wei; Wu, Qiong; van Velthoven, Michelle Helena; Chen, Li; Du, Xiaozhen; Zhang, Yanfeng; Rudan, Igor; Car, Josip

2015-01-01

Objective To test the effectiveness of multiple interventions on increasing the response rate of text messaging for longitudinal data collection. Methods Our cohort included 283 caregivers of children aged 6–12 months who were participating in an anemia program in rural China. Using text messages to collect data on anemia medication adherence, we conducted a delayed randomized controlled trial to test multiple interventions (an additional four reminders; a ¥5.0 (US$0.79) credit reward for replying; and a feedback text message). After a 6-week pilot study with week 7 as the baseline measurement, we randomly allocated all participants into two groups: group 1 (n = 142) and group 2 (n = 141). During weeks 8–11, we introduced the interventions to group 1, and in weeks 12–15 the intervention was introduced to both groups. We compared the response rates between groups and explored factors affecting the response rate. Results During weeks 8–11, the response rates in group 1 increased and were significantly higher than in group 2 (p<0.05). During weeks 12–15, the response rate increased significantly in group 2 (p>0.05) and slightly decreased in group 1. Younger participants or participants who had children with lower hemoglobin concentration were more likely to reply (p = 0.02). Sending four reminders on the second day contributed to only 286 (11.7%) extra text messages. Discussion Our study showed that multiple interventions were effective in increasing response rate of text messaging data collection in rural China. Conclusions Larger multi-site studies are needed to find the most effective way of using these interventions to allow usage of text messaging data collection for health research. PMID:25332355

A methodology for the assessment of manned flight simulator fidelity

NASA Technical Reports Server (NTRS)

Hess, Ronald A.; Malsbury, Terry N.

1989-01-01

A relatively simple analytical methodology for assessing the fidelity of manned flight simulators for specific vehicles and tasks is offered. The methodology is based upon an application of a structural model of the human pilot, including motion cue effects. In particular, predicted pilot/vehicle dynamic characteristics are obtained with and without simulator limitations. A procedure for selecting model parameters can be implemented, given a probable pilot control strategy. In analyzing a pair of piloting tasks for which flight and simulation data are available, the methodology correctly predicted the existence of simulator fidelity problems. The methodology permitted the analytical evaluation of a change in simulator characteristics and indicated that a major source of the fidelity problems was a visual time delay in the simulation.

The Effects of an Early Motor Skill Intervention on Motor Skills, Levels of Physical Activity, and Socialization in Young Children with Autism Spectrum Disorder: A Pilot Study

ERIC Educational Resources Information Center

Ketcheson, Leah; Hauck, Janet; Ulrich, Dale

2017-01-01

Despite evidence suggesting one of the earliest indicators of an eventual autism spectrum disorder diagnoses is an early motor delay, there remain very few interventions targeting motor behavior as the primary outcome for young children with autism spectrum disorder. The aim of this pilot study was to measure the efficacy of an intensive motor…

Prefrontal Hemodynamics in Toddlers at Rest: A Pilot Study of Developmental Variability

PubMed Central

Anderson, Afrouz A.; Smith, Elizabeth; Chowdhry, Fatima A.; Thurm, Audrey; Condy, Emma; Swineford, Lauren; Manwaring, Stacy S.; Amyot, Franck; Matthews, Dennis; Gandjbakhche, Amir H.

2017-01-01

Functional near infrared spectroscopy (fNIRS) is a non-invasive functional neuroimaging modality. Although, it is amenable to use in infants and young children, there is a lack of fNIRS research within the toddler age range. In this study, we used fNIRS to measure cerebral hemodynamics in the prefrontal cortex (PFC) in 18–36 months old toddlers (n = 29) as part of a longitudinal study that enrolled typically-developing toddlers as well as those “at risk” for language and other delays based on presence of early language delays. In these toddlers, we explored two hemodynamic response indices during periods of rest during which time audiovisual children's programming was presented. First, we investigate Lateralization Index, based on differences in oxy-hemoglobin saturation from left and right prefrontal cortex. Then, we measure oxygenation variability (OV) index, based on variability in oxygen saturation at frequencies attributed to cerebral autoregulation. Preliminary findings show that lower cognitive (including language) abilities are associated with fNIRS measures of both lower OV index and more extreme Lateralization index values. These preliminary findings show the feasibility of using fNIRS in toddlers, including those at risk for developmental delay, and lay the groundwork for future studies. PMID:28611578

OMV mission simulator

NASA Technical Reports Server (NTRS)

Cok, Keith E.

1989-01-01

The Orbital Maneuvering Vehicle (OMV) will be remotely piloted during rendezvous, docking, or proximity operations with target spacecraft from a ground control console (GCC). The real-time mission simulator and graphics being used to design a console pilot-machine interface are discussed. A real-time orbital dynamics simulator drives the visual displays. The dynamics simulator includes a J2 oblate earth gravity model and a generalized 1962 rotating atmospheric and drag model. The simulator also provides a variable-length communication delay to represent use of the Tracking and Data Relay Satellite System (TDRSS) and NASA Communications (NASCOM). Input parameter files determine the graphics display. This feature allows rapid prototyping since displays can be easily modified from pilot recommendations. A series of pilot reviews are being held to determine an effective pilot-machine interface. Pilots fly missions with nominal to 3-sigma dispersions in translational or rotational axes. Console dimensions, switch type and layout, hand controllers, and graphic interfaces are evaluated by the pilots and the GCC simulator is modified for subsequent runs. Initial results indicate a pilot preference for analog versus digital displays and for two 3-degree-of-freedom hand controllers.

Evaluating Alerting and Guidance Performance of a UAS Detect-And-Avoid System

NASA Technical Reports Server (NTRS)

Lee, Seung Man; Park, Chunki; Thipphavong, David P.; Isaacson, Douglas R.; Santiago, Confesor

2016-01-01

A key challenge to the routine, safe operation of unmanned aircraft systems (UAS) is the development of detect-and-avoid (DAA) systems to aid the UAS pilot in remaining "well clear" of nearby aircraft. The goal of this study is to investigate the effect of alerting criteria and pilot response delay on the safety and performance of UAS DAA systems in the context of routine civil UAS operations in the National Airspace System (NAS). A NAS-wide fast-time simulation study was conducted to assess UAS DAA system performance with a large number of encounters and a broad set of DAA alerting and guidance system parameters. Three attributes of the DAA system were controlled as independent variables in the study to conduct trade-off analyses: UAS trajectory prediction method (dead-reckoning vs. intent-based), alerting time threshold (related to predicted time to LoWC), and alerting distance threshold (related to predicted Horizontal Miss Distance, or HMD). A set of metrics, such as the percentage of true positive, false positive, and missed alerts, based on signal detection theory and analysis methods utilizing the Receiver Operating Characteristic (ROC) curves were proposed to evaluate the safety and performance of DAA alerting and guidance systems and aid development of DAA system performance standards. The effect of pilot response delay on the performance of DAA systems was evaluated using a DAA alerting and guidance model and a pilot model developed to support this study. A total of 18 fast-time simulations were conducted with nine different DAA alerting threshold settings and two different trajectory prediction methods, using recorded radar traffic from current Visual Flight Rules (VFR) operations, and supplemented with DAA-equipped UAS traffic based on mission profiles modeling future UAS operations. Results indicate DAA alerting distance threshold has a greater effect on DAA system performance than DAA alerting time threshold or ownship trajectory prediction method. Further analysis on the alert lead time (time in advance of predicted loss of well clear at which a DAA alert is first issued) indicated a strong positive correlation between alert lead time and DAA system performance (i.e. the ability of the UAS pilot to maneuver the unmanned aircraft to remain well clear). While bigger distance thresholds had beneficial effects on alert lead time and missed alert rate, it also generated a higher rate of false alerts. In the design and development of DAA alerting and guidance systems, therefore, the positive and negative effects of false alerts and missed alerts should be carefully considered to achieve acceptable alerting system performance by balancing false and missed alerts. The results and methodology presented in this study are expected to help stakeholders, policymakers and standards committees define the appropriate setting of DAA system parameter thresholds for UAS that ensure safety while minimizing operational impacts to the NAS and equipage requirements for its users before DAA operational performance standards can be finalized.

An investigation into pilot and system response to critical in-flight events, volume 1

NASA Technical Reports Server (NTRS)

Rockwell, T. H.; Giffin, W. C.

1981-01-01

The scope of a critical in-flight event (CIFE) with emphasis on pilot management of available resources is described. Detailed scenarios for both full mission simulation and written testing of pilot responses to CIFE's, and statistical relationships among pilot characteristics and observed responses are developed. A model developed to described pilot response to CIFE and an analysis of professional fight crews compliance with specified operating procedures and the relationships with in-flight errors are included.

Preliminary Validation of the Small Aircraft Transportation System Higher Volume Operations (SATS HVO) Concept

NASA Technical Reports Server (NTRS)

Williams, Daniel; Consiglio, Maria; Murdoch, Jennifer; Adams, Catherine

2004-01-01

This document provides a preliminary validation of the Small Aircraft Transportation System (SATS) Higher Volume Operations (HVO) concept for normal conditions. Initial results reveal that the concept provides reduced air traffic delays when compared to current operations without increasing pilot workload. Characteristic to the SATS HVO concept is the establishment of a newly defined area of flight operations called a Self-Controlled Area (SCA) which would be activated by air traffic control (ATC) around designated non-towered, non-radar airports. During periods of poor visibility, SATS pilots would take responsibility for separation assurance between their aircraft and other similarly equipped aircraft in the SCA. Using onboard equipment and simple instrument flight procedures, they would then be better able to approach and land at the airport or depart from it. This concept would also require a new, ground-based automation system, typically located at the airport that would provide appropriate sequencing information to the arriving aircraft. Further validation of the SATS HVO concept is required and is the subject of ongoing research and subsequent publications.

Applications of flight control system methods to an advanced combat rotorcraft

NASA Technical Reports Server (NTRS)

Tischler, Mark B.; Fletcher, Jay W.; Morris, Patrick M.; Tucker, George T.

1989-01-01

Advanced flight control system design, analysis, and testing methodologies developed at the Ames Research Center are applied in an analytical and flight test evaluation of the Advanced Digital Optical Control System (ADOCS) demonstrator. The primary objectives are to describe the knowledge gained about the implications of digital flight control system design for rotorcraft, and to illustrate the analysis of the resulting handling-qualities in the context of the proposed new handling-qualities specification for rotorcraft. Topics covered in-depth are digital flight control design and analysis methods, flight testing techniques, ADOCS handling-qualities evaluation results, and correlation of flight test results with analytical models and the proposed handling-qualities specification. The evaluation of the ADOCS demonstrator indicates desirable response characteristics based on equivalent damping and frequency, but undersirably large effective time-delays (exceeding 240 m sec in all axes). Piloted handling-qualities are found to be desirable or adequate for all low, medium, and high pilot gain tasks; but handling-qualities are inadequate for ultra-high gain tasks such as slope and running landings.

Physiological and behavioral responses to an exposure of pitch illusion in the simulator.

PubMed

Cheung, Bob; Hofer, Kevin; Heskin, Raquel; Smith, Andrew

2004-08-01

It has been suggested that a pilot's physiological and behavioral responses during disorientation can provide a real-time model of pilot state in order to optimize performance. We investigated whether there were consistent behavioral or physiological "markers" that can be monitored during a single episode of disorientation. An Integrated Physiological Trainer with a closed loop interactive aircraft control and point of gaze/eye-tracking device was employed. There were 16 subjects proficient in maintaining straight and level flight and with procedures in changing attitude who were exposed to yaw rotation and a brief head roll to 35 +/- 2 degrees. On return to upright head position, subjects were required to initiate either an ascent or descent to a prescribed attitude. BP, HR, skin conductance, eye movements, and point of gaze were monitored throughout the onset, duration, and immediately after the disorientation insult. Simultaneously, airspeed and power settings were recorded. Compared with the control condition, a significant increase (p < 0.01) in HR, HR variability, and mean arterial BP was observed during the disorientation. Flight performance decrement was reflected by a significant delay in setting power for attitude change and deviation in maintaining airspeed (p < 0.01). Changes in cardiovascular responses appear to be correlated with the onset of disorientation. The correlation of changing eye-tracking behavior and flight performance decrement is consistent with our previous findings. Further study is required to determine whether these findings can be extrapolated to repeated exposures and to other disorientation scenarios.

Reviewing and piloting methods for decreasing discount rates; someone, somewhere in time.

PubMed

Parouty, Mehraj B Y; Krooshof, Daan G M; Westra, Tjalke A; Pechlivanoglou, Petros; Postma, Maarten J

2013-08-01

There has been substantial debate on the need for decreasing discounting for monetary and health gains in economic evaluations. Next to the discussion on differential discounting, a way to identify the need for such discounting strategies is through eliciting the time preferences for monetary and health outcomes. In this article, the authors investigate the perceived time preference for money and health gains through a pilot survey on Dutch university students using methods on functional forms previously suggested. Formal objectives of the study were to review such existing methods and to pilot them on a convenience sample using a questionnaire designed for this specific purpose. Indeed, a negative relation between the time of delay and the variance of the discounting rate for all models was observed. This study was intended as a pilot for a large-scale population-based investigation using the findings from this pilot on wording of the questionnaire, interpretation, scope and analytic framework.

Analysis of Recreational Boating Impact on Navigation Lock Performance

DTIC Science & Technology

1989-12-01

seeing the large craft at night. Another comment, a common one at most locks, was the lack of knowledge of rules by many recreational boaters. Several...cause of time delays, and not recreational boats. However, one of the pilots indicated that water skiers were major hazards to commercial barges as...they cut across the path of commercial tows below the line of sight of the pilot. Recreational boaters and particularly those pulling skiers should be

Hip Hop HEALS: Pilot Study of a Culturally Targeted Calorie Label Intervention to Improve Food Purchases of Children.

PubMed

Williams, Olajide; DeSorbo, Alexandra; Sawyer, Vanessa; Apakama, Donald; Shaffer, Michele; Gerin, William; Noble, James

2016-02-01

We explored the effect of a culturally targeted calorie label intervention on food purchasing behavior of elementary school students. We used a quasi-experimental design with two intervention schools and one control school to assess food purchases of third through fifth graders at standardized school food sales before and after the intervention (immediate and delayed) in schools. The intervention comprised three 1-hour assembly-style hip-hop-themed multimedia classes. A mean total of 225 children participated in two baseline preintervention sales with and without calorie labels; 149 children participated in immediate postintervention food sales, while 133 children participated in the delayed sales. No significant change in purchased calories was observed in response to labels alone before the intervention. However, a mean decline in purchased calories of 20% (p < .01) and unhealthy foods (p < .01) was seen in immediately following the intervention compared to baseline purchases, and this persisted without significant decay after 7 days and 12 days. A 3-hour culturally targeted calorie label intervention may improve food-purchasing behavior of children. © 2015 Society for Public Health Education.

A Study of the Characteristics of Human-Pilot Control Response to Simulated Aircraft Lateral Motions

NASA Technical Reports Server (NTRS)

Cheatham, Donald C

1954-01-01

Report presents the results of studies made in an attempt to provide information on the control operations of the human pilot. These studies included an investigation of the ability of pilots to control simulated unstable yawing oscillations, a study of the basic characteristics of human-pilot control response, and a study to determine whether and to what extent pilot control response can be represented in an analytical form.

Expertise and responsibility effects on pilots' reactions to flight deck alerts in a simulator.

PubMed

Zheng, Yiyuan; Lu, Yanyu; Yang, Zheng; Fu, Shan

2014-11-01

Flight deck alerts provide system malfunction information designed to lead corresponding pilot reactions aimed at guaranteeing flight safety. This study examined the roles of expertise and flight responsibility and their relationship to pilots' reactions to flight deck alerts. There were 17 pilots composing 12 flight crews that were assigned into pairs according to flight hours and responsibilities. The experiment included 9 flight scenarios and was carried out in a CRJ-200 flight simulator. Pilot performance was recorded by a wide angle video camera, and four kinds of reactions to alerts were defined for analysis. Pilots tended to have immediate reactions to uninterrupted cautions, with a turning off rate as high as 75%. However, this rate decreased sharply when pilots encountered interrupted cautions and warnings; they also exhibited many wrong reactions to warnings. Pilots with more expertise had more reactions to uninterrupted cautions than those with less expertise, both as pilot flying and pilot monitoring. Meanwhile, the pilot monitoring, regardless of level of expertise, exhibited more reactions than the pilot flying. In addition, more experienced pilots were more likely to have wrong reactions to warnings while acting as the monitoring pilot. These results suggest that both expertise and flight responsibility influence pilots' reactions to alerts. Considering crew pairing strategy, when a pilot flying is a less experienced pilot, a more experience pilot is suggested to be the monitoring pilot. The results of this study have implications for understanding pilots' behaviors to flight deck alerts, calling for specialized training and design of approach alarms on the flight deck.

Design considerations of manipulator and feel system characteristics in roll tracking

NASA Technical Reports Server (NTRS)

Johnston, Donald E.; Aponso, Bimal L.

1988-01-01

A fixed-base simulation was performed to identify and quantify interactions between the pilot's hand/arm neuromuscular subsystem and such control system features of typical modern fighter aircraft roll rate command mechanizations as: (1) force versus displacement sensing side-stick type manipulator, (2) feel force/displacement gradient, (3) feel system versus command prefilter dynamic lag, and (4) flight control system effective time delay. The experiment encompassed some 48 manipulator/filter/aircraft configurations. Displacement side-stick experiment results are given and compared with the previous force sidestick experiment results. Attention is focused on control bandwidth, excitement (peaking) of the neuromuscular mode, feel force/displacement gradient effects, time delay effects, etc. Section 5 is devoted to experiments with a center-stick in which force versus displacement sensing, feel system lag, and command prefilter lag influences on tracking performance and pilot preference are investigated.

The iron status at birth of neonates with risk factors for developing iron deficiency: a pilot study.

PubMed

MacQueen, B C; Christensen, R D; Ward, D M; Bennett, S T; O'Brien, E A; Sheffield, M J; Baer, V L; Snow, G L; Weaver Lewis, K A; Fleming, R E; Kaplan, J

2017-04-01

Small-for-gestational-age (SGA) neonates, infants of diabetic mothers (IDM) and very-low-birth weight premature neonates (VLBW) are reported to have increased risk for developing iron deficiency and possibly associated neurocognitive delays. We conducted a pilot study to assess iron status at birth in at-risk neonates by measuring iron parameters in umbilical cord blood from SGA, IDM, VLBW and comparison neonates. Six of the 50 infants studied had biochemical evidence of iron deficiency at birth. Laboratory findings consistent with iron deficiency were found in one SGA, one IDM, three VLBW, and one comparison infant. None of the infants had evidence of iron deficiency anemia. Evidence of biochemical iron deficiency at birth was found in 17% of screened neonates. Studies are needed to determine whether these infants are at risk for developing iron-limited erythropoiesis, iron deficiency anemia or iron-deficient neurocognitive delay.

Simulation System Fidelity Assessment at the Vertical Motion Simulator

NASA Technical Reports Server (NTRS)

Beard, Steven D.; Reardon, Scott E.; Tobias, Eric L.; Aponso, Bimal L.

2013-01-01

Fidelity is a word that is often used but rarely understood when talking about groundbased simulation. Assessing the cueing fidelity of a ground based flight simulator requires a comparison to actual flight data either directly or indirectly. Two experiments were conducted at the Vertical Motion Simulator using the GenHel UH-60A Black Hawk helicopter math model that was directly compared to flight data. Prior to the experiment the simulator s motion and visual system frequency responses were measured, the aircraft math model was adjusted to account for the simulator motion system delays, and the motion system gains and washouts were tuned for the individual tasks. The tuned motion system fidelity was then assessed against the modified Sinacori criteria. The first experiments showed similar handling qualities ratings (HQRs) to actual flight for a bob-up and sidestep maneuvers. The second experiment showed equivalent HQRs between flight and simulation for the ADS33 slalom maneuver for the two pilot participants. The ADS33 vertical maneuver HQRs were mixed with one pilot rating the flight and simulation the same while the second pilot rated the simulation worse. In addition to recording HQRs on the second experiment, an experimental Simulation Fidelity Rating (SFR) scale developed by the University of Liverpool was tested for applicability to engineering simulators. A discussion of the SFR scale for use on the Vertical Motion Simulator is included in this paper.

Pilot-model measurements of pilot responses in a lateral-directional control task

NASA Technical Reports Server (NTRS)

Adams, J. J.

1976-01-01

Pilot response during an aircraft bank-angle compensatory control task was measured by using an adaptive modeling technique. In the main control loop, which is the bank angle to aileron command loop, the pilot response was the same as that measured previously in single-input, single-output systems. The pilot used a rudder to aileron control coordination that canceled up to 80 percent of the vehicle yawing moment due to aileron deflection.

An investigation into pilot and system response to critical in-flight events. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

Rockwell, T. H.; Griffin, W. C.

1981-01-01

Critical in-flight events (CIFE) that threaten the aircraft were studied. The scope of the CIFE was described and defined with emphasis on characterizing event development, detection and assessment; pilot information requirements, sources, acquisition, and interpretation, pilot response options, decision processed, and decision implementation and event outcome. Detailed scenarios were developed for use in simulators and paper and pencil testing for developing relationships between pilot performance and background information as well as for an analysis of pilot reaction decision and feedback processes. Statistical relationships among pilot characteristics and observed responses to CIFE's were developed.

Interpreting the handling qualities of aircraft with stability and control augmentation

NASA Technical Reports Server (NTRS)

Hodgkinson, J.; Potsdam, E. H.; Smith, R. E.

1990-01-01

The general process of designing an aircraft for good flying qualities is first discussed. Lessons learned are pointed out, with piloted evaluation emerging as a crucial element. Two sources of rating variability in performing these evaluations are then discussed. First, the finite endpoints of the Cooper-Harper scale do not bias parametric statistical analyses unduly. Second, the wording of the scale does introduce some scatter. Phase lags generated by augmentation systems, as represented by equivalent time delays, often cause poor flying qualities. An analysis is introduced which allows a designer to relate any level of time delay to a probability of loss of aircraft control. This view of time delays should, it is hoped, allow better visibility of the time delays in the design process.

Promoting early presentation of breast cancer in older women: sustained effect of an intervention to promote breast cancer awareness in routine clinical practice.

PubMed

Dodd, Rachael H; Forster, Alice S; Sellars, Sarah; Patnick, Julietta; Ramirez, Amanda J; Forbes, Lindsay J L

2017-06-05

Older women have poorer survival from breast cancer, which may be at least partly due to poor breast cancer awareness leading to delayed presentation and more advanced stage at diagnosis. In a randomised trial, an intervention to promote early presentation of breast cancer in older women increased breast cancer awareness at 1 year compared with usual care (24 versus 4%). We examined its effectiveness in routine clinical practice. We piloted the intervention delivered by practising health professionals to women aged about 70 in four breast screening services. We measured the effect on breast cancer awareness at 1 year compared with comparison services, where women did not receive the intervention. At 1 year, 25% of women in pilot services were breast cancer aware compared with 4% in comparison services (p = 0.001). The components of breast cancer awareness were knowledge of breast cancer non-lump symptoms (pilot: 63% vs comparison: 82% at 1 year; OR = 2.56, 95% CI 1.92-3.42), knowledge of age related risk (pilot: 8% vs comparison: 36% at 1 year; OR = 5.56, 95% CI 4.0-7.74) and reported breast checking (pilot: 70% vs comparison: 78% at 1 year; OR = 1.49, 95% CI 1.13-1.96). The intervention may be as effective in routine clinical practice as in a randomised controlled trial. This intervention has the potential to reduce patient delay in the diagnosis of breast cancer in older women. The PEP trial was registered with the International Standard Registered Clinical/soCial sTudy Number (ISRCTN) as a clinical trial ( ISRCTN31994827 ) on 3rd October 2007.

Effect of shaping sensor data on pilot response

NASA Technical Reports Server (NTRS)

Bailey, Roger M.

1990-01-01

The pilot of a modern jet aircraft is subjected to varying workloads while being responsible for multiple, ongoing tasks. The ability to associate the pilot's responses with the task/situation, by modifying the way information is presented relative to the task, could provide a means of reducing workload. To examine the feasibility of this concept, a real time simulation study was undertaken to determine whether preprocessing of sensor data would affect pilot response. Results indicated that preprocessing could be an effective way to tailor the pilot's response to displayed data. The effects of three transformations or shaping functions were evaluated with respect to the pilot's ability to predict and detect out-of-tolerance conditions while monitoring an electronic engine display. Two nonlinear transformations, on being the inverse of the other, were compared to a linear transformation. Results indicate that a nonlinear transformation that increases the rate-or-change of output relative to input tends to advance the prediction response and improve the detection response, while a nonlinear transformation that decreases the rate-of-change of output relative to input tends to lengthen the prediction response and make detection more difficult.

An approach to the determination of aircraft handling qualities using pilot transfer functions

NASA Technical Reports Server (NTRS)

Adams, J. J.; Hatch, H. G., Jr.

1978-01-01

It was shown that a correlation exists between pilot-aircraft system closed-loop characteristics, determined by using analytical expressions for pilot response along with the analytical expression for the aircraft response, and pilot ratings obtained in many previous flight and simulation studies. Two different levels of preferred pilot response were used. These levels were: (1) a static gain and a second-order lag function with a lag time constant of 0.2 second; and (2) a static gain, a lead time constant of 1 second, and a 0.2-second lag time constant. If a system response with a pitch-angle time constant of 2.6 seconds and a stable oscillatory mode of motion with a period of 2.5 seconds could be achieved with the first-level pilot model, it was shown that the pilot rating will be satisfactory for that vehicle.

Contingency Tracking during Unsignaled Delayed Reinforcement

ERIC Educational Resources Information Center

Keely, Josue; Feola, Tyler; Lattal, Kennon A.

2007-01-01

Three experiments were conducted with rats in which responses on one lever (labeled the functional lever) produced reinforcers after an unsignaled delay period that reset with each response during the delay. Responses on a second, nonfunctional, lever did not initiate delays, but, in the first and third experiments, such responses during the last…

A Pilot Model for the NASA Simplified Aid for EVA Rescue (SAFER) (Single-Axis Pitch Task)

NASA Astrophysics Data System (ADS)

Handley, Patrick Mark

This thesis defines, tests, and validates a descriptive pilot model for a single-axis pitch control task of the Simplified Aid for EVA Rescue (SAFER). SAFER is a small propulsive jetpack used by astronauts for self-rescue. Pilot model research supports development of improved self-rescue strategies and technologies through insights into pilot behavior.This thesis defines a multi-loop pilot model. The innermost loop controls the hand controller, the middle loop controls pitch rate, and the outer loop controls pitch angle. A human-in-the-loop simulation was conducted to gather data from a human pilot. Quantitative and qualitative metrics both indicate that the model is an acceptable fit to the human data. Fuel consumption was nearly identical; time to task completion matched very well. There is some evidence that the model responds faster to initial pitch rates than the human, artificially decreasing the model's time to task completion. This pilot model is descriptive, not predictive, of the human pilot. Insights are made into pilot behavior from this research. Symmetry implies that the human responds to positive and negative initial conditions with the same strategy. The human pilot appears indifferent to pitch angles within 0.5 deg, coasts at a constant pitch rate 1.09 deg/s, and has a reaction delay of 0.1 s.

Measurement of human pilot dynamic characteristics in flight simulation

NASA Technical Reports Server (NTRS)

Reedy, James T.

1987-01-01

Fast Fourier Transform (FFT) and Least Square Error (LSE) estimation techniques were applied to the problem of identifying pilot-vehicle dynamic characteristics in flight simulation. A brief investigation of the effects of noise, input bandwidth and system delay upon the FFT and LSE techniques was undertaken using synthetic data. Data from a piloted simulation conducted at NASA Ames Research Center was then analyzed. The simulation was performed in the NASA Ames Research Center Variable Stability CH-47B helicopter operating in fixed-basis simulator mode. The piloting task consisted of maintaining the simulated vehicle over a moving hover pad whose motion was described by a random-appearing sum of sinusoids. The two test subjects used a head-down, color cathode ray tube (CRT) display for guidance and control information. Test configurations differed in the number of axes being controlled by the pilot (longitudinal only versus longitudinal and lateral), and in the presence or absence of an important display indicator called an 'acceleration ball'. A number of different pilot-vehicle transfer functions were measured, and where appropriate, qualitatively compared with theoretical pilot- vehicle models. Some indirect evidence suggesting pursuit behavior on the part of the test subjects is discussed.

Delayed Rapid Response Team Activation Is Associated With Increased Hospital Mortality, Morbidity, and Length of Stay in a Tertiary Care Institution.

PubMed

Barwise, Amelia; Thongprayoon, Charat; Gajic, Ognjen; Jensen, Jeffrey; Herasevich, Vitaly; Pickering, Brian W

2016-01-01

To identify whether delays in rapid response team activation contributed to worse patient outcomes (mortality and morbidity). Retrospective observational cohort study including all rapid response team activations in 2012. Tertiary academic medical center. All those 18 years old or older who had a rapid response team call activated. Vital sign data were abstracted from individual patient electronic medical records for the 24 hours before the rapid response team activation took place. Patients were considered to have a delayed rapid response team activation if more than 1 hour passed between the first appearance in the record of an abnormal vital sign meeting rapid response team criteria and the activation of an rapid response team. None. A total of 1,725 patients were included in the analysis. Data were compared between those who had a delayed rapid response team activation and those who did not. Fifty seven percent patients met the definition of delayed rapid response team activation. Patients in high-frequency physiologic monitored environments were more likely to experience delay than their floor counterparts. In the no-delay group, the most common reasons for rapid response team activation were tachycardia/bradycardia at 29% (217/748), respiratory distress/low SpO2 at 28% (213/748), and altered level of consciousness at 23% (170/748) compared with respiratory distress/low SpO2 at 43% (423/977), tachycardia/bradycardia at 33% (327/977), and hypotension at 27% (261/977) in the delayed group. The group with no delay had a higher proportion of rapid response team calls between 8:00 and 16:00, whereas those with delay had a higher proportion of calls between midnight and 08:00. The delayed group had higher hospital mortality (15% vs 8%; adjusted odds ratio, 1.6; p = 0.005); 30-day mortality (20% vs 13%; adjusted odds ratio, 1.4; p = 0.02); and hospital length of stay (7 vs 6 d; relative prolongation, 1.10; p = 0.02) compared with the no-delay group. Delays in rapid response team activation occur frequently and are independently associated with worse patient mortality and morbidity outcomes.

An analysis of student programmatic delays in postsecondary flight training programs : a national study

DOT National Transportation Integrated Search

1996-01-01

Since the passage of the Airline Deregulation Act (ADA) in 1978, the need for professionally--trained air carrier pilots in the United States has expanded substantially. Postsecondary academic institutions have replaced the military as a major source...

Real-Time Monitoring and Prediction of the Pilot Vehicle System (PVS) Closed-Loop Stability

NASA Astrophysics Data System (ADS)

Mandal, Tanmay Kumar

Understanding human control behavior is an important step for improving the safety of future aircraft. Considerable resources are invested during the design phase of an aircraft to ensure that the aircraft has desirable handling qualities. However, human pilots exhibit a wide range of control behaviors that are a function of external stimulus, aircraft dynamics, and human psychological properties (such as workload, stress factor, confidence, and sense of urgency factor). This variability is difficult to address comprehensively during the design phase and may lead to undesirable pilot-aircraft interaction, such as pilot-induced oscillations (PIO). This creates the need to keep track of human pilot performance in real-time to monitor the pilot vehicle system (PVS) stability. This work focused on studying human pilot behavior for the longitudinal axis of a remotely controlled research aircraft and using human-in-the-loop (HuIL) simulations to obtain information about the human controlled system (HCS) stability. The work in this dissertation is divided into two main parts: PIO analysis and human control model parameters estimation. To replicate different flight conditions, this study included time delay and elevator rate limiting phenomena, typical of actuator dynamics during the experiments. To study human control behavior, this study employed the McRuer model for single-input single-output manual compensatory tasks. McRuer model is a lead-lag controller with time delay which has been shown to adequately model manual compensatory tasks. This dissertation presents a novel technique to estimate McRuer model parameters in real-time and associated validation using HuIL simulations to correctly predict HCS stability. The McRuer model parameters were estimated in real-time using a Kalman filter approach. The estimated parameters were then used to analyze the stability of the closed-loop HCS and verify them against the experimental data. Therefore, the main contribution of this dissertation is the design of an unscented Kalman filter-based algorithm to estimate McRuer model parameters in real time, and a framework to validate this algorithm for single-input single-output manual compensatory tasks to predict instabilities.

Enhancement of the bulbocavernosus reflex during intraoperative neurophysiological monitoring through the use of double train stimulation: a pilot study.

PubMed

Skinner, Stanley; Chiri, Chala A; Wroblewski, Jill; Transfeldt, Ensor E

2007-02-01

Electrophysiological bulbocavernosus reflex (BCR) testing, during surgeries in which the constituent neural components are at risk, might supplement other low sacral (S2-4) stimulation/recording techniques. However, intraoperative BCR is not always reliably implemented. We proposed to analyze BCR signals in five surgical patients monitored with the novel application of double train stimulation (DTS) to determine if the potential could be enhanced. We prospectively planned a regime of DTS BCR with a series of intertrain delays in five monitored patients at risk for low sacral neural injury. Patients were maintained with propofol, opiate infusion, and low inhalant anesthesia without muscle relaxant. Cutaneous sensory nerves of the penis (or clitoris) were stimulated using two consecutive pulse trains (DTS). Intertrain delays were 75, 100, 125, 150, 175, 200, and 250 ms. For BCR recording, uncoated paired wires were inserted into the external anal sphincter (EAS) bilaterally. For each trial, waveform amplitude, duration, and turn count measures for the first (single train) and second (double train) response were recorded. Percent increase/decrease of the second train response compared to the first train response was calculated. There was at least a 30% increase in measures of amplitude, turn count, and duration of the second train response in 22/28, 22/28, and 14/28 of the total trials respectively. There was an insufficient number of independent observations to determine statistical significance. Intraoperative BCR is currently obtained with some difficulty using pulse train stimulation. Our preliminary evidence has identified BCR waveform enhancement using DTS and suggests that the reliability of intraoperative BCR acquisition may be further improved by the addition of this technique. Our data are insufficient to define the best intertrain interval.

Performance analysis and simulation of the SPS reference phase control system

NASA Technical Reports Server (NTRS)

Lindsey, W. C.; Chie, C. M.

1980-01-01

The major elements required in the operation of an SPS which employs retrodirectivity as a means of pointing the beam to Earth include the spacetenna, the rectenna, and the pilot signal transmitter. The phase control system is faced with several problems: (1) path delay variations due to imperfect SPS circular orbits; (2) ionospheric effects; (3) initial phase beam forming; (4) beam pointing; (5) beam safing; (6) high power phase noise effects; and (7) interference. The use of SOLARISM, a computer program to select pilot signal parameters and evaluate SPS performance is described.

Working hours associated with unintentional sleep at work among airline pilots

PubMed Central

Marqueze, Elaine Cristina; Nicola, Ana Carolina B; Diniz, Dag Hammarskjoeld M D; Fischer, Frida Marina

2017-01-01

ABSTRACT OBJECTIVE Tto identify factors associated with unintentional sleep at work of airline pilots. METHODS This is a cross-sectional epidemiological study conducted with 1,235 Brazilian airline pilots, who work national or international flights. Data collection has been performed online. We carried out a bivariate and multiple logistic regression analysis, having as dependent variable unintentional sleep at work. The independent variables were related to biodemographic data, characteristics of the work, lifestyle, and aspects of sleep. RESULTS The prevalence of unintentional sleep while flying the airplane was 57.8%. The factors associated with unintentional sleep at work were: flying for more than 65 hours a month, frequent technical delays, greater need for recovery after work, work ability below optimal, insufficient sleep, and excessive sleepiness. CONCLUSIONS The occurrence of unintentional sleep at work of airline pilots is associated with factors related to the organization of the work and health. PMID:28678902

Impact of Conflict Avoidance Responsibility Allocation on Pilot Workload in a Distributed Air Traffic Management System

NASA Technical Reports Server (NTRS)

Ligda, Sarah V.; Dao, Arik-Quang V.; Vu, Kim-Phuong; Strybel, Thomas Z.; Battiste, Vernol; Johnson, Walter W.

2010-01-01

Pilot workload was examined during simulated flights requiring flight deck-based merging and spacing while avoiding weather. Pilots used flight deck tools to avoid convective weather and space behind a lead aircraft during an arrival into Louisville International airport. Three conflict avoidance management concepts were studied: pilot, controller or automation primarily responsible. A modified Air Traffic Workload Input Technique (ATWIT) metric showed highest workload during the approach phase of flight and lowest during the en-route phase of flight (before deviating for weather). In general, the modified ATWIT was shown to be a valid and reliable workload measure, providing more detailed information than post-run subjective workload metrics. The trend across multiple workload metrics revealed lowest workload when pilots had both conflict alerting and responsibility of the three concepts, while all objective and subjective measures showed highest workload when pilots had no conflict alerting or responsibility. This suggests that pilot workload was not tied primarily to responsibility for resolving conflicts, but to gaining and/or maintaining situation awareness when conflict alerting is unavailable.

Cetacean Social Behavioral Response to Sonar Exposure

DTIC Science & Technology

2015-09-30

Lam FPA, Tyack PLT, Miller PJO (in review). Disturbance-specific social responses in long-finned pilot whales, Globicephala melas .  Fieldwork...the social behavioral response of long-finned pilot whales (Globicephala melas ) revealed that a unifying characteristic of their behavioral response...Globicephala melas . 6 Visser F. et al. (in review). Vocal foragers and silent crowds: the socio-behavioural context of long- finned pilot whale

In-flight evaluation of a fiber optic helmet-mounted display

NASA Astrophysics Data System (ADS)

Jennings, Sion A.; Gubbels, Arthur W.; Swail, Carl P.; Craig, Greg

1998-08-01

The National Research Council of Canada (NRC), in conjunction with the Canadian Department of National Defence (DND), is investigating the use of helmet-mounted displays (HMD) to improve pilot situational awareness in all-weather search and rescue helicopter operations. The National Research Council has installed a visually coupled HMD system in the NRC Bell 205 Airborne Simulator. Equipped with a full authority fly-by-wire control system, the Bell 205 has variable stability characteristics, which makes the airborne simulator the ideal platform for the integrated flight testing of HMDs in a simulated operational environment. This paper presents preliminary results from flight test of the NRC HMD. These results are in the form of numerical head tracker data, and subjective handling qualities ratings. Flight test results showed that the HMD degraded handling qualities due to reduced acuity, limited field-of-view, time delays in the sensor platform, and fatigue caused by excessive helmet inertia. Some evidence was found to support the hypothesis of an opto-kinetic cervical reflex whereby a pilot pitches and rolls his head in response to aircraft movements to maintain a level horizon in their field-of- view.

Intelligent Engine Systems Work Element 1.2: Malfunction and Operator Error Reduction

NASA Technical Reports Server (NTRS)

Wiseman, Matthew

2005-01-01

Jet engines, although highly reliable and safe, do experience malfunctions that cause flight delays, passenger stress, and in some cases, in conjunction with inappropriate crew response, contribute to airplane accidents. On rare occasions, the anomalous engine behavior is not recognized until it is too late for the pilots to do anything to prevent or mitigate the resulting engine malfunction causing in-flight shutdowns (IFSDs), aborted takeoffs (ATOs), or loss of thrust control (LOTC). In some cases, the crew response to a myriad of external stimuli and existing training procedures is the source of the problem mentioned above. The problem is the reduction of jet engine malfunctions (IFSDs, ATOs, and LOTC) and inappropriate crew response (PSM+ICR) through the use of evolving and advanced technologies. The solution is to develop the overall system health maintenance architecture, detection and accommodation technologies, processes, and enhanced crew interfaces that would enable a significant reduction in IFSDs, ATOs, and LOTC. This program defines requirements and proposes a preliminary design concept of an architecture that enables the realization of the solution.

Neo-Institutional Analysis on Response Patterns of Pilot Schools

ERIC Educational Resources Information Center

Shin, Chol-Kyun

2016-01-01

This study examines response patterns of pilot schools in the neo-institutional perspective to make improvements on the pilot school systematic framework. In order to achieve this goal, in-depth interviews were conducted to obtain qualitative data. The results show that pilot schools either (a) actively adopt or (b) ceremonially adopt an education…

Impact assessment of energy-efficient lighting in patients with lupus erythematosus: a pilot study.

PubMed

Fenton, L; Dawe, R; Ibbotson, S; Ferguson, J; Silburn, S; Moseley, H

2014-03-01

Patients with lupus erythematosus (LE) are often abnormally photosensitive. Ultraviolet (UV) exposure can not only induce cutaneous lesions but may also contribute to systemic flares and disease progression. Various forms of energy-efficient lighting have been shown to emit UV radiation. To determine the effects of these emissions on individuals with LE. This assessment investigated cutaneous responses to repeated exposures from three types of lighting: compact fluorescent lamp (CFL), light-emitting diode (LED) and energy-efficient halogen (EEH). The subjects were 15 patients with LE and a control group of five healthy volunteers. No cutaneous LE lesions were induced by any of the light sources. Delayed skin erythema was induced at the site of CFL irradiation in six of the 15 patients with LE and two of the five healthy subjects. Erythema was increased in severity and more persistent in patients with LE. One patient with LE produced a positive delayed erythema to the EEH. A single patient with LE produced immediate abnormal erythemal responses to the CFL, LED and EEH. Further investigation revealed that this patient also had solar urticaria. All other subjects had negative responses to LED exposure. Compact fluorescent lamps emit UV that can induce skin erythema in both individuals with LE and healthy individuals when situated in close proximity. However, this occurs to a greater extent and is more persistent in patients with LE. EEHs emit UVA that can induce erythema in patients with LE. LEDs provide a safer alternative light source without risk of UV exposure. © 2013 British Association of Dermatologists.

Post-injection feasibility study with the reflectivity method for the Ketzin pilot site, Germany (CO2 storage in a saline aquifer)

NASA Astrophysics Data System (ADS)

Ivanova, Alexandra; Kempka, Thomas; Huang, Fei; Diersch [Gil], Magdalena; Lüth, Stefan

2016-04-01

3D time-lapse seismic surveys (4D seismic) have proven to be a suitable technique for monitoring of injected CO2, because when CO2 replaces brine as a free gas it considerably affects elastic properties of porous media. Forward modeling of a 4D seismic response to the CO2-fluid substitution in a storage reservoir is an inevitable step in such studies. At the Ketzin pilot site (CO2 storage) 67 kilotons of CO2 were injected into a saline aquifer between 2008 and 2013. In order to track migration of CO2 at Ketzin, 3D time-lapse seismic data were acquired by means of a baseline pre-injection survey in 2005 and 3 monitor surveys: in 2009, 2012 and in 2015 (the 1st post-injection survey). Results of the 4D seismic forward modeling with the reflectivity method suggest that effects of the injected CO2 on the 4D seismic data at Ketzin are significant regarding both seismic amplitudes and time delays. These results prove the corresponding observations in the real 4D seismic data at the Ketzin pilot site. But reservoir heterogeneity and seismic resolution, as well as random and coherent seismic noise are negative factors to be considered in this interpretation. Results of the 4D seismic forward modeling with the reflectivity method support the conclusion that even small amounts of injected CO2 can be monitored in such post-injected saline aquifer as the CO2 storage reservoir at the Ketzin pilot site both qualitatively and quantitatively with considerable uncertainties (Lüth et al., 2015). Reference: Lueth, S., Ivanova, A., Kempka, T. (2015): Conformity assessment of monitoring and simulation of CO2 storage: A case study from the Ketzin pilot site. - International Journal of Greenhouse Gas Control, 42, p. 329-339.

Evaluation of Piloted Inputs for Onboard Frequency Response Estimation

NASA Technical Reports Server (NTRS)

Grauer, Jared A.; Martos, Borja

2013-01-01

Frequency response estimation results are presented using piloted inputs and a real-time estimation method recently developed for multisine inputs. A nonlinear simulation of the F-16 and a Piper Saratoga research aircraft were subjected to different piloted test inputs while the short period stabilator/elevator to pitch rate frequency response was estimated. Results show that the method can produce accurate results using wide-band piloted inputs instead of multisines. A new metric is introduced for evaluating which data points to include in the analysis and recommendations are provided for applying this method with piloted inputs.

Timely response to secure messages from primary care patients.

PubMed

Rohrer, James E; North, Frederick; Angstman, Kurt B; Oberhelman, Sara S; Meunier, Matthew R

2013-01-01

To assess delays in response to patient secure e-mail messages in primary care. Secure electronic messages are initiated by primary care patients. Timely response is necessary for patient safety and quality. A database of secure messages. A random sample of 353 secure electronic messages initiated by primary care patients treated in 4 clinics. Message not opened after 12 hours or messages not responded to after 36 hours. A total of 8.5% of electronic messages were not opened within 12 hours, and 17.6% did not receive a response in 36 hours. Clinic location, being a clinic employee, and patient sex were not related to delays. Patients older than 50 years were more likely to receive a delayed response (25.7% delayed, P = .013). The risk of both kinds of delays was higher on weekends (P < .001 for both). The e-mail message system resulted in high rates of delayed response. Delays were concentrated on weekends (Friday-Sunday). Reducing delayed responses may require automatic rerouting of messages to message centers staffed 24-7 or other mechanisms to manage this after-hours work flow.

Synthesized speech rate and pitch effects on intelligibility of warning messages for pilots

NASA Technical Reports Server (NTRS)

Simpson, C. A.; Marchionda-Frost, K.

1984-01-01

In civilian and military operations, a future threat-warning system with a voice display could warn pilots of other traffic, obstacles in the flight path, and/or terrain during low-altitude helicopter flights. The present study was conducted to learn whether speech rate and voice pitch of phoneme-synthesized speech affects pilot accuracy and response time to typical threat-warning messages. Helicopter pilots engaged in an attention-demanding flying task and listened for voice threat warnings presented in a background of simulated helicopter cockpit noise. Performance was measured by flying-task performance, threat-warning intelligibility, and response time. Pilot ratings were elicited for the different voice pitches and speech rates. Significant effects were obtained only for response time and for pilot ratings, both as a function of speech rate. For the few cases when pilots forgot to respond to a voice message, they remembered 90 percent of the messages accurately when queried for their response 8 to 10 sec later.

Women's Health and Mindfulness (WHAM): A Randomized Intervention Among Older Lesbian/Bisexual Women.

PubMed

Ingraham, Natalie; Harbatkin, Dawn; Lorvick, Jennifer; Plumb, Marj; Minnis, Alexandra M

2017-05-01

Lesbian and bisexual (LB) women have higher body weight than heterosexual women. Interventions focused on health and well-being versus weight loss may be more likely to succeed among LB women. This article describes effects of Women's Health and Mindfulness, a 12-week pilot intervention addressing mindfulness, healthy eating, and physical activity, on outcomes associated with chronic disease risk among overweight and obese LB women older than 40 years. Eighty women were randomized, using a stepped-wedge design, to either an immediate- or a delayed-start intervention group; the delayed-start group served as the control. Eligible participants were aged 40 years or older, identified as LB, and had a body mass index of 27 or greater. We compared differences in biological markers of chronic disease, mindfulness, nutrition, and physical activity between immediate- and delayed-start intervention groups. We observed clinically significant improvements in low-density lipoprotein cholesterol but no change in hemoglobin A1c. We found evidence of intervention effects on improved mindfulness and mindful eating scores and on nutrition (improved vegetable intake). The Women's Health and Mindfulness pilot intervention appears to have initiated positive behavioral and physical health changes in this population. Refinements to the intervention model, such as extended intervention duration, and longer term follow-up are warranted to determine sustained effects.

The effectiveness of airline pilot training for abnormal events.

PubMed

Casner, Stephen M; Geven, Richard W; Williams, Kent T

2013-06-01

To evaluate the effectiveness of airline pilot training for abnormal in-flight events. Numerous accident reports describe situations in which pilots responded to abnormal events in ways that were different from what they had practiced many times before. One explanation for these missteps is that training and testing for these skills have become a highly predictable routine for pilots who arrive to the training environment well aware of what to expect. Under these circumstances, pilots get plentiful practice in responding to abnormal events but may get little practice in recognizing them and deciding which responses to offer. We presented 18 airline pilots with three abnormal events that are required during periodic training and testing. Pilots were presented with each event under the familiar circumstances used during training and also under less predictable circumstances as they might occur during flight. When presented in the routine ways seen during training, pilots gave appropriate responses and showed little variability. However, when the abnormal events were presented unexpectedly, pilots' responses were less appropriate and showed great variability from pilot to pilot. The results suggest that the training and testing practices used in airline training may result in rote-memorized skills that are specific to the training situation and that offer modest generalizability to other situations. We recommend a more complete treatment of abnormal events that allows pilots to practice recognizing the event and choosing and recalling the appropriate response. The results will aid the improvement of existing airline training practices.

A pilot study to evaluate runoff quantity from green roofs.

PubMed

Lee, Ju Young; Lee, Min Jung; Han, Mooyoung

2015-04-01

The use of green roofs is gaining increased recognition in many countries as a solution that can be used to improve environmental quality and reduce runoff quantity. To achieve these goals, pilot-scale green roof assemblies have been constructed and operated in an urban setting. From a stormwater management perspective, green roofs are 42.8-60.8% effective in reducing runoff for 200 mm soil depth and 13.8-34.4% effective in reducing runoff for 150 mm soil depth. By using Spearman rank correlation analysis, high rainfall intensity was shown to have a negative relationship with delayed occurrence time, demonstrating that the soil media in green roofs do not efficiently retain rainwater. Increasing the number of antecedent dry days can help to improve water retention capacity and delay occurrence time. From the viewpoint of runoff water quality, green roofs are regarded as the best management practice by filtration and adsorption through growth media (soil). Copyright © 2015 Elsevier Ltd. All rights reserved.

The iron status at birth of neonates with risk factors for developing iron deficiency: a pilot study

PubMed Central

MacQueen, BC; Christensen, RD; Ward, DM; Bennett, ST; O’Brien, EA; Sheffield, MJ; Baer, VL; Snow, GL; Lewis, KA Weaver; Fleming, RE; Kaplan, J

2016-01-01

OBJECTIVE Small-for-gestational-age (SGA) neonates, infants of diabetic mothers (IDM) and very-low-birth weight premature neonates (VLBW) are reported to have increased risk for developing iron deficiency and possibly associated neurocognitive delays. STUDY DESIGN We conducted a pilot study to assess iron status at birth in at-risk neonates by measuring iron parameters in umbilical cord blood from SGA, IDM, VLBW and comparison neonates. RESULTS Six of the 50 infants studied had biochemical evidence of iron deficiency at birth. Laboratory findings consistent with iron deficiency were found in one SGA, one IDM, three VLBW, and one comparison infant. None of the infants had evidence of iron deficiency anemia. CONCLUSIONS Evidence of biochemical iron deficiency at birth was found in 17% of screened neonates. Studies are needed to determine whether these infants are at risk for developing iron-limited erythropoiesis, iron deficiency anemia or iron-deficient neurocognitive delay. PMID:27977019

Improved pupil dilation with medication-soaked pledget sponges.

PubMed

Weddle, Celeste; Thomas, Nikki; Dienemann, Jacqueline

2013-08-01

Use of multiple preoperative drops for pupil dilation has been shown to be inexact, to delay surgery, and to cause dissatisfaction among perioperative personnel. This article reports on an evidence-based, quality improvement project to locate and appraise research on improved effectiveness and efficiency of mydriasis (ie, pupillary dilation), and the subsequent implementation of a pledget-sponge procedure for pupil dilation at one ambulatory surgery center. Project leaders used an evidence-based practice model to assess the problem, research options for improvement, define goals, and implement a pilot project to test the new dilation technique. Outcomes from the pilot project showed a reduced number of delays caused by poor pupil dilation and a decrease in procedure turnover time. The project team solicited informal feedback from preoperative nurses, which reflected increased satisfaction in preparing patients for cataract procedures. After facility administrators and surgeons accepted the procedure change, it was adopted for preoperative use for all patients undergoing cataract surgery at the ambulatory surgery center. Copyright © 2013 AORN, Inc. Published by Elsevier Inc. All rights reserved.

Social Reinforcement Delays in Free-Flying Honey Bees (Apis mellifera L.)

PubMed Central

Craig, David Philip Arthur; Grice, James W.; Varnon, Chris A.; Gibson, B.; Sokolowski, Michel B. C.; Abramson, Charles I.

2012-01-01

Free-flying honey bees (Apis mellifera L.) reactions were observed when presented with varying schedules of post-reinforcement delays of 0 s, 300 s, or 600 s. We measured inter-visit-interval, response length, inter-response-time, and response rate. Honey bees exposed to these post-reinforcement delay intervals exhibit one of several patterns compared to groups not encountering delays, and had longer inter-visit-intervals. We observed no group differences in inter-response time. Honey bees with higher response rates tended to not finish the experiment. The removal of the delay intervals increased response rates for those subjects that completed the trials. PMID:23056425

Computer simulation of multiple pilots flying a modern high performance helicopter

NASA Technical Reports Server (NTRS)

Zipf, Mark E.; Vogt, William G.; Mickle, Marlin H.; Hoelzeman, Ronald G.; Kai, Fei; Mihaloew, James R.

1988-01-01

A computer simulation of a human response pilot mechanism within the flight control loop of a high-performance modern helicopter is presented. A human response mechanism, implemented by a low order, linear transfer function, is used in a decoupled single variable configuration that exploits the dominant vehicle characteristics by associating cockpit controls and instrumentation with specific vehicle dynamics. Low order helicopter models obtained from evaluations of the time and frequency domain responses of a nonlinear simulation model, provided by NASA Lewis Research Center, are presented and considered in the discussion of the pilot development. Pilot responses and reactions to test maneuvers are presented and discussed. Higher level implementation, using the pilot mechanisms, are discussed and considered for their use in a comprehensive control structure.

14 CFR 91.3 - Responsibility and authority of the pilot in command.

Code of Federal Regulations, 2010 CFR

2010-01-01

... in command. 91.3 Section 91.3 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... § 91.3 Responsibility and authority of the pilot in command. (a) The pilot in command of an aircraft is...-flight emergency requiring immediate action, the pilot in command may deviate from any rule of this part...

14 CFR 91.3 - Responsibility and authority of the pilot in command.

Code of Federal Regulations, 2012 CFR

2012-01-01

... in command. 91.3 Section 91.3 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... § 91.3 Responsibility and authority of the pilot in command. (a) The pilot in command of an aircraft is...-flight emergency requiring immediate action, the pilot in command may deviate from any rule of this part...

14 CFR 91.3 - Responsibility and authority of the pilot in command.

Code of Federal Regulations, 2011 CFR

2011-01-01

... in command. 91.3 Section 91.3 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... § 91.3 Responsibility and authority of the pilot in command. (a) The pilot in command of an aircraft is...-flight emergency requiring immediate action, the pilot in command may deviate from any rule of this part...

14 CFR 91.3 - Responsibility and authority of the pilot in command.

Code of Federal Regulations, 2013 CFR

2013-01-01

... in command. 91.3 Section 91.3 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... § 91.3 Responsibility and authority of the pilot in command. (a) The pilot in command of an aircraft is...-flight emergency requiring immediate action, the pilot in command may deviate from any rule of this part...

14 CFR 91.3 - Responsibility and authority of the pilot in command.

Code of Federal Regulations, 2014 CFR

2014-01-01

... in command. 91.3 Section 91.3 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... § 91.3 Responsibility and authority of the pilot in command. (a) The pilot in command of an aircraft is...-flight emergency requiring immediate action, the pilot in command may deviate from any rule of this part...

Energy management - The delayed flap approach

NASA Technical Reports Server (NTRS)

Bull, J. S.

1976-01-01

Flight test evaluation of a Delayed Flap approach procedure intended to provide reductions in noise and fuel consumption is underway using the NASA CV-990 test aircraft. Approach is initiated at a high airspeed (240 kt) and in a drag configuration that allows for low thrust. The aircraft is flown along the conventional ILS glide slope. A Fast/Slow message display signals the pilot when to extend approach flaps, landing gear, and land flaps. Implementation of the procedure in commercial service may require the addition of a DME navigation aid co-located with the ILS glide slope transmitter. The Delayed Flap approach saves 250 lb of fuel over the Reduced Flap approach, with a 95 EPNdB noise contour only 43% as large.

Signal functions in delayed reinforcement

PubMed Central

Lattal, Kennon A.

1984-01-01

Three experiments were conducted with pigeons to examine the role of the signal in delay-of-reinforcement procedures. In the first, a blackout accompanying a period of nonreinforcement increased key-peck response rates maintained by immediate reinforcement. The effects of dissociating the blackout from the delay interval were examined in the second experiment. In three conditions, blackouts and unsignaled delays were negatively correlated or occurred randomly with respect to one another. A signaled delay and an unsignaled delay that omitted the blackouts were studied in two other conditions. All delay-of-reinforcement conditions generally produced response rates lower than those produced by immediate reinforcement. Signaled delays maintained higher response rates than did any of the various unsignaled-delay conditions, with or without dissociated blackouts. The effects of these latter conditions did not differ systematically from one another. The final experiment showed that response rates varied as a function of the frequency with which a blackout accompanied delay intervals. By eliminating a number of methodological difficulties present in previous delay-of-reinforcement experiments, these results suggest the importance of the signal in maintaining responding during delay-of-reinforcement procedures and, conversely, the importance of the delay interval in decreasing responding. PMID:16812387

77 FR 11137 - Government-Owned Inventions; Availability for Licensing

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-24

... nonspecific, and the diagnosis is frequently difficult and delayed. The inventors established a rapid ELISA assay to evaluate biomarker levels in serum. The ELISA assay tests a novel combination of two biomarkers...-invasive ELISA serum assay. Potential for high sensitivity. Cost effective. Development Stage: Pilot. Early...

UAS Air Traffic Controller Acceptability Study-2: Effects of Communications Delays and Winds in Simulation

NASA Technical Reports Server (NTRS)

Comstock, James R., Jr.; Ghatas, Rania W.; Consiglio, Maria C.; Chamberlain, James P.; Hoffler, Keith D.

2016-01-01

This study evaluated the effects of Communications Delays and Winds on Air Traffic Controller ratings of acceptability of horizontal miss distances (HMDs) for encounters between UAS and manned aircraft in a simulation of the Dallas-Ft. Worth East-side airspace. Fourteen encounters per hour were staged in the presence of moderate background traffic. Seven recently retired controllers with experience at DFW served as subjects. Guidance provided to the UAS pilots for maintaining a given HMD was provided by information from self-separation algorithms displayed on the Multi-Aircraft Simulation System. Winds tested did not affect the acceptability ratings. Communications delays tested included 0, 400, 1200, and 1800 msec. For longer communications delays, there were changes in strategy and communications flow that were observed and reported by the controllers. The aim of this work is to provide useful information for guiding future rules and regulations applicable to flying UAS in the NAS.

Evaluation of several secondary tasks in the determination of permissible time delays in simulator visual and motion cues

NASA Technical Reports Server (NTRS)

Miller, G. K., Jr.; Riley, D. R.

1978-01-01

The effect of secondary tasks in determining permissible time delays in visual-motion simulation of a pursuit tracking task was examined. A single subject, a single set of aircraft handling qualities, and a single motion condition in tracking a target aircraft that oscillates sinusoidally in altitude were used. In addition to the basic simulator delays the results indicate that the permissible time delay is about 250 msec for either a tapping task, an adding task, or an audio task and is approximately 125 msec less than when no secondary task is involved. The magnitudes of the primary task performance measures, however, differ only for the tapping task. A power spectraldensity analysis basically confirms the result by comparing the root-mean-square performance measures. For all three secondary tasks, the total pilot workload was quite high.

Magnitude of visual accommodation to a head-up display

NASA Technical Reports Server (NTRS)

Leitner, E. F.; Haines, R. F.

1981-01-01

The virtual image symbology of head-up displays (HUDs) is presented at optical infinity to the pilot. This design feature is intended to help pilots maintain visual focus distance at optical infinity. However, the accommodation response could be nearer than optical infinity, due to an individual's dark focus response. Accommodation responses were measured of two age groups of airline pilots to: (1) static symbology on a HUD; (2) a landing site background at optical infinity; (3) the combination of the HUD symbology and the landing site background; and (4) complete darkness. Results indicate that magnitude of accommodation to HUD symbology, with and without the background, is not significantly different from an infinity focus response for either age group. The dark focus response is significantly closer than optical infinity for the younger pilots, but not the older pilots, a finding consistent with previous research.

Contrast-Enhanced Ultrasonography of Hepatocellular Carcinoma After Chemoembolisation Using Drug-Eluting Beads: A Pilot Study Focused on Sustained Tumor Necrosis

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

Moschouris, Hippocrates; Malagari, Katerina; Papadaki, Marina Georgiou

The purpose of this study was to assess the use of contrast-enhanced ultrasonography (CEUS) and the sustained antitumor effect of drug-eluting beads used for transarterial chemoembolisation (TACE) of unresectable hepatocellular carcinoma (HCC). Ten patients with solitary, unresectable HCC underwent CEUS before, 2 days after, and 35 to 40 days after TACE using a standard dose (4 ml) of drug-eluting beads (DC Beads; Biocompatibles, Surrey, UK) preloaded with doxorubicin (25 mg doxorubicin/ml hydrated beads). For CEUS, a second-generation contrast agent (SonoVue, Bracco, Milan, Italy) and a low mechanical-index technique were used. A part of the tumor was characterized as necrotic ifmore » it showed complete lack of enhancement. The percentage of necrosis was calculated at the sonographic section that depicted the largest diameter of the tumor. Differences in the extent of early (2 days after TACE) and delayed (35 to 40 days after TACE) necrosis were quantitatively and subjectively assessed. Early post-TACE tumor necrosis ranged from 21% to 70% (mean 43.5% {+-} 19%). There was a statistically significant (p = 0.0012, paired Student t test) higher percentage of delayed tumor necrosis, which ranged from 24% to 88% (mean 52.3% {+-} 20.3%). Subjective evaluation showed a delayed obvious increase of the necrotic areas in 5 patients. In 2 patients, tumor vessels that initially remained patent disappeared on the delayed follow-up. A part of tumor necrosis after chemoembolisation of HCC with DEB seems to take place later than 2 days after TACE. CEUS may provide evidence for the sustained antitumor effect of DEB-TACE. Nevertheless, the ideal time for the imaging evaluation of tumor response remains to be defined.« less

Attributions of Responsibility and Blame for Procrastination Behavior.

PubMed

Rahimi, Sonia; Hall, Nathan C; Pychyl, Timothy A

2016-01-01

The present study examined the relationship between procrastination, delay, blameworthiness, and moral responsibility. Undergraduate students (N = 240) were provided two scenarios in which the reason for inaction (procrastination, delay), the target (self, other), and the outcome (positive, negative) were manipulated, and students were asked to rate the moral responsibility and blameworthiness of the agent. Results indicated that individuals who procrastinated were seen as more morally responsible and blameworthy than those who experienced delay. More specifically, after a negative outcome, procrastination was associated with more moral responsibility, whereas delay was associated with less moral responsibility. After a positive outcome, individuals perceived procrastination as deserving of less moral responsibility, and delays as associated with more moral responsibility. Finally, a three-way interaction showed that participants rated procrastination that resulted in failure as deserving of responsibility when engaged in by others as opposed to oneself.

Modeling human pilot cue utilization with applications to simulator fidelity assessment.

PubMed

Zeyada, Y; Hess, R A

2000-01-01

An analytical investigation to model the manner in which pilots perceive and utilize visual, proprioceptive, and vestibular cues in a ground-based flight simulator was undertaken. Data from a NASA Ames Research Center vertical motion simulator study of a simple, single-degree-of-freedom rotorcraft bob-up/down maneuver were employed in the investigation. The study was part of a larger research effort that has the creation of a methodology for determining flight simulator fidelity requirements as its ultimate goal. The study utilized a closed-loop feedback structure of the pilot/simulator system that included the pilot, the cockpit inceptor, the dynamics of the simulated vehicle, and the motion system. With the exception of time delays that accrued in visual scene production in the simulator, visual scene effects were not included in this study. Pilot/vehicle analysis and fuzzy-inference identification were employed to study the changes in fidelity that occurred as the characteristics of the motion system were varied over five configurations. The data from three of the five pilots who participated in the experimental study were analyzed in the fuzzy-inference identification. Results indicate that both the analytical pilot/vehicle analysis and the fuzzy-inference identification can be used to identify changes in simulator fidelity for the task examined.

Conflict Resolution Automation and Pilot Situation Awareness

NASA Technical Reports Server (NTRS)

Dao, Arik-Quang V.; Brandt, Summer L.; Bacon, Paige; Kraut, Josh; Nguyen, Jimmy; Minakata, Katsumi; Raza, Hamzah; Rozovski, David; Johnson, Walter W.

2010-01-01

This study compared pilot situation awareness across three traffic management concepts. The Concepts varied in terms of the allocation of traffic avoidance responsibility between the pilot on the flight deck, the air traffic controllers, and a conflict resolution automation system. In Concept 1, the flight deck was equipped with conflict resolution tools that enable them to fully handle the responsibility of weather avoidance and maintaining separation between ownship and surrounding traffic. In Concept 2, pilots were not responsible for traffic separation, but were provided tools for weather and traffic avoidance. In Concept 3, flight deck tools allowed pilots to deviate for weather, but conflict detection tools were disabled. In this concept pilots were dependent on ground based automation for conflict detection and resolution. Situation awareness of the pilots was measured using online probes. Results showed that individual situation awareness was highest in Concept 1, where the pilots were most engaged, and lowest in Concept 3, where automation was heavily used. These findings suggest that for conflict resolution tasks, situation awareness is improved when pilots remain in the decision-making loop.

Engaging Pediatricians in Developmental Screening: The Effectiveness of Academic Detailing

ERIC Educational Resources Information Center

Honigfeld, Lisa; Chandhok, Laura; Spiegelman, Kenneth

2012-01-01

Use of formal developmental screening tools in the pediatric medical home improves early identification of children with developmental delays and disorders, including Autism Spectrum Disorders. A pilot study evaluated the impact of an academic detailing module in which trainers visited 43 pediatric primary care practices to provide education about…

Measuring border delay and crossing times at the US-Mexico border : final report on automated crossing and wait time measurement.

DOT National Transportation Integrated Search

2012-08-01

A pilot test implemented a radio frequency identification (RFID) system to automatically measure travel times of US-bound commercial vehicles at a selected Port of Entry (POE) on the USMexico border under long-term, real-world conditions. The init...

Binaural Sensory Aid: Case Studies of Its Use by Two Children

ERIC Educational Resources Information Center

Strelow, E. R.; And Others

1978-01-01

The adaptation of the binaural sensory aid for use by blind children is discussed in the context of a pilot study carried out with two blind children; one an intellectually competent 6-year-old girl and the other a developmentally delayed 2-1/2-year-old boy. (Author)

Attributions of Responsibility and Blame for Procrastination Behavior

PubMed Central

Rahimi, Sonia; Hall, Nathan C.; Pychyl, Timothy A.

2016-01-01

The present study examined the relationship between procrastination, delay, blameworthiness, and moral responsibility. Undergraduate students (N = 240) were provided two scenarios in which the reason for inaction (procrastination, delay), the target (self, other), and the outcome (positive, negative) were manipulated, and students were asked to rate the moral responsibility and blameworthiness of the agent. Results indicated that individuals who procrastinated were seen as more morally responsible and blameworthy than those who experienced delay. More specifically, after a negative outcome, procrastination was associated with more moral responsibility, whereas delay was associated with less moral responsibility. After a positive outcome, individuals perceived procrastination as deserving of less moral responsibility, and delays as associated with more moral responsibility. Finally, a three-way interaction showed that participants rated procrastination that resulted in failure as deserving of responsibility when engaged in by others as opposed to oneself. PMID:27547197

How time delay and network design shape response patterns in biochemical negative feedback systems.

PubMed

Börsch, Anastasiya; Schaber, Jörg

2016-08-24

Negative feedback in combination with time delay can bring about both sustained oscillations and adaptive behaviour in cellular networks. Here, we study which design features of systems with delayed negative feedback shape characteristic response patterns with special emphasis on the role of time delay. To this end, we analyse generic two-dimensional delay differential equations describing the dynamics of biochemical signal-response networks. We investigate the influence of several design features on the stability of the model equilibrium, i.e., presence of auto-inhibition and/or mass conservation and the kind and/or strength of the delayed negative feedback. We show that auto-inhibition and mass conservation have a stabilizing effect, whereas increasing abruptness and decreasing feedback threshold have a de-stabilizing effect on the model equilibrium. Moreover, applying our theoretical analysis to the mammalian p53 system we show that an auto-inhibitory feedback can decouple period and amplitude of an oscillatory response, whereas the delayed feedback can not. Our theoretical framework provides insight into how time delay and design features of biochemical networks act together to elicit specific characteristic response patterns. Such insight is useful for constructing synthetic networks and controlling their behaviour in response to external stimulation.

Criteria for Handling Qualities of Military Aircraft.

DTIC Science & Technology

1982-06-01

loop precognitive manner. The pilot is able to apply discrete, step-like inputs which more or less exactly produce the desired aircraft response. Some...While closed loop operation depends upon the frequency domain response characteristics, successful precognitive control requires the time domain...represents the other extreme of the pilot task from the precognitive time response situation. Mich work was done in attempting to predict pilot opinion from

Charting a New Path: Modernizing the U.S. Air Force Fighter Pilots Career Development

DTIC Science & Technology

2015-12-01

truly provides no new incentives for undecided fighter pilots and is proving to be an antiquated attempt to maintain the fighter pilot force...growing technological requirements. Weapons shops are responsible for a growing number of responsibilities to support combat operations. Crypto

The Biochemical Basis of Hydroxymethylglutaryl-CoA Reductase Inhibitors as Neuroprotective Agents in Aneurysmal Subarachnoid Hemorrhage

PubMed Central

Wong, George Kwok Chu; Poon, Wai Sang

2010-01-01

Aneurysmal subarachnoid hemorrhage (SAH) has the highest morbidity and mortality rates of all types of stroke. Many aneurysmal SAH patients continue to suffer from significant neurological morbidity and mortality directly related to delayed cerebral ischemia. Pilot clinical studies of the use of Hydroxymethylglutaryl-CoA Reductase Inhibitors (statins) in aneurysmal SAH patients have reported a reduction in delayed cerebral ischemia and better clinical outcomes. We review the biochemical effects of statins on endothelium vascular function, glutamate-mediated neurotoxicity, inflammatory changes, and oxidative injuries, with reference to their possible neuroprotective effects in aneurysmal SAH.

Computer simulation of a single pilot flying a modern high-performance helicopter

NASA Technical Reports Server (NTRS)

Zipf, Mark E.; Vogt, William G.; Mickle, Marlin H.; Hoelzeman, Ronald G.; Kai, Fei; Mihaloew, James R.

1988-01-01

Presented is a computer simulation of a human response pilot model able to execute operational flight maneuvers and vehicle stabilization of a modern high-performance helicopter. Low-order, single-variable, human response mechanisms, integrated to form a multivariable pilot structure, provide a comprehensive operational control over the vehicle. Evaluations of the integrated pilot were performed by direct insertion into a nonlinear, total-force simulation environment provided by NASA Lewis. Comparisons between the integrated pilot structure and single-variable pilot mechanisms are presented. Static and dynamically alterable configurations of the pilot structure are introduced to simulate pilot activities during vehicle maneuvers. These configurations, in conjunction with higher level, decision-making processes, are considered for use where guidance and navigational procedures, operational mode transfers, and resource sharing are required.

Crew workload in JASDF C-1 transport flights: I. Change in heart rate and salivary cortisol.

PubMed

Kakimoto, Y; Nakamura, A; Tarui, H; Nagasawa, Y; Yagura, S

1988-06-01

The physiological responses of heart rate and salivary cortisol for six paired captains and co-pilots during JASDF scheduled transport flights were compared to assess crew workload. The relative change of both responses showed similar patterns and were influenced significantly by whether pilots were controlling the aircraft. Moreover, differences in flying experience and responsibility of captains and co-pilots influenced the two physiological responses; heart rate and salivary cortisol measures increased more for both captains and co-pilots while they were in control of the aircraft than when they were not. Compared to captains, co-pilots showed much higher activation and variability in relative change of heart rate and salivary cortisol between periods of controlling and non-controlling the aircraft. On the other hand, captains showed relatively constant responses comparing aircraft controlling and non-controlling periods, especially in the cruise phase of flight. Salivary cortisol may be a useful, non-invasive method of assess crew workload.

UAS Integration into the NAS: iHTL: DAA Display Evaluation Preliminary Results

NASA Technical Reports Server (NTRS)

Fern, Lisa; Rorie, Conrad; Shively, Jay

2014-01-01

The integrated human-in-the-loop (iHITL) simulation examined the effect of four different Detect-and-Avoid (DAA) display concepts on unmanned aircraft system (UAS) pilots' ability to maintain safe separation. The displays varied in the type and amount of guidance they provided to pilots. The study's background and methodology are discussed, followed by a presentation of the preliminary 'measured response' data (i.e., pilots' end-to-end response time in reacting to traffic alerts on their DAA display). Results indicate that display type had moderate to no affect on pilot measured response times.

Behavioral effects of delayed timeouts from reinforcement.

PubMed

Byrne, Tom; Poling, Alan

2017-03-01

Timeouts are sometimes used in applied settings to reduce target responses, and in some circumstances delays are unavoidably imposed between the onset of a timeout and the offset of the response that produces it. The present study examined the effects of signaled and unsignaled timeouts in rats exposed to concurrent fixed-ratio 1 fixed-ratio 1 schedules of food delivery, where each response on one lever, the location of which changed across conditions, produced both food and a delayed 10-s timeout. Delays of 0 to 38 s were examined. Delayed timeouts often, but not always, substantially reduced the number of responses emitted on the lever that produced timeouts relative to the number emitted on the lever that did not produce timeouts. In general, greater sensitivity was observed to delayed timeouts when they were signaled. These results demonstrate that delayed timeouts, like other delayed consequences, can affect behavior, albeit less strongly than immediate consequences. © 2017 Society for the Experimental Analysis of Behavior.

Neural Correlates of a Default Response in a Delayed Go/No-Go Task

ERIC Educational Resources Information Center

Kalenscher, Tobias; Gunturkun, Onur; Calabrese, Pasquale; Gehlen, Walter; Kalt, Thomas; Diekamp, Bettina

2005-01-01

Working memory, the ability to temporarily retain task-relevant information across a delay, is frequently investigated using delayed matching-to-sample (DMTS) or delayed Go/No-Go tasks (DGNG). In DMTS tasks, sample cues instruct the animal which type of response has to be executed at the end of a delay. Typically, performance decreases with…

Effects of music therapy in the treatment of children with delayed speech development - results of a pilot study.

PubMed

Gross, Wibke; Linden, Ulrike; Ostermann, Thomas

2010-07-21

Language development is one of the most significant processes of early childhood development. Children with delayed speech development are more at risk of acquiring other cognitive, social-emotional, and school-related problems. Music therapy appears to facilitate speech development in children, even within a short period of time. The aim of this pilot study is to explore the effects of music therapy in children with delayed speech development. A total of 18 children aged 3.5 to 6 years with delayed speech development took part in this observational study in which music therapy and no treatment were compared to demonstrate effectiveness. Individual music therapy was provided on an outpatient basis. An ABAB reversal design with alternations between music therapy and no treatment with an interval of approximately eight weeks between the blocks was chosen. Before and after each study period, a speech development test, a non-verbal intelligence test for children, and music therapy assessment scales were used to evaluate the speech development of the children. Compared to the baseline, we found a positive development in the study group after receiving music therapy. Both phonological capacity and the children's understanding of speech increased under treatment, as well as their cognitive structures, action patterns, and level of intelligence. Throughout the study period, developmental age converged with their biological age. Ratings according to the Nordoff-Robbins scales showed clinically significant changes in the children, namely in the areas of client-therapist relationship and communication. This study suggests that music therapy may have a measurable effect on the speech development of children through the treatment's interactions with fundamental aspects of speech development, including the ability to form and maintain relationships and prosodic abilities. Thus, music therapy may provide a basic and supportive therapy for children with delayed speech development. Further studies should be conducted to investigate the mechanisms of these interactions in greater depth. The trial is registered in the German clinical trials register; Trial-No.: DRKS00000343.

Pilot tests of a seat belt gearshift delay on the belt use of commercial fleet drivers : traffic tech.

DOT National Transportation Integrated Search

2010-04-01

Wearing a seat belt has been shown effective in avoiding : or reducing serious injury due to traffic crashes. While : belt use rates in the United States increased from under : 60% in 1994 to 83% in 2008, a substantial number of drivers : still drive...

Developmental and Behavioral Performance of Internationally Adopted Preschoolers: A Pilot Study

ERIC Educational Resources Information Center

Jacobs, Emma; Miller, Laurie C.; Tirella, Linda G.

2010-01-01

Most international adoptees (IA) have rapid catch-up of the delays common at arrival. However, it is not known whether development at arrival predicts later abilities or school readiness. Therefore, we comprehensively evaluated language, fine motor, visual reception (VR), executive function (EF), attention (ATT), and sensory skills (SS) in IA…

ASD, a Psychiatric Disorder, or Both? Psychiatric Diagnoses in Adolescents with High-Functioning ASD

ERIC Educational Resources Information Center

Mazefsky, Carla A.; Oswald, Donald P.; Day, Taylor N.; Eack, Shaun M.; Minshew, Nancy J.; Lainhart, Janet E.

2012-01-01

Varied presentations of emotion dysregulation in autism complicate diagnostic decision making and may lead to inaccurate psychiatric diagnoses or delayed autism diagnosis for high-functioning children. This pilot study aimed to determine the concordance between prior psychiatric diagnoses and the results of an autism-specific psychiatric interview…

Group Therapy for Anxiety in Children with Autism Spectrum Disorder

ERIC Educational Resources Information Center

McConachie, Helen; McLaughlin, Eleanor; Grahame, Victoria; Taylor, Helen; Honey, Emma; Tavernor, Laura; Rodgers, Jacqui; Freeston, Mark; Hemm, Cahley; Steen, Nick; Le Couteur, Ann

2014-01-01

Aim: To investigate the acceptability and feasibility of adapted group therapy for anxiety in children with autism spectrum disorder in a pilot randomised controlled trial. Method: A total of 32 children aged 9-13 years were randomised to immediate or delayed therapy using the "Exploring Feelings" manual (Attwood, 2004). Child and parent…

Evaluation of a LENA-Based Online Intervention for Parents of Young Children

ERIC Educational Resources Information Center

Gilkerson, Jill; Richards, Jeffrey A.; Topping, Keith

2017-01-01

The efficacy of a pilot version of an online parent intervention that combined Language ENvironment Analysis (LENA)-based automated language environment feedback technology with Internet capabilities was investigated. Seventy-two parents of typically developing children aged 9 to 21 months were assigned to immediate- or delayed-treatment (control)…

Characteristics and Predictors of Early and Delayed Responders to Ranibizumab Treatment in Neovascular Age-Related Macular Degeneration: A Retrospective Analysis from the ANCHOR, MARINA, HARBOR, and CATT Trials.

PubMed

Gale, Richard; Korobelnik, Jean-Francois; Yang, Yit; Wong, Tien Y

2016-01-01

This retrospective review examined visual acuity (VA) in subjects with neovascular age-related macular degeneration and identified early and delayed response to ranibizumab. MARINA, ANCHOR, HARBOR, and CATT published data were examined for response with monthly versus individualized dosing and predictors of early versus delayed response. Data were available for 1,631 subjects; 18-29% were early gainers and 15-16% were delayed gainers. Of the early gainers, 72-83% maintained their best-corrected VA gain at month 12 with monthly or individualized dosing. Delayed gainers in HARBOR almost reached the same level of response as early gainers by 12 months who were able to maintain their response. The main predictor of response was baseline VA. There are two distinct types of ranibizumab response; some responded by month 3, while others took up to 12 months. In delayed responders, this may have implications for switching or not switching therapies. © 2016 The Author(s) Published by S. Karger AG, Basel.

A Methodology for Evaluating the Fidelity of Ground-Based Flight Simulators

NASA Technical Reports Server (NTRS)

Zeyada, Y.; Hess, R. A.

1999-01-01

An analytical and experimental investigation was undertaken to model the manner in which pilots perceive and utilize visual, proprioceptive, and vestibular cues in a ground-based flight simulator. The study was part of a larger research effort which has the creation of a methodology for determining flight simulator fidelity requirements as its ultimate goal. The study utilized a closed-loop feedback structure of the pilot/simulator system which included the pilot, the cockpit inceptor, the dynamics of the simulated vehicle and the motion system. With the exception of time delays which accrued in visual scene production in the simulator, visual scene effects were not included in this study. The NASA Ames Vertical Motion Simulator was used in a simple, single-degree of freedom rotorcraft bob-up/down maneuver. Pilot/vehicle analysis and fuzzy-inference identification were employed to study the changes in fidelity which occurred as the characteristics of the motion system were varied over five configurations i The data from three of the five pilots that participated in the experimental study were analyzed in the fuzzy inference identification. Results indicate that both the analytical pilot/vehicle analysis and the fuzzyinference identification can be used to reflect changes in simulator fidelity for the task examined.

A Methodology for Evaluating the Fidelity of Ground-Based Flight Simulators

NASA Technical Reports Server (NTRS)

Zeyada, Y.; Hess, R. A.

1999-01-01

An analytical and experimental investigation was undertaken to model the manner in which pilots perceive and utilize visual, proprioceptive, and vestibular cues in a ground-based flight simulator. The study was part of a larger research effort which has the creation of a methodology for determining flight simulator fidelity requirements as its ultimate goal. The study utilized a closed-loop feedback structure of the pilot/simulator system which included the pilot, the cockpit inceptor, the dynamics of the simulated vehicle and the motion system. With the exception of time delays which accrued in visual scene production in the simulator, visual scene effects were not included in this study. The NASA Ames Vertical Motion Simulator was used in a simple, single-degree of freedom rotorcraft bob-up/down maneuver. Pilot/vehicle analysis and fuzzy-inference identification were employed to study the changes in fidelity which occurred as the characteristics of the motion system were varied over five configurations. The data from three of the five pilots that participated in the experimental study were analyzed in the fuzzy-inference identification. Results indicate that both the analytical pilot/vehicle analysis and the fuzzy-inference identification can be used to reflect changes in simulator fidelity for the task examined.

Analysis of responses of cold pressor tests on pilots and executives

NASA Technical Reports Server (NTRS)

Swaroop, R.

1977-01-01

Statistical analyses were performed to study the relationship between cold pressor test responses and certain medical attributes of a group of 81 pilots and a group of 466 executives. The important results of this study were as follows: There was a significant relationship between a subject's cold pressor test response and his profession (that is, pilot or executive). The executives' diastolic cold pressor test responses were significantly related to their medical conditions, and their families' medical conditions. Significant relationships were observed between executives' diastolic and systolic cold pressor test responses and their history of tranquilizer and cardiac drug use.

Pilot study of pyridostigmine in constipated patients with autonomic neuropathy.

PubMed

Bharucha, Adil E; Low, Phillip A; Camilleri, Michael; Burton, Duane; Gehrking, Tonette L; Zinsmeister, Alan R

2008-08-01

The effects of cholinesterase inhibitors, which increase colonic motility in health, on chronic constipation are unknown. Our aims were to evaluate the efficacy of cholinesterase inhibitors for dysautonomia and chronic constipation and to assess whether acute effects could predict the long term response. In this single-blind study, 10 patients with autonomic neuropathy and constipation were treated with placebo (2 weeks), followed by an escalating dose of pyridostigmine to the maximum tolerated dose (i.e., 180-540 mg daily) for 6 weeks. Symptoms and gastrointestinal transit were assessed at 2 and 8 weeks. The acute effects of neostigmine on colonic transit and motility were also assessed. At baseline, 4, 6, and 3 patients had delayed gastric, small intestinal, and colonic transit respectively. Pyridostigmine was well tolerated in most patients, improved symptoms in 4 patients, and accelerated the geometric center for colonic transit at 24 h by > or =0.7 unit in 3 patients. The effects of i.v. neostigmine on colonic transit and compliance predicted (P < 0.05) the effects of pyridostigmine on colonic transit. Pyridostigmine improves colonic transit and symptoms in some patients with autonomic neuropathy and constipation. The motor response to neostigmine predicted the response to oral pyridostigmine.

Diagnostic delay in psychogenic seizures and the association with anti-seizure medication trials.

PubMed

Kerr, Wesley T; Janio, Emily A; Le, Justine M; Hori, Jessica M; Patel, Akash B; Gallardo, Norma L; Bauirjan, Janar; Chau, Andrea M; D'Ambrosio, Shannon R; Cho, Andrew Y; Engel, Jerome; Cohen, Mark S; Stern, John M

2016-08-01

The average delay from first seizure to diagnosis of psychogenic non-epileptic seizures (PNES) is over 7 years. The reason for this delay is not well understood. We hypothesized that a perceived decrease in seizure frequency after starting an anti-seizure medication (ASM) may contribute to longer delays, but the frequency of such a response has not been well established. Time from onset to diagnosis, medication history and associated seizure frequency was acquired from the medical records of 297 consecutive patients with PNES diagnosed using video-electroencephalographic monitoring. Exponential regression was used to model the effect of medication trials and response on diagnostic delay. Mean diagnostic delay was 8.4 years (min 1 day, max 52 years). The robust average diagnostic delay was 2.8 years (95% CI: 2.2-3.5 years) based on an exponential model as 10 to the mean of log10 delay. Each ASM trial increased the robust average delay exponentially by at least one third of a year (Wald t=3.6, p=0.004). Response to ASM trials did not significantly change diagnostic delay (Wald t=-0.9, p=0.38). Although a response to ASMs was observed commonly in these patients with PNES, the presence of a response was not associated with longer time until definitive diagnosis. Instead, the number of ASMs tried was associated with a longer delay until diagnosis, suggesting that ASM trials were continued despite lack of response. These data support the guideline that patients with seizures should be referred to epilepsy care centers after failure of two medication trials. Copyright © 2016 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Kalman filter estimation of human pilot-model parameters

NASA Technical Reports Server (NTRS)

Schiess, J. R.; Roland, V. R.

1975-01-01

The parameters of a human pilot-model transfer function are estimated by applying the extended Kalman filter to the corresponding retarded differential-difference equations in the time domain. Use of computer-generated data indicates that most of the parameters, including the implicit time delay, may be reasonably estimated in this way. When applied to two sets of experimental data obtained from a closed-loop tracking task performed by a human, the Kalman filter generated diverging residuals for one of the measurement types, apparently because of model assumption errors. Application of a modified adaptive technique was found to overcome the divergence and to produce reasonable estimates of most of the parameters.

Flight deck disturbance management: a simulator study of diagnosis and recovery from breakdowns in pilot-automation coordination.

PubMed

Nikolic, Mark I; Sarter, Nadine B

2007-08-01

To examine operator strategies for diagnosing and recovering from errors and disturbances as well as the impact of automation design and time pressure on these processes. Considerable efforts have been directed at error prevention through training and design. However, because errors cannot be eliminated completely, their detection, diagnosis, and recovery must also be supported. Research has focused almost exclusively on error detection. Little is known about error diagnosis and recovery, especially in the context of event-driven tasks and domains. With a confederate pilot, 12 airline pilots flew a 1-hr simulator scenario that involved three challenging automation-related tasks and events that were likely to produce erroneous actions or assessments. Behavioral data were compared with a canonical path to examine pilots' error and disturbance management strategies. Debriefings were conducted to probe pilots' system knowledge. Pilots seldom followed the canonical path to cope with the scenario events. Detection of a disturbance was often delayed. Diagnostic episodes were rare because of pilots' knowledge gaps and time criticality. In many cases, generic inefficient recovery strategies were observed, and pilots relied on high levels of automation to manage the consequences of an error. Our findings describe and explain the nature and shortcomings of pilots' error management activities. They highlight the need for improved automation training and design to achieve more timely detection, accurate explanation, and effective recovery from errors and disturbances. Our findings can inform the design of tools and techniques that support disturbance management in various complex, event-driven environments.

Evaluation and treatment of low and anxious mood in Chinese-speaking international students studying in Scotland: study protocol of a pilot randomised controlled trial.

PubMed

Zheng, Mengyi; McClay, Carrie-Anne; Wilson, Sarah; Williams, Christopher

2015-01-01

Low mood is a common mental health problem affecting up to 121 million people worldwide and is common in students, particularly international students. Cognitive behavioural therapy (CBT) is known to be effective as a treatment for low mood and anxiety when delivered one to one by an expert practitioner, however this can be expensive and many services have waiting lists and delayed access. A range of additional ways of increasing access to services includes the offer of online courses such as computerised CBT as a possible additional pathway for care. This project aims to test the feasibility of a pilot randomised controlled trial of an online CBT-based life skills course with Chinese-speaking international students experiencing low mood and anxiety. Chinese-speaking international students with symptoms of low mood and/or anxiety will be recruited from the University of Glasgow, Scotland. Participants will be remotely randomised to receive either immediate access (IA) or delayed access (DA) to a guided/supported online CBT-based life skills package, the "Living Life" package (Chinese version). Participants will be randomly assigned to IA or DA to the intervention. The primary end point will be at 3 months when the delayed group will be offered the intervention. Levels of depression, anxiety, social functioning and satisfaction will be assessed. This pilot study will test the trial design, ability to recruit, gather completed questionnaires, test drop-out rates and investigate completion and acceptability of the package. The study aims to reduce uncertainties about the delivery of a future substantive study and will also inform a sample size calculation for that subsequent substantive randomised controlled trial (RCT) which will be carried out to determine the effectiveness of the online package in improving low mood and anxiety in the Chinese-speaking student population. Current Controlled Trials ISRCTN30816908.

An experimental study of the effect of a pilot flame on technically pre-mixed, self-excited combustion instabilities

NASA Astrophysics Data System (ADS)

O'Meara, Bridget C.

Combustion instabilities are a problem facing the gas turbine industry in the operation of lean, pre-mixed combustors. Secondary flames known as "pilot flames" are a common passive control strategy for eliminating combustion instabilities in industrial gas turbines, but the underlying mechanisms responsible for the pilot flame's stabilizing effect are not well understood. This dissertation presents an experimental study of a pilot flame in a single-nozzle, swirl-stabilized, variable length atmospheric combustion test facility and the effect of the pilot on combustion instabilities. A variable length combustor tuned the acoustics of the system to excite instabilities over a range of operating conditions without a pilot flame. The inlet velocity was varied from 25 -- 50 m/s and the equivalence ratio was varied from 0.525 -- 0.65. This range of operating conditions was determined by the operating range of the combustion test facility. Stability at each operating condition and combustor length was characterized by measurements of pressure oscillations in the combustor. The effect of the pilot flame on the magnitude and frequency of combustor stability was then investigated. The mechanisms responsible for the pilot flame effect were studied using chemiluminescence flame images of both stable and unstable flames. Stable flame structure was investigated using stable flame images of CH* chemiluminescence emission. The effect of the pilot on stable flame metrics such as flame length, flame angle, and flame width was investigated. In addition, a new flame metric, flame base distance, was defined to characterize the effect of the pilot flame on stable flame anchoring of the flame base to the centerbody. The effect of the pilot flame on flame base anchoring was investigated because the improved stability with a pilot flame is usually attributed to improved flame anchoring through the recirculation of hot products from the pilot to the main flame base. Chemiluminescence images of unstable flames were used to identify several instability mechanisms and infer how these mechanisms are affected by the pilot flame. Flame images of cases in which the pilot flame did not eliminate the instability were investigated to understand why the pilot flame is not effective in certain cases. The phase of unstable pilot flame oscillations was investigated to determine how the phase of pilot flame oscillations may affect its ability to interfere with instability mechanisms in the main flame. A forced flame response study was conducted to determine the effect of inlet velocity oscillation amplitude on the pilot flame. The flame response was characterized by measurements of velocity oscillations in the injector and chemiluminescence intensity oscillations determined from flame images. As the forcing amplitude increases, the pilot flame's effect on the flame transfer function magnitude becomes weaker. Flame images show that as the forcing amplitude increases, the pilot flame oscillations increase, leading to an ineffective pilot. The results of the flame response portion of this study highlight the effect of instability amplitude on the ability of a pilot flame to eliminate a combustion instability.

Cabergoline in the Treatment of Male Orgasmic Disorder—A Retrospective Pilot Analysis

PubMed Central

Hollander, Adam B.; Pastuszak, Alexander W.; Hsieh, Tung-Chin; Johnson, William G.; Scovell, Jason M.; Mai, Christina K.; Lipshultz, Larry I.

2016-01-01

Introduction Male orgasmic disorder is common, with few treatment options. Cabergoline is a dopamine agonist that acts centrally to normalize serum prolactin that could improve orgasmic dysfunction. Aims To determine whether cabergoline increases the potential for orgasm in men with orgasmic disorder. Methods A retrospective chart review of men treated in a single andrology clinic for delayed orgasm or anorgasmia in a pilot study using cabergoline 0.5 mg twice weekly was performed. Duration of treatment and response were noted. Medical records were examined for other factors including history of prostatectomy and concomitant androgen supplementation. Main Outcome Measures Subjective improvement in orgasmic function resulting from cabergoline treatment. Results Of 131 men treated with cabergoline for orgasmic disorder, 87 (66.4%) reported subjective improvement in orgasm and 44 (33.6%) reported no change in orgasm. Duration of therapy (P = .03) and concomitant testosterone therapy (P = .02) were associated with a significant positive response to cabergoline treatment. No differences were found between injectable and non-injectable testosterone formulations (P = .90), and neither age (P = .90) nor prior prostatectomy (P = .41) influenced the outcome of cabergoline treatment. Serum testosterone levels before (P = .26) and after (P = .81) treatment were not significantly different in responders vs non-responders. Conclusion Cabergoline is a potentially effective and easy-to-administer treatment for male orgasmic disorder, the efficacy of which appears to be independent of patient age or orgasmic disorder etiology. Prospective randomized trials are needed to determine the true role of cabergoline in the treatment of this disorder. PMID:26944776

Pilot and Controller Workload and Situation Awareness with Three Traffic Management Concept

NASA Technical Reports Server (NTRS)

Vu, Kim-Phuong L.; Strybel, Thomas Z.; Kraut, Joshua; Bacon, Paige; Minakata, Katsumi; Battiste, Vernol; Johnson, Walter

2010-01-01

This paper reports on workload and situation awareness of pilots and controllers participating in a human-in-the-loop simulation using three different distributed air-ground traffic management concepts. Eight experimental pilots started the scenario in an en-route phase of flight and were asked to avoid convective weather while performing spacing and merging tasks along with a continuous descent approach (CDA) into Louisville Standiford Airport (SDF). Two controllers managed the sectors through which the pilots flew, with one managing a sector that included the Top of Descent, and the other managing a sector that included the merge point for arrival into SDF. At 3-minute intervals in the scenario, pilots and controllers were probed on their workload or situation awareness. We employed one of three concepts of operation that distributed separation responsibility across human controllers, pilots, and automation to measure changes in operator situation awareness and workload. We found that when pilots were responsible for separation, they had higher levels of awareness, but not necessarily higher levels of workload. When controllers are responsible and actively engaged, they showed higher workload levels compared to pilots and changes in awareness that were dependent on sector characteristics.

PARAMETRIC ANALYSIS OF DELAYED PRIMARY AND CONDITIONED REINFORCERS

PubMed Central

Leon, Yanerys; Borrero, John C.; DeLeon, Iser G.

2016-01-01

We examined the effects of delayed reinforcement on the responding of individuals with intellectual disabilities. Three conditions were evaluated: (a) food reinforcement, (b) token reinforcement with a postsession exchange opportunity, and (c) token reinforcement with a posttrial exchange opportunity. Within each condition, we assessed responding given (a) a no-reinforcement baseline, (b) immediate reinforcement, and (c) delayed reinforcement, in which responses produced a reinforcer after 1 of 6 delays. Results suggest that delayed food produced greater response persistence than did delayed tokens. PMID:27174440

Piloted Ignition to Flaming in Smoldering Fire-Retarded Polyurethane Foam

NASA Technical Reports Server (NTRS)

Putzeys, O.; Fernandez-Pello, A. C.; Urban, D. L.

2007-01-01

Experimental results are presented on the piloted transition from smoldering to flaming in the fire-retarded polyurethane foam Pyrell . The samples are small rectangular blocks with a square cross section, vertically placed in the wall of a vertical wind tunnel. Three of the vertical sample sides are insulated and the fourth side is exposed to an upward oxidizer flow of variable oxygen concentration and to a variable radiant heat flux. The gases emitted from the smoldering reaction pass upwards through a pilot, which consists of a coiled resistance heating wire. In order to compensate for the solid-phase and gas-phase effects of the fire retardants on the piloted transition from smoldering to flaming in Pyrell, it was necessary to assist the process by increasing the power supplied to the smolder igniter and the pilot (compared to that used for non-fire retarded foam). The experiments indicate that the piloted transition from smoldering to flaming occurs when the gaseous mixture at the pilot passes the lean flammability limit. It was found that increasing the oxygen concentration or the external heat flux increases the likelihood of a piloted transition from smoldering to flaming, and generally decreases the time delay to transition. The piloted transition to flaming is observed in oxygen concentrations of 23% and above in both low-density and high-density Pyrell. Comparisons with previous experiments show that the piloted transition from smoldering to flaming is possible under a wider range of external conditions (i.e. lower oxygen concentration) than the spontaneous transition from smoldering to flaming. The results show that the fire retardants in Pyrell are very effective in preventing the piloted transition to flaming in normal air, but Pyrell is susceptible to smoldering and the piloted transition to flaming in oxygen-enriched environments. Therefore, precautions should be taken in the design of applications of Pyrell in oxygen-enriched environments to reduce to the risk of a piloted transition to flaming.

Extended follow-up of anti-HBe-positive patients with chronic hepatitis B retreated with ribavirin and interferon-alpha.

PubMed

Carreño, V; Rico, M A; Pardo, M; Quiroga, J A

2001-11-01

In a pilot study of combination therapy with ribavirin and IFN alpha conducted in anti-HBe-positive individuals with chronic hepatitis B, 21% of patients achieved a sustained ALT normalization and clearance of hepatitis B virus (HBV) DNA as measured by PCR. The present work has assessed whether these sustained responses are lasting long-term. In addition, IFN gamma levels were tested serially in serum as a measure of the immune system activation during treatment. By extending the post-treatment follow-up period 2 years the occurrence of delayed HBV DNA relapses was observed. A low serum level of IFN gamma was detected during and after treatment. IFN gamma demonstrated a multiphasic time-course: the amount of IFN gamma increased in parallel with reductions in HBV DNA but also with ALT flare-ups. In conclusion, the extended follow-up study of anti-HBe-positive patients after combined treatment with ribavirin and IFN alpha has shown that sustained responses are lasting in 17% patients but also that a late onset HBV DNA relapse may occur.

Improved Lunar Lander Handling Qualities Through Control Response Type and Display Enhancements

NASA Technical Reports Server (NTRS)

Mueller, Eric Richard; Bilimoria, Karl D.; Frost, Chad Ritchie

2010-01-01

A piloted simulation that studied the handling qualities for a precision lunar landing task from final approach to touchdown is presented. A vehicle model based on NASA's Altair Lunar Lander was used to explore the design space around the nominal vehicle configuration to determine which combination of factors provides satisfactory pilot-vehicle performance and workload; details of the control and propulsion systems not available for that vehicle were derived from Apollo Lunar Module data. The experiment was conducted on a large motion base simulator. Eight Space Shuttle and Apollo pilot astronauts and three NASA test pilots served as evaluation pilots, providing Cooper-Harper ratings, Task Load Index ratings and qualitative comments. Each pilot flew seven combinations of control response types and three sets of displays, including two varieties of guidance and a nonguided approach. The response types included Rate Command with Attitude Hold, which was used in the original Apollo Moon landings, a Velocity Increment Command response type designed for up-and-away flight, three response types designed specifically for the vertical descent portion of the trajectory, and combinations of these. It was found that Velocity Increment Command significantly improved handling qualities when compared with the baseline Apollo design, receiving predominantly Level 1 ratings. This response type could be flown with or without explicit guidance cues, something that was very difficult with the baseline design, and resulted in approximately equivalent touchdown accuracies and propellant burn as the baseline response type. The response types designed to be used exclusively in the vertical descent portion of the trajectory did not improve handling qualities.

Resistance to Change of Responding Maintained by Unsignaled Delays to Reinforcement: A Response-Bout Analysis

ERIC Educational Resources Information Center

Podlesnik, Christopher A.; Jimenez-Gomez, Corina; Ward, Ryan D.; Shahan, Timothy A.

2006-01-01

Previous experiments have shown that unsignaled delayed reinforcement decreases response rates and resistance to change. However, the effects of different delays to reinforcement on underlying response structure have not been investigated in conjunction with tests of resistance to change. In the present experiment, pigeons responded on a…

Preterm infants' sympathetic arousal and associated behavioral responses to sound stimuli in the neonatal intensive care unit.

PubMed

Salavitabar, Arash; Haidet, Kim Kopenhaver; Adkins, Cherie S; Susman, Elizabeth J; Palmer, Charles; Storm, Hanne

2010-06-01

To evaluate the utility of skin conductance (SC) as a measure of autonomic arousal to sound stimuli in preterm infants. A pilot cross-sectional, correlations study. Eleven preterm infants with a mean gestational age of 31.6 weeks without anomalies or conditions associated with neurodevelopmental delay composed the sample. On days 5-7 of life, the following infant responses were simultaneously recorded in response to naturally occurring sound stimuli in the NICU: real-time measurements of heart rate, respiratory rate, and oxygen saturations; sympathetic-mediated sweating via SC; and behavioral responses using the Newborn Individualized Developmental Care and Assessment Program naturalistic observation. Baseline sound levels (BSL, <55 dBA) and high sound levels (HSL, >65 dBA) were measured to index patterns of response during a nonhandling period preceding care. Mean heart rate during precare was directly associated with higher SC increases to sound stimuli (r[10] = 0.697, P = .017). The SC during HSL was significantly higher than that during BSL (P < .0001). Males demonstrated higher SC increases to sound stimuli than females (P = .030). Changes in SC induced by increases in sound intensity were associated with lower attention responses (r[10] = -0.92, P < .0001) and lower summated behavioral responses (r[10] = -0.59, P = .054). SC provides a noninvasive, sensitive measure of sympathetic arousal that may not be apparent in behavioral cues or states, or determined by standard physiological responses alone.

Alzheimer’s Disease and Its Treatment With a Novel Transdermal Patch Therapy: Survey of Caregiver Experiences

PubMed Central

Pepp, Mike

2012-01-01

Objective: To investigate experiences and perceptions of caregivers of patients with Alzheimer’s disease using transdermal patch therapy. Method: Assessment methods for the pilot study comprised an interview between the caregiver and a moderator, an interview between 1 moderator and 2 caregivers, or a video diary. The subsequent quantitative study involved a 45-minute telephone questionnaire. For both studies, participants were required to be the principal caregiver of a patient with Alzheimer’s disease who had been receiving transdermal patch therapy for at least 3 months. Their responses were grouped into the following 6 themes: interpersonal relationships, impact on caregivers, from symptoms to treatment, help and support for caregivers, daily routine, and caregiver experience with the patch. Results: Overall, 206 caregivers were enrolled from France, Germany, Greece, Spain, and the United States between July 2009 and January 2011 (pilot study: N = 56; quantitative study: N = 150). The studies revealed that caregivers of patients with Alzheimer’s disease experienced emotional and practical impacts, and many felt that they had not received sufficient information from health care providers about Alzheimer’s disease, treatment options, or available support. In the quantitative study, 47% of caregivers who had been caring for the patient prior to diagnosis (61% of total respondents) felt that there had been a delay in seeking medical advice, frequently due to slow onset of symptoms of Alzheimer’s disease. In both studies, patch therapy was considered more convenient and easier to administer than oral treatments. The practical and efficacy advantages of the patch often translated into emotional benefits. Conclusions: With recent data highlighting the importance of early initiation of symptomatic Alzheimer’s disease therapy and the importance of reaching an optimal therapeutic dose, reasons for delay in treatment initiation need to be explored. Information that patients and caregivers receive at the time of diagnosis may aid therapeutic decisions. PMID:23251856

The Impact of Suggestive Maneuver Guidance on UAS Pilots Performing the Detect and Avoid Function

NASA Technical Reports Server (NTRS)

Rorie, Conrad; Fern, Lisa; Shively, Jay

2016-01-01

This presentation discusses the results of a recent UAS Integration into the NAS human-in-the-loop simulation. In the study, 16 active UAS pilots flew a UAS through civil airspace and were tasked with maintaining well clear from other aircraft in the area. Pilots performed the task with four different detect and avoid (DAA) traffic displays, each of which varied in the form of guidance it provided to pilots The present findings focus on how the different displays impacted pilots' measured response to scripted conflicts with their aircraft. Measured response is made up of several components, each of which help inform our understanding of the pilots' role in the overall detect and avoid task.

Team play with a powerful and independent agent: a full-mission simulation study.

PubMed

Sarter, N B; Woods, D D

2000-01-01

One major problem with pilot-automation interaction on modern flight decks is a lack of mode awareness; that is, a lack of knowledge and understanding of the current and future status and behavior of the automation. A lack of mode awareness is not simply a pilot problem; rather, it is a symptom of a coordination breakdown between humans and machines. Recent changes in automation design can therefore be expected to have an impact on the nature of problems related to mode awareness. To examine how new automation properties might affect pilot-automation coordination, we performed a full-mission simulation study on one of the most advanced automated aircraft, the Airbus A-320. The results of this work indicate that mode errors and "automation surprises" still occur on these advanced aircraft. However, there appear to be more opportunities for delayed or missing interventions with undesirable system activities, possibly because of higher system autonomy and coupling.

Scaling-up vaccine production: implementation aspects of a biomass growth observer and controller.

PubMed

Soons, Zita I T A; van den IJssel, Jan; van der Pol, Leo A; van Straten, Gerrit; van Boxtel, Anton J B

2009-04-01

This study considers two aspects of the implementation of a biomass growth observer and specific growth rate controller in scale-up from small- to pilot-scale bioreactors towards a feasible bulk production process for whole-cell vaccine against whooping cough. The first is the calculation of the oxygen uptake rate, the starting point for online monitoring and control of biomass growth, taking into account the dynamics in the gas-phase. Mixing effects and delays are caused by amongst others the headspace and tubing to the analyzer. These gas phase dynamics are modelled using knowledge of the system in order to reconstruct oxygen consumption. The second aspect is to evaluate performance of the monitoring and control system with the required modifications of the oxygen consumption calculation on pilot-scale. In pilot-scale fed-batch cultivation good monitoring and control performance is obtained enabling a doubled concentration of bulk vaccine compared to standard batch production.

Trajectory Orientation: A Technology-Enabled Concept Requiring a Shift in Controller Roles and Responsibilities

NASA Technical Reports Server (NTRS)

Leiden, Ken; Green, Steven

2000-01-01

The development of a decision support tool (DST) for the en-route domain with accurate conflict prediction time horizons of 20 minutes has introduced an interesting problem. A 20 minute time horizon for conflict prediction often results in the predicted conflict occurring one or more sectors downstream from the sector controller who "owns" (i-e., is responsible for the safe separation of aircraft) one or both of the aircraft in the conflict pair. Based on current roles and responsibilities of today's en route controllers, the upstream controller would not resolve this conflict. In most cases, the downstream controller would wait until the conflicting aircraft entered higher sector before resolving the conflict. This results in a delay of several minutes from the time when the conflict was initially predicted. This delay is inefficient from both a controller workload and user's cost of operations perspective. Trajectory orientation, a new concept for facilitating an efficient, conflict-free flight path across several sectors while conforming to metering or miles-in-trail spacing, is proposed as an alternative to today's sector-oriented method. This concept necessitates a fundamental shift in thinking about inter-sector coordination. Instead of operating independently, with the main focus on protecting their internal airspace, controllers would work cooperatively, depending on each other for well-planned, conflict-free flow of aircraft. To support the trajectory orientation concept, a long time horizon (15 to 20 minutes) for conflict prediction and resolution would most likely be a primary requirement. In addition, new tools, such as controller-pilot data link will be identified to determine their necessity and applicability for trajectory orientation. Finally, with significant controller participation from selected Air Route Traffic Control Centers, potential shifts in R-side/D-side roles and responsibilities as well as the creation of a new controller position for multi-sector planning will be examined to determine the most viable solutions.

Greenhouse gas emissions during composting of dairy manure: Delaying pile mixing does not reduce overall emissions

USDA-ARS?s Scientific Manuscript database

The effect of the timing of pile mixing on greenhouse gas (GHG) emissions during dairy manure composting was determined using large flux chambers designed to completely cover replicate pilot-scale compost piles. GHG emissions from compost piles that were mixed at 2, 3, 4, or 5 weeks after initial c...

Facilitated Playgroups to Promote Speech and Language Skills of Young Children with Communication Delays: A Pilot Study

ERIC Educational Resources Information Center

Green, Katherine B.; Towson, Jacqueline A.; Head, Cynthia; Janowski, Brittany; Smith, Laura

2018-01-01

Family-centered practices that build caregiver capacity are a central focus of early intervention services for young children with disabilities. The purpose of this study was to evaluate the feasibility of adapting the "Parents Interacting with Infants" (PIWI) facilitated playgroup model to target effective communication strategies for…

Computer-aided testing of pilot response to critical in-flight events

NASA Technical Reports Server (NTRS)

Giffin, W. C.; Rockwell, T. H.

1984-01-01

This research on pilot response to critical in-flight events employs a unique methodology including an interactive computer-aided scenario-testing system. Navigation displays, instrument-panel displays, and assorted textual material are presented on a touch-sensitive CRT screen. Problem diagnosis scenarios, destination-diversion scenarios and combined destination/diagnostic tests are available. A complete time history of all data inquiries and responses is maintained. Sample results of diagnosis scenarios obtained from testing 38 licensed pilots are presented and discussed.

The Impact of Integrated Maneuver Guidance Information on UAS Pilots Performing the Detect and Avoid Task

NASA Technical Reports Server (NTRS)

Rorie, Conrad; Fern, Lisa

2015-01-01

The integrated human-in-the-loop (iHITL) simulation examined the effect of four different Detect-and-Avoid (DAA) display concepts on unmanned aircraft system (UAS) pilots' ability to maintain safe separation. The displays varied in the type and amount of guidance they provided to pilots. The study's background and methodology are discussed, followed by the 'measured response' data (i.e., pilots' end-to-end response time in reacting to traffic alerts on their DAA display). Results indicate that display type had a significant impact on how long pilot's spent interacting with the interface (i.e., edit times).

Reaction time in pilots during intervals of high sustained g.

PubMed

Truszczynski, Olaf; Lewkowicz, Rafal; Wojtkowiak, Mieczyslaw; Biernacki, Marcin P

2014-11-01

An important problem for pilots is visual disturbances occurring under +Gz acceleration. Assessment of the degree of intensification of these disturbances is generally accepted as the acceleration tolerance level (ATL) criterion determined in human centrifuges. The aim of this research was to evaluate the visual-motor responses of pilots during rapidly increasing acceleration contained in cyclic intervals of +6 Gz to the maximum ATL. The study involved 40 male pilots ages 32-41 yr. The task was a quick and faultless response to the light stimuli presented on a light bar during exposure to acceleration until reaching the ATL. Simple response time (SRT) measurements were performed using a visual-motor analysis system throughout the exposures which allowed assessment of a pilot's ATL. There were 29 pilots who tolerated the initial phase of interval acceleration and achieved +6 Gz, completing the test at ATL. Relative to the control measurements, the obtained results indicate a significant effect of the applied acceleration on response time. SRT during +6 Gz exposure was not significantly longer compared with the reaction time between each of the intervals. SRT and erroneous reactions indicated no statistically significant differences between the "lower" and "higher" ATL groups. SRT measurements over the +6-Gz exposure intervals did not vary between "lower" and "higher" ATL groups and, therefore, are not useful in predicting pilot performance. The gradual exposure to the maximum value of +6 Gz with exposure to the first three intervals on the +6-Gz plateau effectively differentiated pilots.

Pilot dynamics for instrument approach tasks: Full panel multiloop and flight director operations

NASA Technical Reports Server (NTRS)

Weir, D. H.; Mcruer, D. T.

1972-01-01

Measurements and interpretations of single and mutiloop pilot response properties during simulated instrument approach are presented. Pilot subjects flew Category 2-like ILS approaches in a fixed base DC-8 simulaton. A conventional instrument panel and controls were used, with simulated vertical gust and glide slope beam bend forcing functions. Reduced and interpreted pilot describing functions and remmant are given for pitch attitude, flight director, and multiloop (longitudinal) control tasks. The response data are correlated with simultaneously recorded eye scanning statistics, previously reported in NASA CR-1535. The resulting combined response and scanning data and their interpretations provide a basis for validating and extending the theory of manual control displays.

Classical conditioning for preserving the effects of short melatonin treatment in children with delayed sleep: a pilot study.

PubMed

van Maanen, Annette; Meijer, Anne Marie; Smits, Marcel G; Oort, Frans J

2017-01-01

Melatonin treatment is effective in treating sleep onset problems in children with delayed melatonin onset, but effects usually disappear when treatment is discontinued. In this pilot study, we investigated whether classical conditioning might help in preserving treatment effects of melatonin in children with sleep onset problems, with and without comorbid attention deficit hyperactivity disorder (ADHD) or autism. After a baseline week, 16 children (mean age: 9.92 years, 31% ADHD/autism) received melatonin treatment for 3 weeks and then gradually discontinued the treatment. Classical conditioning was applied by having children drink organic lemonade while taking melatonin and by using a dim red light lamp that was turned on when children went to bed. Results were compared with a group of 41 children (mean age: 9.43 years, 34% ADHD/autism) who received melatonin without classical conditioning. Melatonin treatment was effective in advancing dim light melatonin onset and reducing sleep onset problems, and positive effects were found on health and behavior problems. After stopping melatonin, sleep returned to baseline levels. We found that for children without comorbidity in the experimental group, sleep latency and sleep start delayed less in the stop week, which suggests an effect of classical conditioning. However, classical conditioning seems counterproductive in children with ADHD or autism. Further research is needed to establish these results and to examine other ways to preserve melatonin treatment effects, for example, by applying morning light.

Parenting Predictors of Delay Inhibition in Socioeconomically Disadvantaged Preschoolers

PubMed Central

Merz, Emily C.; Landry, Susan H.; Zucker, Tricia A.; Barnes, Marcia A.; Assel, Michael; Taylor, Heather B.; Lonigan, Christopher J.; Phillips, Beth M.; Clancy-Menchetti, Jeanine; Eisenberg, Nancy; Spinrad, Tracy L.; Valiente, Carlos; de Villiers, Jill; Consortium, the School Readiness Research

2016-01-01

This study examined longitudinal associations between specific parenting factors and delay inhibition in socioeconomically disadvantaged preschoolers. At Time 1, parents and 2- to 4-year-old children (mean age = 3.21 years; N = 247) participated in a videotaped parent-child free play session, and children completed delay inhibition tasks (gift delay-wrap, gift delay-bow, and snack delay tasks). Three months later, at Time 2, children completed the same set of tasks. Parental responsiveness was coded from the parent-child free play sessions, and parental directive language was coded from transcripts of a subset of 127 of these sessions. Structural equation modeling was used, and covariates included age, gender, language skills, parental education, and Time 1 delay inhibition. Results indicated that in separate models, Time 1 parental directive language was significantly negatively associated with Time 2 delay inhibition, and Time 1 parental responsiveness was significantly positively associated with Time 2 delay inhibition. When these parenting factors were entered simultaneously, Time 1 parental directive language significantly predicted Time 2 delay inhibition whereas Time 1 parental responsiveness was no longer significant. Findings suggest that parental language that modulates the amount of autonomy allotted the child may be an important predictor of early delay inhibition skills. PMID:27833461

Human Factors of Remotely Piloted Aircraft

NASA Technical Reports Server (NTRS)

Hobbs, Alan Neville

2014-01-01

The civilian use of remotely piloted, or unmanned aircraft is expected to increase rapidly in the years ahead. Despite being referred to as unmanned some of the major challenges confronting this emerging sector relate to human factors. As unmanned aircraft systems (UAS) are introduced into civil airspace, a failure to adequately consider human factors could result in preventable accidents that may not only result in loss of life, but may also undermine public confidence in remotely piloted operations. Key issues include pilot situational awareness, collision avoidance in the absence of an out-the-window view, the effects of time delays in communication and control systems, control handovers, the challenges of very long duration flights, and the design of the control station. Problems have included poor physical layout of controls, non-intuitive automation interfaces, an over-reliance on text displays, and complicated sequences of menu selection to perform routine tasks. Some of the interface problems may have been prevented had an existing regulation or cockpit design principle been applied. In other cases, the design problems may indicate a lack of suitable guidance material.

Reaction time in pilots at sustained acceleration of +4.5 G(z).

PubMed

Truszczynski, Olaf; Wojtkowiak, Mieczyslaw; Lewkowicz, Rafal; Biernacki, Marcin P; Kowalczuk, Krzysztof

2013-08-01

Pilots flying at very high speed are exposed to the effects of prolonged accelerations while changing their flight path. The aim of this research was to assess the impact of sustained accelerations on the visual-motor response times of pilots and the acceleration tolerance level (ATL) as a measure of pilots' endurance to applied +G(z). The study involved 18 young pilots, 23-25 yr of age. The subjects' task was to quickly and accurately respond to the light stimuli presented on a light bar during exposure to acceleration at +4.5 G(z) and until reaching the ATL. Simple response time (SRT) measurements were performed using a visual-motor analysis system throughout the exposures, which allowed the assessment of a pilot's ATL. The pilots' ATL ranged from 270 to 366 s (Mean = 317.7 +/- 26.15 SD). The analysis of the SRT indicated a significant effect of duration of acceleration on the visual response time. The results of the post hoc comparisons showed that SRT increased with longer durations of the same level of +G(z) load and then decreased, reaching values similar to the controls. Exposure to prolonged acceleration of +4.5 G(z) significantly increases SRT. There was no statistically significant difference in SRT between the pilots with "short" and "long" time exposures. A pilot's SRT during a prolonged +4.5 G(z) exposure could be a reliable indicator of pilot G performance in the fast jet. Deterioration of SRT may be used to predict imminent +G(z) endurance limits between pilots with widely varying endurance abilities.

Divergence compensation for hardware-in-the-loop simulation of stiffness-varying discrete contact in space

NASA Astrophysics Data System (ADS)

Qi, Chenkun; Zhao, Xianchao; Gao, Feng; Ren, Anye; Hu, Yan

2016-11-01

The hardware-in-the-loop (HIL) contact simulation for flying objects in space is challenging due to the divergence caused by the time delay. In this study, a divergence compensation approach is proposed for the stiffness-varying discrete contact. The dynamic response delay of the motion simulator and the force measurement delay are considered. For the force measurement delay, a phase lead based force compensation approach is used. For the dynamic response delay of the motion simulator, a response error based force compensation approach is used, where the compensation force is obtained from the real-time identified contact stiffness and real-time measured position response error. The dynamic response model of the motion simulator is not required. The simulations and experiments show that the simulation divergence can be compensated effectively and satisfactorily by using the proposed approach.

Motion Cueing Algorithm Development: Piloted Performance Testing of the Cueing Algorithms

NASA Technical Reports Server (NTRS)

Houck, Jacob A. (Technical Monitor); Telban, Robert J.; Cardullo, Frank M.; Kelly, Lon C.

2005-01-01

The relative effectiveness in simulating aircraft maneuvers with both current and newly developed motion cueing algorithms was assessed with an eleven-subject piloted performance evaluation conducted on the NASA Langley Visual Motion Simulator (VMS). In addition to the current NASA adaptive algorithm, two new cueing algorithms were evaluated: the optimal algorithm and the nonlinear algorithm. The test maneuvers included a straight-in approach with a rotating wind vector, an offset approach with severe turbulence and an on/off lateral gust that occurs as the aircraft approaches the runway threshold, and a takeoff both with and without engine failure after liftoff. The maneuvers were executed with each cueing algorithm with added visual display delay conditions ranging from zero to 200 msec. Two methods, the quasi-objective NASA Task Load Index (TLX), and power spectral density analysis of pilot control, were used to assess pilot workload. Piloted performance parameters for the approach maneuvers, the vertical velocity upon touchdown and the runway touchdown position, were also analyzed but did not show any noticeable difference among the cueing algorithms. TLX analysis reveals, in most cases, less workload and variation among pilots with the nonlinear algorithm. Control input analysis shows pilot-induced oscillations on a straight-in approach were less prevalent compared to the optimal algorithm. The augmented turbulence cues increased workload on an offset approach that the pilots deemed more realistic compared to the NASA adaptive algorithm. The takeoff with engine failure showed the least roll activity for the nonlinear algorithm, with the least rudder pedal activity for the optimal algorithm.

Do Right- and Left-Handed Monkeys Differ on Cognitive Measures?

NASA Technical Reports Server (NTRS)

Hopkins, William D.; Washburn, David A.

1994-01-01

Twelve left- and 14 right-handed monkeys were compared on 6 measures of cognitive performance (2 maze-solving tasks, matching-to-sample, delayed matching-to-sample, delayed response using spatial cues, and delayed response using form cues). The dependent variable was trials-to-training criterion for each of the 6 tasks. Significant differences were found between left- and right-handed monkeys on the 2 versions of the delayed response task. Right-handed monkeys reached criterion significantly faster on the form cue version of the task, whereas left-handed monkeys reached criterion significantly faster on delayed response for spatial position (p less than .05). The results suggest that sensitive hand preference measures of laterality can reveal differences in cognitive performance, which in turn may reflect underlying laterality in functional organization of the nervous system.

The Effects of Aviation Weather Information Systems on General Aviation Weather Information Systems on General Pilots' Workload

NASA Technical Reports Server (NTRS)

Scerbo, Mark; Coyne, Joseph; Burt, Jennifer L. (Technical Monitor)

2002-01-01

My work at NASA Langley has focused around Aviation Weather Information CAWING displays. The majority of my time at LYRIC has been spent on the Workload and Relative Position (WaRP) Study. The goal of this project is to determine how an AWIN display at various positions within the cockpit affects pilot performance and workload. The project is being conducted in Languages Cessna 206H research aircraft. During the past year the design of the experiment was finalized and approved. Despite facing several delays the data collection was completed in early February. Alter the completion of the data collection an extensive data entry task began. This required recording air speed, altitude, course heading, bank angle, and vertical speed information from videos of the primary flight displays. This data was then used to determine root mean square error (RMSE) for each experimental condition. In addition to the performance data (RMSE) taken from flight path deviation, the study also collected data on pilot;s accuracy in reporting weather information, and a subjective rating of workload from the pilot. The data for this experiment is currently being analyzed. Overall the current experiment should help to determine potential costs and benefits associated with AWIN displays. The data will be used to determine if a private pilot can safely fly a general aviation aircraft while operating a weather display. Clearly a display that adds to the pilot#s already heavy workload represents a potential problem. The study will compare the use of an AWIN display to conventional means of acquiring weather data. The placement of the display within the cockpit (i.e., either on the yoke, kneeboard, or panel) will be also compared in terms of workload, performance, and pilot preference.

Flight Deck Data Link Displays: An Evaluation of Textual and Graphical Implementations

NASA Technical Reports Server (NTRS)

McGann, Alison; Lozito, Sandy; Corker, Kevin; Ashford, Rose (Technical Monitor)

2001-01-01

In Experiment 1, 16 pilots participated in a part-task simulation study that evaluated pilot data link communication for short and long message types and for two textual formats. No differences were found between the two textual formats when evaluating data link transaction times and pilot performance on a secondary task. Pilots initiated flight changes more quickly with the T-Scan format, where location of clearance information roughly corresponded to the cockpit instrument layout. Longer messages were less problematic than two short messages sent in close succession as pilots required more verbal clarification for closely spaced messages. 24 pilots participated in a second experiment that evaluated pilot communication performance for textual data link, two implementations of graphical data link, and a combined graphical and textual information modality. The two modalities incorporating text resulted in significantly faster transaction times and better performance on the secondary task than the two graphical-only implementations. The interval between messages was also more systematically varied in Experiment 2, and a short interval between messages significantly increased the access time for the second message. This delay in access was long enough to increase significantly the total transaction time of the second message, and this effect was exaggerated for the graphical-only implementations. Time to view the message before acknowledgement and time to initiate flight changes were not affected by the interval manipulation, This suggests that pilots adopt a sequential message handling strategy, and presenting messages closely in succession may present operational problems in a data link Air Traffic Control (ATC) environment. The results of this study also indicate that the perceived importance of message content is currently a crucial element in pilot data link communication.

General Aviation Pilots' Perceived Usage and Valuation of Aviation Weather Information Sources

NASA Technical Reports Server (NTRS)

Latorella, Kara; Lane, Suzanne; Garland, Daniel

2002-01-01

Aviation suffers many accidents due to the lack of good weather information in flight. Existing aviation weather information is difficult to obtain when it is most needed and is not well formatted for in-flight use. Because it is generally presented aurally, aviation weather information is difficult to integrate with spatial flight information and retain for reference. Efforts, by NASA's Aviation Weather Information (AWIN) team and others, to improve weather information accessibility, usability and decision aiding will enhance General Aviation (GA) pilots' weather situation awareness and decision-making and therefore should improve the safety of GA flight. Consideration of pilots' economic concerns will ensure that in-flight weather information systems are financially accessible to GA pilots as well. The purpose of this survey was to describe how aviation operator communities gather and use weather information as well as how weather related decisions are made between flight crews and supporting personnel. Pilots of small GA aircraft experience the most weather-related accidents as well as the most fatal weather related accident. For this reason, the survey design and advertisement focused on encouraging participation from GA pilots. Perhaps as a result of this emphasis, most responses, 97 responses or 85% of the entire response set, were from GA pilots, This paper presents only analysis of these GA pilots' responses. The insights provided by this survey regarding GA pilots' perceived value and usage of current aviation weather information. services, and products provide a basis for technological approaches to improve GA safety. Results of this survey are discussed in the context of survey limitations and prior work, and serve as the foundation for a model of weather information value, guidance for the design of in-flight weather information systems, and definition of further research toward their development.

Comparison of Postural Responses to Galvanic Vestibular Stimulation between Pilots and the General Populace

PubMed Central

Yang, Yang; Pu, Fang; Lv, Xiaoning; Li, Shuyu; Li, Jing; Li, Deyu; Li, Minggao

2015-01-01

Galvanic vestibular stimulation (GVS) can be used to study the body's response to vestibular stimuli. This study aimed to investigate whether postural responses to GVS were different between pilots and the general populace. Bilateral bipolar GVS was applied with a constant-current profile to 12 pilots and 12 control subjects via two electrodes placed over the mastoid processes. Both GVS threshold and the center of pressure's trajectory (COP's trajectory) were measured. Position variability of COP during spontaneous body sway and peak displacement of COP during GVS-induced body sway were calculated in the medial-lateral direction. Spontaneous body sway was slight for all subjects, and there was no significant difference in the value of COP position variability between the pilots and controls. Both the GVS threshold and magnitude of GVS-induced body deviation were similar for different GVS polarities. GVS thresholds were similar between the two groups, but the magnitude of GVS-induced body deviation in the controls was significantly larger than that in the pilots. The pilots showed less GVS-induced body deviation, meaning that pilots may have a stronger ability to suppress vestibular illusions. PMID:25632395

The effects of time delays on a telepathology user interface.

PubMed Central

Carr, D.; Hasegawa, H.; Lemmon, D.; Plaisant, C.

1992-01-01

Telepathology enables a pathologist to examine physically distant tissue samples by microscope operation over a communication link. Communication links can impose time delays which cause difficulties in controlling the remote device. Such difficulties were found in a microscope teleoperation system. Since the user interface is critical to pathologist's acceptance of telepathology, we redesigned the user interface for this system, built two different versions (a keypad whose movement commands operated by specifying a start command followed by a stop command and a trackball interface whose movement commands were incremental and directly proportional to the rotation of the trackball). We then conducted a pilot study to determine the effect of time delays on the new user interfaces. In our experiment, the keypad was the faster interface when the time delay is short. There was no evidence to favor either the keypad or trackball when the time delay was longer. Inexperienced participants benefitted by allowing them to move long distances over the microscope slide by dragging the field-of-view indicator on the touchscreen control panel. The experiment suggests that changes could be made to the trackball interface which would improve its performance. PMID:1482878

An investigation into pilot and system response to critical in-flight events, volume 2

NASA Technical Reports Server (NTRS)

Rockwell, T. H.; Giffin, W. C.

1981-01-01

Critical in-flight event is studied using mission simulation and written tests of pilot responses. Materials and procedures used in knowledge tests, written tests, and mission simulations are included

Caudate responses to reward anticipation associated with delay discounting behavior in healthy youth

PubMed Central

Benningfield, Margaret M.; Blackford, Jennifer U.; Ellsworth, Melissa E.; Samanez-Larkin, Gregory R.; Martin, Peter R.; Cowan, Ronald L.; Zald, David H.

2014-01-01

Background Choices requiring delay of gratification made during adolescence can have significant impact on life trajectory. Willingness to delay gratification can be measured using delay discounting tasks that require a choice between a smaller immediate reward and a larger delayed reward. Individual differences in the subjective value of delayed rewards are associated with risk for development of psychopathology including substance abuse. The neurobiological underpinnings related to these individual differences early in life are not fully understood. Using functional magnetic resonance imaging (fMRI), we tested the hypothesis that individual differences in delay discounting behavior in healthy youth are related to differences in responsiveness to potential reward. Method Nineteen 10 to 14 year-olds performed a monetary incentive delay task to assess neural sensitivity to potential reward and a questionnaire to measure discounting of future monetary rewards. Results Left ventromedial caudate activation during anticipation of potential reward was negatively correlated with delay discounting behavior. There were no regions where brain responses during notification of reward outcome were associated with discounting behavior. Conclusions Brain activation during anticipation of potential reward may serve as a marker for individual differences in ability or willingness to delay gratification in healthy youth. PMID:24309299

The Use of Message Framing to Promote Sexual Risk Reduction in Young Adolescents: A Pilot Exploratory Study

ERIC Educational Resources Information Center

Camenga, Deepa R.; Hieftje, Kimberly D.; Fiellin, Lynn E.; Edelman, E. Jennifer; Rosenthal, Marjorie S.; Duncan, Lindsay R.

2014-01-01

Few studies have explored the application of message framing to promote health behaviors in adolescents. In this exploratory study, we examined young adolescents' selection of gain- versus loss-framed images and messages when designing an HIV-prevention intervention to promote delayed sexual initiation. Twenty-six adolescents (aged 10-14 years)…

The combined effect of pressure and oxygen concentration on piloted ignition of a solid combustible

Treesearch

Sara McAllister; Carlos Fernandez-Pello; David Urban; Gary Ruff

2010-01-01

There are a number of situations when fires may occur at low pressures and oxygen concentrations that are different than standard atmospheric conditions, such as in buildings at high elevation, airplanes, and spacecraft. The flammability of materials may be affected by these environmental conditions. Since ignition delay is a measure of material flammability and...

Navigating Bioethical Waters: Two Pilot Projects in Problem-Based Learning for Future Bioscience and Biotechnology Professionals.

PubMed

Berry, Roberta M; Levine, Aaron D; Kirkman, Robert; Blake, Laura Palucki; Drake, Matthew

2016-12-01

We believe that the professional responsibility of bioscience and biotechnology professionals includes a social responsibility to contribute to the resolution of ethically fraught policy problems generated by their work. It follows that educators have a professional responsibility to prepare future professionals to discharge this responsibility. This essay discusses two pilot projects in ethics pedagogy focused on particularly challenging policy problems, which we call "fractious problems". The projects aimed to advance future professionals' acquisition of "fractious problem navigational" skills, a set of skills designed to enable broad and deep understanding of fractious problems and the design of good policy resolutions for them. A secondary objective was to enhance future professionals' motivation to apply these skills to help their communities resolve these problems. The projects employed "problem based learning" courses to advance these learning objectives. A new assessment instrument, "Skills for Science/Engineering Ethics Test" (SkillSET), was designed and administered to measure the success of the courses in doing so. This essay first discusses the rationale for the pilot projects, and then describes the design of the pilot courses and presents the results of our assessment using SkillSET in the first pilot project and the revised SkillSET 2.0 in the second pilot project. The essay concludes with discussion of observations and results.

Effect of deferasirox + erythropoietin vs erythropoietin on erythroid response in Low/Int-1-risk MDS patients: Results of the phase II KALLISTO trial.

PubMed

Gattermann, Norbert; Coll, Rosa; Jacobasch, Lutz; Allameddine, Allameddine; Azmon, Amin; DeBonnett, Laurie; Bruederle, Andreas; Jin, Jie

2018-05-19

Erythropoiesis-stimulating agents (ESAs) remain first-choice to treat symptomatic anemia and delay transfusion dependence in most patients with lower-risk myelodysplastic syndromes (MDS) without del(5q). Deferasirox increased erythroid responses in some lower-risk MDS patients in clinical trials, and adding low-dose deferasirox to ESA treatment may further improve erythroid response. KALLISTO (NCT01868477) was a randomized, open-label, multicenter, phase II study. Lower-risk MDS patients received deferasirox at 10 mg/kg/day (dispersible tablets) or 7 mg/kg/day (film-coated tablets) plus erythropoietin (n=11), or erythropoietin alone (n=12) for 24 weeks. The primary endpoint was the between-group difference in erythroid response within 12 weeks. Erythroid response occurred in 27.3% of patients receiving deferasirox plus erythropoietin versus 41.7% of patients receiving erythropoietin alone within 12 weeks (difference 14.4%; 95% CI -24.0, 48.16). Within 24 weeks, the hematologic response rate was 27.3% with deferasirox plus erythropoietin versus 50% with erythropoietin alone, and hematologic improvement rates were 45.5% versus 100%. Deferasirox plus erythropoietin was generally well tolerated. In this small pilot study, combining low-dose deferasirox with erythropoietin did not improve erythroid response. It remains of interest to investigate early chelation approaches with even lower deferasirox doses plus erythropoietin in lower-risk MDS patients before the onset of transfusion dependence. Deferasirox, erythropoietin, myelodysplastic syndromes, anemia, therapy, hematologic response, erythroid response, clinical trials This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

[Information value of "additional tasks" method to evaluate pilot's work load].

PubMed

Gorbunov, V V

2005-01-01

"Additional task" method was used to evaluate pilot's work load in prolonged flight. Calculated through durations of latent periods of motor responses, quantitative criterion of work load is more informative for objective evaluation of pilot's involvement in his piloting functions rather than of other registered parameters.

Magnetoencephalographic Imaging of Auditory and Somatosensory Cortical Responses in Children with Autism and Sensory Processing Dysfunction

PubMed Central

Demopoulos, Carly; Yu, Nina; Tripp, Jennifer; Mota, Nayara; Brandes-Aitken, Anne N.; Desai, Shivani S.; Hill, Susanna S.; Antovich, Ashley D.; Harris, Julia; Honma, Susanne; Mizuiri, Danielle; Nagarajan, Srikantan S.; Marco, Elysa J.

2017-01-01

This study compared magnetoencephalographic (MEG) imaging-derived indices of auditory and somatosensory cortical processing in children aged 8–12 years with autism spectrum disorder (ASD; N = 18), those with sensory processing dysfunction (SPD; N = 13) who do not meet ASD criteria, and typically developing control (TDC; N = 19) participants. The magnitude of responses to both auditory and tactile stimulation was comparable across all three groups; however, the M200 latency response from the left auditory cortex was significantly delayed in the ASD group relative to both the TDC and SPD groups, whereas the somatosensory response of the ASD group was only delayed relative to TDC participants. The SPD group did not significantly differ from either group in terms of somatosensory latency, suggesting that participants with SPD may have an intermediate phenotype between ASD and TDC with regard to somatosensory processing. For the ASD group, correlation analyses indicated that the left M200 latency delay was significantly associated with performance on the WISC-IV Verbal Comprehension Index as well as the DSTP Acoustic-Linguistic index. Further, these cortical auditory response delays were not associated with somatosensory cortical response delays or cognitive processing speed in the ASD group, suggesting that auditory delays in ASD are domain specific rather than associated with generalized processing delays. The specificity of these auditory delays to the ASD group, in addition to their correlation with verbal abilities, suggests that auditory sensory dysfunction may be implicated in communication symptoms in ASD, motivating further research aimed at understanding the impact of sensory dysfunction on the developing brain. PMID:28603492

A novel perspective to calibrate temporal delays in cerebrovascular reactivity using hypercapnic and hyperoxic respiratory challenges.

PubMed

Champagne, Allen A; Bhogal, Alex A; Coverdale, Nicole S; Mark, Clarisse I; Cook, Douglas J

2017-12-05

Redistribution of blood flow across different brain regions, arising from the vasoactive nature of hypercapnia, can introduce errors when examining cerebrovascular reactivity (CVR) response delays. In this study, we propose a novel analysis method to characterize hemodynamic delays in the blood oxygen level dependent (BOLD) response to hypercapnia, and hyperoxia, as a way to provide insight into transient differences in vascular reactivity between cortical regions, and across tissue depths. A pseudo-continuous arterial spin labeling sequence was used to acquire BOLD and cerebral blood flow simultaneously in 19 healthy adults (12 F; 20 ± 2 years) during boxcar CO 2 and O 2 gas inhalation paradigms. Despite showing distinct differences in hypercapnia-induced response delay times (P < 0.05; Bonferroni corrected), grey matter regions showed homogenous hemodynamic latencies (P > 0.05) once calibrated for bolus arrival time derived using non-vasoactive hyperoxic gas challenges. Longer hypercapnic temporal delays were observed as the depth of the white matter tissue increased, although no significant differences in response lag were found during hyperoxia across tissue depth, or between grey and white matter. Furthermore, calibration of hypercapnic delays using hyperoxia revealed that deeper white matter layers may be more prone to dynamic redistribution of blood flow, which introduces response lag times ranging between 1 and 3 s in healthy subjects. These findings suggest that the combination of hypercapnic and hyperoxic gas-inhalation MRI can be used to distinguish between differences in CVR that arise as a result of delayed stimulus arrival time (due to the local architecture of the cerebrovasculature), or preferential blood flow distribution. Calibrated response delays to hypercapnia provide important insights into cerebrovascular physiology, and may be used to correct response delays associated with vascular impairment. Copyright © 2017. Published by Elsevier Inc.

Downhole delay assembly for blasting with series delay

DOEpatents

Ricketts, Thomas E.

1982-01-01

A downhole delay assembly is provided which can be placed into a blasthole for initiation of explosive in the blasthole. The downhole delay assembly includes at least two detonating time delay devices in series in order to effect a time delay of longer than about 200 milliseconds in a round of explosions. The downhole delay assembly provides a protective housing to prevent detonation of explosive in the blasthole in response to the detonation of the first detonating time delay device. There is further provided a connection between the first and second time delay devices. The connection is responsive to the detonation of the first detonating time delay device and initiates the second detonating time delay device. A plurality of such downhole delay assemblies are placed downhole in unfragmented formation and are initiated simultaneously for providing a round of explosive expansions. The explosive expansions can be used to form an in situ oil shale retort containing a fragmented permeable mass of formation particles.

Transport delay compensation for computer-generated imagery systems

NASA Technical Reports Server (NTRS)

Mcfarland, Richard E.

1988-01-01

In the problem of pure transport delay in a low-pass system, a trade-off exists with respect to performance within and beyond a frequency bandwidth. When activity beyond the band is attenuated because of other considerations, this trade-off may be used to improve the performance within the band. Specifically, transport delay in computer-generated imagery systems is reduced to a manageable problem by recognizing frequency limits in vehicle activity and manual-control capacity. Based on these limits, a compensation algorithm has been developed for use in aircraft simulation at NASA Ames Research Center. For direct measurement of transport delays, a beam-splitter experiment is presented that accounts for the complete flight simulation environment. Values determined by this experiment are appropriate for use in the compensation algorithm. The algorithm extends the bandwidth of high-frequency flight simulation to well beyond that of normal pilot inputs. Within this bandwidth, the visual scene presentation manifests negligible gain distortion and phase lag. After a year of utilization, two minor exceptions to universal simulation applicability have been identified and subsequently resolved.

Effects of music therapy in the treatment of children with delayed speech development - results of a pilot study

PubMed Central

2010-01-01

Background Language development is one of the most significant processes of early childhood development. Children with delayed speech development are more at risk of acquiring other cognitive, social-emotional, and school-related problems. Music therapy appears to facilitate speech development in children, even within a short period of time. The aim of this pilot study is to explore the effects of music therapy in children with delayed speech development. Methods A total of 18 children aged 3.5 to 6 years with delayed speech development took part in this observational study in which music therapy and no treatment were compared to demonstrate effectiveness. Individual music therapy was provided on an outpatient basis. An ABAB reversal design with alternations between music therapy and no treatment with an interval of approximately eight weeks between the blocks was chosen. Before and after each study period, a speech development test, a non-verbal intelligence test for children, and music therapy assessment scales were used to evaluate the speech development of the children. Results Compared to the baseline, we found a positive development in the study group after receiving music therapy. Both phonological capacity and the children's understanding of speech increased under treatment, as well as their cognitive structures, action patterns, and level of intelligence. Throughout the study period, developmental age converged with their biological age. Ratings according to the Nordoff-Robbins scales showed clinically significant changes in the children, namely in the areas of client-therapist relationship and communication. Conclusions This study suggests that music therapy may have a measurable effect on the speech development of children through the treatment's interactions with fundamental aspects of speech development, including the ability to form and maintain relationships and prosodic abilities. Thus, music therapy may provide a basic and supportive therapy for children with delayed speech development. Further studies should be conducted to investigate the mechanisms of these interactions in greater depth. Trial registration The trial is registered in the German clinical trials register; Trial-No.: DRKS00000343 PMID:20663139

A Breathing-Based Meditation Intervention for Patients With Major Depressive Disorder Following Inadequate Response to Antidepressants: A Randomized Pilot Study.

PubMed

Sharma, Anup; Barrett, Marna S; Cucchiara, Andrew J; Gooneratne, Nalaka S; Thase, Michael E

2017-01-01

To evaluate feasibility, efficacy, and tolerability of Sudarshan Kriya yoga (SKY) as an adjunctive intervention in patients with major depressive disorder (MDD) with inadequate response to antidepressant treatment. Patients with MDD (defined by DSM-IV-TR) who were depressed despite ≥ 8 weeks of antidepressant treatment were randomized to SKY or a waitlist control (delayed yoga) arm for 8 weeks. The primary efficacy end point was change in 17-item Hamilton Depression Rating Scale (HDRS-17) total score from baseline to 2 months. The key secondary efficacy end points were change in Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI) total scores. Analyses of the intent-to-treat (ITT) and completer sample were performed. The study was conducted at the University of Pennsylvania between October 2014 and December 2015. In the ITT sample (n = 25), the SKY arm (n = 13) showed a greater improvement in HDRS-17 total score compared to waitlist control (n = 12) (-9.77 vs 0.50, P = .0032). SKY also showed greater reduction in BDI total score versus waitlist control (-17.23 vs -1.75, P = .0101). Mean changes in BAI total score from baseline were significantly greater for SKY than waitlist (ITT mean difference: -5.19; 95% CI, -0.93 to -9.34; P = .0097; completer mean difference: -6.23; 95% CI, -1.39 to -11.07; P = .0005). No adverse events were reported. Results of this randomized, waitlist-controlled pilot study suggest the feasibility and promise of an adjunctive SKY-based intervention for patients with MDD who have not responded to antidepressants. ClinicalTrials.gov identifier: NCT02616549. © Copyright 2016 Physicians Postgraduate Press, Inc.

Online CBT life skills programme for low mood and anxiety: study protocol for a pilot randomized controlled trial.

PubMed

Williams, Christopher; McClay, Carrie-Anne; Martinez, Rebeca; Morrison, Jill; Haig, Caroline; Jones, Ray; Farrand, Paul

2016-04-27

Low mood is a common mental health problem with significant health consequences. Studies have shown that cognitive behavioural therapy (CBT) is an effective treatment for low mood and anxiety when delivered one-to-one by an expert practitioner. However, access to this talking therapy is often limited and waiting lists can be long, although a range of low-intensity interventions that can increase access to services are available. These include guided self-help materials delivered via books, classes and online packages. This project aims to pilot a randomized controlled trial of an online CBT-based life skills course with community-based individuals experiencing low mood and anxiety. Individuals with elevated symptoms of depression will be recruited directly from the community via online and newspaper advertisements. Participants will be remotely randomized to receive either immediate access or delayed access to the Living Life to the Full guided online CBT-based life skills package, with telephone or email support provided whilst they use the online intervention. The primary end point will be at 3 months post-randomization, at which point the delayed-access group will be offered the intervention. Levels of depression, anxiety, social functioning and satisfaction will be assessed. This pilot study will test the trial design, and ability to recruit and deliver the intervention. Drop-out rates will be assessed and the completion and acceptability of the package will be investigated. The study will also inform a sample size power calculation for a subsequent substantive randomized controlled trial. ISRCTN ISRCTN12890709.

Analysis of Ignition Behavior in a Turbocharged Direct Injection Dual Fuel Engine Using Propane and Methane as Primary Fuels

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

Polk, A. C.; Gibson, C. M.; Shoemaker, N. T.

2013-05-24

This paper presents experimental analyses of the ignition delay (ID) behavior for diesel-ignited propane and diesel-ignited methane dual fuel combustion. Two sets of experiments were performed at a constant speed (1800 rev/min) using a 4-cylinder direct injection diesel engine with the stock ECU and a wastegated turbocharger. First, the effects of fuel-air equivalence ratios (© pilot ¼ 0.2-0.6 and © overall ¼ 0.2-0.9) on IDs were quantified. Second, the effects of gaseous fuel percent energy substitution (PES) and brake mean effective pressure (BMEP) (from 2.5 to 10 bar) on IDs were investigated. With constant © pilot (> 0.5), increasing ©more » overall with propane initially decreased ID but eventually led to premature propane autoignition; however, the corresponding effects with methane were relatively minor. Cyclic variations in the start of combustion (SOC) increased with increasing © overall (at constant © pilot), more significantly for propane than for methane. With increasing PES at constant BMEP, the ID showed a nonlinear (initially increasing and later decreasing) trend at low BMEPs for propane but a linearly decreasing trend at high BMEPs. For methane, increasing PES only increased IDs at all BMEPs. At low BMEPs, increasing PES led to significantly higher cyclic SOC variations and SOC advancement for both propane and methane. Finally, the engine ignition delay (EID) was also shown to be a useful metric to understand the influence of ID on dual fuel combustion.« less

GM1 ganglioside in Parkinson's disease: Pilot study of effects on dopamine transporter binding.

PubMed

Schneider, Jay S; Cambi, Franca; Gollomp, Stephen M; Kuwabara, Hiroto; Brašić, James R; Leiby, Benjamin; Sendek, Stephanie; Wong, Dean F

2015-09-15

GM1 ganglioside has been suggested as a treatment for Parkinson's disease (PD), potentially having symptomatic and disease modifying effects. The current pilot imaging study was performed to examine effects of GM1 on dopamine transporter binding, as a surrogate measure of disease progression, studied longitudinally. Positron emission tomography (PET) imaging data were obtained from a subset of subjects enrolled in a delayed start clinical trial of GM1 in PD [1]: 15 Early-start (ES) subjects, 14 Delayed-start (DS) subjects, and 11 Comparison (standard-of-care) subjects. Treatment subjects were studied over a 2.5 year period while Comparison subjects were studied over 2 years. Dynamic PET scans were performed over 90 min following injection of [(11)C]methylphenidate. Regional values of binding potential (BPND) were analyzed for several striatal volumes of interest. Clinical results for this subset of subjects were similar to those previously reported for the larger study group. ES subjects showed early symptomatic improvement and slow symptom progression over the study period. DS and Comparison subjects were initially on the same symptom progression trajectory but diverged once DS subjects received GM1 treatment. Imaging results showed significant slowing of BPND loss in several striatal regions in GM1-treated subjects and in some cases, an increased BPND in some striatal regions was detected after GM1 use. Results of this pilot imaging study provide additional data to suggest a potential disease modifying effect of GM1 on PD. These results need to be confirmed in a larger number of subjects. Copyright © 2015 Elsevier B.V. All rights reserved.

A situation-response model for intelligent pilot aiding

NASA Technical Reports Server (NTRS)

Schudy, Robert; Corker, Kevin

1987-01-01

An intelligent pilot aiding system needs models of the pilot information processing to provide the computational basis for successful cooperation between the pilot and the aiding system. By combining artificial intelligence concepts with the human information processing model of Rasmussen, an abstraction hierarchy of states of knowledge, processing functions, and shortcuts are developed, which is useful for characterizing the information processing both of the pilot and of the aiding system. This approach is used in the conceptual design of a real time intelligent aiding system for flight crews of transport aircraft. One promising result was the tentative identification of a particular class of information processing shortcuts, from situation characterizations to appropriate responses, as the most important reliable pathway for dealing with complex time critical situations.

Pilot interaction with automated airborne decision making systems

NASA Technical Reports Server (NTRS)

Rouse, W. B.; Chu, Y. Y.; Greenstein, J. S.; Walden, R. S.

1976-01-01

An investigation was made of interaction between a human pilot and automated on-board decision making systems. Research was initiated on the topic of pilot problem solving in automated and semi-automated flight management systems and attempts were made to develop a model of human decision making in a multi-task situation. A study was made of allocation of responsibility between human and computer, and discussed were various pilot performance parameters with varying degrees of automation. Optimal allocation of responsibility between human and computer was considered and some theoretical results found in the literature were presented. The pilot as a problem solver was discussed. Finally the design of displays, controls, procedures, and computer aids for problem solving tasks in automated and semi-automated systems was considered.

A queueing model of pilot decision making in a multi-task flight management situation

NASA Technical Reports Server (NTRS)

Walden, R. S.; Rouse, W. B.

1977-01-01

Allocation of decision making responsibility between pilot and computer is considered and a flight management task, designed for the study of pilot-computer interaction, is discussed. A queueing theory model of pilot decision making in this multi-task, control and monitoring situation is presented. An experimental investigation of pilot decision making and the resulting model parameters are discussed.

Serotonin delays habituation of leech swim response to touch.

PubMed

Alkatout, Bilal A; Marvin, Nicole M; Crisp, Kevin M

2007-08-22

Serotonin, acting through a cAMP-signaling pathway, delayed habituation to criterion of the leech's swim response to touch. This delay was reversed by crushing the connective between serotonin-exposed and serotonin-naive ganglia, and correlated with an increase in spontaneous impulse activity in this connective. We suggest that increased activity in intersegmental interneurons may play a role in maintaining swim responsiveness when concentrations of serotonin are elevated.

Pilot study of pyridostigmine in constipated patients with autonomic neuropathy

PubMed Central

Bharucha, Adil E.; Camilleri, Michael; Burton, Duane; Low, Phillip A.; Gehrking, Tonette L.; Zinsmeister, Alan R.

2008-01-01

Background The effects of cholinesterase inhibitors, which increase colonic motility in health, on chronic constipation are unknown. Our aims were to evaluate the efficacy of cholinesterase inhibitors for dysautonomia and chronic constipation and to assess whether acute effects could predict the long term response. Methods In this single-blind study, 10 patients with autonomic neuropathy and constipation were treated with placebo (2 weeks), followed by an escalating dose of pyridostigmine to the maximum tolerated dose (i.e., 180–540 mg daily) for 6 weeks. Symptoms and gastrointestinal transit were assessed at 2 and 8 weeks. The acute effects of neostigmine on colonic transit and motility were also assessed. Results At baseline, 4, 6, and 3 patients had delayed gastric, small intestinal, and colonic transit respectively. Pyridostigmine was well tolerated in most patients, improved symptoms in 4 patients, and accelerated the geometric center for colonic transit at 24 h by ≥0.7 unit in 3 patients. The effects of i.v. neostigmine on colonic transit and compliance predicted (P < 0.05) the effects of pyridostigmine on colonic transit. Conclusions Pyridostigmine improves colonic transit and symptoms in some patients with autonomic neuropathy and constipation. The motor response to neostigmine predicted the response to oral pyridostigmine. PMID:18622640

Vertical flight path steering system for aircraft

NASA Technical Reports Server (NTRS)

Lambregts, Antonius A. (Inventor)

1983-01-01

Disclosed is a vertical flight path angle steering system for aircraft, utilizing a digital flight control computer which processes pilot control inputs and aircraft response parameters into suitable elevator commands and control information for display to the pilot on a cathode ray tube. The system yields desirable airplane control handling qualities and responses as well as improvements in pilot workload and safety during airplane operation in the terminal area and under windshear conditions.

3S2: Behavioral Response Studies of Cetaceans to Navy Sonar Signals in Norwegian Waters

DTIC Science & Technology

2015-09-30

long-finned pilot (Globicephala melas ), and sperm whales (Physeter macrocephalus) to naval sonar. Aquatic Mammals 38: 362-401. Moretti, D., Thomas, L...2014). The social context of individual foraging behaviour in long-finned pilot whales (Globicephala melas ). Behaviour 151: 1453-1477. DOI: 10.1163...response thresholds for avoidance of sonar by free-ranging long-finned pilot whales (Globicephala melas ). Mar. Poll. Bull.83: 165-180. DOI: 10.1016

3S2: Behavioral Response Studies of Cetaceans to Navy Sonar Signals in Norwegian Waters

DTIC Science & Technology

2015-09-30

experimental exposures of killer (Orcinus orca), long-finned pilot (Globicephala melas ), and sperm whales (Physeter macrocephalus) to naval sonar. Aquatic...Kvadsheim P.H., Huisman J. and Tyack P.L. (2014). The social context of individual foraging behaviour in long-finned pilot whales (Globicephala melas ...Wensveen P.J., Miller P. J. O. (2014). High response thresholds for avoidance of sonar by free-ranging long-finned pilot whales (Globicephala melas

Gender differences in navigational memory: pilots vs. nonpilots.

PubMed

Verde, Paola; Piccardi, Laura; Bianchini, Filippo; Guariglia, Cecilia; Carrozzo, Paolo; Morgagni, Fabio; Boccia, Maddalena; Di Fiore, Giacomo; Tomao, Enrico

2015-02-01

The coding of space as near and far is not only determined by arm-reaching distance, but is also dependent on how the brain represents the extension of the body space. Recent reports suggest that the dissociation between reaching and navigational space is not limited to perception and action but also involves memory systems. It has been reported that gender differences emerged only in adverse learning conditions that required strong spatial ability. In this study we investigated navigational versus reaching memory in air force pilots and a control group without flight experience. We took into account temporal duration (working memory and long-term memory) and focused on working memory, which is considered critical in the gender differences literature. We found no gender effects or flight hour effects in pilots but observed gender effects in working memory (but not in learning and delayed recall) in the nonpilot population (Women's mean = 5.33; SD= 0.90; Men's mean = 5.54; SD= 0.90). We also observed a difference between pilots and nonpilots in the maintenance of on-line reaching information: pilots (mean = 5.85; SD=0.76) were more efficient than nonpilots (mean = 5.21; SD=0.83) and managed this type of information similarly to that concerning navigational space. In the navigational learning phase they also showed better navigational memory (mean = 137.83; SD=5.81) than nonpilots (mean = 126.96; SD=15.81) and were significantly more proficient than the latter group. There is no gender difference in a population of pilots in terms of navigational abilities, while it emerges in a control group without flight experience. We found also that pilots performed better than nonpilots. This study suggests that once selected, male and female pilots do not differ from each other in visuo-spatial abilities and spatial navigation.

Delayed, but not immediate, feedback after multiple-choice questions increases performance on a subsequent short-answer, but not multiple-choice, exam: evidence for the dual-process theory of memory.

PubMed

Sinha, Neha; Glass, Arnold Lewis

2015-01-01

Three experiments, two performed in the laboratory and one embedded in a college psychology lecture course, investigated the effects of immediate versus delayed feedback following a multiple-choice exam on subsequent short answer and multiple-choice exams. Performance on the subsequent multiple-choice exam was not affected by the timing of the feedback on the prior exam; however, performance on the subsequent short answer exam was better following delayed than following immediate feedback. This was true regardless of the order in which immediate versus delayed feedback was given. Furthermore, delayed feedback only had a greater effect than immediate feedback on subsequent short answer performance following correct, confident responses on the prior exam. These results indicate that delayed feedback cues a student's prior response and increases subsequent recollection of that response. The practical implication is that delayed feedback is better than immediate feedback during academic testing.

Disturbance-specific social responses in long-finned pilot whales, Globicephala melas

PubMed Central

Visser, Fleur; Curé, Charlotte; Kvadsheim, Petter H.; Lam, Frans-Peter A.; Tyack, Peter L.; Miller, Patrick J. O.

2016-01-01

Social interactions among animals can influence their response to disturbance. We investigated responses of long-finned pilot whales to killer whale sound playbacks and two anthropogenic sources of disturbance: tagging effort and naval sonar exposure. The acoustic scene and diving behaviour of tagged individuals were recorded along with the social behaviour of their groups. All three disturbance types resulted in larger group sizes, increasing social cohesion during disturbance. However, the nature and magnitude of other responses differed between disturbance types. Tagging effort resulted in a clear increase in synchrony and a tendency to reduce surface logging and to become silent (21% of cases), whereas pilot whales increased surface resting during sonar exposure. Killer whale sounds elicited increased calling rates and the aggregation of multiple groups, which approached the sound source together. This behaviour appears to represent a mobbing response, a likely adaptive social defence against predators or competitors. All observed response-tactics would reduce risk of loss of group coordination, suggesting that, in social pilot whales, this could drive behavioural responses to disturbance. However, the behavioural means used to achieve social coordination depends upon other considerations, which are disturbance-specific. PMID:27353529

Disturbance-specific social responses in long-finned pilot whales, Globicephala melas

NASA Astrophysics Data System (ADS)

Visser, Fleur; Curé, Charlotte; Kvadsheim, Petter H.; Lam, Frans-Peter A.; Tyack, Peter L.; Miller, Patrick J. O.

2016-06-01

Social interactions among animals can influence their response to disturbance. We investigated responses of long-finned pilot whales to killer whale sound playbacks and two anthropogenic sources of disturbance: tagging effort and naval sonar exposure. The acoustic scene and diving behaviour of tagged individuals were recorded along with the social behaviour of their groups. All three disturbance types resulted in larger group sizes, increasing social cohesion during disturbance. However, the nature and magnitude of other responses differed between disturbance types. Tagging effort resulted in a clear increase in synchrony and a tendency to reduce surface logging and to become silent (21% of cases), whereas pilot whales increased surface resting during sonar exposure. Killer whale sounds elicited increased calling rates and the aggregation of multiple groups, which approached the sound source together. This behaviour appears to represent a mobbing response, a likely adaptive social defence against predators or competitors. All observed response-tactics would reduce risk of loss of group coordination, suggesting that, in social pilot whales, this could drive behavioural responses to disturbance. However, the behavioural means used to achieve social coordination depends upon other considerations, which are disturbance-specific.

Disturbance-specific social responses in long-finned pilot whales, Globicephala melas.

PubMed

Visser, Fleur; Curé, Charlotte; Kvadsheim, Petter H; Lam, Frans-Peter A; Tyack, Peter L; Miller, Patrick J O

2016-06-29

Social interactions among animals can influence their response to disturbance. We investigated responses of long-finned pilot whales to killer whale sound playbacks and two anthropogenic sources of disturbance: tagging effort and naval sonar exposure. The acoustic scene and diving behaviour of tagged individuals were recorded along with the social behaviour of their groups. All three disturbance types resulted in larger group sizes, increasing social cohesion during disturbance. However, the nature and magnitude of other responses differed between disturbance types. Tagging effort resulted in a clear increase in synchrony and a tendency to reduce surface logging and to become silent (21% of cases), whereas pilot whales increased surface resting during sonar exposure. Killer whale sounds elicited increased calling rates and the aggregation of multiple groups, which approached the sound source together. This behaviour appears to represent a mobbing response, a likely adaptive social defence against predators or competitors. All observed response-tactics would reduce risk of loss of group coordination, suggesting that, in social pilot whales, this could drive behavioural responses to disturbance. However, the behavioural means used to achieve social coordination depends upon other considerations, which are disturbance-specific.

Corticofugal modulation of time-domain processing of biosonar information in bats.

PubMed

Yan, J; Suga, N

1996-08-23

The Jamaican mustached bat has delay-tuned neurons in the inferior colliculus, medial geniculate body, and auditory cortex. The responses of these neurons to an echo are facilitated by a biosonar pulse emitted by the bat when the echo returns with a particular delay from a target located at a particular distance. Electrical stimulation of cortical delay-tuned neurons increases the delay-tuned responses of collicular neurons tuned to the same echo delay as the cortical neurons and decreases those of collicular neurons tuned to different echo delays. Cortical neurons improve information processing in the inferior colliculus by way of the corticocollicular projection.

Air Traffic Control Response to Delays: A System Study of Newark International Airport

NASA Technical Reports Server (NTRS)

Evans, Antony D.; Clarke, John-Paul

2002-01-01

Airport delays are a significant problem in the United States air transportation system. Between 1999 and 2000 the number of flights delayed increased by 20 percent despite only a 0.4% increase in total operations. Newark International Airport (EWR), one of New York City's primary airports, is one of the airports in the United States most impacted by delays. Newark had the highest percentage of operations delayed in 1999, and was second only to LaGuardia Airport in 2000. Nearly 85% of delays at Newark are caused by adverse weather impacting an airport that may be characterized as having limited capacity and a very full schedule. Although Newark is heavily impacted by weather, delays have not increased significantly since 1998. This indicates that the airlines, air traffic control (ATC), and the Port Authority of New York and New Jersey have successfully adapted. On June 29, 2000, a research team from MIT visited Newark airport to assess the effectiveness of any adaptations made, and to collect data on airline and ATC departure operations, and of the national and local weather affecting the airport. Airline and ATC personnel were also interviewed. Results of this study indicate that airspace capacity limitations downstream of the airport are a primary flow constraint at the airport, and that these constraints are the source of most surface delays. A number of tactical ATC responses to delays were examined, including the application of restrictions, re-routing with the help of the National Playbook, and the use of decision-aiding tools such as the Dynamic Spacing Program (DSP) and the Integrated Terminal Weather System (ITWS). Improved interfacility communications and further utilization of runway 11-29 were identified as other tactical responses to delays, whilst the formation of the Air Traffic Control System Command Center and the New York Airspace redesign were identified as thekey strategic ATC responses to delays. Particularly the New York airspace redesign has great potential to reduce delays at the airport. Because delays at Newark are caused by downstream flow constraints, the responses at the airport can be applied to other airports as delays from downstream constraints increase. Such an increase in delays system wide from downstream constraints is inevitable as the system becomes more congested.

Answering Fixed Response Items in Chemistry: A Pilot Study.

ERIC Educational Resources Information Center

Hateley, R. J.

1979-01-01

Presents a pilot study on student thinking in chemistry. Verbal comments of a group of six college students were recorded and analyzed to identify how each student arrives at the correct answer in fixed response items in chemisty. (HM)

Summary of responses to the connected vehicle pilot deployment program’s request for information (RFI).

DOT National Transportation Integrated Search

2014-05-01

This document is a summary of all responses the USDOT received from the Connected Vehicle Pilot Deployment Programs Request for Information (RFI) Notice put out by the Federal Highway Administration on 03/12/2014.

Replicating human expertise of mechanical ventilation waveform analysis in detecting patient-ventilator cycling asynchrony using machine learning.

PubMed

Gholami, Behnood; Phan, Timothy S; Haddad, Wassim M; Cason, Andrew; Mullis, Jerry; Price, Levi; Bailey, James M

2018-06-01

- Acute respiratory failure is one of the most common problems encountered in intensive care units (ICU) and mechanical ventilation is the mainstay of supportive therapy for such patients. A mismatch between ventilator delivery and patient demand is referred to as patient-ventilator asynchrony (PVA). An important hurdle in addressing PVA is the lack of a reliable framework for continuously and automatically monitoring the patient and detecting various types of PVA. - The problem of replicating human expertise of waveform analysis for detecting cycling asynchrony (i.e., delayed termination, premature termination, or none) was investigated in a pilot study involving 11 patients in the ICU under invasive mechanical ventilation. A machine learning framework is used to detect cycling asynchrony based on waveform analysis. - A panel of five experts with experience in PVA evaluated a total of 1377 breath cycles from 11 mechanically ventilated critical care patients. The majority vote was used to label each breath cycle according to cycling asynchrony type. The proposed framework accurately detected the presence or absence of cycling asynchrony with sensitivity (specificity) of 89% (99%), 94% (98%), and 97% (93%) for delayed termination, premature termination, and no cycling asynchrony, respectively. The system showed strong agreement with human experts as reflected by the kappa coefficients of 0.90, 0.91, and 0.90 for delayed termination, premature termination, and no cycling asynchrony, respectively. - The pilot study establishes the feasibility of using a machine learning framework to provide waveform analysis equivalent to an expert human. Copyright © 2018 Elsevier Ltd. All rights reserved.

Implementation of a Breast/Reconstruction Surgery Coordinator to Reduce Preoperative Delays for Patients Undergoing Mastectomy With Immediate Reconstruction

PubMed Central

Losk, Katya; Mallory, Melissa A.; Camuso, Kristen; Cutone, Linda; Caterson, Stephanie; Bunnell, Craig A.

2016-01-01

Purpose: Mastectomy with immediate reconstruction (MIR) requires coordination between breast and reconstructive surgical teams, leading to increased preoperative delays that may adversely impact patient outcomes and satisfaction. Our cancer center established a target of 28 days from initial consultation with the breast surgeon to MIR. We sought to determine if a centralized breast/reconstructive surgical coordinator (BRC) could reduce care delays. Methods: A 60-day pilot to evaluate the impact of a BRC on timeliness of care was initiated at our cancer center. All reconstructive surgery candidates were referred to the BRC, who had access to surgical clinic and operating room schedules. The BRC worked with both surgical services to identify the earliest surgery dates and facilitated operative bookings. The median time to MIR and the proportion of MIR cases that met the time-to-treatment goal was determined. These results were compared with a baseline cohort of patients undergoing MIR during the same time period (January to March) in 2013 and 2014. Results: A total of 99 patients were referred to the BRC (62% cancer, 21% neoadjuvant, 17% prophylactic) during the pilot period. Focusing exclusively on patients with a cancer diagnosis, an 18.5% increase in the percentage of cases meeting the target (P = .04) and a 7-day reduction to MIR (P = .02) were observed. Conclusion: A significant reduction in time to MIR was achieved through the implementation of the BRC. Further research is warranted to validate these findings and assess the impact the BRC has on operational efficiency and workflows. PMID:26883406

Attentional Bias to Beauty with Evolutionary Benefits: Evidence from Aesthetic Appraisal of Landscape Architecture

PubMed Central

Zhang, Wei; Tang, Xiaoxiang; He, Xianyou; Lai, Shuxian

2018-01-01

Substantial evidence suggests that beauty is associated with the survival and reproduction of organisms. Landscape architecture is composed of a series of natural elements that have significant evolutionary implications. The present study used one pilot material ratings and three experiments to examine the mechanisms of aesthetic appraisals of landscape architecture. The results confirmed that landscape architecture elicited a sense of beauty and captured visual attention more easily than other types of architecture during explicit aesthetic rating task (Experiment 1) and implicit aesthetic perception task (dot-probe paradigm, Experiment 2). Furthermore, the spatial cueing paradigm revealed that response latencies were significantly faster for landscape architecture than non-landscape architecture on valid trials, but there was no significant difference in this contrast on invalid trials at 150-ms stimulus onset asynchrony (SOA, Experiment 3a). At 500-ms SOA (Experiment 3b), participants responded significantly faster for landscape architecture on valid trials, but reacted significantly slower for landscape architecture on invalid trials. The findings indicated that the beauty of landscape architecture can be perceived implicitly, and only faster orienting of attention, but not delayed disengagement of attention was generated at early stages of the processing of landscape architecture. However, the attentional bias at later stages of attentional processes may be resulted from both faster orienting of attention and delayed disengagement of attention from landscape architecture photographs. PMID:29467696

Attentional Bias to Beauty with Evolutionary Benefits: Evidence from Aesthetic Appraisal of Landscape Architecture.

PubMed

Zhang, Wei; Tang, Xiaoxiang; He, Xianyou; Lai, Shuxian

2018-01-01

Substantial evidence suggests that beauty is associated with the survival and reproduction of organisms. Landscape architecture is composed of a series of natural elements that have significant evolutionary implications. The present study used one pilot material ratings and three experiments to examine the mechanisms of aesthetic appraisals of landscape architecture. The results confirmed that landscape architecture elicited a sense of beauty and captured visual attention more easily than other types of architecture during explicit aesthetic rating task (Experiment 1) and implicit aesthetic perception task (dot-probe paradigm, Experiment 2). Furthermore, the spatial cueing paradigm revealed that response latencies were significantly faster for landscape architecture than non-landscape architecture on valid trials, but there was no significant difference in this contrast on invalid trials at 150-ms stimulus onset asynchrony (SOA, Experiment 3a). At 500-ms SOA (Experiment 3b), participants responded significantly faster for landscape architecture on valid trials, but reacted significantly slower for landscape architecture on invalid trials. The findings indicated that the beauty of landscape architecture can be perceived implicitly, and only faster orienting of attention, but not delayed disengagement of attention was generated at early stages of the processing of landscape architecture. However, the attentional bias at later stages of attentional processes may be resulted from both faster orienting of attention and delayed disengagement of attention from landscape architecture photographs.

Effects of a single dose of a flavonoid-rich blueberry drink on memory in 8 to 10 y old children.

PubMed

Whyte, Adrian R; Williams, Claire M

2015-03-01

Recent evidence from animals and adult humans has demonstrated potential benefits to cognition from flavonoid supplementation. The aim of this study was to investigate whether these cognitive benefits extended to a sample of school-aged children. Using a crossover design, with a washout of at least 7 d between drinks, 14 children ages 8 to 10 y consumed either a flavonoid-rich blueberry drink or a matched vehicle. Two h after consumption, the children completed a battery of five cognitive tests comprising the Go-NoGo, Stroop, Rey's Auditory Verbal Learning Task, Object Location Task, and a Visual N-back. In comparison to the vehicle, the blueberry drink produced significant improvements in the delayed recall of a previously learned list of words, showing for the first time a cognitive benefit for acute flavonoid intervention in children. However, performance on a measure of proactive interference indicated that the blueberry intervention led to a greater negative impact of previously memorized words on the encoding of a set of new words. There was no benefit of our blueberry intervention for measures of attention, response inhibition, or visuospatial memory. Although findings are mixed, the improvements in delayed recall found in this pilot study suggest that, following acute flavonoid-rich blueberry interventions, school-aged children encode memory items more effectively. Copyright © 2015 Elsevier Inc. All rights reserved.

Micropore closure kinetics are delayed following microneedle insertion in elderly subjects.

PubMed

Kelchen, Megan N; Siefers, Kyle J; Converse, Courtney C; Farley, Matthew J; Holdren, Grant O; Brogden, Nicole K

2016-03-10

Transdermal delivery is an advantageous method of drug administration, particularly for an elderly population. Microneedles (MNs) allow transdermal delivery of otherwise skin-impermeable drugs by creating transient micropores that bypass the barrier function of the skin. The response of aging skin to MNs has not been explored, and we report for the first time that micropore closure is delayed in elderly subjects in a manner that is dependent upon MN length, number, and occlusion of the micropores. Twelve control subjects (25.6±2.8years) and 16 elderly subjects (77.3±6.8years) completed the study. Subjects were treated with MNs of 500μm or 750μm length, in arrays containing 10 or 50 MNs. Impedance measurements made at baseline, post-MN insertion, and at predetermined time points demonstrated that restoration of the skin barrier is significantly slower in elderly subjects under both occluded and non-occluded conditions. This was confirmed via calculation of the total permeable area created by the micropores (which would approximate the area available for drug delivery), as well as calculation of the micropore half-life. This pilot study demonstrates that longer timeframes are required to restore the barrier function of aged skin following MN insertion, suggesting that drug delivery windows could be longer following one treatment with a MN array. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of Omega-3 and -6 Supplementation on Language in Preterm Toddlers Exhibiting Autism Spectrum Disorder Symptoms

ERIC Educational Resources Information Center

Sheppard, Kelly W.; Boone, Kelly M.; Gracious, Barbara; Klebanoff, Mark A.; Rogers, Lynette K.; Rausch, Joseph; Bartlett, Christopher; Coury, Daniel L.; Keim, Sarah A.

2017-01-01

Delayed language development may be an early indicator of autism spectrum disorder (ASD). Early intervention is critical for children with ASD, and the present study presents pilot data on a clinical trial of omega-3 and -6 fatty acid supplementation and language development, a secondary trial outcome, in children at risk for ASD. We randomized 31…

High-intensity Interval Training and Continuous Aerobic Exercise Interventions to Promote Self-initiated Quit Attempts in Young Adults Who Smoke: Feasibility, Acceptability, and Lessons Learned from a Randomized Pilot Trial.

PubMed

Allen, Alicia; Carlson, Samantha C; Bosch, Tyler A; Eberly, Lynn E; Okuyemi, Kola; Nair, Uma; Gordon, Judith S

2018-05-14

While exercise significantly reduces craving for cigarettes, the effect of exercise on self-initiation of quit attempts is less known. Therefore, this randomized pilot study explored the effect of starting an exercise program on self-initiated quit attempts, and also the feasibility and acceptability of a novel exercise intervention, high-intensity interval training (HIIT), as compared with a more traditional continuous aerobic (CA) exercise intervention. Participants smoked (≥5 cigarettes/d), were aged 18 to 40 years, and wanted to increase their exercise. Participants were randomized into 1 of 3 groups: HIIT, CA, and delayed control. All participants attended follow-up visits at weeks 4, 8, and 12. Outcomes included measures of feasibility (eg, visit attendance) and acceptability (eg, satisfaction), and also changes in smoking behavior (eg, quit attempts during follow-up) and proxies to quit attempts (eg, positive affect). Overall, there were no differences in terms of feasibility and acceptability between the HITT (n = 12) and CA (n = 9) groups. Based on both self-report and objective measurement, the exercise groups (HIIT and CA) increased their physical activity as compared with the delayed treatment group (n = 11). Compared with HIIT and delayed control, CA (n = 9) had significant favorable changes in positive affect (eg, at week 8, HIIT: +0.25 ± 2.21, delayed control: -5.11 ± 2.23, CA: +5.50 ± 2.23; P = 0.0153). These observations suggest that HIIT is as feasible and acceptable as CA, though CA may have a more favorable effect on proxies to quit attempts (eg, positive affect). Fully powered studies are needed to examine the effect of HIIT versus CA on quit attempts.

Air/fuel ratio visualization in a diesel spray

NASA Astrophysics Data System (ADS)

Carabell, Kevin David

1993-01-01

To investigate some features of high pressure diesel spray ignition, we have applied a newly developed planar imaging system to a spray in an engine-fed combustion bomb. The bomb is designed to give flow characteristics similar to those in a direct injection diesel engine yet provide nearly unlimited optical access. A high pressure electronic unit injector system with on-line manually adjustable main and pilot injection features was used. The primary scalar of interest was the local air/fuel ratio, particularly near the spray plumes. To make this measurement quantitative, we have developed a calibration LIF technique. The development of this technique is the key contribution of this dissertation. The air/fuel ratio measurement was made using biacetyl as a seed in the air inlet to the engine. When probed by a tripled Nd:YAG laser the biacetyl fluoresces, with a signal proportional to the local biacetyl concentration. This feature of biacetyl enables the fluorescent signal to be used as as indicator of local fuel vapor concentration. The biacetyl partial pressure was carefully controlled, enabling estimates of the local concentration of air and the approximate local stoichiometry in the fuel spray. The results indicate that the image quality generated with this method is sufficient for generating air/fuel ratio contours. The processes during the ignition delay have a marked effect on ignition and the subsequent burn. These processes, vaporization and pre-flame kinetics, very much depend on the mixing of the air and fuel. This study has shown that poor mixing and over-mixing of the air and fuel will directly affect the type of ignition. An optimal mixing arrangement exists and depends on the swirl ratio in the engine, the number of holes in the fuel injector and the distribution of fuel into a pilot and main injection. If a short delay and a diffusion burn is desired, the best mixing parameters among those surveyed would be a high swirl ratio, a 4-hole nozzle and a small pilot. This arrangement provided the best combination of short ignition delay and diffusion burn for the majority of cases.

A direct approach for the design of chirp stimuli used for the recording of auditory brainstem responses

PubMed Central

Elberling, Claus; Don, Manuel

2010-01-01

A recent study evaluates auditory brainstem responses (ABRs) evoked by chirps of different durations (sweeping rates) [Elberling et al. (2010). J. Acoust. Soc. Am. 128, 215–223]. The study demonstrates that shorter chirps are most efficient at higher levels of stimulation whereas longer chirps are most efficient at lower levels. Mechanisms other than the traveling wave delay, in particular, upward spread of excitation and changes in cochlear-neural delay with level, are suggested to be responsible for these findings. As a consequence, delay models based on estimates of the traveling wave delay are insufficient for the design of chirp stimuli, and another delay model based on a direct approach is therefore proposed. The direct approach uses ABR-latencies from normal-hearing subjects in response to octave-band chirps over a wide range of levels. The octave-band chirps are constructed by decomposing a broad-band chirp, and constitute a subset of the chirp. The delay compensations of the proposed model are similar to those found in the previous experimental study, which thus verifies the results of the proposed model. PMID:21110591

Preliminary efficacy and safety of an oromucosal standardized cannabis extract in chemotherapy-induced nausea and vomiting.

PubMed

Duran, Marta; Pérez, Eulàlia; Abanades, Sergio; Vidal, Xavier; Saura, Cristina; Majem, Margarita; Arriola, Edurne; Rabanal, Manel; Pastor, Antoni; Farré, Magí; Rams, Neus; Laporte, Joan-Ramon; Capellà, Dolors

2010-11-01

Despite progress in anti-emetic treatment, many patients still suffer from chemotherapy-induced nausea and vomiting (CINV). This is a pilot, randomized, double-blind, placebo-controlled phase II clinical trial designed to evaluate the tolerability, preliminary efficacy, and pharmacokinetics of an acute dose titration of a whole-plant cannabis-based medicine (CBM) containing delta-9-tetrahydrocannabinol and cannabidiol, taken in conjunction with standard therapies in the control of CINV. Patients suffering from CINV despite prophylaxis with standard anti-emetic treatment were randomized to CBM or placebo, during the 120 h post-chemotherapy period, added to standard anti-emetic treatment. Tolerability was measured as the number of withdrawals from the study during the titration period because of adverse events (AEs). The endpoint for the preliminary efficacy analysis was the proportion of patients showing complete or partial response. Seven patients were randomized to CBM and nine to placebo. Only one patient in the CBM arm was withdrawn due to AEs. A higher proportion of patients in the CBM group experienced a complete response during the overall observation period [5/7 (71.4%) with CMB vs. 2/9 (22.2%) with placebo, the difference being 49.2% (95% CI 1%, 75%)], due to the delayed period. The incidence of AEs was higher in the CBM group (86% vs. 67%). No serious AEs were reported. The mean daily dose was 4.8 sprays in both groups. Compared with placebo, CBM added to standard antiemetic therapy was well tolerated and provided better protection against delayed CINV. These results should be confirmed in a phase III clinical trial. © 2010 Department of Health, Generalitat of Catalonia. British Journal of Clinical Pharmacology © 2010 The British Pharmacological Society.

Extending Validated Human Performance Models to Explore NextGen Concepts

NASA Technical Reports Server (NTRS)

Gore, Brian Francis; Hooey, Becky Lee; Mahlstedt, Eric; Foyle, David C.

2012-01-01

To meet the expected increases in air traffic demands, NASA and FAA are researching and developing Next Generation Air Transportation System (NextGen) concepts. NextGen will require substantial increases in the data available to pilots on the flight deck (e.g., weather,wake, traffic trajectory predictions, etc.) to support more precise and closely coordinated operations (e.g., self-separation, RNAV/RNP, and closely spaced parallel operations, CSPOs). These NextGen procedures and operations, along with the pilot's roles and responsibilities, must be designed with consideration of the pilot's capabilities and limitations. Failure to do so will leave the pilots, and thus the entire aviation system, vulnerable to error. A validated Man-machine Integration and design Analysis System (MIDAS) v5 model was extended to evaluate anticipated changes to flight deck and controller roles and responsibilities in NextGen approach and Land operations. Compared to conditions when the controllers are responsible for separation on decent to land phase of flight, the output from these model predictions suggest that the flight deck response time to detect the lead aircraft blunder will decrease, pilot scans to the navigation display will increase, and workload will increase.

Launch of the Apollo 17 lunar landing mission

NASA Image and Video Library

1972-12-07

S72-55482 (7 Dec. 1972) --- The huge, 363-feet tall Apollo 17 (Spacecraft 114/Lunar Module 12/Saturn 512) space vehicle is launched from Pad A., Launch Complex 39, Kennedy Space Center (KSC), Florida, at 12:33 a.m. (EST), Dec. 7, 1972. Apollo 17, the final lunar landing mission in NASA's Apollo program, was the first nighttime liftoff of the Saturn V launch vehicle. Aboard the Apollo 17 spacecraft were astronaut Eugene A. Cernan, commander; astronaut Ronald E. Evans, command module pilot; and scientist-astronaut Harrison H. Schmitt, lunar module pilot. Flame from the five F-1 engines of the Apollo/Saturn first (S-1C) stage illuminates the nighttime scene. A two-hour and 40-minute hold delayed the Apollo 17 launching.

Launch of the Apollo 17 lunar landing mission

NASA Image and Video Library

1972-09-07

S72-55070 (7 Dec. 1972) --- The huge, 363-feet tall Apollo 17 (Spacecraft 114/Lunar Module 12/Saturn 512) space vehicle is launched from Pad A, Launch Complex 39, Kennedy Space Center (KSC), Florida, at 12:33 a.m. (EST), Dec. 7, 1972. Apollo 17, the final lunar landing mission in NASA's Apollo program, was the first nighttime liftoff of the Saturn V launch vehicle. Aboard the Apollo 17 spacecraft were astronaut Eugene A. Cernan, commander; astronaut Ronald E. Evans, command module pilot; and scientist-astronaut Harrison H. Schmitt, lunar module pilot. Flame from the five F-1 engines of the Apollo/Saturn first (S-1C) stage illuminates the nighttime scene. A two-hour and 40-minute hold delayed the Apollo 17 launching.

Social Ecology and Group Cohesion in Pilot Whales and their Responses to Playback of Anthropogenic and Natural Sounds

DTIC Science & Technology

2014-09-30

responses to biologically relevant ( killer whale and conspecific) and anthropogenic (mid-frequency sonar) sound stimuli that will be analysed in a...Curé, C., Antunes, R., Samarra, F., Alves, A. C., Visser, F., Kvadsheim, P. H. and Miller, P. J. O. (2012). Pilot Whales Attracted to Killer Whale ... Killer (Orcinus orca), Long-Finned Pilot (Globicephala melas), and Sperm (Physeter macrocephalus) Whales to Naval Sonar. Aquatic Mammals 38, 362-401

Cognitive Behavioral Treatment for Recurrent Binge Eating in Adolescent Girls: A Pilot Trial

PubMed Central

DeBar, Lynn L.; Wilson, G. Terence; Yarborough, Bobbi Jo; Burns, Beryl; Oyler, Barbara; Hildebrandt, Tom; Clarke, Gregory N.; Dickerson, John; Striegel, Ruth H.

2013-01-01

There is a need for treatment interventions to address the high prevalence of disordered eating throughout adolescence and early adulthood. We developed an adolescent-specific manualized CBT protocol to treat female adolescents with recurrent binge eating and tested its efficacy in a small, pilot randomized controlled trial. We present lessons learned in recruiting adolescents, a description of our treatment approach, acceptability of the treatment for teens and parents, as well as results from the pilot trial. Participants in the CBT group had significantly fewer posttreatment eating binges than those in a treatment as usual/delayed treatment (TAU-DT) control group; 100% of CBT participants were abstinent at follow-up. Our results provide preliminary support for the efficacy of this adolescent adaptation of evidence-based CBT for recurrent binge eating. The large, robust effect size estimate observed for the main outcome (NNT=2) places this among the larger effects observed for any mental health intervention. PMID:23645978

A piloted simulation investigation of yaw dynamics requirements for turreted gun use in low-level helicopter air combat

NASA Technical Reports Server (NTRS)

Decker, William A.; Morris, Patrick M.; Williams, Jeffrey N.

1988-01-01

A piloted, fixed-base simulation study was conducted to investigate the handling qualities requirements for helicopter air-to-air combat using turreted guns in the near-terrain environment. The study used a version of the helicopter air combat system developed at NASA Ames Research Center for one-on-one air combat. The study focused on the potential trade-off between gun angular movement capability and required yaw axis response. Experimental variables included yaw axis response frequency and damping and the size of the gun-movement envelope. A helmet position and sighting system was used for pilot control of gun aim. Approximately 340 simulated air combat engagements were evaluated by pilots from the Army and industry. Results from the experiment indicate that a highly-damped, high frequency yaw response was desired for Level I handling qualities. Pilot preference for those characteristics became more pronounced as gun turret movement was restricted; however, a stable, slow-reacting platform could be used with a large turret envelope. Most pilots preferred to engage with the opponent near the own-ship centerline. Turret elevation restriction affected the engagement more than azimuth restrictions.

Do short international layovers allow sufficient opportunity for pilots to recover?

PubMed

Lamond, Nicole; Petrilli, Renée M; Dawson, Drew; Roach, Gregory D

2006-01-01

For Australian pilots, short layovers (<40 h) are a feature of many international patterns. However, anecdotal reports suggest that flight crew members find patterns with short slips more fatiguing than those with a longer international layover, as they restrict the opportunity to obtain sufficient sleep. The current study aimed to determine whether pilots operating international patterns with short layovers have sufficient opportunity to recover prior to the inbound flight. Nineteen international pilots (ten captains, nine first officers) operating a direct return pattern from Australia to Los Angeles (LAX) with a short (n = 9) 9+/-0.8 h (mean+/-S.D) or long (n = 10) 62.2+/-0.9 h LAX layover wore an activity monitor and kept a sleep/duty diary during the pattern. Immediately before and after each flight, pilots completed a 5 min PalmPilot-based psychomotor vigilance task (Palm-PVT). Flights were of comparable duration outbound (3.5+/-0.6 h) and inbound (14.3+/-0.6 h) and timing. The amount of sleep obtained in-flight did not significantly vary as a function of layover length. However, pilots obtained significantly more sleep during the inbound (3.7+/-0.8 h) than the outbound flight (2.2+/-0.8 h). Pilots with the shorter layover obtained significantly less sleep in total during layover (14.0+/-2.7 h vs. 19.6+/-2.5), due to significantly fewer sleep periods (3.0+/-0.7 vs. 4.0+/-0.9). However, neither mean sleep duration nor the sleep obtained in the 24 h prior to the inbound flight significantly differed as a function of layover length. Response speed significantly varied across the pattern, and a significant interaction was also observed. For pilots with a short layover, response speed was significantly slower at the end of both the outbound and inbound flight, and prior to the inbound flight (i.e., at the end of layover), relative to response speed at the start of the pattern (pre-trip). Similarly, response speed for the longer layover was slower at the end of the outbound flight compared to pre-trip (approaching significance, p = 0.073). However, response speed at the beginning of the inbound flight was significantly faster than pre-trip and did not significantly differ from pre-trip at the end of the inbound flight. The data suggest that short slips (<40 h) do not allow pilots the opportunity to obtain sufficient sleep to reverse the effects of fatigue accumulated during the outbound flight. As a result, their response speed prior to the inbound flight is substantially slower than the response speed of flight crew with a longer layover.

Delayed system response times affect immediate physiology and the dynamics of subsequent button press behavior.

PubMed

Kohrs, Christin; Hrabal, David; Angenstein, Nicole; Brechmann, André

2014-11-01

System response time research is an important issue in human-computer interactions. Experience with technical devices and general rules of human-human interactions determine the user's expectation, and any delay in system response time may lead to immediate physiological, emotional, and behavioral consequences. We investigated such effects on a trial-by-trial basis during a human-computer interaction by measuring changes in skin conductance (SC), heart rate (HR), and the dynamics of button press responses. We found an increase in SC and a deceleration of HR for all three delayed system response times (0.5, 1, 2 s). Moreover, the data on button press dynamics was highly informative since subjects repeated a button press with more force in response to delayed system response times. Furthermore, the button press dynamics could distinguish between correct and incorrect decisions and may thus even be used to infer the uncertainty of a user's decision. Copyright © 2014 Society for Psychophysiological Research.

Comparative Analysis of Conventional Electronic and OZ Concept Displays for Aircraft Energy Management

NASA Astrophysics Data System (ADS)

Baker, Erik Reese

A repeated-measures, within-subjects design was conducted on 58 participant pilots to assess mean differences on energy management situation awareness response time and response accuracy between a conventional electronic aircraft display, a primary flight display (PFD), and an ecological interface design aircraft display, the OZ concept display. Participants were associated with a small Midwestern aviation university, including student pilots, flight instructors, and faculty with piloting experience. Testing consisted of observing 15 static screenshots of each cockpit display type and then selecting applicable responses from 27 standardized responses for each screen. A paired samples t-test was computed comparing accuracy and response time for the two displays. There was no significant difference in means between PFD Response Time and OZ Response Time. On average, mean PFD Accuracy was significantly higher than mean OZ Accuracy (MDiff = 13.17, SDDiff = 20.96), t(57) = 4.78, p < .001, d = 0.63. This finding showed operational potential for the OZ display, since even without first training to proficiency on the previously unseen OZ display, participant performance differences were not operationally remarkable. There was no significant correlation between PFD Response Time and PFD Accuracy, but there was a significant correlation between OZ Response Time and OZ Accuracy, r (58) = .353, p < .01. These findings suggest the participant familiarity of the PFD resulted in accuracy scores unrelated to response time, compared to the participants unaccustomed with the OZ display where longer response times manifested in greater understanding of the OZ display. PFD Response Time and PFD Accuracy were not correlated with pilot flight hours, which was not expected. It was thought that increased experience would translate into faster and more accurate assessment of the aircraft stimuli. OZ Response Time and OZ Accuracy were also not correlated with pilot flight hours, but this was expected. This was consistent with previous research that observed novice operators performing as well as experienced professional pilots on dynamic flight tasks with the OZ display. A demographic questionnaire and a feedback survey were included in the trial. An equivalent three-quarters majority of participants rated the PFD as "easy" and the OZ as "confusing", yet performance accuracy and response times between the two displays were not operationally different.

Uncoupling VOR and vestibuloautonomic retention to Coriolis acceleration training in student pilots and control subjects.

PubMed

Wang, Linjie; Cao, Yi; Tan, Cheng; Zhao, Qi; He, Siyang; Niu, Dongbin; Tang, Guohua; Zou, Peng; Xing, Lei

2017-01-01

Explore the different vestibular physiologic response retention patterns after Coriolis acceleration training in student pilots and extend the results for use with Chinese astronauts in the future. Twelve healthy control male subjects were screened from males familiar with vestibular training and who physically resembled the astronauts. Fourteen student pilots were selected from 23 participants by rotational vestibular function tests. All subjects were exposed to five-day continuous or intermittent Coriolis acceleration training. Subjective motion sickness (MS) symptom scores, electrocardiography, electrogastrography (EGG), post-rotatory nystagmus and renin-angiotensin system responses were measured before, during and after rotational vestibular function tests at different times after vestibular training. Subjects could tolerate 10 min or 15 min of vestibular with mild MS symptoms. Retention of vestibular autonomic responses (retention of MS symptom scores, heart rate variability, power density of EGG, variations in levels of arginine vasopressin) were approximately 1 week for control subjects and approximately 5 weeks for student pilots. Decreases in slow-phase velocity of post-rotatory nystagmus were maintained for 14 weeks for control subjects and 9 weeks for student pilots. Retention of the vestibulo-autonomic reaction after vestibular training was different for control subjects and student pilots. All parameters related to autonomic responses could be maintained at low levels after vestibular training for approximately 1 week for control subjects and approximately 5 weeks for student pilots. Uncoupling patterns between post-rotatory nystagmus and the vestibulo-autonomic reaction may be helpful in the design of clinical rehabilitation plans for balance-disorder patients and for exploration of artificial gravity in future space missions.

[Chronic noise exposure and the cardiovascular system in aircraft pilots].

PubMed

Tomei, F; Papaleo, B; Baccolo, T P; Tomao, E; Alfi, P; Fantini, S

1996-01-01

The aim of this study was to assess whether pilots are exposed to any risk of effects on the cardiovascular apparatus, whether chronic exposure to noise can be a risk factor for this occupation, the importance of intensity, length and type of exposure to noise, and if any relationship exists between audiometric deficits and cardiovascular effects. The study comprised 416 pilots subdivided into two groups according to the different levels of chronic exposure to noise, and a group of 150 control subjects not exposed to noise. The results showed: a) a higher prevalence of hypertension, nearly always diastolic, and of ECG abnormalities in the group of pilots of turboprop aircraft compared to jet plane pilots and to controls (p < 0.005 and p < 0.01 respectively); b) a higher prevalence of orthostatic hypotension in the two groups of pilots than in the controls (p < 0.05); c) a higher prevalence of hypertension with audiometric deficit compared to hypertension without audiometric deficit both in the more heavily and in the less heavily exposed to noise (p < 0.05), and a higher prevalence of hypertension with audiometric deficit in subjects exposed to higher levels of noise compared to hypertension with deficit but in subjects with lower levels of exposure (p < 0.05); d) a higher prevalence of abnormalities of basal, maximum effort and recovery ECG in pilots exposed to higher noise intensity (p < 0.05); e) improved hypertensive response to ergometric test in pilots with basal hypertension; f) subjects with a maximal load up to 120 W belonged prevalently to the group exposed to more intense noise (p < 0.001), while those with maximal load up to 210 W (p < 0.001) belonged to the group exposed to less intense noise. Considering that pilots are comparable for traditional cardiovascular risk factors, including age, both within the group and with the controls, the results confirm 1) that pilots could be exposed to the risk of effects on the cardiovascular apparatus, 2) that noise could be one of the risk factors and that cardiovascular effects could be related to intensity, type and length of exposure, age being the same, 3) that vascular damage is often accompanied by hearing loss even if the response of the auditory apparatus is different from the response of the cardiovascular apparatus, 4) that the postural diminution of arterial blood pressure might be a sign of a cardiovascular effect of noise. Lastly, a higher hypertensive response in hypertensive pilots suggests that basal hypertension is not reversible. Also a longer exposure to noise seems to influence the cardiovascular apparatus, causing a decrease in the response to work loads due to a lower sympathetic adaptability. The altered response of sympathetic activity to the postural modifications in the more exposed subjects and the response to lower work loads in pilots exposed to more intense noise, suggests a hypothesis of catecholamine depletion and alteration of baroceptor sensitivity as a consequence of chronic sympathetic activation due to chronic exposure to noise.

Pilot response to peripheral vision cues during instrument flying tasks.

DOT National Transportation Integrated Search

1968-02-01

In an attempt to more closely associate the visual aspects of instrument flying with that of contact flight, a study was made of human response to peripheral vision cues relating to aircraft roll attitude. Pilots, ranging from 52 to 12,000 flying hou...

Development of the Casparian strip is delayed by blue light in pea stems.

PubMed

Karahara, Ichirou; Takaya, Eliko; Fujibayashi, Shigetaka; Inoue, Hiroshi; Weller, James L; Reid, James B; Sugai, Michizo

2011-11-01

To understand the regulatory mechanisms involved in tissue development by light, the kinetics of regulation of Casparian strip (CS) development in garden pea stems was studied. We found that short-term irradiation with white light delayed the development of the CS and used this delay to assess the quantitative effect of light on CS development. We examined the effect of the duration and fluence rates of white light treatment on CS development and observed a significant relationship between fluence and the delay in CS development indicating that the Bunsen-Roscoe law of reciprocity holds for this response. The effect of white light irradiation was not inhibited in the presence of a photosynthetic inhibitor, DCMU, or a carotenoid biosynthesis inhibitor, Norflurazon, indicating that the delay in CS development by light is a photomorphogenetic response rather than a subsidiary effect mediated by photosynthetic activity. An action spectrum for the response displayed a major peak in the blue-light region, suggesting a dominant role for blue-light receptors. A minor peak in the red-light region also suggested the possible involvement of phytochromes. Although phytochromes are known to contribute to blue-light responses, phytochrome-deficient mutants showed a normal delay of CS development in response to blue light, indicating that the response is not mediated by phytochrome and suggesting a role for one or more specific blue-light receptors.

The Effects of Longitudinal Control-System Dynamics on Pilot Opinion and Response Characteristics as Determined from Flight Tests and from Ground Simulator Studies

NASA Technical Reports Server (NTRS)

Sadoff, Melvin

1958-01-01

The results of a fixed-base simulator study of the effects of variable longitudinal control-system dynamics on pilot opinion are presented and compared with flight-test data. The control-system variables considered in this investigation included stick force per g, time constant, and dead-band, or stabilizer breakout force. In general, the fairly good correlation between flight and simulator results for two pilots demonstrates the validity of fixed-base simulator studies which are designed to complement and supplement flight studies and serve as a guide in control-system preliminary design. However, in the investigation of certain problem areas (e.g., sensitive control-system configurations associated with pilot- induced oscillations in flight), fixed-base simulator results did not predict the occurrence of an instability, although the pilots noted the system was extremely sensitive and unsatisfactory. If it is desired to predict pilot-induced-oscillation tendencies, tests in moving-base simulators may be required. It was found possible to represent the human pilot by a linear pilot analog for the tracking task assumed in the present study. The criterion used to adjust the pilot analog was the root-mean-square tracking error of one of the human pilots on the fixed-base simulator. Matching the tracking error of the pilot analog to that of the human pilot gave an approximation to the variation of human-pilot behavior over a range of control-system dynamics. Results of the pilot-analog study indicated that both for optimized control-system dynamics (for poor airplane dynamics) and for a region of good airplane dynamics, the pilot response characteristics are approximately the same.

A Twin Study of Spatial and Non-Spatial Delayed Response Performance in Middle Age

ERIC Educational Resources Information Center

Kremen, William S.; Mai, Tuan; Panizzon, Matthew S.; Franz, Carol E.; Blankfeld, Howard M.; Xian, Hong; Eisen, Seth A.; Tsuang, Ming T.; Lyons, Michael J.

2011-01-01

Delayed alternation and object alternation are classic spatial and non-spatial delayed response tasks. We tested 632 middle-aged male veteran twins on variants of these tasks in order to compare test difficulty, measure their inter-correlation, test order effects, and estimate heritabilities (proportion of observed variance due to genetic…

Delays in Global Disease Outbreak Responses: Lessons from H1N1, Ebola, and Zika

PubMed Central

Silverberg, Sarah L.

2018-01-01

In global disease outbreaks, there are significant time delays between the source of an outbreak and collective action. Some delay is necessary, but recent delays have been extended by insufficient surveillance capacity and time-consuming efforts to mobilize action. Three public health emergencies of international concern (PHEICs)—H1N1, Ebola, and Zika—allow us to identify and compare sources of delays and consider seven hypotheses about what influences the length of delays. These hypotheses can then motivate further research that empirically tests them. The three PHEICs suggest that deferred global mobilization is a greater source of delay than is poor surveillance capacity. These case study outbreaks support hypotheses that we see quicker responses for novel diseases when outbreaks do not coincide with holidays and when US citizens are infected. They do not support hypotheses that we see quicker responses for more severe outbreaks or those that threaten larger numbers of people. Better understanding the reason for delays can help target policy interventions and identify the kind of global institutional changes needed to reduce the spread and severity of future PHEICs. PMID:29345996

Modeling human response errors in synthetic flight simulator domain

NASA Technical Reports Server (NTRS)

Ntuen, Celestine A.

1992-01-01

This paper presents a control theoretic approach to modeling human response errors (HRE) in the flight simulation domain. The human pilot is modeled as a supervisor of a highly automated system. The synthesis uses the theory of optimal control pilot modeling for integrating the pilot's observation error and the error due to the simulation model (experimental error). Methods for solving the HRE problem are suggested. Experimental verification of the models will be tested in a flight quality handling simulation.

Operational and Functional Description of the AERA Packages,

DTIC Science & Technology

1983-09-11

implications: * Very early coordination with the pilot may be effected, to allow the pilot to resolve the problem (since he has primary responsibility for...but that this is a situation of which the controller and the pilot may want to be aware for planning purposes. 4.3.2.3 Controller’s Response The primary ...data link will be greatly expanded in AERA 2.01. The primary capability that affects the operation of t he ATC system is that non-control messages

The role of luteinizing hormone-releasing hormone in the diagnosis of constitutional delayed puberty

PubMed Central

Sagel, Julius; Distiller, Larry A.; Joffe, Barry I.

1975-01-01

The presumptive diagnosis of constitutional delayed adolescence is difficult to substantiate. Clinical examination and routine biochemical testing are not sufficient to exclude isolated gonadotrophin deficiency. Seven males are reported who presented with delayed puberty. These patients were given 100 μg luteinizing hormone-releasing hormone (LH-RH) intravenously, and the luteinizing hormone (LH) and follicle stimulating hormone (FSH) responses were measured. Three of four males who were completely prepubertal (Stage 1) had a normal adult male response. These three patients have progressed further into puberty several months after this diagnostic test. The fourth patient in stage 1 puberty had a prepubertal LH response. A year later the response became adult in type, and 3 months thereafter stage 2 puberty was evident. The LH response to LH-RH thus appears to have some prognostic value in the assessment of males presenting with delayed puberty. PMID:1105498

Acquisition and Retention of Esperanto: The Case for Error Correction and Immediate Feedback

ERIC Educational Resources Information Center

Brosvic, Gary M.; Epstein, Michael L.; Dihoff, Roberta E.; Cook, Michael J.

2006-01-01

Participants completed 5 laboratory examinations during which the number of responses permitted (1 response, up to 4 responses) and the timing of feedback (no feedback control: Scantron form; delayed feedback: end-of-test, 24-hr delay; immediate feedback: assistant, response form) were manipulated. Participants completed a 100-item cumulative…

Survey of piloting factors in V/STOL aircraft with implications for flight control system design

NASA Technical Reports Server (NTRS)

Ringland, R. F.; Craig, S. J.

1977-01-01

Flight control system design factors involved for pilot workload relief are identified. Major contributors to pilot workload include configuration management and control and aircraft stability and response qualities. A digital fly by wire stability augmentation, configuration management, and configuration control system is suggested for reduction of pilot workload during takeoff, hovering, and approach.

Pilot modeling and closed-loop analysis of flexible aircraft in the pitch tracking task

NASA Technical Reports Server (NTRS)

Schmidt, D. K.

1983-01-01

The issue addressed in the appropriate modeling technique for pilot vehicle analysis of large flexible aircraft, when the frequency separation between the rigid-body mode and the dynamic aeroelastic modes is reduced. This situation was shown to have significant effects on pitch-tracking performance and subjective rating of the task, obtained via fixed base simulation. Further, the dynamics in these cases are not well modeled with a rigid-body-like model obtained by including only 'static elastic' effects, for example. It is shown that pilot/vehicle analysis of this data supports the hypothesis that an appropriate pilot-model structure is an optimal-control pilot model of full order. This is in contrast to the contention that a representative model is of reduced order when the subject is controlling high-order dynamics as in a flexible vehicle. The key appears to be in the correct assessment of the pilot's objective of attempting to control 'rigid-body' vehicle response, a response that must be estimated by the pilot from observations contaminated by aeroelastic dynamics. Finally, a model-based metric is shown to correlate well with the pilot's subjective ratings.

Development and pilot testing of daily Interactive Voice Response (IVR) calls to support antiretroviral adherence in India: A mixed-methods pilot study

PubMed Central

Swendeman, Dallas; Jana, Smarajit; Ray, Protim; Mindry, Deborah; Das, Madhushree; Bhakta, Bhumi

2015-01-01

This two-phase pilot study aimed to design, pilot, and refine an automated Interactive Voice Response (IVR) intervention to support antiretroviral adherence for people living with HIV (PLH), in Kolkata, India. Mixed-methods formative research included a community advisory board (CAB) for IVR message development, one-month pre-post pilot, post-pilot focus groups, and further message development. Two IVR calls are made daily, timed to patients’ dosing schedules, with brief messages (<1-minute) on strategies for self-management of three domains: medical (adherence, symptoms, co-infections), mental health (social support, stress, positive cognitions), and nutrition and hygiene (per PLH preferences). Three ART appointment reminders are also sent each month. One-month pilot results (n=46, 80% women, 60% sex workers) found significant increases in self-reported ART adherence, both within past three days (p=0.05) and time since missed last dose (p=0.015). Depression was common. Messaging content and assessment domains were expanded for testing in a randomized trial is currently underway. PMID:25638037

Development and Pilot Testing of Daily Interactive Voice Response (IVR) Calls to Support Antiretroviral Adherence in India: A Mixed-Methods Pilot Study.

PubMed

Swendeman, Dallas; Jana, Smarajit; Ray, Protim; Mindry, Deborah; Das, Madhushree; Bhakta, Bhumi

2015-06-01

This two-phase pilot study aimed to design, pilot, and refine an automated interactive voice response (IVR) intervention to support antiretroviral adherence for people living with HIV (PLH), in Kolkata, India. Mixed-methods formative research included a community advisory board for IVR message development, 1-month pre-post pilot, post-pilot focus groups, and further message development. Two IVR calls are made daily, timed to patients' dosing schedules, with brief messages (<1-min) on strategies for self-management of three domains: medical (adherence, symptoms, co-infections), mental health (social support, stress, positive cognitions), and nutrition and hygiene (per PLH preferences). Three ART appointment reminders are also sent each month. One-month pilot results (n = 46, 80 % women, 60 % sex workers) found significant increases in self-reported ART adherence, both within past three days (p = 0.05) and time since missed last dose (p = 0.015). Depression was common. Messaging content and assessment domains were expanded for testing in a randomized trial currently underway.

Assessment of Crew Workload for the RAH-66 Comanche Force Development Experiment 1

DTIC Science & Technology

2001-10-01

Scale and a cockpit controls and displays usability questionnaire . Results of the assessment indicate that (a) workload was tolerable for the pilots...Workload Levels Between Front Seat and Back Seat 13 3.4 Pilot Responses to Controls and Displays Usability Questionnaire 13 3.5 HMD Symbology 13 4... questionnaire . The data were analyzed to determine if the pilot flying the aircraft (pilot on controls) and the pilot operating the mission equipment

Incorporating Data Link Messaging into a Multi-function Display for General Aviation Aircraft

NASA Technical Reports Server (NTRS)

Adams, Catherine A.; Murdoch, Jennifer L.

2006-01-01

One objective of the Small Aircraft Transportation System (SATS) Project is to increase the capacity and utilization of small non-towered, non-radar equipped airports by transferring traffic management activities to an automated system and separation responsibilities to general aviation (GA) pilots. This paper describes the development of a research multi-function display (MFD) to support the interaction between pilots and an automated Airport Management Module (AMM). Preliminary results of simulation and flight tests indicate that adding the responsibility of monitoring other traffic for self-separation does not increase pilots subjective workload levels. Pilots preferred using the enhanced MFD to execute flight procedures, reporting improved situation awareness over conventional instrument flight rules (IFR) procedures.

ASTRONAUT COOPER, GORDON - PRELAUNCH MERCURY-ATLAS (MA)-9 - "FAITH 7" - INSERTION - CAPE CANAVERAL, FL

NASA Image and Video Library

1963-05-14

S63-06259 (14 May 1963) --- Astronaut L. Gordon Cooper Jr., prime pilot for the Mercury-Atlas 9 (MA-9) mission, is assisted into his "Faith 7" Mercury spacecraft early morning on May 14, 1963. Cooper remained in the spacecraft for approximately five hours and then climbed out again as the mission was delayed because of trouble at a tracking station. Photo credit: NASA

Effect of pregnancy on the pharmacokinetics of paclitaxel: a case report.

PubMed

Lycette, Jennifer L; Dul, Carrie L; Munar, Myrna; Belle, Donna; Chui, Stephen Y; Koop, Dennis R; Nichols, Craig R

2006-10-01

Breast cancer during pregnancy is increasingly common as women delay childbearing until later in life. Safe administration of adjuvant chemotherapy during pregnancy has been reported. Physiologic and metabolic changes during pregnancy could alter the pharmacokinetics of these agents. This is a pilot study to prospectively study the pharmacokinetics of chemotherapeutic agents during pregnancy. Herein, we report the initial results with paclitaxel in the first patient.

Utility of the advanced chronic kidney disease patient management tools: case studies.

PubMed

Patwardhan, Meenal B; Matchar, David B; Samsa, Gregory P; Haley, William E

2008-01-01

Appropriate management of advanced chronic kidney disease (CKD) delays or limits its progression. The Advanced CKD Patient Management Toolkit was developed using a process-improvement technique to assist patient management and address CKD-specific management issues. We pilot tested the toolkit in 2 community nephrology practices, assessed the utility of individual tools, and evaluated the impact on conformance to an advanced CKD guideline through patient chart abstraction. Tool use was distinct in the 2 sites and depended on the site champion's involvement, the extent of process reconfiguration demanded by a tool, and its perceived value. Baseline conformance varied across guideline recommendations (averaged 54%). Posttrial conformance increased in all clinical areas (averaged 59%). Valuable features of the toolkit in real-world settings were its ability to: facilitate tool selection, direct implementation efforts in response to a baseline performance audit, and allow selection of tool versions and customizing them. Our results suggest that systematically created, multifaceted, and customizable tools can promote guideline conformance.

A-Salivary antibody responses as an indicator of waterborne infections: Pilot community study before and after installation of UV treatment

EPA Science Inventory

This ongoing project involves the development, validation and pilot application of a multiplex immunoassay based on Luminex microsphere technology to measure salivary antibody responses to the potentially-waterborne pathogens, noroviruses (Norwalk, VA387 and VA207), rotaviruses, ...

Monaural and binaural response properties of neurons in the inferior colliculus of the rabbit: effects of sodium pentobarbital.

PubMed

Kuwada, S; Batra, R; Stanford, T R

1989-02-01

1. We studied the effects of sodium pentobarbital on 22 neurons in the inferior colliculus (IC) of the rabbit. We recorded changes in the sensitivity of these neurons to monaural stimulation and to ongoing interaural time differences (ITDs). Monaural stimuli were tone bursts at or near the neuron's best frequency. The ITD was varied by delivering tones that differed by 1 Hz to the two ears, resulting in a 1-Hz binaural beat. 2. We assessed a neuron's ITD sensitivity by calculating three measures from the responses to binaural beats: composite delay, characteristic delay (CD), and characteristic phase (CP). To obtain the composite delay, we first derived period histograms by averaging, showing the response at each stimulating frequency over one period of the beat frequency. Second, the period histograms were replotted as a function of their equivalent interaural delay and then averaged together to yield the composite delay curve. Last, we calculated the composite peak or trough delay by fitting a parabola to the peak or trough of this composite curve. The composite delay curve represents the average response to all frequencies within the neuron's responsive range, and the peak reflects the interaural delay that produces the maximum response. The CD and CP were estimated from a weighted fit of a regression line to the plot of the mean interaural phase of the response versus the stimulating frequency. The slope and phase intercept of this regression line yielded estimates of CD and CP, respectively. These two quantities are thought to reflect the mechanism of ITD sensitivity, which involves the convergence of phase-locked inputs on a binaural cell. The CD estimates the difference in the time required for the two inputs to travel from either ear to this cell, whereas the CP reflects the interaural phase difference of the inputs at this cell. 3. Injections of sodium pentobarbital at subsurgical dosages (less than 25 mg/kg) almost invariably altered the neuron's response rate, response latency, response pattern, and spontaneous activity. Most of these changes were predictable and consistent with an enhancement of inhibitory influences. For example, if the earliest response was inhibitory, later excitation was usually reduced and latency increased. If the earliest response was excitatory, the level of this excitation was unaltered or slightly enhanced, and changes in latency were minimal. 4. The neuron's response pattern also changed in a predictable way. For example, a response with an inhibitory pause could either change to a response with a longer pause or to a response with an onset only.(ABSTRACT TRUNCATED AT 400 WORDS)

Two memories for geographical slant: separation and interdependence of action and awareness

NASA Technical Reports Server (NTRS)

Creem, S. H.; Proffitt, D. R.; Kaiser, M. K. (Principal Investigator)

1998-01-01

The present study extended previous findings of geographical slant perception, in which verbal judgments of the incline of hills were greatly overestimated but motoric (haptic) adjustments were much more accurate. In judging slant from memory following a brief or extended time delay, subjects' verbal judgments were greater than those given when viewing hills. Motoric estimates differed depending on the length of the delay and place of response. With a short delay, motoric adjustments made in the proximity of the hill did not differ from those evoked during perception. When given a longer delay or when taken away from the hill, subjects' motoric responses increased along with the increase in verbal reports. These results suggest two different memorial influences on action. With a short delay at the hill, memory for visual guidance is separate from the explicit memory informing the conscious response. With short or long delays away from the hill, short-term visual guidance memory no longer persists, and both motor and verbal responses are driven by an explicit representation. These results support recent research involving visual guidance from memory, where actions become influenced by conscious awareness, and provide evidence for communication between the "what" and "how" visual processing systems.

Connected vehicle pilot deployment program phase 1, deployment outreach plan -- New York City.

DOT National Transportation Integrated Search

2016-07-19

This document is a high level plan that describes the Outreach Plan for the New York City Connected Vehicle Pilot Deployment. The plan defines the communications strategy for the CV Pilot Deployment; identifies roles and responsibilities of persons t...

Acute ethanol effects on neural encoding of reward size and delay in the nucleus accumbens

PubMed Central

Gutman, Andrea L.

2016-01-01

Acute ethanol administration can cause impulsivity, resulting in increased preference for immediately available rewards over delayed but more valuable alternatives. The manner in which reward size and delay are represented in neural firing is not fully understood, and very little is known about ethanol effects on this encoding. To address this issue, we used in vivo electrophysiology to characterize neural firing in the core of the nucleus accumbens (NAcc) in rats responding for rewards that varied in size or delay after vehicle or ethanol administration. The NAcc is a central element in the circuit that governs decision-making and importantly, promotes choice of delayed rewards. We found that NAcc firing in response to reward-predictive cues encoded anticipated reward value after vehicle administration, but ethanol administration disrupted this encoding, resulting in a loss of discrimination between immediate and delayed rewards in cue-evoked neural responses. In addition, NAcc firing occurring at the time of the operant response (lever pressing) was inversely correlated with behavioral response latency, such that increased firing rates were associated with decreased latencies to lever press. Ethanol administration selectively attenuated this lever press-evoked firing when delayed but not immediate rewards were expected. These effects on neural firing were accompanied by increased behavioral latencies to respond for delayed rewards. Our results suggest that ethanol effects on NAcc cue- and lever press-evoked encoding may contribute to ethanol-induced impulsivity. PMID:27169507

INfluence of Successful Periodontal Intervention in REnal Disease (INSPIRED): study protocol for a randomised controlled pilot clinical trial.

PubMed

Sharma, Praveen; Cockwell, Paul; Dietrich, Thomas; Ferro, Charles; Ives, Natalie; Chapple, Iain L C

2017-11-13

Patients with chronic kidney disease (CKD) exhibit increased morbidity and mortality which is associated with an increased systemic inflammatory burden. Identifying and managing comorbid diseases that contribute to this load may inform novel care pathways that could have a beneficial impact on the morbidity/mortality associated with CKD. Periodontitis, a highly prevalent, chronic inflammatory disease affecting the supporting structures of teeth, is associated with an increased systemic inflammatory and oxidative stress burden and the successful treatment of periodontitis has been shown to reduce both. This pilot study aims to gather data to inform a definitive study into the impact of successful periodontal treatment on the cardio-renal health of patients with CKD. This pilot study will employ a randomised, controlled, parallel-group design. Sixty adult patients, with CKD with a high risk of progression and with periodontitis, from the Queen Elizabeth Hospital, Birmingham, will be randomised to receive either immediate, intensive periodontal treatment (n = 30) or treatment at a delay of 12 months (n = 30). Patients will be excluded if they have reached end-stage renal disease or have received specialist periodontal treatment in the previous year. Periodontal treatment will be delivered under local anaesthetic, on an outpatient basis, over several visits by a qualified dental hygienist at the Birmingham Dental Hospital, UK. Patients in the delayed-treatment arm will continue to receive the standard community level of periodontal care for a period of 12 months followed by the intensive periodontal treatment. Randomization will occur using a centralised telephone randomisation service, following baseline assessments. The assessor of periodontal health will be blinded to the patients' treatment allocation. Patients in either arm will be followed up at 3-monthly intervals for 18 months. Aside from the pilot outcomes to inform the practicalities of a larger trial later, data on cardio-renal function, periodontal health and patient-reported outcomes will be collected at each time point. This pilot randomised controlled trial will investigate the viability of undertaking a larger-scale study investigating the effect of treating periodontitis and maintaining periodontal health on cardio-renal outcomes in patients with CKD. National Institute of Health Research (NIHR) Clinical Research Network (UKCRN ID: 18458), ID: ISRCTN10227738 . Registered retrospectively to both registers on 23 April 2015.

High thresholds for avoidance of sonar by free-ranging long-finned pilot whales (Globicephala melas).

PubMed

Antunes, R; Kvadsheim, P H; Lam, F P A; Tyack, P L; Thomas, L; Wensveen, P J; Miller, P J O

2014-06-15

The potential effects of exposing marine mammals to military sonar is a current concern. Dose-response relationships are useful for predicting potential environmental impacts of specific operations. To reveal behavioral response thresholds of exposure to sonar, we conducted 18 exposure/control approaches to 6 long-finned pilot whales. Source level and proximity of sonar transmitting one of two frequency bands (1-2 kHz and 6-7 kHz) were increased during exposure sessions. The 2-dimensional movement tracks were analyzed using a changepoint method to identify the avoidance response thresholds which were used to estimate dose-response relationships. No support for an effect of sonar frequency or previous exposures on the probability of response was found. Estimated response thresholds at which 50% of population show avoidance (SPLmax=170 dB re 1 μPa, SELcum=173 dB re 1 μPa(2) s) were higher than previously found for other cetaceans. The US Navy currently uses a generic dose-response relationship to predict the responses of cetaceans to naval active sonar, which has been found to underestimate behavioural impacts on killer whales and beaked whales. The navy curve appears to match more closely our results with long-finned pilot whales, though it might underestimate the probability of avoidance for pilot-whales at long distances from sonar sources. Copyright © 2014 Elsevier Ltd. All rights reserved.

Ignition Delay of Combustible Materials in Normoxic Equivalent Environments

NASA Technical Reports Server (NTRS)

McAllister, Sara; Fernandez-Pello, Carlos; Ruff, Gary; Urban, David

2009-01-01

Material flammability is an important factor in determining the pressure and composition (fraction of oxygen and nitrogen) of the atmosphere in the habitable volume of exploration vehicles and habitats. The method chosen in this work to quantify the flammability of a material is by its ease of ignition. The ignition delay time was defined as the time it takes a combustible material to ignite after it has been exposed to an external heat flux. Previous work in the Forced Ignition and Spread Test (FIST) apparatus has shown that the ignition delay in the currently proposed space exploration atmosphere (approximately 58.6 kPa and32% oxygen concentration) is reduced by 27% compared to the standard atmosphere used in the Space Shuttle and Space Station. In order to determine whether there is a safer environment in terms of material flammability, a series of piloted ignition delay tests using polymethylmethacrylate (PMMA) was conducted in the FIST apparatus to extend the work over a range of possible exploration atmospheres. The exploration atmospheres considered were the normoxic equivalents, i.e. reduced pressure conditions with a constant partial pressure of oxygen. The ignition delay time was seen to decrease as the pressure was reduced along the normoxic curve. The minimum ignition delay observed in the normoxic equivalent environments was nearly 30% lower than in standard atmospheric conditions. The ignition delay in the proposed exploration atmosphere is only slightly larger than this minimum. Interms of material flammability, normoxic environments with a higher pressure relative to the proposed pressure would be desired.

Intraspecific priority effects modify compensatory responses to changes in hatching phenology in an amphibian.

PubMed

Murillo-Rincón, Andrea P; Kolter, Nora A; Laurila, Anssi; Orizaola, Germán

2017-01-01

In seasonal environments, modifications in the phenology of life-history events can alter the strength of time constraints experienced by organisms. Offspring can compensate for a change in timing of hatching by modifying their growth and development trajectories. However, intra- and interspecific interactions may affect these compensatory responses, in particular if differences in phenology between cohorts lead to significant priority effects (i.e. the competitive advantage that early-hatching individuals have over late-hatching ones). Here, we conducted a factorial experiment to determine whether intraspecific priority effects can alter compensatory phenotypic responses to hatching delay in a synchronic breeder by rearing moor frog (Rana arvalis) tadpoles in different combinations of phenological delay and food abundance. Tadpoles compensated for the hatching delay by speeding up their development, but only when reared in groups of individuals with identical hatching phenology. In mixed phenology groups, strong competitive effects by non-delayed tadpoles prevented the compensatory responses and delayed larvae metamorphosed later than in single phenology treatments. Non-delayed individuals gained advantage from developing with delayed larvae by increasing their developmental and growth rates as compared to single phenology groups. Food shortage prolonged larval period and reduced mass at metamorphosis in all treatments, but it did not prevent compensatory developmental responses in larvae reared in single phenology groups. This study demonstrates that strong intraspecific priority effects can constrain the compensatory growth and developmental responses to phenological change, and that priority effects can be an important factor explaining the maintenance of synchronic life histories (i.e. explosive breeding) in seasonal environments. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

Father's role in parent training for children with developmental delay.

PubMed

Bagner, Daniel M

2013-08-01

The current pilot study was a quasi-experimental examination of the impact of father involvement in parent training among 44 families with a young child who presented with elevated externalizing behavior problems and developmental delay. All families were offered to receive Parent-Child Interaction Therapy (PCIT), an evidence-based parent-training intervention, at a hospital-based outpatient clinic. Single-mother families were significantly more likely to drop out of treatment than two-parent families. Of the families that completed treatment, children from families in which a father participated in treatment had lower levels of parent-reported externalizing behavior problems than children from single-mother families and children from two-parent families in which the father did not participate in treatment. Additionally, children from father-involved families were significantly more compliant during a cleanup task than children from single-mother families following treatment. The current study is consistent with the limited research examining father involvement in parent training and extends the findings to children with developmental delay. These findings highlight the importance of involving fathers in parent training, particularly when working with children with developmental delay. © 2013 American Psychological Association

Parental concerns, provider response, and timeliness of autism spectrum disorder diagnosis.

PubMed

Zuckerman, Katharine Elizabeth; Lindly, Olivia Jasmine; Sinche, Brianna Kathleen

2015-06-01

To assess differences between child age at first parental concern and age at first parental discussion of concerns with a health care provider among children with autism spectrum disorder (ASD) vs those with intellectual disability/developmental delay (ID/DD), and to assess whether provider response to parental concerns is associated with delays in ASD diagnosis. Using nationally representative data from the 2011 Survey of Pathways to Diagnosis and Treatment, we compared child age at parent's first developmental concern with age at first discussion of concerns with a provider, and categorized provider response as proactive or reassuring/passive, among 1420 children with ASD and 2098 children with ID/DD. In the children with ASD, we tested the association between provider response type and years of diagnostic delay. Compared with children with ID/DD, children with ASD were younger when parents first had concerns and first discussed those concerns with a provider. Compared with parents of children with ID/DD, parents of children with ASD were less likely to receive proactive responses to their concerns and more likely to receive reassuring/passive responses. Among children with ASD, those with more proactive provider responses to concerns had shorter delays in ASD diagnosis compared with those with passive/reassuring provider responses. Although parents of children with ASD have early concerns, delays in diagnosis are common, particularly when providers' responses are reassuring or passive, highlighting the need for targeted improvements in primary care. Copyright © 2015 Elsevier Inc. All rights reserved.

A Nonlinear Model for Transient Responses from Light-Adapted Wolf Spider Eyes

PubMed Central

DeVoe, Robert D.

1967-01-01

A quantitative model is proposed to test the hypothesis that the dynamics of nonlinearities in retinal action potentials from light-adapted wolf spider eyes may be due to delayed asymmetries in responses of the visual cells. For purposes of calculation, these delayed asymmetries are generated in an analogue by a time-variant resistance. It is first shown that for small incremental stimuli, the linear behavior of such a resistance describes peaking and low frequency phase lead in frequency responses of the eye to sinusoidal modulations of background illumination. It also describes the overshoots in linear step responses. It is next shown that the analogue accounts for nonlinear transient and short term DC responses to large positive and negative step stimuli and for the variations in these responses with changes in degree of light adaptation. Finally, a physiological model is proposed in which the delayed asymmetries in response are attributed to delayed rectification by the visual cell membrane. In this model, cascaded chemical reactions may serve to transduce visual stimuli into membrane resistance changes. PMID:6056011

Gravitropism in higher plant shoots. I - A role for ethylene

NASA Technical Reports Server (NTRS)

Wheeler, Raymond M.; Salisbury, Frank B.

1981-01-01

Two inhibitors of ethylene synthesis, Co(2+) and aminoethoxyvinylglycine (AVG), and two inhibitors of ethylene action, Ag(+) and CO2, are shown to delay the gravitropic response of cocklebur (Xanthium strumarium L.), tomato (Lycopersicon esculentum Mill.), and castor bean (Ricinus communis L.) stems. Gentle shaking on a mechanical shaker does not inhibit the gravitropic response, but vigorous hand shaking for 120 seconds delays the response somewhat. AVG and Ag(+) further delay the response of mechanically stimulated plants. AVG retards the storage of bending energy but not of stimulus. In gravitropism, graviperception may first stimulate ethylene evolution, which may then influence bending directly, or responses involving ethylene could be more indirect.

Effect of Pressure on Piloted Ignition Delay of PMMA

NASA Technical Reports Server (NTRS)

McAllister, Sara; Lai, Janice; Scott, Sarah; Ramirez-Correa, Amelia; Fernandez-Pello, Carlos; Urban, David; Ruff, Gary

2008-01-01

In order to reduce the risk of decompression sickness associated with spacewalks, NASA is considering designing the next generation of exploration vehicles and habitats with a different cabin environment than used previously. The proposed environment uses a total cabin pressure of 52.7 to 58.6 kPa with an oxygen concentration of 30 to 34% by volume and was chosen with material flammability in mind. Because materials may burn differently under these conditions and there is little information on how this new environment affects the flammability of the materials onboard, it is important to conduct material flammability experiments at the intended exploration atmosphere. One method to evaluate material flammability is by its ease of ignition. To this end, piloted ignition delay tests were conducted in the Forced Ignition and Spread Test (FIST) apparatus subject to this new environment. In these tests, polymethylmethacylate (PMMA) was exposed to a range of oxidizer flow velocities and externally applied heat fluxes. The ultimate goal is to determine the individual effect of pressure and the combined effect of pressure and oxygen concentration on the ignition delay. Tests were conducted for a baseline case of normal pressure and oxygen concentration, low pressure (58.6 kPa) with normal oxygen (21%). Future work will focus on low pressure with 32% oxygen concentration (space exploration atmosphere - SEA) conditions. It was found that reducing the pressure while keeping the oxygen concentration at 21% reduced the ignition time by 17% on average. It was also noted that the critical heat flux for ignition decreases in low-pressure conditions. Because tests conducted in standard atmospheric conditions will underpredict the flammability of materials intended for use on spacecraft, fire safety onboard at exploration atmospheres may be compromised.

Piloted Ignition Delay of PMMA in Space Exploration Atmospheres

NASA Technical Reports Server (NTRS)

McAllister, Sara; Fernandez-Pello, Carlos; Urban, David; Ruff, Gary

2007-01-01

In order to reduce the risk of decompression sickness associated with extravehicular activity (EVA), NASA is designing the next generation of exploration vehicles and habitats with a different cabin environment than used previously. The proposed environment uses a total cabin pressure of 52.7 to 58.6 kPa with an oxygen concentration of 30 to 34% by volume and was chosen with material flammability in mind. Because materials may burn differently under these conditions and there is little information on how this new environment affects the flammability of the materials onboard, it is important to conduct material flammability experiments at the intended exploration atmosphere. One method to evaluate material flammability is by its ease of ignition. To this end, piloted ignition delay tests were conducted in the Forced Ignition and Spread Test (FIST) apparatus subject to this new environment. In these tests, polymethylmethacylate (PMMA) was exposed to a range of oxidizer flow velocities and externally applied heat fluxes. Tests were conducted for a baseline case of normal pressure and oxygen concentration, low pressure (58.6 kPa) with normal oxygen (21%), and low pressure with 32% oxygen concentration conditions to determine the individual effect of pressure and the combined effect of pressure and oxygen concentration on the ignition delay. It was found that reducing the pressure while keeping the oxygen concentration at 21% reduced the ignition time by 17% on average. Increasing the oxygen concentration at low pressures reduced the ignition time by an additional 10%. It was also noted that the critical heat flux for ignition decreases at exploration atmospheres. These results show that tests conducted in standard atmospheric conditions will underpredict the ignition of materials intended for use on spacecraft and that, at these conditions, materials are more susceptible to ignition than at current spacecraft atmospheres.

The Parental Emotional Response to Children Index.

PubMed

Lambek, Rikke; Sonuga-Barke, Edmund; Psychogiou, Lamprini; Thompson, Margaret; Tannock, Rosemary; Daley, David; Damm, Dorte; Thomsen, Per Hove

2017-04-01

The current study introduces the Parental Emotional Response to Children Index (PERCI), a new questionnaire specifically designed to measure parents' emotional response to ADHD and related behaviors (delay discounting and delay aversion). The PERCI was completed by parents of 6- to 14-year-old children with ( n = 126) and without ( n = 160) ADHD. Factor analysis confirmed five separate subscales with acceptable psychometric properties. Parents of children with ADHD reported a stronger emotional response to ADHD behaviors than parents of typically developing children and inattention symptoms evoked the strongest emotional response in parents regardless of child diagnostic status. Parents' emotional responses appear to be differentiated in terms of specific ADHD-related triggers mapping onto the different domains of ADHD and delay-related responses. Further research is required to understand changes in parental emotional responses over time and their impact on children's developmental trajectories.

How long can fisheries management delay action in response to ecosystem and climate change?

PubMed

Brown, Christopher J; Fulton, Elizabeth A; Possingham, Hugh P; Richardson, Anthony J

2012-01-01

Sustainable management of fisheries is often compromised by management delaying implementation of regulations that reduce harvest, in order to maintain higher catches in the short-term. Decreases or increases in fish population growth rate driven by environmental change, including ecosystem and climate change, affect the harvest that can be taken sustainably. If not acted on rapidly, environmental change could result in unsustainable fishing or missed opportunity for higher catches. Using simulation models of harvested fish populations influenced by environmental change, we explore how long fisheries managers can afford to wait before changing harvest regulations in response to changes in population growth. If environmental change causes population declines, delays greater than five years increase the probability of population collapse. Species with fast and highly variable population growth rates are more susceptible to collapse under delays and should be a priority for revised management where delays occur. Generally, the long-term cost of delay, in terms of lost fishing opportunity, exceeds the short-term benefits of overfishing. Lowering harvest limits and monitoring for environmental change can alleviate the impact of delays; however, these measures may be more costly than reducing delays. We recommend that management systems that allow rapid responses to population growth changes be enacted for fisheries management to adapt to ecosystem and climate change.

A Comparative Data-Based Modeling Study on Respiratory CO2 Gas Exchange during Mechanical Ventilation

PubMed Central

Kim, Chang-Sei; Ansermino, J. Mark; Hahn, Jin-Oh

2016-01-01

The goal of this study is to derive a minimally complex but credible model of respiratory CO2 gas exchange that may be used in systematic design and pilot testing of closed-loop end-tidal CO2 controllers in mechanical ventilation. We first derived a candidate model that captures the essential mechanisms involved in the respiratory CO2 gas exchange process. Then, we simplified the candidate model to derive two lower-order candidate models. We compared these candidate models for predictive capability and reliability using experimental data collected from 25 pediatric subjects undergoing dynamically varying mechanical ventilation during surgical procedures. A two-compartment model equipped with transport delay to account for CO2 delivery between the lungs and the tissues showed modest but statistically significant improvement in predictive capability over the same model without transport delay. Aggregating the lungs and the tissues into a single compartment further degraded the predictive fidelity of the model. In addition, the model equipped with transport delay demonstrated superior reliability to the one without transport delay. Further, the respiratory parameters derived from the model equipped with transport delay, but not the one without transport delay, were physiologically plausible. The results suggest that gas transport between the lungs and the tissues must be taken into account to accurately reproduce the respiratory CO2 gas exchange process under conditions of wide-ranging and dynamically varying mechanical ventilation conditions. PMID:26870728

A seat cushion to provide realistic acceleration cues for aircraft simulators

NASA Technical Reports Server (NTRS)

Ashworth, B. R.

1976-01-01

A seat cushion to provide acceleration cues for aircraft simulator pilots was built, performance tested, and evaluated. The four cell seat, using a thin air cushion with highly responsive pressure control, attempts to reproduce the same events which occur in an aircraft seat under acceleration loading. The pressure controller provides seat cushion responses which are considered adequate for current high performance aircraft simulations. The initial tests of the seat cushions have resulted in excellent pilot opinion of the cushion's ability to provide realistic and useful cues to the simulator pilot.

A nonlinear delayed model for the immune response in the presence of viral mutation

NASA Astrophysics Data System (ADS)

Messias, D.; Gleria, Iram; Albuquerque, S. S.; Canabarro, Askery; Stanley, H. E.

2018-02-01

We consider a delayed nonlinear model of the dynamics of the immune system against a viral infection that contains a wild-type virus and a mutant. We consider the finite response time of the immune system and find sustained oscillatory behavior as well as chaotic behavior triggered by the presence of delays. We present a numeric analysis and some analytical results.

Combining destination diversion decisions and critical in-flight event diagnosis in computer aided testing of pilots

NASA Technical Reports Server (NTRS)

Rockwell, T. H.; Giffin, W. C.; Romer, D. J.

1984-01-01

Rockwell and Giffin (1982) and Giffin and Rockwell (1983) have discussed the use of computer aided testing (CAT) in the study of pilot response to critical in-flight events. The present investigation represents an extension of these earlier studies. In testing pilot responses to critical in-flight events, use is made of a Plato-touch CRT system operating on a menu based format. In connection with the typical diagnostic problem, the pilot was presented with symptoms within a flight scenario. In one problem, the pilot has four minutes for obtaining the information which is needed to make a diagnosis of the problem. In the reported research, the attempt has been made to combine both diagnosis and diversion scenario into a single computer aided test. Tests with nine subjects were conducted. The obtained results and their significance are discussed.

76 FR 20699 - Fellowship Placement Pilot Program Requests for Expressions of Interest To Administer Pilot

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-13

... program. The Administrator will be primarily responsible for marketing and advertising the program in... demonstrated history of direct public service or placement of public servants within the last 24 months. This... success of the fellowship program. iii. What it thinks the key responsibilities of the local organizations...

A piloted simulation of helicopter air combat to investigate effects of variations in selected performance and control response characteristics

NASA Technical Reports Server (NTRS)

Lewis, Michael S.; Mansur, M. Hossein; Chen, Robert T. N.

1987-01-01

A piloted simulation study investigating handling qualities and flight characteristics required for helicopter air to air combat is presented. The Helicopter Air Combat system was used to investigate this role for Army rotorcraft. Experimental variables were the maneuver envelope size (load factor and sideslip), directional axis handling qualities, and pitch and roll control-response type. Over 450 simulated, low altitude, one-on-one engagements were conducted. Results from the experiment indicate that a well damped directional response, low sideforce caused by sideslip, and some effective dihedral are all desirable for weapon system performance, good handling qualities, and low pilot workload. An angular rate command system was favored over the attitude type pitch and roll response for most applications, and an enhanced maneuver envelope size over that of current generation aircraft was found to be advantageous. Pilot technique, background, and experience are additional factors which had a significant effect on performance in the air combat tasks investigated. The implication of these results on design requirements for future helicopters is presented.

Linking the Pilot Structural Model and Pilot Workload

NASA Technical Reports Server (NTRS)

Bachelder, Edward; Hess, Ronald; Aponso, Bimal; Godfroy-Cooper, Martine

2018-01-01

Behavioral models are developed that closely reproduced pulsive control response of two pilots using markedly different control techniques while conducting a tracking task. An intriguing find was that the pilots appeared to: 1) produce a continuous, internally-generated stick signal that they integrated in time; 2) integrate the actual stick position; and 3) compare the two integrations to either issue or cease a pulse command. This suggests that the pilots utilized kinesthetic feedback in order to sense and integrate stick position, supporting the hypothesis that pilots can access and employ the proprioceptive inner feedback loop proposed by Hess's pilot Structural Model. A Pilot Cost Index was developed, whose elements include estimated workload, performance, and the degree to which the pilot employs kinesthetic feedback. Preliminary results suggest that a pilot's operating point (parameter values) may be based on control style and index minimization.

Delay-induced stochastic bifurcations in a bistable system under white noise

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

Sun, Zhongkui, E-mail: sunzk@nwpu.edu.cn; Fu, Jin; Xu, Wei

2015-08-15

In this paper, the effects of noise and time delay on stochastic bifurcations are investigated theoretically and numerically in a time-delayed Duffing-Van der Pol oscillator subjected to white noise. Due to the time delay, the random response is not Markovian. Thereby, approximate methods have been adopted to obtain the Fokker-Planck-Kolmogorov equation and the stationary probability density function for amplitude of the response. Based on the knowledge that stochastic bifurcation is characterized by the qualitative properties of the steady-state probability distribution, it is found that time delay and feedback intensity as well as noise intensity will induce the appearance of stochasticmore » P-bifurcation. Besides, results demonstrated that the effects of the strength of the delayed displacement feedback on stochastic bifurcation are accompanied by the sensitive dependence on time delay. Furthermore, the results from numerical simulations best confirm the effectiveness of the theoretical analyses.« less

77 FR 16232 - Disease, Disability, and Injury Prevention and Control Special Emphasis Panel (SEP): A Pilot...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-20

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention Disease, Disability, and Injury Prevention and Control Special Emphasis Panel (SEP): A Pilot Surveillance for High... in response to ``A Pilot Surveillance for High Impact/Low Prevalence Congenital and Inherited...

Finite-time hybrid projective synchronization of the drive-response complex networks with distributed-delay via adaptive intermittent control

NASA Astrophysics Data System (ADS)

Cheng, Lin; Yang, Yongqing; Li, Li; Sui, Xin

2018-06-01

This paper studies the finite-time hybrid projective synchronization of the drive-response complex networks. In the model, general transmission delays and distributed delays are also considered. By designing the adaptive intermittent controllers, the response network can achieve hybrid projective synchronization with the drive system in finite time. Based on finite-time stability theory and several differential inequalities, some simple finite-time hybrid projective synchronization criteria are derived. Two numerical examples are given to illustrate the effectiveness of the proposed method.

A Novel Energy Saving Algorithm with Frame Response Delay Constraint in IEEE 802.16e

NASA Astrophysics Data System (ADS)

Nga, Dinh Thi Thuy; Kim, Mingon; Kang, Minho

Sleep-mode operation of a Mobile Subscriber Station (MSS) in IEEE 802.16e effectively saves energy consumption; however, it induces frame response delay. In this letter, we propose an algorithm to quickly find the optimal value of the final sleep interval in sleep-mode in order to minimize energy consumption with respect to a given frame response delay constraint. The validations of our proposed algorithm through analytical results and simulation results suggest that our algorithm provide a potential guidance to energy saving.

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

Allowing Brief Delays in Responding Improves Event-Based Prospective Memory for Young Adults Living with HIV Disease

PubMed Central

Loft, Shayne; Doyle, Katie L.; Naar-King, Sylvie; Outlaw, Angulique Y.; Nichols, Sharon L.; Weber, Erica; Blackstone, Kaitlin; Woods, Steven Paul

2014-01-01

Event-based prospective memory (PM) tasks require individuals to remember to perform an action when they encounter a specific cue in the environment, and have clear relevance for daily functioning for individuals with HIV. In many everyday tasks, the individual must not only maintain the intent to perform the PM task, but the PM task response also competes with the alternative and more habitual task response. The current study examined whether event-based PM can be improved by slowing down the pace of the task environment. Fifty-seven young adults living with HIV performed an ongoing lexical decision task while simultaneously performing a PM task of monitoring for a specific word (which was focal to the ongoing task of making lexical decisions) or syllable contained in a word (which was nonfocal). Participants were instructed to refrain from making task responses until after a tone was presented, which occurred at varying onsets (0–1600ms) after each stimulus appeared. Improvements in focal and non-focal PM accuracy were observed with response delays of 600ms. Furthermore, the difference in PM accuracy between the low demand focal PM task and the resource demanding non-focal PM task was reduced by half across increasingly longer delays, falling from 31% at 0ms delay to only 14% at 1600ms delay. The degree of ongoing task response slowing for the PM conditions, relative to a control condition that did not have a PM task and made lexical decisions only, also decreased with increased delay. Overall, the evidence indicates that delaying the task responses of younger HIV-infected adults increased the probability that the PM relevant features of task stimuli were adequately assessed prior to the ongoing task response, and by implication that younger HIV infected adults can more adequately achieve PM goals when the pace of the task environment is slowed down. PMID:25116075

Ultrafast scanning probe microscopy

DOEpatents

Weiss, S.; Chemla, D.S.; Ogletree, D.F.; Botkin, D.

1995-05-16

An ultrafast scanning probe microscopy method is described for achieving subpicosecond-temporal resolution and submicron-spatial resolution of an observation sample. In one embodiment of the present claimed invention, a single short optical pulse is generated and is split into first and second pulses. One of the pulses is delayed using variable time delay means. The first pulse is then directed at an observation sample located proximate to the probe of a scanning probe microscope. The scanning probe microscope produces probe-sample signals indicative of the response of the probe to characteristics of the sample. The second pulse is used to modulate the probe of the scanning probe microscope. The time delay between the first and second pulses is then varied. The probe-sample response signal is recorded at each of the various time delays created between the first and second pulses. The probe-sample response signal is then plotted as a function of time delay to produce a cross-correlation of the probe sample response. In so doing, the present invention provides simultaneous subpicosecond-temporal resolution and submicron-spatial resolution of the sample. 6 Figs.

Ultrafast scanning probe microscopy

DOEpatents

Weiss, Shimon; Chemla, Daniel S.; Ogletree, D. Frank; Botkin, David

1995-01-01

An ultrafast scanning probe microscopy method for achieving subpicosecond-temporal resolution and submicron-spatial resolution of an observation sample. In one embodiment of the present claimed invention, a single short optical pulse is generated and is split into first and second pulses. One of the pulses is delayed using variable time delay means. The first pulse is then directed at an observation sample located proximate to the probe of a scanning probe microscope. The scanning probe microscope produces probe-sample signals indicative of the response of the probe to characteristics of the sample. The second pulse is used to modulate the probe of the scanning probe microscope. The time delay between the first and second pulses is then varied. The probe-sample response signal is recorded at each of the various time delays created between the first and second pulses. The probe-sample response signal is then plotted as a function of time delay to produce a cross-correlation of the probe sample response. In so doing, the present invention provides simultaneous subpicosecond-temporal resolution and submicron-spatial resolution of the sample.

Investigating the Impact of Cognitive Load and Motivation on Response Control in Relation to Delay Discounting in Children with ADHD.

PubMed

Martinelli, Mary K; Mostofsky, Stewart H; Rosch, Keri S

2017-10-01

Attention-deficit/hyperactivity disorder (ADHD) is characterized by deficits in impulse control across a range of behaviors, from simple actions to those involving complex decision-making (e.g., preference for smaller-sooner versus larger later rewards). This study investigated whether changes in motor response control with increased cognitive load and motivational contingencies are associated with decision-making in the form of delay discounting among 8-12 year old children with and without ADHD. Children with ADHD (n = 26; 8 girls) and typically developing controls (n = 40; 11 girls) completed a standard go/no-go (GNG) task, a GNG task with motivational contingencies, a GNG task with increased cognitive load, and two measures of delay discounting: a real-time task in which the delays and immediately consumable rewards are experienced in real-time, and a classic task involving choices about money at longer delays. Children with ADHD, particularly girls, exhibited greater delay discounting than controls during the real-time discounting task, whereas diagnostic groups did not significantly differ on the classic discounting task. The effect of cognitive load on response control was uniquely associated with greater discounting on the real-time task for children with ADHD, but not for control children. The effect of motivational contingencies on response control was not significantly associated with delay discounting for either diagnostic group. The findings from this study help to inform our understanding of the factors that influence deficient self-control in ADHD, suggesting that impairments in cognitive control may contribute to greater delay discounting in ADHD.

PILOT STUDY: Report on the CCPR Pilot Comparison: Spectral Responsivity 10 nm to 20 nm

NASA Astrophysics Data System (ADS)

Scholze, Frank; Vest, Robert; Saito, Terubumi

2010-01-01

The CCPR Pilot Comparison on spectral responsivity in the 10 nm to 20 nm spectral range was carried out within the framework of the CIPM Mutual Recognition Arrangement by three laboratories: PTB (Germany), NIST (USA), and NMIJ/AIST (Japan) with PTB acting as the central and reporting laboratory. All participating laboratories used monochromatized synchrotron radiation. PTB and NIST used a cryogenic radiometer as the primary standard detector and NMIJ, an ionization chamber with extrapolation by a wavelength-independent detector. The aim of the pilot comparison was to check the accuracy of the radiometric scale of spectral responsivity in the short wavelength EUV spectral range which has recently gained in technological importance. The wavelengths of measurement were from 11.5 nm to 20 nm in 0.5 nm steps and additionally 12.2 nm. The comparison was carried out through the calibration of a group of transfer standard detectors. Two sets of three diodes of types AXUV and SXUV from International Radiation Detectors, Inc. were used for the comparison. The comparison had the form of a star comparison: Pilot-lab A-pilot-lab B-pilot, PTB acting as the pilot laboratory. All results were communicated directly to the pilot laboratory. The report describes in detail the measurements made at PTB and summarizes the reports submitted by the participants. Measurements carried out by the pilot laboratory before and after the circulation of the detectors proved that the stability of the detectors was sufficient for the comparison. For the type AXUV detectors, however, changes in their responsivity contributed to the uncertainty of the comparison. Measurement results from participants and their associated uncertainties were analyzed in this report according to the Guidelines for CCPR Comparison Report Preparation. The uncertainty contributions were separated, as to whether they are wavelength dependent or not. All bilateral DoE are well within the respective k = 2 expanded uncertainty ranges for all wavelengths. The separated non-wavelength-dependent and wavelength-dependent uncertainty contributions are consistent with the respective wavelength-averaged DoE and wavelength-dependent variations of all bilateral DoE. Main text. To reach the main text of this paper, click on Final Report. The final report has been peer-reviewed and approved for publication by the CCPR WG-KC

High Resolution Exponential Modeling of Fully Polarized Radar Returns

DTIC Science & Technology

1989-11-01

the Poincare I polarization sphere. To avoid this ambiguity, the following alterations to the tilt need to...at the back end, and back toward the front (delayed by one- half the cylinder diameter to account for the two-way propagation delay). The two scatterers...tail responses correspond to the trailing edge of the fuselage-cylinder and to the creeping wave response (delayed by one- half the cylinder

Reinforcer Control by Comparison-Stimulus Color and Location in a Delayed Matching-to-Sample Task

ERIC Educational Resources Information Center

Alsop, Brent; Jones, B. Max

2008-01-01

Six pigeons were trained in a delayed matching-to-sample task involving bright- and dim-yellow samples on a central key, a five-peck response requirement to either sample, a constant 1.5-s delay, and the presentation of comparison stimuli composed of red on the left key and green on the right key or vice versa. Green-key responses were…

Response procedure, memory, and dichotic emotion recognition.

PubMed

Voyer, Daniel; Dempsey, Danielle; Harding, Jennifer A

2014-03-01

Three experiments investigated the role of memory and rehearsal in a dichotic emotion recognition task by manipulating the response procedure as well as the interval between encoding and retrieval while taking into account order of report. For all experiments, right-handed undergraduates were presented with dichotic pairs of the words bower, dower, power, and tower pronounced in a sad, angry, happy, or neutral tone of voice. Participants were asked to report the two emotions presented on each trial by clicking on the corresponding drawings or words on a computer screen, either following no delay or a five second delay. Experiment 1 applied the delay conditions as a between-subjects factor whereas it was a within-subject factor in Experiment 2. In Experiments 1 and 2, more correct responses occurred for the left than the right ear, reflecting a left ear advantage (LEA) that was slightly larger with a nonverbal than a verbal response. The LEA was also found to be larger with no delay than with the 5s delay. In addition, participants typically responded first to the left ear stimulus. In fact, the first response produced a LEA whereas the second response produced a right ear advantage. Experiment 3 involved a concurrent task during the delay to prevent rehearsal. In Experiment 3, the pattern of results supported the claim that rehearsal could account for the findings of the first two experiments. The findings are interpreted in the context of the role of rehearsal and memory in models of dichotic listening. Copyright © 2013 Elsevier Inc. All rights reserved.

Alternative Perspectives on Risk

NASA Technical Reports Server (NTRS)

Davison, Jeannie; Orasanu, J.; Connors, Mary M. (Technical Monitor)

1997-01-01

The goal of the commercial air transport system is to provide air transportation to the flying public at an acceptable cost with minimal risk. in an ideal situation these three goals would support each other. In fact, it is sometimes the case that the goals conflict: getting passengers to their destinations on time may conflict with fixing a minor mechanical malfunction that may or may not impact safety; flying a route that will avoid turbulence, thereby providing passengers with a more comfortable ride, may consume more fuel; managing traffic density may mean aircraft are delayed or must use an approach that will result in a long taxi to their gates, costing time and fuel. Various players in the system--pilots, dispatchers, controllers, as well as managers in the airline carriers and traffic management system--make decisions every day that involve trade-offs of benefits and costs. The prospect of revisions in the air traffic management system, with shifts in responsibilities from controllers to users, including airline operations center personnel and pilots, means that individuals may be performing either new jobs or old jobs under new guidance. It will be essential to know how the various players (a) perceive the risks and benefits associated with the decisions they will make under the old and new control structures, and (b) how much risk they are willing to accept in making decisions. Risk is here defined as the probability and magnitude of negative events (after Slovic, 1987). Of primary interest are risks associated with traffic, weather, and operational factors such as schedule, fuel consumption, and passenger service. Previous research has documented differences between groups in perceptions of risks associated with both everyday and aviation related situations. Risk perception varies as a function of familiarity with the situation, degree to which one is potentially affected by the risk, the level of control one has over the situation, and one's level of experience and responsibility in the situation. In our presentation we will consider several factors that may influence differences in risk perception, risk tolerance and risk management among the three major categories of participants in the aviation system (pilots, dispatchers, and controllers). Primary factors that may affect risk attitudes (the collective term we will use for the three components of risk) include: expertise or job-specific knowledge or training, personal involvement or vulnerability to consequences, goals, time horizon (imminence of consequences), span of control and type of control, and information or technology support. These will be considered in the context of five different types of risk (physical threat, economic, social, legal, and ethical). A study designed to study differences between pilots and controllers in their perceptions and responses to traffic risks under the present and a user-preferred control situation will be described. Future studies involving dispatchers' risk perceptions regarding various types of risk will be discussed.

How Newspaper Advertising Sales Managers Spend Their Time: A Pilot Study.

ERIC Educational Resources Information Center

Hudson, Jerry C.; Saathoff, Roger C.

A pilot study examined how newspaper advertising sales managers in five southwestern states spend their time during a typical work day. Of the 360 questionnaires mailed, 176 responses were received. The largest number of responses (93) came from retail sales managers of newspapers in markets with less than 50,000 population. The questionnaire…

Autism and exergaming: effects on repetitive behaviors and cognition.

PubMed

Anderson-Hanley, Cay; Tureck, Kimberly; Schneiderman, Robyn L

2011-01-01

Autism is a neurodevelopmental disorder that leads to impairment in social skills and delay in language development, and results in repetitive behaviors and restricted interests that impede academic and social involvement. Physical exercise has been shown to decrease repetitive behaviors in autistic children and improve cognitive function across the life-span. Exergaming combines physical and mental exercise simultaneously by linking physical activity movements to video game control and may yield better compliance with exercise. In this investigation, two pilot studies explored the potential behavioral and cognitive benefits of exergaming. In Pilot I, twelve children with autism spectrum disorders completed a control task and an acute bout of Dance Dance Revolution (DDR); in Pilot II, ten additional youths completed an acute bout of cyber cycling. Repetitive behaviors and executive function were measured before and after each activity. Repetitive behaviors significantly decreased, while performance on Digits Backwards improved following the exergaming conditions compared with the control condition. Additional research is needed to replicate these findings, and to explore the application of exergaming for the management of behavioral disturbance and to increase cognitive control in children on the autism spectrum.

Autism and exergaming: effects on repetitive behaviors and cognition

PubMed Central

Anderson-Hanley, Cay; Tureck, Kimberly; Schneiderman, Robyn L

2011-01-01

Autism is a neurodevelopmental disorder that leads to impairment in social skills and delay in language development, and results in repetitive behaviors and restricted interests that impede academic and social involvement. Physical exercise has been shown to decrease repetitive behaviors in autistic children and improve cognitive function across the life-span. Exergaming combines physical and mental exercise simultaneously by linking physical activity movements to video game control and may yield better compliance with exercise. In this investigation, two pilot studies explored the potential behavioral and cognitive benefits of exergaming. In Pilot I, twelve children with autism spectrum disorders completed a control task and an acute bout of Dance Dance Revolution (DDR); in Pilot II, ten additional youths completed an acute bout of cyber cycling. Repetitive behaviors and executive function were measured before and after each activity. Repetitive behaviors significantly decreased, while performance on Digits Backwards improved following the exergaming conditions compared with the control condition. Additional research is needed to replicate these findings, and to explore the application of exergaming for the management of behavioral disturbance and to increase cognitive control in children on the autism spectrum. PMID:22114543

Lesions Responsible for Delayed Oral Transit Time in Post-stroke Dysphagia.

PubMed

Moon, Hyun Im; Yoon, Seo Yeon; Yi, Tae Im; Jeong, Yoon Jeong; Cho, Tae Hwan

2018-06-01

Some stroke patients show oral phase dysphagia, characterized by a markedly prolonged oral transit time that hinders oral feeding. The aim of this study was to clarify the clinical characteristics and lesions responsible for delayed swallowing. We reviewed 90 patients with stroke. The oral processing time plus the postfaucial aggregation time required to swallow semisolid food was assessed. The patients were divided into two groups according to oral transit time, and we analyzed the differences in characteristics such as demographic factors, lesion factors, and cognitive function. Logistic regression analyses were performed to examine the predictors of delayed oral transit time. Lesion location and volume were measured on brain magnetic resonance images. We generated statistic maps of lesions related to delayed oral phase in swallowing using voxel-based lesion symptom mapping (VLSM). The group of patients who showed delayed oral transit time had significantly low cognitive function. Also, in a regression model, delayed oral phase was predicted with low K-MMSE (Korean version of the Mini Mental Status Exam). Using VLSM, we found the lesion location to be associated with delayed oral phase after adjusting for K-MMSE score. Although these results did not reach statistical significance, they showed the lesion pattern with predominant distribution in the left frontal lobe. Delayed oral phase in post-stroke patients was not negligible clinically. Patients' cognitive impairments affect the oral transit time. When adjusting it, we found a trend that the lesion responsible for delayed oral phase was located in the left frontal lobe, though the association did not reach significance. The delay might be related to praxis function.

TASAR Flight Trial 2: Assessment of Air Traffic Controller Acceptability of TASAR Requests

NASA Technical Reports Server (NTRS)

Idris, Husni; Enea, Gabriele

2016-01-01

In support of the Flight Trial (FT-2) of NASA's prototype of the Traffic Aware Strategic Aircrew Requests (TASAR) concept, observations were conducted at the air traffic facilities to identify and assess the main factors that affect the acceptability of pilot requests by air traffic controllers. Two observers shadowed air traffic controllers at the Atlanta (ZTL) and Jacksonville (ZJX) air traffic control centers as the test flight pilot made pre-scripted requests to invoke acceptability issues and then they interviewed the observed and other controllers voluntarily. Fifty controllers were interviewed with experience ranging from one to thirty-five years. All interviewed controllers were enthusiastic about the technology and accounting for sector boundaries in pilot requests, particularly if pilots can be made aware of high workload situations. All interviewed controllers accept more than fifty percent of pilot requests; forty percent of them reject less than ten percent of requests. The most common reason for rejecting requests is conflicting with traffic followed by violating letters of agreement (LOAs) and negatively impacting neighboring sector workload, major arrival and departure flows and flow restrictions. Thirty-six requests were made during the test, eight of which were rejected due to: the aircraft already handed off to another sector, violating LOA, opposing traffic, intruding into an active special use airspace (SUA), intruding into another center, weather, and unfamiliarity with the requested waypoint. Nine requests were accepted with delay mostly because the controller needed to locate unfamiliar waypoints or to coordinate with other controllers.

Microwave fiber optics delay line

NASA Astrophysics Data System (ADS)

Slayman, C.; Yen, H. W.

1980-01-01

A microwave delay line is one of the devices used in EW systems for preserving the frequency and phase contents of RF signals. For such applications, delay lines are required to have large dynamic range, wide bandwidth, low insertion loss, and a linear response. The basic components of a fiber-optics delay line are: an optical source, a wideband optical modulator, a spool of single-mode fiber with appropriate length to provide a given microwave signal delay, and a high-speed photodetector with an RF amplifier. This contract program is to study the feasibility of such a fiber-optic delay line in the frequency range of 4.0 to 6.5 GHz. The modulation scheme studied is the direct modulation of injection lasers. The most important issue identified is the frequency response of the injection laser and the photodetector.

Emotional arousal predicts intertemporal choice

PubMed Central

Lempert, Karolina M.; Johnson, Eli; Phelps, Elizabeth A.

2016-01-01

People generally prefer immediate rewards to rewards received after a delay, often even when the delayed reward is larger. This phenomenon is known as temporal discounting. It has been suggested that preferences for immediate rewards may be due to their being more concrete than delayed rewards. This concreteness may evoke an enhanced emotional response. Indeed, manipulating the representation of a future reward to make it more concrete has been shown to heighten the reward’s subjective emotional intensity, making people more likely to choose it. Here we use an objective measure of arousal – pupil dilation – to investigate if emotional arousal mediates the influence of delayed reward concreteness on choice. We recorded pupil dilation responses while participants made choices between immediate and delayed rewards. We manipulated concreteness through time interval framing: delayed rewards were presented either with the date on which they would be received (e.g., “$30, May 3”; DATE condition, more concrete) or in terms of delay to receipt (e.g., “$30, 7 days; DAYS condition, less concrete). Contrary to prior work, participants were not overall more patient in the DATE condition. However, there was individual variability in response to time framing, and this variability was predicted by differences in pupil dilation between conditions. Emotional arousal increased as the subjective value of delayed rewards increased, and predicted choice of the delayed reward on each trial. This study advances our understanding of the role of emotion in temporal discounting. PMID:26882337

Social Ecology and Group Cohesion in Pilot Whales and Their Responses to Playback of Anthropogenic and Natural Sounds

DTIC Science & Technology

2015-09-30

Minvielle-Sebastia, L. and Guinet, C. (2008). Long-term social structure of long-finned pilot whales (Globicephala melas ) in the Strait of Gibraltar. Acta...Severity of Behavioral Changes Observed During Experimental Exposures of Killer (Orcinus orca), Long-Finned Pilot (Globicephala melas ), and Sperm

"The stone which the builders rejected...": Delay of reinforcement and response rate on fixed-interval and related schedules.

PubMed

Wearden, J H; Lejeune, Helga

2006-02-28

The article deals with response rates (mainly running and peak or terminal rates) on simple and on some mixed-FI schedules and explores the idea that these rates are determined by the average delay of reinforcement for responses occurring during the response periods that the schedules generate. The effects of reinforcement delay are assumed to be mediated by a hyperbolic delay of reinforcement gradient. The account predicts that (a) running rates on simple FI schedules should increase with increasing rate of reinforcement, in a manner close to that required by Herrnstein's equation, (b) improving temporal control during acquisition should be associated with increasing running rates, (c) two-valued mixed-FI schedules with equiprobable components should produce complex results, with peak rates sometimes being higher on the longer component schedule, and (d) that effects of reinforcement probability on mixed-FI should affect the response rate at the time of the shorter component only. All these predictions were confirmed by data, although effects in some experiments remain outside the scope of the model. In general, delay of reinforcement as a determinant of response rate on FI and related schedules (rather than temporal control on such schedules) seems a useful starting point for a more thorough analysis of some neglected questions about performance on FI and related schedules.

Analysis of general aviation single-pilot IFR incident data obtained from the NASA aviation safety reporting system

NASA Technical Reports Server (NTRS)

Bergeron, H. P.

1980-01-01

Data obtained from the NASA Aviation Safety Reporting System (ASRS) data base were used to determine problems in general aviation single pilot IFR operations. The data examined consisted of incident reports involving flight safety in the National Aviation System. Only those incidents involving general aviation fixed wing aircraft flying under IFR in instrument meteorological conditions were analyzed. The data were cataloged into one of five major problem areas: (1) controller judgement and response problems; (2) pilot judgement and response problems; (3) air traffic control intrafacility and interfacility conflicts; (4) ATC and pilot communications problems; and (5) IFR-VFR conflicts. The significance of the related problems, and the various underlying elements associated with each are discussed. Previous ASRS reports covering several areas of analysis are reviewed.

Incorporating data link messaging into a multi-function display to support the Small Aircraft Transportation System (SATS) and the self-separation of general aviation aircraft.

PubMed

Adams, Catherine A; Murdoch, Jennifer L; Consiglio, Maria C; Williams, Daniel M

2007-07-01

One objective of the Small Aircraft Transportation System (SATS) Project is to increase the capacity and utilization of small non-towered, non-radar equipped airports by transferring traffic management activities to an automated system and separation responsibilities to general aviation (GA) pilots. This paper describes the development of a research multi-function display (MFD) to support the interaction between pilots and an automated Airport Management Module (AMM). Preliminary results of simulation and flight tests indicate that adding the responsibility of monitoring other traffic for self-separation does not increase pilots' subjective workload levels. Pilots preferred using the enhanced MFD to execute flight procedures, reporting improved situation awareness (SA) over conventional instrument flight rules (IFR) procedures.

Short-term and long-term memory in early temporal lobe dysfunction.

PubMed

Hershey, T; Craft, S; Glauser, T A; Hale, S

1998-01-01

Following medial temporal damage, mature humans are impaired in retaining new information over long delays but not short delays. The question of whether a similar dissociation occurs in children was addressed by testing children (ages 7-16) with unilateral temporal lobe epilepsy (TLE) and controls on short- and long-term memory tasks, including a spatial delayed response task (SDR). Early-onset TLE did not affect performance on short delays on SDR, but it did impair performance at the longest delay (60 s), similar to adults with unilateral medial temporal damage. In addition, early-onset TLE affected performance on pattern recall, spatial span, and verbal span with rehearsal interference. No differences were found on story recall or on a response inhibition task.

Can an aircraft be piloted via sonification with an acceptable attentional cost? A comparison of blind and sighted pilots.

PubMed

Valéry, Benoît; Scannella, Sébastien; Peysakhovich, Vsevolod; Barone, Pascal; Causse, Mickaël

2017-07-01

In the aeronautics field, some authors have suggested that an aircraft's attitude sonification could be used by pilots to cope with spatial disorientation situations. Such a system is currently used by blind pilots to control the attitude of their aircraft. However, given the suspected higher auditory attentional capacities of blind people, the possibility for sighted individuals to use this system remains an open question. For example, its introduction may overload the auditory channel, which may in turn alter the responsiveness of pilots to infrequent but critical auditory warnings. In this study, two groups of pilots (blind versus sighted) performed a simulated flight experiment consisting of successive aircraft maneuvers, on the sole basis of an aircraft sonification. Maneuver difficulty was varied while we assessed flight performance along with subjective and electroencephalographic (EEG) measures of workload. The results showed that both groups of participants reached target-attitudes with a good accuracy. However, more complex maneuvers increased subjective workload and impaired brain responsiveness toward unexpected auditory stimuli as demonstrated by lower N1 and P3 amplitudes. Despite that the EEG signal showed a clear reorganization of the brain in the blind participants (higher alpha power), the brain responsiveness to unexpected auditory stimuli was not significantly different between the two groups. The results suggest that an auditory display might provide useful additional information to spatially disoriented pilots with normal vision. However, its use should be restricted to critical situations and simple recovery or guidance maneuvers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Binaural interaction in low-frequency neurons in inferior colliculus of the cat. I. Effects of long interaural delays, intensity, and repetition rate on interaural delay function.

PubMed

Kuwada, S; Yin, T C

1983-10-01

Detailed, quantitative studies were made of the interaural phase sensitivity of 197 neurons with low best frequency in the inferior colliculus (IC) of the barbiturate-anesthetized cat. We analyzed the responses of single cells to interaural delays in which tone bursts were delivered to the two ears via sealed earphones and the onset of the tone to one ear with respect to the other was varied. For most (80%) cells the discharge rate is a cyclic function of interaural delay at a period corresponding to that of the stimulating frequency. The cyclic nature of the interaural delay curve indicates that these cells are sensitive to the interaural phase difference. These cells are distributed throughout the low-frequency zone of the IC, but they are less numerous in the medial and caudal zones. Cells with a wide variety of response patterns will exhibit interaural phase sensitivities at stimulating frequencies up to 3,100 Hz, although above 2,500 Hz the number of such cells decrease markedly. Using dichotic stimuli we could study the cell's sensitivity to the onset delay and interaural phase independently. The large majority of IC cells respond only to changes in interaural phase, with no sensitivity to the onset delay. However, a small number (7%) of cells exhibit a sensitivity to the onset delay as well as to the interaural phase disparity, and most of these cells show an onset response. The effects of changing the stimulus intensity equally to both ears or of changing the interaural intensity difference on the mean interaural phase were studied. While some neurons are not affected by level changes, others exhibit systematic phase shifts for both average and interaural intensity variations, and there is a continuous distribution of sensitivities between these extremes. A few cells also showed systematic changes in the shape of the interaural delay curves as a function of interaural intensity difference, especially at very long delays. These shifts can be interpreted as a form of time-intensity trading. A few cells demonstrated orderly changes in the interaural delay curve as the repetition rate of the stimulus was varied. Some of these changes are consonant with an inhibitory effect that occurs at stimulus offset. The responses of the neurons show a strong bias for stimuli that would originate from he contralateral sound field; 77% of the responses display mean interaural phase angles that are less than 0.5 of a cycle, which are delays to the ipsilateral tone.(ABSTRACT TRUNCATED AT 400 WORDS)

Determinants of choice for pigeons and humans on concurrent-chains schedules of reinforcement.

PubMed

Belke, T W; Pierce, W D; Powell, R A

1989-09-01

Concurrent-chains schedules of reinforcement were arranged for humans and pigeons. Responses of humans were reinforced with tokens exchangeable for money, and key pecks of 4 birds were reinforced with food. Variable-interval 30-s and 40-s schedules operated in the terminal links of the chains. Condition 1 exposed subjects to variable-interval 90-s and variable-interval 30-s initial links, respectively. Conditions 2 and 3 arranged equal initial-link schedules of 40 s or 120 s. Experimental conditions tested the descriptive adequacy of five equations: reinforcement density, delay reduction, modified delay reduction, matching and maximization. Results based on choice proportions and switch rates during the initial links showed that pigeons behaved in accord with delay-reduction models, whereas humans maximized overall rate of reinforcement. As discussed by Logue and associates in self-control research, different types of reinforcement may affect sensitivity to delay differentially. Pigeons' responses were reinforced with food, a reinforcer that is consumable upon presentation. Humans' responses were reinforced with money, a reinforcer exchanged for consumable reinforcers after it was earned. Reinforcers that are immediately consumed may generate high sensitivity to delay and behavior described as delay reduction. Reinforces with longer times to consumption may generate low sensitivity to delay and behavior that maximizes overall payoff.

The big brown bat's perceptual dimension of target range

NASA Astrophysics Data System (ADS)

Simmons, James A.

2005-09-01

Big brown bats determine the distance to targets from echo delay, but information actually is entered onto the bat's psychological delay scale from two sources. The first is the target-ranging system itself, from the time that elapses between single-spike neural responses evoked by the broadcast and similar responses evoked by echoes at different delays. These responses register the FM sweeps of broadcasts or echoes, and the associated system of neural delay lines and coincidence detectors cross correlates the spectrograms along the time axis. The second source is the echo spectrum, which relates to shape expressed as range profile. The target-ranging system extracts this by fanning out to encompass parallel representations of many possible notch frequencies and notch widths in echoes. Bats perceive delay separations of 5-30 μs and have a resolution limit of about 2 μs, but interference amplifies small delay separations by transposing them into large changes in notch frequency, so only perception of intervals smaller than 5 μs is surprising. Experiments with phase-shifted echoes show that the psychological time scale can represent two different delays originating entirely in the time domain when they are at least as close together as 10 μs. [Work supported by NIH and ONR.

Staff views of an opportunistic chlamydia testing pilot in a primary health organisation.

PubMed

McKernon, Stephen; Azariah, Sunita

2013-12-01

The Auckland chlamydia pilot was one of three pilots funded by the Ministry of Health to trial implementation of the 2008 Chlamydia Management Guidelines prior to national roll-out. To assess what elements in the testing programme pilot worked best for staff and to determine how an opportunistic testing programme could be better configured to meet staff needs and preferences. A staff survey listed key chlamydia testing tasks in chronological order, and service interventions supporting these tasks. Staff were asked to rate each task on its difficulty prior to the pilot, and then on the difference the pilot had made to each task. They were also asked to rate service interventions on their usefulness during the pilot implementation. The survey had a response rate of 94%. The testing tasks posing the greatest difficulties to staff were those involving patient interactions (41%) and management of follow-up (52%). About 70% of staff felt tasks were improved by the pilot. Staff considered the three most useful service interventions to be a chlamydia-specific template created for the practice management system, provision of printed patient resources, and regular team discussions with other staff. A significant proportion of staff reported difficulties with routine tasks required for opportunistic testing for chlamydia, highlighting the need to involve staff during programme design. Practice nurse-led approaches to future opportunistic testing programmes should be considered as nurses had a more positive response to the pilot and nurse-led approaches have been shown to be successful overseas.

Knowing When to Be "Rational": Flexible Economic Decision Making and Executive Function in Preschool Children

ERIC Educational Resources Information Center

Lee, Wendy S. C.; Carlson, Stephanie M.

2015-01-01

Failure to delay gratification may not indicate poor control or irrationality, but might be an adaptive response. Two studies investigated 3.5- and 4.5-year-old children's ability to adapt their delay and saving behavior when their preference (e.g., to delay or not delay) became nonadaptive. In Study 1 (N = 140), children's delay preference was…

Speed Profiles for Deceleration Guidance During Rollout and Turnoff (ROTO)

NASA Technical Reports Server (NTRS)

Barker, L. Keith; Hankins, Walter W., III; Hueschen, Richard M.

1999-01-01

Two NASA goals are to enhance airport safety and to improve capacity in all weather conditions. This paper contributes to these goals by examining speed guidance profiles to aid a pilot in decelerating along the runway to an exit. A speed profile essentially tells the pilot what the airplane's speed should be as a function of where the airplane is on the runway. While it is important to get off the runway as soon as possible (when striving to minimize runway occupancy time), the deceleration along a speed profile should be constrained by passenger comfort. Several speed profiles are examined with respect to their maximum decelerations and times to reach exit speed. One profile varies speed linearly with distance; another has constant deceleration; and two related nonlinear profiles delay maximum deceleration (braking) to reduce time spent on the runway.

Ensemble codes involving hippocampal neurons are at risk during delayed performance tests.

PubMed

Hampson, R E; Deadwyler, S A

1996-11-26

Multielectrode recording techniques were used to record ensemble activity from 10 to 16 simultaneously active CA1 and CA3 neurons in the rat hippocampus during performance of a spatial delayed-nonmatch-to-sample task. Extracted sources of variance were used to assess the nature of two different types of errors that accounted for 30% of total trials. The two types of errors included ensemble "miscodes" of sample phase information and errors associated with delay-dependent corruption or disappearance of sample information at the time of the nonmatch response. Statistical assessment of trial sequences and associated "strength" of hippocampal ensemble codes revealed that miscoded error trials always followed delay-dependent error trials in which encoding was "weak," indicating that the two types of errors were "linked." It was determined that the occurrence of weakly encoded, delay-dependent error trials initiated an ensemble encoding "strategy" that increased the chances of being correct on the next trial and avoided the occurrence of further delay-dependent errors. Unexpectedly, the strategy involved "strongly" encoding response position information from the prior (delay-dependent) error trial and carrying it forward to the sample phase of the next trial. This produced a miscode type error on trials in which the "carried over" information obliterated encoding of the sample phase response on the next trial. Application of this strategy, irrespective of outcome, was sufficient to reorient the animal to the proper between trial sequence of response contingencies (nonmatch-to-sample) and boost performance to 73% correct on subsequent trials. The capacity for ensemble analyses of strength of information encoding combined with statistical assessment of trial sequences therefore provided unique insight into the "dynamic" nature of the role hippocampus plays in delay type memory tasks.

Mycophenolate mofetil prevents the delayed T cell response after pilocarpine-induced status epilepticus in mice

PubMed Central

Engelmann, Robby; Sellmann, Tina; Köhling, Rüdiger; Müller-Hilke, Brigitte

2017-01-01

Growing clinical and laboratory evidence corroborates a role for the immune system in the pathophysiology of epilepsy. In order to delineate the immune response following pilocarpine-induced status epilepticus (SE) in the mouse, we monitored the kinetics of leukocyte presence in the hippocampus over the period of four weeks. SE was induced following a ramping protocol of pilocarpine injection into 4–5 weeks old C57BL/6 mice. Brains were removed at days 1–4, 14 or 28 after SE, and the hippocampi were analyzed via flow cytometry, via quantitative reverse transcriptase PCR (qRT-PCR) and via immunohistochemistry. Epileptogenesis was confirmed by Timm staining of mossy fiber sprouting in the inner molecular layer of the dentate gyrus. The flow cytometry data revealed a biphasic immune response following pilocarpine-induced SE with a transient increase in activated CD11b+ and F4/80+ macrophages within the first four days replaced by an increase in CD3+ T-lymphocytes around day 28. This delayed T cell response was confirmed via qRT-PCR and via immunohistochemistry. In addition, qRT-PCR data could show that the delayed T cell response was associated with an increased CD8/CD4 ratio indicating a cytotoxic T cell response after SE. Intriguingly, early intervention with mycophenolate mofetil administration on days 0–3 after SE prevented this delayed T cell response. These results show an orchestrated immunological sequela and provide evidence that the delayed T cell response is sensitive to early immunomodulatory intervention. PMID:29182639

Minimizing delays in the Jordanian construction industry by adopting BIM technology

NASA Astrophysics Data System (ADS)

Btoush, M.; Harun, A. T.

2017-11-01

The Jordanian construction industry plays a significant role and contributes immensely to the gross domestic product (GDP) of the economy. However, the Jordanian public work and housing ministry and most industry players including engineers and contractors have reported that most of the projects experience delays which lead time and cost overruns, and extra efforts. The main causes of delays identified by researchers include poor scheduling and planning, change orders, site conditions, weather, late deliveries, incompetent technical staff. To address these challenges, the implementation of building information modelling (BIM) is paramount. This paper presents BIM as a powerful tool for reducing delays in Jordan construction projects. The paper focuses on two main parts; the first part involves the identification of the major causes of delays, and the second part is to accurately outline the roles and responsibilities of BIM specialist in construction projects. Finally, the paper matches the roles and responsibilities of BIM specialist and the causes of delays, and how the delays are addressed through BIM specialist.

A Pilot Study Examining Activity Participation, Sensory Responsiveness, and Competence in Children with High Functioning Autism Spectrum Disorder

ERIC Educational Resources Information Center

Reynolds, Stacey; Bendixen, Roxanna M.; Lawrence, Tami; Lane, Shelly J.

2011-01-01

This pilot study explored activity patterns in children with and without ASD and examined the role of sensory responsiveness in determining children's level of competence in activity performance. Twenty-six children with high functioning ASD and twenty-six typically-developing children 6-12 years old were assessed using the Sensory Profile and the…

Response-based Multimedia and the Culture of the Classroom: A Pilot Study of "Kid's Space" in Four Elementary Classrooms. Report Series 2.26.

ERIC Educational Resources Information Center

Meskill, Carla; Swan, Karen

A pilot study describes the prototype design and classroom implementation of "Kid's Space," a response-based multimedia application for literature teaching and learning. "Kid's Space" was designed around the metaphor of a universe populated by the individual student's world. Each world supports a variety of personal spaces in…

Pilot study demonstrating effectiveness of targeted education to improve informed consent understanding in AIDS clinical trials.

PubMed

Sengupta, Sohini; Lo, Bernard; Strauss, Ronald P; Eron, Joseph; Gifford, Allen L

2011-11-01

Assessing and improving informed consent understanding is equally important as obtaining consent from participants in clinical trial research, but developing interventions to target gaps in participants' informed consent understanding remains a challenge. We used a randomized controlled study design to pilot test an educational intervention to improve actual informed consent understanding of new enrollees in the Adult AIDS Clinical Trial Group (AACTG). Questionnaires were administered to 24 enrollees to assess their baseline understanding on eight elements of informed consent associated with AIDS clinical trials. Enrollees who scored 18/21(85%) or less were randomly assigned to in-person, targeted education (intervention), or delayed education (control). Two follow-up assessments were administered. Repeated measures ANOVA was performed to determine intervention effectiveness in improving actual informed consent understanding over time. Actual understanding improved at the immediate post-intervention time point with a significant score difference of 2.5 when comparing the intervention and delayed groups. In addition, there was a significant score difference of 3.2 when comparing baseline to three-month follow-up for the two groups, suggesting a statistically significant intervention effect to improve actual understanding of the basic elements of informed consent. The findings demonstrated that one-time targeted education can improve actual informed consent understanding one week after the intervention, but retention of these concepts may require periodic monitoring to ensure comprehension throughout the course of a clinical trial.

Baseline Behavior of Pilot Whales and their Responses to Playback of Anthropogenic and Natural Sounds

DTIC Science & Technology

2013-09-30

Minvielle-Sebastia, L. and Guinet, C. (2008b). Diet of the social groups of long-finned pilot whales (Globicephala melas ) in the Strait of Gibraltar...structure of long-finned pilot whales (Globicephala melas ) in the Strait of Gibraltar. Acta Ethologica 11, 81-94. DeRuiter, S. L., Boyd, I. L., Claridge

Extensiveness--Accuracy of Parent Information about Virginia Beach 45-15 Pilot Program.

ERIC Educational Resources Information Center

Schlechty Associates, Chapel Hill, NC.

A preliminary analysis of parent responses to questions related to factual information about the Virginia Beach 45-15 pilot elementary school program, where students attend classes 45 days and break 15 days year round, is provided. Specifically, the information component of the Virginia Beach 45-15 Pilot Project Questionnaire, which consists of…

Automated Pilot Performance Assessment in the T-37: A Feasibility Study. Final Report (May 1968-April 1971).

ERIC Educational Resources Information Center

Knoop, Patricia A.; Welde, William L.

Air Force investigators conducted a three year program to develop a capability for automated quantification and assessment of in-flight pilot performance. Such a capability enhances pilot training by making ratings more objective, valid, reliable and sensitive, and by freeing instructors from rating responsibilities, allowing them to concentrate…

Testing Telephone and Web Surveys for Studying Men's Sexual Assault Perpetration Behaviors

ERIC Educational Resources Information Center

DiNitto, Diana M.; Busch-Armendariz, Noel Bridget; Bender, Kimberly; Woo, Hyeyoung; Tackett-Gibson, Melissa; Dyer, James

2008-01-01

Three pilot studies were conducted to obtain information about sexual assault perpetration from adult men in the United States. Each used the same random digit-dial sampling and recruitment strategy. One pilot was administered by telephone and two via the Web. Response rates in all pilots were low. Although results cannot be generalized beyond the…

APF530 (granisetron injection extended-release) in a three-drug regimen for delayed CINV in highly emetogenic chemotherapy.

PubMed

Schnadig, Ian D; Agajanian, Richy; Dakhil, Christopher; Gabrail, Nashat Y; Smith, Robert E; Taylor, Charles; Wilks, Sharon T; Schwartzberg, Lee S; Cooper, William; Mosier, Michael C; Payne, J Yvette; Klepper, Michael J; Vacirca, Jeffrey L

2016-06-01

APF530, extended-release granisetron, provides sustained release for ≥5 days for acute- and delayed-phase chemotherapy-induced nausea and vomiting (CINV). We compared efficacy and safety of APF530 versus ondansetron for delayed CINV after highly emetogenic chemotherapy (HEC), following a guideline-recommended three-drug regimen. HEC patients received APF530 500 mg subcutaneously or ondansetron 0.15 mg/kg intravenously, with dexamethasone and fosaprepitant. Primary end point was delayed-phase complete response (no emesis or rescue medication). A higher percentage of APF530 versus ondansetron patients had delayed-phase complete response (p = 0.014). APF530 was generally well tolerated; treatment-emergent adverse event incidence was similar across arms, mostly mild-to-moderate injection-site reactions. APF530 versus the standard three-drug regimen provided superior control of delayed-phase CINV following HEC. ClinicalTrials.gov : NCT02106494.

Predicting Pilot Performance in Off-Nominal Conditions: A Meta-Analysis and Model Validation

NASA Technical Reports Server (NTRS)

Wickens, C.D.; Hooey, B.L.; Gore, B.F.; Sebok, A.; Koenecke, C.; Salud, E.

2009-01-01

Pilot response to off-nominal (very rare) events represents a critical component to understanding the safety of next generation airspace technology and procedures. We describe a meta-analysis designed to integrate the existing data regarding pilot accuracy of detecting rare, unexpected events such as runway incursions in realistic flight simulations. Thirty-five studies were identified and pilot responses were categorized by expectancy, event location, and whether the pilot was flying with a highway-in-the-sky display. All three dichotomies produced large, significant effects on event miss rate. A model of human attention and noticing, N-SEEV, was then used to predict event noticing performance as a function of event salience and expectancy, and retinal eccentricity. Eccentricity is predicted from steady state scanning by the SEEV model of attention allocation. The model was used to predict miss rates for the expectancy, location and highway-in-the-sky (HITS) effects identified in the meta-analysis. The correlation between model-predicted results and data from the meta-analysis was 0.72.

Effects of a Velocity-Vector Based Command Augmentation System and Synthetic Vision System Terrain Portrayal and Guidance Symbology Concepts on Single-Pilot Performance

NASA Technical Reports Server (NTRS)

Liu, Dahai; Goodrich, Kenneth H.; Peak, Bob

2010-01-01

This study investigated the effects of synthetic vision system (SVS) concepts and advanced flight controls on the performance of pilots flying a light, single-engine general aviation airplane. We evaluated the effects and interactions of two levels of terrain portrayal, guidance symbology, and flight control response type on pilot performance during the conduct of a relatively complex instrument approach procedure. The terrain and guidance presentations were evaluated as elements of an integrated primary flight display system. The approach procedure used in the study included a steeply descending, curved segment as might be encountered in emerging, required navigation performance (RNP) based procedures. Pilot performance measures consisted of flight technical performance, perceived workload, perceived situational awareness and subjective preference. The results revealed that an elevation based generic terrain portrayal significantly improved perceived situation awareness without adversely affecting flight technical performance or workload. Other factors (pilot instrument rating, control response type, and guidance symbology) were not found to significantly affect the performance measures.

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

Mixed Modeling of a SAW Delay Line Using VHDL-AMS

NASA Technical Reports Server (NTRS)

Wilson, William C.; Atkinson, Gary M.

2006-01-01

To aid in the development of SAW sensors for aerospace applications we have created a model of a SAW Delay line using VHDL. The model implements the Impulse Response method to calculate the frequency response, impedance, and insertion loss. The model includes optimization for the number of finger pairs in the IDTs and for the aperture height. This paper presents the model and the results from the model for a SAW delay line design.

The effect of modifying response and performance feedback parameters on the CNV in humans

NASA Technical Reports Server (NTRS)

Otto, D. A.; Leifer, L. J.

1972-01-01

The effect on the CNV of sustained and delayed motor response with the dominant and nondominant hand in the presence and absence of visual performance feedback, was studied in 15 male adults. Monopolar scalp recordings were obtained at Fz, Cz, Pz, and bilaterally over the motor hand area. Results indicated that the magnitude of the CNV was greater in the delayed than sustained response task, greater in the presence than absence of feedback, and greater over the motor hand area contralateral to movement. Frontal CNV habituated in the sustained, but not the delayed response task, suggested that frontal negative variations in the former case signify an orienting response to novelty or uncertainty. The absence of habituation in the delay condition was interpreted in terms of the motor inhibitory function of frontal association cortex. Performance feedback appeared to enhance CNV indirectly by increasing the motivation of subjects. A multiprocess conception of CNV was proposed in which vortex-negative slow potentials reflect a multiplicity of psychophysiological processes occurring at a variety of cortical and subcortical locations in the brain preparatory to a motor or mental action.

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.

Hatch plasticity in response to varied inundation frequency in Aedes albopictus.

PubMed

Vitek, Christopher J; Livdahl, Todd

2009-07-01

Eggs of container-breeding mosquitoes are able to withstand drought conditions as an egg and hatch when submerged. Frequent rainfall can be simulated by frequent submersion, and drought conditions can be simulated by infrequent submersion. We examined the hatch response of Aedes albopictus (Skuse) eggs to simulated drought conditions. Ae. albopictus eggs from a strain originating outside Kobe, Japan, were subjected to one of three treatments; high-frequency hatch stimulation consisting of submerging the eggs in a nutrient broth mixture every 3 d, low-frequency hatch stimulation consisting of submerging the eggs every 7 d, and delayed high-frequency hatch stimulation. Eggs that were subjected to lower-frequency stimulation showed a significant decrease in hatch delay, which was the opposite of the predicted response. This decrease in hatch delay may be an example of hatch plasticity in response to drought conditions. This response could not be explained as a result of the difference in the ages of the eggs on any given stimulus. A decreased hatch delay response to potential drought conditions combined with rapid larval development may enable Ae. albopictus, whose eggs are not as desiccation resistant as some other container-breeding mosquitoes, to survive extended drought.

Effects of Reinforcer Probability, Delay, and Response Requirements on the Choices of Rats and Pigeons: Possible Species Differences

ERIC Educational Resources Information Center

Mazur, James E.

2005-01-01

In Experiment 1 with rats, a left lever press led to a 5-s delay and then a possible reinforcer. A right lever press led to an adjusting delay and then a certain reinforcer. This delay was adjusted over trials to estimate an indifference point, or a delay at which the two alternatives were chosen about equally often. Indifference points increased…

Satellite Delivery of Aviation Weather Data

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Haendel, Richard

2001-01-01

With aviation traffic continuing to increase worldwide, reducing the aviation accident rate and aviation schedule delays is of critical importance. In the United States, the National Aeronautics and Space Administration (NASA) has established the Aviation Safety Program and the Aviation System Capacity Program to develop and test new technologies to increase aviation safety and system capacity. Weather is a significant contributor to aviation accidents and schedule delays. The timely dissemination of weather information to decision makers in the aviation system, particularly to pilots, is essential in reducing system delays and weather related aviation accidents. The NASA Glenn Research Center is investigating improved methods of weather information dissemination through satellite broadcasting directly to aircraft. This paper describes an on-going cooperative research program with NASA, Rockwell Collins, WorldSpace, Jeppesen and American Airlines to evaluate the use of satellite digital audio radio service (SDARS) for low cost broadcast of aviation weather information, called Satellite Weather Information Service (SWIS). The description and results of the completed SWIS Phase 1 are presented, and the description of the on-going SWIS Phase 2 is given.

Promoting weight control at the worksite: a pilot program of self-motivation using payroll-based incentives.

PubMed

Jeffery, R W; Forster, J L; Snell, M K

1985-03-01

Thirty-six individuals participated in a worksite weight-loss program in which the central component was a self-motivation program of biweekly payroll deductions refunded contingent on meeting self-selected weight-loss goals. Half were assigned to early treatment and the remainder to a delayed treatment control group. Nine additional individuals also enrolled at the time of delayed treatment and were included in descriptive analyses of factors associated with weight loss. Results showed low program attrition over 6 months (6%) and mean weight losses (12.3 lb) that are competitive with those obtained in clinical settings. Although not different at baseline, participants in the delayed treatment group lost more than twice as much weight as those in the early treatment condition. This difference was interpreted as either a strong seasonal effect or a critical mass effect related to the proportion of employees at the worksite participating in the program. We conclude that self-motivation programs for health behavior change using the payroll system as an organization framework offer a promising new methodology for promoting healthful behaviors in work settings.

Prehospital delay, contributing aspects and responses to symptoms among Norwegian women and men with first time acute myocardial infarction.

PubMed

Løvlien, M; Schei, B; Hole, T

2007-12-01

In patients with acute myocardial infarction (AMI), the delay between the onset of symptoms and hospital admission is a critical factor in reducing morbidity and mortality. To assess gender differences in prehospital delay among women and men with first time AMI, generate more knowledge about aspects influencing this delay and investigate responses to acute symptoms. Of 738 eligible patients, 149 women and 384 men responded to a questionnaire (72%). Over half of both women and men waited over one hour before they called for medical assistance and more than half the patients had a total prehospital delay exceeding two hours. Rapid development of symptoms and symptoms matching expectations reduced, self medication and consulting the spouse increased patient delay in both genders. Calling the Emergency Medical Service (EMS) reduced and calling a general practitioner increased total prehospital delay in both genders. ST-ELEVATION: (STEMI), symptoms experienced as unbearable and attributed as cardiac reduced patient delay, and symptoms from the back, shoulders or between scapulae increased prehospital delay, only in men. How patients responded to symptoms had vital impact on prehospital delay among both genders, but the experience and interpretation of symptoms had more influence in men than in women.

The critical dimensions of the response-reinforcer contingency.

PubMed

Williams, B A.

2001-05-03

Two major dimensions of any contingency of reinforcement are the temporal relation between a response and its reinforcer, and the relative frequency of the reinforcer given the response versus when the response has not occurred. Previous data demonstrate that time, per se, is not sufficient to explain the effects of delay-of-reinforcement procedures; needed in addition is some account of the events occurring in the delay interval. Moreover, the effects of the same absolute time values vary greatly across situations, such that any notion of a standard delay-of-reinforcement gradient is simplistic. The effects of reinforcers occurring in the absence of a response depend critically upon the stimulus conditions paired with those reinforcers, in much the same manner as has been shown with Pavlovian contingency effects. However, it is unclear whether the underlying basis of such effects is response competition or changes in the calculus of causation.

Factors Influencing the Decisions and Actions of Pilots and Air Traffic Controllers in Three Plausible NextGen Environments

NASA Technical Reports Server (NTRS)

Vu, Kim-Phuong L.; Strybel, Thomas Z.; Battiste, Vernol; Johnson, Walter

2011-01-01

In the current air traffic management (ATM) system, pilots and air traffic controllers have well-established roles and responsibilities: pilots fly aircraft and are concerned with energy management, fuel efficiency, and passenger comfort; controllers separate aircraft and are concerned with safety and management of traffic flows. Despite having different goals and obligations, both groups must be able to effectively communicate and interact with each other for the ATM system to work. This interaction will become even more challenging as traffic volume increases dramatically in the near future. To accommodate this increase, by 2025 the national air transportation system in the U.S. will go through a transformation that will modernize the ATM system and make it safer, more effective, and more efficient. This new system, NextGen, will change how pilots and controllers perform their tasks by incorporating advanced technologies and employing new procedures. It will also distribute responsibility between pilots, controllers and automation over such tasks as maintaining aircraft separation. The present chapter describes three plausible concepts of operations that allocate different ATM responsibilities to these groups. We describe how each concept changes the role of each operator and the types of decisions and actions performed by them.

Frequency adaptation in controlled stochastic resonance utilizing delayed feedback method: two-pole approximation for response function.

PubMed

Tutu, Hiroki

2011-06-01

Stochastic resonance (SR) enhanced by time-delayed feedback control is studied. The system in the absence of control is described by a Langevin equation for a bistable system, and possesses a usual SR response. The control with the feedback loop, the delay time of which equals to one-half of the period (2π/Ω) of the input signal, gives rise to a noise-induced oscillatory switching cycle between two states in the output time series, while its average frequency is just smaller than Ω in a small noise regime. As the noise intensity D approaches an appropriate level, the noise constructively works to adapt the frequency of the switching cycle to Ω, and this changes the dynamics into a state wherein the phase of the output signal is entrained to that of the input signal from its phase slipped state. The behavior is characterized by power loss of the external signal or response function. This paper deals with the response function based on a dichotomic model. A method of delay-coordinate series expansion, which reduces a non-Markovian transition probability flux to a series of memory fluxes on a discrete delay-coordinate system, is proposed. Its primitive implementation suggests that the method can be a potential tool for a systematic analysis of SR phenomenon with delayed feedback loop. We show that a D-dependent behavior of poles of a finite Laplace transform of the response function qualitatively characterizes the structure of the power loss, and we also show analytical results for the correlation function and the power spectral density.

Functional brain development in growth-restricted and constitutionally small fetuses: a fetal magnetoencephalography case-control study.

PubMed

Morin, E C; Schleger, F; Preissl, H; Braendle, J; Eswaran, H; Abele, H; Brucker, S; Kiefer-Schmidt, I

2015-08-01

Fetal magnetoencephalography records fetal brain activity non-invasively. Delayed brain responses were reported for fetuses weighing below the tenth percentile. To investigate whether this delay indicates delayed brain maturation resulting from placental insufficiency, this study distinguished two groups of fetuses below the tenth percentile: growth-restricted fetuses with abnormal umbilical artery Doppler velocity (IUGR) and constitutionally small-for-gestational-age fetuses with normal umbilical artery Doppler findings (SGA) were compared with fetuses of adequate weight for gestational age (AGA), matched for age and behavioural state. A case-control study of matched pairs. Fetal magnetoencephalography-Center at the University Hospital of Tuebingen. Fourteen IUGR fetuses and 23 SGA fetuses were matched for gestational age and fetal behavioural state with 37 healthy, normal-sized fetuses. A 156-channel fetal magentoencephalography system was used to record fetal brain activity. Light flashes as visual stimulation were applied to the fetus. The Student's t-test for paired groups was performed. Latency of fetal visual evoked magnetic responses (VER). The IUGR fetuses showed delayed VERs compared with controls (IUGR, 233.1 ms; controls, 184.6 ms; P = 0.032). SGA fetuses had similar evoked response latencies compared with controls (SGA, 216.1 ms; controls, 219.9 ms; P = 0.828). Behavioural states were similarly distributed. Visual evoked responses are delayed in IUGR fetuses, but not in SGA. Fetal behavioural state as an influencing factor of brain response latency was accounted for in the comparison. This reinforces that delayed brain maturation is the result of placental insufficiency. © 2015 Royal College of Obstetricians and Gynaecologists.

Increased impulsive action in rats: effects of morphine in a short and long fixed-delay response inhibition task.

PubMed

Mahoney, Megan K; Silveira, Mason M; Olmstead, Mary C

2013-12-01

Impulsive action is mediated through several neurochemical systems, although it is not clear which role each of these plays in the inability to withhold inappropriate responses. Manipulations of the opioid system alter impulsive action in rodents, although the effects are not consistent across tasks. Previously, we speculated that these discrepancies reflect differences in the cognitive mechanisms that control responding in each task. We investigated whether the effect of morphine, a mu opioid receptor (MOR) agonist, on impulsive action depends on the ability of the subjects to time the interval during which they must inhibit a response. Male Long-Evans rats were trained in a response inhibition (RI) task to withhold responding for sucrose during a 4- or 60-s delay; impulsive action was assessed as increased responding during the delay. The rats were tested following an injection of morphine (0, 1, 3, 6 mg/kg). In a subsequent experiment, the effects of morphine (6 mg/kg) plus the MOR antagonist naloxone (0, 0.3, 1, 3 mg/kg) were investigated. Morphine increased impulsive action, but had different effects in the two conditions: the drug increased the proportion of premature responses as the 4-s interval progressed and produced a general increase in responding across the 60-s interval. Naloxone blocked all morphine-induced effects. The finding that morphine increases impulsive action in a fixed-delay RI task contrasts with our previous evidence which shows no effect in the same task with a variable delay. Thus, MORs disrupt impulsive action only when rats can predict the delay to respond.

BALANCE, BODY MOTION AND MUSCLE ACTIVITY AFTER HIGH VOLUME SHORT TERM DANCE-BASED REHABILITATION IN INDIVIDUALS WITH PARKINSON’S DISEASE: A PILOT STUDY

PubMed Central

McKay, J. Lucas; Ting, Lena H.; Hackney, Madeleine E.

2016-01-01

BACKGROUND AND PURPOSE The objectives of this pilot study were to 1) evaluate the feasibility and investigate the efficacy of a 3-week, high volume (450 minutes/week) Adapted Tango intervention for community dwelling individuals with mild-moderate PD, and to 2) investigate the potential efficacy of Adapted Tango in modifying electromyographic (EMG) activity and center of body mass (CoM) displacement during automatic postural responses to support surface perturbations. METHODS Individuals with PD (n=26) were recruited for high volume Adapted Tango (15 lessons, 1.5 hour each over 3 weeks). Twenty participants were assessed with clinical balance and gait measures before and after the intervention. Nine participants were also assessed with support-surface translation perturbations. RESULTS Overall adherence to the intervention was 77%. At posttest, peak forward CoM displacement was reduced (4.0±0.9 cm, pretest, vs. 3.7±1.1 cm, posttest; P=0.03; Cohen’s d=0.30) and correlated to improvements on Berg Balance Scale (BBS; rho=−0.68; P=0.04) and Dynamic Gait Index (rho=−0.75; P=0.03). Overall antagonist onset time was delayed (27 ms; P=0.02; d=0.90) and duration was reduced (56 ms, ≈39%, P=0.02; d=0.45). Reductions in EMG magnitude were also observed (P<0.05). DISCUSSION AND CONCLUSIONS Adherence was acceptable and improvements on clinical measures of balance and gait were comparable to that obtained with lower volume, 12-week programs. Following participation in Adapted Tango, changes in kinematic and some EMG measures of perturbation responses were observed in addition to improvements in clinical measures. We conclude that 3-week, high volume Adapted Tango is feasible and represents a viable alternative to longer duration adapted dance programs. Video Abstract available for more insights from the authors (see Supplemental Digital Content 1) PMID:27576092

Global Temperature and Salinity Pilot Project

NASA Technical Reports Server (NTRS)

Searle, Ben

1992-01-01

Data exchange and data management programs have been evolving over many years. Within the international community there are two main programs to support the exchange, management and processing of real time and delayed mode data. The Intergovernmental Oceanographic Commission (IOC) operate the International Oceanographic Data and Information Exchange (IODE) program which coordinates the exchange of delayed mode data between national oceanographic data centers, World Data Centers and the user community. The Integrated Global Ocean Services System is a joint IOC/World Meteorological Organization (WMO) program for the exchange and management of real-time data. These two programs are complemented by mechanisms that have been established within scientific programs to exchange and manage project data sets. In particular TOGA and WOCE have identified a data management requirement and established the appropriate infrastructure to achieve this. Where GTSPP fits into this existing framework is discussed.

Waveforms and Sonic Boom Perception and Response (WSPR): Low-Boom Community Response Program Pilot Test Design, Execution, and Analysis

NASA Technical Reports Server (NTRS)

Page, Juliet A.; Hodgdon, Kathleen K.; Krecker, Peg; Cowart, Robbie; Hobbs, Chris; Wilmer, Clif; Koening, Carrie; Holmes, Theresa; Gaugler, Trent; Shumway, Durland L.;

Pilot-in-the-Loop Evaluation of a Yaw Rate to Throttle Feedback Control with Enhanced Engine Response

NASA Technical Reports Server (NTRS)

Litt, Jonathan S.; Guo, Ten-Huei; Sowers, T. Shane; Chicatelli, Amy K.; Fulton, Christopher E.; May, Ryan D.; Owen, A. Karl

2012-01-01

This paper describes the implementation and evaluation of a yaw rate to throttle feedback system designed to replace a damaged rudder. It can act as a Dutch roll damper and as a means to facilitate pilot input for crosswind landings. Enhanced propulsion control modes were implemented to increase responsiveness and thrust level of the engine, which impact flight dynamics and performance. Piloted evaluations were performed to determine the capability of the engines to substitute for the rudder function under emergency conditions. The results showed that this type of implementation is beneficial, but the engines' capability to replace the rudder is limited.

Evaluating Nextgen Closely Spaced Parallel Operations Concepts with Validated Human Performance Models: Flight Deck Guidelines

NASA Technical Reports Server (NTRS)

Hooey, Becky Lee; Gore, Brian Francis; Mahlstedt, Eric; Foyle, David C.

2013-01-01

The objectives of the current research were to develop valid human performance models (HPMs) of approach and land operations; use these models to evaluate the impact of NextGen Closely Spaced Parallel Operations (CSPO) on pilot performance; and draw conclusions regarding flight deck display design and pilot-ATC roles and responsibilities for NextGen CSPO concepts. This document presents guidelines and implications for flight deck display designs and candidate roles and responsibilities. A companion document (Gore, Hooey, Mahlstedt, & Foyle, 2013) provides complete scenario descriptions and results including predictions of pilot workload, visual attention and time to detect off-nominal events.

Simulator Investigations of the Problems of Flying a Swept-Wing Transport Aircraft in Heavy Turbulence

NASA Technical Reports Server (NTRS)

Bray, Richard S.; Larsen, William E.

1965-01-01

An investigation of several factors which may contribute to the problem of piloting jet transport aircraft in heavy turbulence was conducted by using a piloted simulator that included the most significant airplane response and cockpit vibrations induced by rough air. Results indicated that the primary fuselage structural frequency contributed significantly to a distracting cockpit environment, and there was obtained evidence of severely reduced instrument flight proficiency during simulated maneuvering flight in heavy turbulence. It is concluded that the addition of similar rough-air response capabilities to training simulators would be of value in pilot indoctrination in turbulent-flight procedures.

Robust Control Design for Flight Control

DTIC Science & Technology

1989-07-01

controller may be designed to produce desired responses to pilot commands, responses to external (atmospheric) disturbances may be unusual and...suggested for stabilizing open loop unstable aircraft result in nonminimum phase zeros in the dynamics as seen by the pilot . This issue has not been...stability test it does retain several essential features of the popular single loop test developed by Nyquist. In particular, it identifies a Nyquist

Degenerative Changes of Spine in Helicopter Pilots

PubMed Central

Byeon, Joo Hyeon; Kim, Jung Won; Jeong, Ho Joong; Sim, Young Joo; Kim, Dong Kyu; Choi, Jong Kyoung; Im, Hyoung June

2013-01-01

Objective To determine the relationship between whole body vibration (WBV) induced helicopter flights and degenerative changes of the cervical and lumbar spine. Methods We examined 186 helicopter pilots who were exposed to WBV and 94 military clerical workers at a military hospital. Questionnaires and interviews were completed for 164 of the 186 pilots (response rate, 88.2%) and 88 of the 94 clerical workers (response rate, 93.6%). Radiographic examinations of the cervical and the lumbar spines were performed after obtaining informed consent in both groups. Degenerative changes of the cervical and lumbar spines were determined using four radiographs per subject, and diagnosed by two independent, blinded radiologists. Results There was no significant difference in general and work-related characteristics except for flight hours and frequency between helicopter pilots and clerical workers. Degenerative changes in the cervical spine were significantly more prevalent in the helicopter pilots compared with control group. In the cervical spine multivariate model, accumulated flight hours (per 100 hours) was associated with degenerative changes. And in the lumbar spine multivariate model, accumulated flight hours (per 100 hours) and age were associated with degenerative changes. Conclusion Accumulated flight hours were associated with degenerative changes of the cervical and lumbar spines in helicopter pilots. PMID:24236259

Chronic lymphadenopathic toxoplasmosis. A case with marked hyperglobulinemia and impaired delayed hypersensitivity responses during active infection.

PubMed

Sheagren, J N; Lunde, M N; Simon, H B

1976-02-01

A patient with lymphadenopathic toxoplasmosis characterized by prolonged symptoms and repeated relapses with isolation of toxoplasma from lymph nodes is described. As the disease persisted and progressed, striking immunologic changes occurred that ultimately resulted in a state of extreme hyperglobulinemia associated with impaired delayed hypersensitivity responses. The case in question illustrates that progressive infection may occur in the face of high antibody levels of all immunoglobulin types whereas the only demonstrable immunologic impairment was of delayed hypersensitivity.

CONCEPTUAL DESIGN ASSESSMENT FOR THE CO-FIRING OF BIO-REFINERY SUPPLIED LIGNIN PROJECT

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

Ted Berglund; Jeffrey T. Ranney; Carol L. Babb

2001-01-01

The major aspects of this project are proceeding toward completion. Prior to this quarter, design criteria, tentative site selection, facility layout, and preliminary facility cost estimates have been completed and issued for review. Processing of bio-solids was completed, providing material for the pilot operations. Pilot facility design, equipment selection, and modification were completed during the fourth quarter. Initial pilot facility shakedown was completed during the fourth quarter. During pilot plant shakedown operations, several production batch test runs were performed. These pilot tests were coupled with laboratory testing to confirm pilot results. In initial batches of operations, cellulose to glucose conversionsmore » of 62.5% and 64.8% were observed in laboratory hydrolysis. As part of this testing, lignin dewatering was tested using laboratory and vendor-supplied filtration equipment. Dewatering tests reported moisture contents in the lignin of between 50% and 60%. Dewatering parameters and options will continue to be investigated during lignin production. After some unavoidable delays, a suitable representative supply of MSW feed material was procured. Shredding of the feed material was completed and final drying of the feed is expected to be completed by late January. Once feed drying is completed, pilot facility production will begin to produce lignin for co-fire testing. Facility modifications are expected to continue to improve facility operations and performance during the first quarter of 2001. The TVA-Colbert facility continues to make progress in evaluating the co-location of the Masada facility on the operation of the power generation facility. The TVA-Colbert fossil plant is fully capable of providing a reliable steam supply. The preferred steam supply connection points and steam pipeline routing have been identified. The environmental review of the pipeline routing has been completed and no major impacts have been identified. Detailed assessment of steam export impacts on the Colbert boiler system continues.« less

Effects of Different Heave Motion Components on Pilot Pitch Control Behavior

NASA Technical Reports Server (NTRS)

Zaal, Petrus M. T.; Zavala, Melinda A.

2016-01-01

The study described in this paper had two objectives. The first objective was to investigate if a different weighting of heave motion components decomposed at the center of gravity, allowing for a higher fidelity of individual components, would result in pilot manual pitch control behavior and performance closer to that observed with full aircraft motion. The second objective was to investigate if decomposing the heave components at the aircraft's instantaneous center of rotation rather than at the center of gravity could result in additional improvements in heave motion fidelity. Twenty-one general aviation pilots performed a pitch attitude control task in an experiment conducted on the Vertical Motion Simulator at NASA Ames under different hexapod motion conditions. The large motion capability of the Vertical Motion Simulator also allowed for a full aircraft motion condition, which served as a baseline. The controlled dynamics were of a transport category aircraft trimmed close to the stall point. When the ratio of center of gravity pitch heave to center of gravity heave increased in the hexapod motion conditions, pilot manual control behavior and performance became increasingly more similar to what is observed with full aircraft motion. Pilot visual and motion gains significantly increased, while the visual lead time constant decreased. The pilot visual and motion time delays remained approximately constant and decreased, respectively. The neuromuscular damping and frequency both decreased, with their values more similar to what is observed with real aircraft motion when there was an equal weighting of the heave of the center of gravity and heave due to rotations about the center of gravity. In terms of open- loop performance, the disturbance and target crossover frequency increased and decreased, respectively, and their corresponding phase margins remained constant and increased, respectively. The decomposition point of the heave components only had limited effects on pilot manual control behavior and performance.

The overall program effects of California's 3-Tier Assessment System pilot on crashes and mobility among senior drivers.

PubMed

Camp, Bayliss J

2013-12-01

In 2007, the California Department of Motor Vehicles (DMV) undertook a pilot study of the 3-Tier Assessment System, the purpose of which was to examine, in a large-scale real-time public agency setting, the effectiveness of this method for both reducing the crash risk of individual drivers and for extending the safe driving years of Californian drivers of all ages. The 3-Tier Assessment System consisted of tiered series of screening tools incorporated into the in-office driver's license renewal process. These screening tools identified drivers with various kinds of functional limitations (physical, visual, and cognitive/perceptual), that might impact safe driving. Paired with the screening tools were educational materials designed to improve drivers' knowledge of their own limitations, including compensating techniques. The present study is a population-based evaluation of the effects of the pilot on subsequent crash risk and mobility outcomes (including delicensure) of participating drivers age 70 and older. Pilot participants were compared with two control groups processed according to standard California DMV license renewal procedures. Because the 3-Tier Assessment System was designed to identify limitations normally associated with aging, the present analyses focus on drivers age 70 and older. However, it should be emphasized that during the 3-Tier pilot the screening tools were applied to drivers of all ages. There were two main findings. First, there were no consistent, statistically significant differences between the pilot and control groups in crash risk in the two years following screening. Second, pilot participants experienced statistically significant effects on mobility. These effects included delays in time to complete their license renewal, an increase in the number of assigned license restrictions, and an increase in the number of customers failing to renew their driving privilege. Based on these findings, suggestions for further research are made. None. © 2013.

Effects of a Responsiveness-Focused Intervention in Family Child Care Homes on Children’s Executive Function

PubMed Central

Merz, Emily C.; Landry, Susan H.; Johnson, Ursula Y.; Williams, Jeffrey M.; Jung, Kwanghee

2016-01-01

Caregiver responsiveness has been theorized and found to support children’s early executive function (EF) development. This study examined the effects of an intervention that targeted family child care provider responsiveness on children’s EF. Family child care providers were randomly assigned to one of two intervention groups or a control group. An intervention group that received a responsiveness-focused online professional development course and another intervention group that received this online course plus weekly mentoring were collapsed into one group because they did not differ on any of the outcome variables. Children (N = 141) ranged in age from 2.5 to 5 years (mean age = 3.58 years; 52% female). At pretest and posttest, children completed delay inhibition tasks (gift delay-wrap, gift delay-bow) and conflict EF tasks (bear/dragon, dimensional change card sort), and parents reported on the children’s level of attention problems. Although there were no main effects of the intervention on children’s EF, there were significant interactions between intervention status and child age for delay inhibition and attention problems. The youngest children improved in delay inhibition and attention problems if they were in the intervention rather than the control group, whereas older children did not. These results suggest that improving family child care provider responsive behaviors may facilitate the development of certain EF skills in young preschool-age children. PMID:26941476

UAS Air Traffic Controller Acceptability Study. 2; Evaluating Detect and Avoid Technology and Communication Delays in Simulation

NASA Technical Reports Server (NTRS)

Comstock, James R., Jr.; Ghatas, Rania W.; Consiglio, Maria C.; Chamberlain, James P.; Hoffler, Keith D.

2015-01-01

This study evaluated the effects of communications delays and winds on air traffic controller ratings of acceptability of horizontal miss distances (HMDs) for encounters between Unmanned Aircraft Systems (UAS) and manned aircraft in a simulation of the Dallas-Ft. Worth (DFW) airspace. Fourteen encounters per hour were staged in the presence of moderate background traffic. Seven recently retired controllers with experience at DFW served as subjects. Guidance provided to the UAS pilots for maintaining a given HMD was provided by information from Detect and Avoid (DAA) self-separation algorithms (Stratway+) displayed on the Multi-Aircraft Control System. This guidance consisted of amber "bands" on the heading scale of the UAS navigation display indicating headings that would result in a loss of well clear between the UAS and nearby traffic. Winds tested were successfully handled by the DAA algorithms and did not affect the controller acceptability ratings of the HMDs. Voice communications delays for the UAS were also tested and included one-way delay times of 0, 400, 1200, and 1800 msec. For longer communications delays, there were changes in strategy and communications flow that were observed and reported by the controllers. The aim of this work is to provide useful information for guiding future rules and regulations applicable to flying UAS in the NAS. Information from this study will also be of value to the Radio Technical Commission for Aeronautics (RTCA) Special Committee 228 - Minimum Performance Standards for UAS.

An evaluation of automatic control system concepts for general aviation airplanes

NASA Technical Reports Server (NTRS)

Stewart, E. C.; Ragsdale, W. A.; Wunschel, A. J.

1988-01-01

A piloted simulation study of automatic longitudinal control systems for general aviation airplanes has been conducted. These automatic control systems were designed to make the simulated airplane easy to fly for a beginning or infrequent pilot. Different control systems are presented and their characteristics are documented. In a conventional airplane control system each cockpit controller commands combinations of both the airspeed and the vertical speed. The best system in the present study decoupled the airspeed and vertical speed responses to cockpit throttle inputs. That is, the cockpit throttle lever commanded only airspeed responses, and the longitudinal wheel position commanded only vertical speed responses. This system significantly reduced the pilot workload throughout an entire mission of the airplane from takeoff to landing. An important feature of the automatic system was that neither changing flap position nor maneuvering in steeply banked turns affected either the airspeed or the vertical speed. All the pilots who flew the control system simulation were favorably impressed with the very low workload and the excellent handling qualities of the simulated airplane.

Physiological responses of pilots to severe weather flying.

DOT National Transportation Integrated Search

1966-07-01

Selected measurements of stress-related and other physiological variables were made on jet aircraft pilots participating in USWB-NSSL turbulent weather programs. Data were gathered from two categories of flying conditions: (1) storm penetration fligh...

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

Franzese, Oscar; Lascurain, Mary Beth; Capps, Gary J

The Federal Motor Carrier Safety Administration (FMCSA) Wireless Roadside Inspection (WRI) Program is researching the feasibility and value of electronically assessing truck and bus driver and vehicle safety at least 25 times more often than is possible using only roadside physical inspections. The WRI program is evaluating the potential benefits to both the motor carrier industry and to government. These potential benefits include reduction in accidents, fatalities and injuries on our highways and keeping safe and legal drivers and vehicles moving on the highways. WRI Pilot tests were conducted to prototype, test and demonstrate the feasibility and benefits of electronicallymore » collecting safety data message sets from in-service commercial vehicles and performing wireless roadside inspections using three different communication methods. This report summarizes the design, conduct and results of the Tennessee CMRS WRI Pilot Test. The purpose of this Pilot test was to demonstrate the implementation of commercial mobile radio services to electronically request and collect safety data message sets from a limited number of commercial vehicles operating in Tennessee. The results of this test have been used in conjunction with the results of the complimentary pilot tests to support an overall assessment of the feasibility and benefits of WRI in enhancing motor carrier safety (reduction in accidents) due to increased compliance (change in motor carrier and driver behavior) caused by conducting frequent safety inspections electronically, at highway speeds, without delay or need to divert into a weigh station« less

Establishing an Operational Data System for Surface Currents Derived from Satellite Altimeters and Scatterometers; Pilot Study for the Tropical Pacific

NASA Astrophysics Data System (ADS)

Lagerloef, G. S.; Cheney, R.; Mitchum, G. T.

2001-12-01

We are initiating a pilot processing system and data center to provide operational ocean surface velocity fields from satellite altimeter and vector wind data. The team includes the above authors plus M. Bourassa (FSU), V.Kousky (NOAA/NCEP), J.Polovina (NOAA/NMFS/Hawaii CoastWatch), R.Legeckis (NOAA/NESDIS), G. Jacobs (NRL), F. Bonjean (ESR), E.Johnson (ESR) and J.Gunn (ESR). Methods to derive surface currents are the outcome of several years of NASA sponsored research and the pilot project will transition that capability to operational oceanographic applications. The regional focus will be the tropical Pacific. Data applications include large scale climate diagnostics and prediction, fisheries management and recruitment, monitoring debris drift, larvae drift, oil spills, fronts and eddies. Additional uses for search and rescue, naval and maritime operations will be investigated. The pilot study will produce velocity maps to be updated on a weekly basis initially, with a goal for eventual 2-day maximum delay from time of satellite measurement. Grid resolution will be 100 km for the basin scale, and finer resolution in the vicinity of the Pacific Islands. Various illustrations of the velocity maps and their applications will be presented. The project's goal is to leave in place an automated system running at NOAA/NESDIS, with an established user clientele and open Internet data access.

Efficacy of Error for the Correction of Initially Incorrect Assumptions and of Feedback for the Affirmation of Correct Responding: Learning in the Classroom

ERIC Educational Resources Information Center

Brosvic, Gary M.; Epstein, Michael L.; Cook, Michael J.; Dihoff, Roberta E.

2005-01-01

Participants completed 5 classroom examinations during which the timing of knowledge of results (no feedback: Scantron form; delayed feedback: end-of-test, 24 hour delay; immediate feedback: educator, response form) and iterative responding (1 response, up to 4 responses) were manipulated. At the end of the semester, each participant completed a…

Spatiotemporal changes of seismic attenuation caused by injected CO2 at the Frio-II pilot site, Dayton, TX, USA

NASA Astrophysics Data System (ADS)

Zhu, Tieyuan; Ajo-Franklin, Jonathan B.; Daley, Thomas M.

2017-09-01

A continuous active source seismic monitoring data set was collected with crosswell geometry during CO2 injection at the Frio-II brine pilot, near Liberty, TX. Previous studies have shown that spatiotemporal changes in the P wave first arrival time reveal the movement of the injected CO2 plume in the storage zone. To further constrain the CO2 saturation, particularly at higher saturation levels, we investigate spatial-temporal changes in the seismic attenuation of the first arrivals. The attenuation changes over the injection period are estimated by the amount of the centroid frequency shift computed by local time-frequency analysis. We observe that (1) at receivers above the injection zone seismic attenuation does not change in a physical trend; (2) at receivers in the injection zone attenuation sharply increases following injection and peaks at specific points varying with distributed receivers, which is consistent with observations from time delays of first arrivals; then, (3) attenuation decreases over the injection time. The attenuation change exhibits a bell-shaped pattern during CO2 injection. Under Frio-II field reservoir conditions, White's patchy saturation model can quantitatively explain both the P wave velocity and attenuation response observed. We have combined the velocity and attenuation change data in a crossplot format that is useful for model-data comparison and determining patch size. Our analysis suggests that spatial-temporal attenuation change is not only an indicator of the movement and saturation of CO2 plumes, even at large saturations, but also can quantitatively constrain CO2 plume saturation when used jointly with seismic velocity.

CONCEPTUAL DESIGN ASSESSMENT FOR THE CO-FIRING OF BIO-REFINERY SUPPLIED LIGNIN PROJECT

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

Ted Berglund; Jeffrey T. Ranney; Carol L. Babb

2001-04-01

The major aspects of this project are proceeding toward completion. Prior to this quarter, design criteria, tentative site selection, facility layout, and preliminary facility cost estimates have been completed and issued for review. Processing of bio-solids was completed, providing material for the pilot operations. Pilot facility design, equipment selection, and modification were completed during the fourth quarter of 2000. Initial pilot facility shakedown was completed during the fourth quarter. After some unavoidable delays, a suitable representative supply of municipal solid waste (MSW) feed material was procured. During this quarter (first quarter of 2001), shredding of the feed material was completedmore » and final feed conditioning was completed. Pilot facility hydrolysis production was completed to produce lignin for co-fire testing. Pilot facility modifications continued to improve facility operations and performance during the first quarter of 2001. Samples of the co-fire fuel material were sent to the co-fire facility for evaluation. The TVA-Colbert facility has neared completion of the task to evaluate the co-location of the Masada facility on the operation of the power generation facility. The TVA-Colbert fossil plant is fully capable of providing a reliable steam supply. The preferred steam supply connection points and steam pipeline routing have been identified. The environmental review of the pipeline routing has been completed and no major impacts have been identified. Detailed assessment of steam export impacts on the Colbert boiler system have been completed and a cost estimate for steam supply system is being developed.« less

Improving the Discharge Process to Optimize Patient Throughput in an Academic Teaching Hospital and Level I Trauma Center

DTIC Science & Technology

2004-02-22

order to minimize Emergency Center overcrowding and ambulance diversions. The purpose of this study was to identify impeding systematic delays in the...turnaround times. A pilot study was conducted on two medicine and two surgery inpatient nursing units to analyze bed turnaround times and discharge times of...to the BTGH executive leadership who identified a need for this study : Mr. George Masi, Associate Administrator; Ms. Beth De Guzman, Chief Nursing

Social Routines and Language Play: Developing Communication Responses in Developmentally Delayed Blind Children.

ERIC Educational Resources Information Center

Rogow, Sally M.

1983-01-01

Social routines, which combined nursery rhymes with carefully planned action sequences, were used to help two young developmentally delayed, visually handicapped children acquire communicative responses. Midway through the 3-year project, one child responded to words for objects, people, and actions. (Author/SEW)

Encoding of Spatio-Temporal Input Characteristics by a CA1 Pyramidal Neuron Model

PubMed Central

Pissadaki, Eleftheria Kyriaki; Sidiropoulou, Kyriaki; Reczko, Martin; Poirazi, Panayiota

2010-01-01

The in vivo activity of CA1 pyramidal neurons alternates between regular spiking and bursting, but how these changes affect information processing remains unclear. Using a detailed CA1 pyramidal neuron model, we investigate how timing and spatial arrangement variations in synaptic inputs to the distal and proximal dendritic layers influence the information content of model responses. We find that the temporal delay between activation of the two layers acts as a switch between excitability modes: short delays induce bursting while long delays decrease firing. For long delays, the average firing frequency of the model response discriminates spatially clustered from diffused inputs to the distal dendritic tree. For short delays, the onset latency and inter-spike-interval succession of model responses can accurately classify input signals as temporally close or distant and spatially clustered or diffused across different stimulation protocols. These findings suggest that a CA1 pyramidal neuron may be capable of encoding and transmitting presynaptic spatiotemporal information about the activity of the entorhinal cortex-hippocampal network to higher brain regions via the selective use of either a temporal or a rate code. PMID:21187899

The effect of response-delay on estimating reachability.

PubMed

Gabbard, Carl; Ammar, Diala

2008-11-01

The experiment was conducted to compare visual imagery (VI) and motor imagery (MI) reaching tasks in a response-delay paradigm designed to explore the hypothesized dissociation between vision for perception and vision for action. Although the visual systems work cooperatively in motor control, theory suggests that they operate under different temporal constraints. From this perspective, we expected that delay would affect MI but not VI because MI operates in real time and VI is postulated to be memory-driven. Following measurement of actual reach, right-handers were presented seven (imagery) targets at midline in eight conditions: MI and VI with 0-, 1-, 2-, and 4-s delays. Results indicted that delay affected the ability to estimate reachability with MI but not with VI. These results are supportive of a general distinction between vision for perception and vision for action.

Comparison of in-flight and ground-based simulator derived flying qualities and pilot performance for approach and landing tasks

NASA Technical Reports Server (NTRS)

Grantham, William D.; Williams, Robert H.

1987-01-01

For the case of an approach-and-landing piloting task emphasizing response to the landing flare, pilot opinion and performance parameters derived from jet transport aircraft six-degree-of-freedom ground-based and in-flight simulators were compared in order to derive data for the flight-controls/flying-qualities engineers. The data thus obtained indicate that ground simulation results tend to be conservative, and that the effect of control sensitivity is more pronounced for ground simulation. The pilot also has a greater tendency to generate pilot-induced oscillation in ground-based simulation than in flight.

Parent Training With High-Risk Immigrant Chinese Families: A Pilot Group Randomized Trial Yielding Practice-Based Evidence

PubMed Central

Lau, Anna S.; Fung, Joey J.; Ho, Lori Y.; Liu, Lisa L.; Gudiño, Omar G.

2013-01-01

We studied the efficacy and implementation outcomes of a culturally responsive parent training (PT) program. Fifty-four Chinese American parents participated in a wait-list controlled group randomized trial (32 immediate treatment, 22 delayed treatment) of a 14-week intervention designed to address the needs of high-risk immigrant families. Parents were eligible for intervention if they were Chinese-speaking immigrants referred from schools, community clinics, or child protective services with concerns about parenting or child behavior problems. Retention and engagement were high with 83% of families attending 10 or more sessions. Results revealed that the treatment was efficacious in reducing negative discipline, increasing positive parenting, and decreasing child externalizing and internalizing problems. Treatment effects were larger among families with higher levels of baseline behavior problems and lower levels of parenting stress. Further augmentation of PT to address immigrant parent stress may be warranted. Qualitative impressions from group leaders suggested that slower pacing and increased rehearsal of skills may improve efficacy for immigrant parents unfamiliar with skills introduced in PT. PMID:21658524

Parent training with high-risk immigrant chinese families: a pilot group randomized trial yielding practice-based evidence.

PubMed

Lau, Anna S; Fung, Joey J; Ho, Lorinda Y; Liu, Lisa L; Gudiño, Omar G

2011-09-01

We studied the efficacy and implementation outcomes of a culturally responsive parent training (PT) program. Fifty-four Chinese American parents participated in a wait-list controlled group randomized trial (32 immediate treatment, 22 delayed treatment) of a 14-week intervention designed to address the needs of high-risk immigrant families. Parents were eligible for intervention if they were Chinese-speaking immigrants referred from schools, community clinics, or child protective services with concerns about parenting or child behavior problems. Retention and engagement were high with 83% of families attending 10 or more sessions. Results revealed that the treatment was efficacious in reducing negative discipline, increasing positive parenting, and decreasing child externalizing and internalizing problems. Treatment effects were larger among families with higher levels of baseline behavior problems and lower levels of parenting stress. Further augmentation of PT to address immigrant parent stress may be warranted. Qualitative impressions from group leaders suggested that slower pacing and increased rehearsal of skills may improve efficacy for immigrant parents unfamiliar with skills introduced in PT. Copyright © 2011. Published by Elsevier Ltd.

A study of the application of permeable pavements as a sustainable technique for the mitigation of soil sealing in cities: A case study in the south of Spain.

PubMed

Rodríguez-Rojas, M I; Huertas-Fernández, F; Moreno, B; Martínez, G; Grindlay, A L

2018-01-01

The use of 'Sustainable Urban Drainage Systems' (SuDS) has become a more sustainable alternative for managing stormwater, greatly reducing the effects of soil sealing. However, the lack of monitored projects is a barrier to their implementation, as the companies which manage sewer systems cannot quantify the impact and cost-efficiency of SuDS. This paper presents a project developed in the south of Spain, in which the hydrological performance of 3 types of permeable pavements has been analyzed. The efficiencies obtained (over 70%), are higher than or similar to the efficiencies of vegetated SuDS, demonstrating the capacity of these pavements for delaying catchment area response and slow flow velocities, reducing the operating costs of sewer systems and the flood risk, while also ensuring service conditions for cities and safety for pedestrian and vehicular circulation. This pilot site has generated results which are sufficiently consistent so as to be representative, and serve as a reference for other cities with a similar climate. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of channel tap spacing on delay-lock tracking

NASA Astrophysics Data System (ADS)

Dana, Roger A.; Milner, Brian R.; Bogusch, Robert L.

1995-12-01

High fidelity simulations of communication links operating through frequency selective fading channels require both accurate channel models and faithful reproduction of the received signal. In modern radio receivers, processing beyond the analog-to-digital converter (A/D) is done digitally, so a high fidelity simulation is actually an emulation of this digital signal processing. The 'simulation' occurs in constructing the output of the A/D. One approach to constructing the A/D output is to convolve the channel impulse response function with the combined impulse response of the transmitted modulation and the A/D. For both link simulations and hardware channel simulators, the channel impulse response function is then generated with a finite number of samples per chip, and the convolution is implemented in a tapped delay line. In this paper we discuss the effects of the channel model tap spacing on the performance of delay locked loops (DLLs) in both direct sequence and frequency hopped spread spectrum systems. A frequency selective fading channel is considered, and the channel impulse response function is constructed with an integer number of taps per modulation symbol or chip. The tracking loop time delay is computed theoretically for this tapped delay line channel model and is compared to the results of high fidelity simulations of actual DLLs. A surprising result is obtained. The performance of the DLL depends strongly on the number of taps per chip. As this number increases the DLL delay approaches the theoretical limit.

Stochastic resonance enhancement of small-world neural networks by hybrid synapses and time delay

NASA Astrophysics Data System (ADS)

Yu, Haitao; Guo, Xinmeng; Wang, Jiang

2017-01-01

The synergistic effect of hybrid electrical-chemical synapses and information transmission delay on the stochastic response behavior in small-world neuronal networks is investigated. Numerical results show that, the stochastic response behavior can be regulated by moderate noise intensity to track the rhythm of subthreshold pacemaker, indicating the occurrence of stochastic resonance (SR) in the considered neural system. Inheriting the characteristics of two types of synapses-electrical and chemical ones, neural networks with hybrid electrical-chemical synapses are of great improvement in neuron communication. Particularly, chemical synapses are conducive to increase the network detectability by lowering the resonance noise intensity, while the information is better transmitted through the networks via electrical coupling. Moreover, time delay is able to enhance or destroy the periodic stochastic response behavior intermittently. In the time-delayed small-world neuronal networks, the introduction of electrical synapses can significantly improve the signal detection capability by widening the range of optimal noise intensity for the subthreshold signal, and the efficiency of SR is largely amplified in the case of pure chemical couplings. In addition, the stochastic response behavior is also profoundly influenced by the network topology. Increasing the rewiring probability in pure chemically coupled networks can always enhance the effect of SR, which is slightly influenced by information transmission delay. On the other hand, the capacity of information communication is robust to the network topology within the time-delayed neuronal systems including electrical couplings.

Sensorimotor responsiveness and resolution in the giraffe.

PubMed

More, Heather L; O'Connor, Shawn M; Brøndum, Emil; Wang, Tobias; Bertelsen, Mads F; Grøndahl, Carsten; Kastberg, Karin; Hørlyck, Arne; Funder, Jonas; Donelan, J Maxwell

2013-03-15

The ability of an animal to detect and respond to changes in the environment is crucial to its survival. However, two elements of sensorimotor control - the time required to respond to a stimulus (responsiveness) and the precision of stimulus detection and response production (resolution) - are inherently limited by a competition for space in peripheral nerves and muscles. These limitations only become more acute as animal size increases. In this paper, we investigated whether the physiology of giraffes has found unique solutions for maintaining sensorimotor performance in order to compensate for their extreme size. To examine responsiveness, we quantified three major sources of delay: nerve conduction delay, muscle electromechanical delay and force generation delay. To examine resolution, we quantified the number and size distribution of nerve fibers in the sciatic nerve. Rather than possessing a particularly unique sensorimotor system, we found that our measurements in giraffes were broadly comparable to size-dependent trends seen across other terrestrial mammals. Consequently, both giraffes and other large animals must contend with greater sensorimotor delays and lower innervation density in comparison to smaller animals. Because of their unconventional leg length, giraffes may experience even longer delays compared with other animals of the same mass when sensing distal stimuli. While there are certainly advantages to being tall, there appear to be challenges as well - our results suggest that giraffes are less able to precisely and accurately sense and respond to stimuli using feedback alone, particularly when moving quickly.

Anthrax vaccine adsorbed: further evidence supporting continuing the vaccination series rather than restarting the series when doses are delayed.

PubMed

Pittman, Phillip R; Cavicchia, M A; Kingsbury, J L; Johnson, N A; Barrera-Oro, J G; Schmader, T; Korman, L; Quinn, X; Ranadive, M

2014-09-03

Whether to restart or continue the series when anthrax vaccine doses are missed is a frequent medical management problem. We applied the noninferiority analysis model to this prospective study comparing the Bacillus anthracis protective antigen (PA) IgG antibody response and lethal toxin neutralization activity at day 28 to the anthrax vaccine adsorbed (AVA) (Biothrax®) administered on schedule or delayed. A total of 600 volunteers were enrolled: 354 in the on-schedule cohort; 246 in the delayed cohort. Differences were noted in immune responses between cohorts (p<0.0001) and among the racial categories (p<0.0001). Controlling for covariates, the delayed cohort was non-inferior to the on-schedule cohort for the rate of 4-fold rise in both anti-PA IgG concentration (p<0.0001) and TNA ED50 titers (p<0.0001); as well as the mean log10-transformed anti-PA IgG concentration (p<0.0001) and the mean log10-transformed TNA ED50 titers (p<0.0001). Providing a missed AVA dose after a delay as long as 5-7 years, elicits anti-PA IgG antibody and TNA ED50 responses that are robust and non-inferior to the responses observed when the 6-month dose is given on-schedule. These important data suggest it is not necessary to restart the series when doses of the anthrax vaccine are delayed as long as 5 or more years. Published by Elsevier Ltd.

"i h8 u": The Influence of Normative Beliefs and Hostile Response Selection in Predicting Adolescents' Mobile Phone Aggression--A Pilot Study

ERIC Educational Resources Information Center

Nicol, Annemarie; Fleming, Michele J.

2010-01-01

Mobile phone aggression (MPA) is a relatively new phenomenon. Using newly developed measures, a pilot study was conducted with 348 adolescents ages 13-17 years to determine the incidence of MPA and victimization in this group of adolescents and to test a proposed model in which hostile response selection mediated the relationship between normative…

The Role of Values, Moral Norms, and Descriptive Norms in Building Occupant Responses to an Energy-Efficiency Pilot Program and to Framing of Related Messages

ERIC Educational Resources Information Center

Arpan, Laura M.; Barooah, Prabir; Subramany, Rahul

2015-01-01

This study examined building occupants' responses associated with an occupant-based energy-efficiency pilot in a university building. The influence of occupants' values and norms as well as effects of two educational message frames (descriptive vs. moral norms cues) on program support were tested. Occupants' personal moral norm to conserve energy…

Response of a WB-47E Airplane to Runway Roughness at Eielson AFB, Alaska, September 1964

NASA Technical Reports Server (NTRS)

Morris, Garland J.; Hall, Albert W.

1965-01-01

An investigation has been conducted to measure the response of a WB-47E airplane to the roughness of the runway at Eielson AFB, Alaska. The acceleration level in the pilot's compartment and the pitching oscillation of the airplane were found to be sufficiently high to possibly cause pilot discomfort and have an adverse effect on the precision of take-off.

Delays in using chromatic and luminance information to correct rapid reaches.

PubMed

Kane, Adam; Wade, Alex; Ma-Wyatt, Anna

2011-09-07

People can use feedback to make online corrections to movements but only if there is sufficient time to integrate the new information and make the correction. A key variable in this process is therefore the speed at which the new information about the target location is coded. Conduction velocities for chromatic signals are lower than for achromatic signals so it may take longer to correct reaches to chromatic stimuli. In addition to this delay, the sensorimotor system may prefer achromatic information over the chromatic information as delayed information may be less valuable when movements are made under time pressure. A down-weighting of chromatic information may result in additional latencies for chromatically directed reaches. In our study, participants made online corrections to reaches to achromatic, (L-M)-cone, and S-cone stimuli. Our chromatic stimuli were carefully adjusted to minimize stimulation of achromatic pathways, and we equated stimuli both in terms of detection thresholds and also by their estimated neural responses. Similar stimuli were used throughout the subjective adjustments and final reaching experiment. Using this paradigm, we found that responses to achromatic stimuli were only slightly faster than responses to (L-M)-cone and S-cone stimuli. We conclude that the sensorimotor system treats chromatic and achromatic information similarly and that the delayed chromatic responses primarily reflect early conduction delays.

Abnormal glucose levels found in transportation accidents : final report.

DOT National Transportation Integrated Search

2000-06-01

Purpose. The Federal Aviation Administration's Office of Aviation Medicine (OAM) is responsible for the certification of pilots with diabetic conditions. Therefore, it is essential for OAM to monitor pilots involved in fatal accidents for abnormal gl...

Local Bifurcations and Optimal Theory in a Delayed Predator-Prey Model with Threshold Prey Harvesting

NASA Astrophysics Data System (ADS)

Tankam, Israel; Tchinda Mouofo, Plaire; Mendy, Abdoulaye; Lam, Mountaga; Tewa, Jean Jules; Bowong, Samuel

2015-06-01

We investigate the effects of time delay and piecewise-linear threshold policy harvesting for a delayed predator-prey model. It is the first time that Holling response function of type III and the present threshold policy harvesting are associated with time delay. The trajectories of our delayed system are bounded; the stability of each equilibrium is analyzed with and without delay; there are local bifurcations as saddle-node bifurcation and Hopf bifurcation; optimal harvesting is also investigated. Numerical simulations are provided in order to illustrate each result.

A model for the pilot's use of motion cues in roll-axis tracking tasks

NASA Technical Reports Server (NTRS)

Levison, W. H.; Junker, A. M.

1977-01-01

Simulated target-following and disturbance-regulation tasks were explored with subjects using visual-only and combined visual and motion cues. The effects of motion cues on task performance and pilot response behavior were appreciably different for the two task configurations and were consistent with data reported in earlier studies for similar task configurations. The optimal-control model for pilot/vehicle systems provided a task-independent framework for accounting for the pilot's use of motion cues. Specifically, the availability of motion cues was modeled by augmenting the set of perceptual variables to include position, rate, acceleration, and accleration-rate of the motion simulator, and results were consistent with the hypothesis of attention-sharing between visual and motion variables. This straightforward informational model allowed accurate model predictions of the effects of motion cues on a variety of response measures for both the target-following and disturbance-regulation tasks.

Quantitative pilomotor axon reflex test: a novel test of pilomotor function.

PubMed

Siepmann, Timo; Gibbons, Christopher H; Illigens, Ben M; Lafo, Jacob A; Brown, Christopher M; Freeman, Roy

2012-11-01

Cutaneous autonomic function can be quantified by the assessment of sudomotor and vasomotor responses. Although piloerector muscles are innervated by the sympathetic nervous system, there are at present no methods to quantify pilomotor function. To quantify piloerection using phenylephrine hydrochloride in humans. Pilot study. Hospital-based study. Twenty-two healthy volunteers (18 males,4 females) aged 24 to 48 years participated in 6 studies. Piloerection was stimulated by iontophoresis of 1% phenylephrine. Silicone impressions of piloerection were quantified by number and area. The direct and indirect responses to phenylephrine iontophoresis were compared on both forearms after pre treatment to topical and subcutaneous lidocaine and iontophoresis of normal saline. Iontophoresis of phenylephrine induced piloerection in both the direct and axon reflex–mediated regions, with similar responses in both arms. Topical lidocaine blocked axon reflex–mediated piloerection post-iontophoresis (mean [SD], 66.6 [19.2] for control impressions vs 7.2 [4.3] for lidocaine impressions;P.001). Subcutaneous lidocaine completely blocked piloerection.The area of axon reflex–mediated piloerection was also attenuated in the lidocaine-treated region postiontophoresis (mean [SD], 46.2 [16.1]cm2 vs 7.2 [3.9]cm2; P.001). Piloerection was delayed in the axon reflex region compared with the direct region. Normal saline did not cause piloerection. Phenylephrine provoked piloerection directly and indirectly through an axon reflex–mediated response that is attenuated by lidocaine. Piloerection is not stimulated by iontophoresis of normal saline alone.The quantitative pilomotor axon reflex test (QPART) may complement other measures of cutaneous autonomic nerve fiber function.

Effect of Mental Arithmetic on heart rate responses during Parabolic Flights: the Barcelona Zero-G Challenge

NASA Astrophysics Data System (ADS)

Osborne, Jeffrey R.; Alonsopérez Lanza, María Victoria; Desclaux, David Ferrer; Goswami, Nandu; González Alonso, Daniel Ventura; Moser, Maximilian; Grote, Vincent; Garcia-Cuadrado, Gloria; Perez-Poch, Antoni

2014-07-01

When an astronaut transitions from a low to high gravitational environment, fluid shifts from the head towards the feet resulting in orthostatic intolerance and syncope. Ground based experiments have shown that by stimulating the cardiovascular system via simple mental stressors, syncope can be delayed, potentially enabling astronauts to reach assistance before loss of consciousness. However, the effect of mental stressors on the stimulation of the cardiovascular system in gravitational environments different than that of Earth's is unknown. As such, this paper investigates the effects that mental stressors under various gravitational environments. To do this, a pilot study was performed in which two participants were flown on two separate parabolic flights that simulated hyper and hypogravity conditions. The plane used was an Aerobatic Single-Engine Cap-10B plane (twin seater), and each participant executed 11 parabolas. The participants were the winners of the Barcelona Zero-G Challenge 2011 organized by UPC Universitat Politècnica de Catalunya-BarcelonaTech and Aeroclub Barcelona-Sabadell. Measurements were made of the participants' hemodynamic and autonomic response throughout the parabolas, using a Chronocord: high precision HRV monitor. Comparisons of the baseline response without mental stressors, and the response with mental stressors during different gravitational loading conditions were made. It was observed that there is an increase in cardiovascular activity during hypo- and hyper-gravity when performing mental arithmetic. Our results show that the twin seater aerobatic single engine CAP-10B aicraft can provide changing gravitational loading conditions for enough periods to study changes in physiological systems.

Evaluation of Flight Deck-Based Interval Management Crew Procedure Feasibility

NASA Technical Reports Server (NTRS)

Wilson, Sara R.; Murdoch, Jennifer L.; Hubbs, Clay E.; Swieringa, Kurt A.

2013-01-01

Air traffic demand is predicted to increase over the next 20 years, creating a need for new technologies and procedures to support this growth in a safe and efficient manner. The National Aeronautics and Space Administration's (NASA) Air Traffic Management Technology Demonstration - 1 (ATD-1) will operationally demonstrate the feasibility of efficient arrival operations combining ground-based and airborne NASA technologies. The integration of these technologies will increase throughput, reduce delay, conserve fuel, and minimize environmental impacts. The ground-based tools include Traffic Management Advisor with Terminal Metering for precise time-based scheduling and Controller Managed Spacing decision support tools for better managing aircraft delay with speed control. The core airborne technology in ATD-1 is Flight deck-based Interval Management (FIM). FIM tools provide pilots with speed commands calculated using information from Automatic Dependent Surveillance - Broadcast. The precise merging and spacing enabled by FIM avionics and flight crew procedures will reduce excess spacing buffers and result in higher terminal throughput. This paper describes a human-in-the-loop experiment designed to assess the acceptability and feasibility of the ATD-1 procedures used in a voice communications environment. This experiment utilized the ATD-1 integrated system of ground-based and airborne technologies. Pilot participants flew a high-fidelity fixed base simulator equipped with an airborne spacing algorithm and a FIM crew interface. Experiment scenarios involved multiple air traffic flows into the Dallas-Fort Worth Terminal Radar Control airspace. Results indicate that the proposed procedures were feasible for use by flight crews in a voice communications environment. The delivery accuracy at the achieve-by point was within +/- five seconds and the delivery precision was less than five seconds. Furthermore, FIM speed commands occurred at a rate of less than one per minute, and pilots found the frequency of the speed commands to be acceptable at all times throughout the experiment scenarios.

A 24-month, double-blind, placebo-controlled multicentre pilot study of the efficacy and safety of nicergoline 60 mg per day in elderly hypertensive patients with leukoaraiosis.

PubMed

Bès, A; Orgogozo, J M; Poncet, M; Rancurel, G; Weber, M; Bertholom, N; Calvez, R; Stehlé, B

1999-05-01

In this pilot study, 72 non-demented and non-depressive elderly hypertensive patients with evidence of leukoaraiosis on cerebral computed tomography scan (Rezek score: > 16) were randomly assigned to receive either nicergoline 30 mg b.i.d. (n = 36) or a placebo (n = 36) for 24 months. All patients received antihypertensives and their hypertension was controlled under treatment. They were evaluated by nine neuropsychological tests exploring memory, concentration, verbal and motor performances, administered at baseline and at every six-month interval during the study period. At baseline, the two groups were comparable for all demographic and clinical characteristics, including cognitive functions, except for the delayed recall of the Auditory Verbal Learning Test (AVLT), which was better in the placebo group (P = 0.04). Changes in scores over time were compared between the two groups. At the last visit, patients on nicergoline (n = 31) were found to have deteriorated less or to have improved more on test scores than the patients on placebo (n = 30). Significant differences were observed for memory function (AVLT short term recall, P = 0.026; AVLT delayed recall, P = 0.013; and, Benton Visual Retention Test, P = 0.002) and attention and concentration (Letter Cancellation Test, P = 0.043; and, WAIS-R Digit Symbol subtest, P = 0.006). The Rezek score remained unchanged in the two groups. Tolerance of nicergoline was similar to that of placebo. In conclusion, this study shows that nicergoline 30 mg b.i. d. administered over a 24-month period attenuates the deterioration in cognitive functions in elderly hypertensive patients with leukoaraiosis. Whether these effects were specific for this type of white matter changes could not be determined in the context of this pilot study. Copyright 1999 Lippincott Williams & Wilkins

Prehospital delay and independent/interdependent construal of self among Japanese patients with acute myocardial infarction.

PubMed

Fukuoka, Yoshimi; Dracup, Kathleen; Rankin, Sally H; Froelicher, Erika Sivarajan; Kobayashi, Fumio; Hirayama, Haro; Ohno, Miyoshi; Matsumoto, David

2005-05-01

Reducing the time from symptom onset to reperfusion therapy is an important approach to minimizing myocardial damage and to preventing death from acute myocardial infarction (AMI). Previous studies suggest that certain ethnic or national groups, such as the Japanese, are more likely to delay in accessing care than other groups. The aims of this paper were the following; (1) to examine whether culture (defined as independent and interdependent construal of self) is associated with delay in accessing medical care in Japanese patients experiencing symptoms of AMI; (2) to determine if the relationship between independent and interdependent construal of self and prehospital delay time is mediated by cognitive responses and/or emotional responses; and (3) to determine if independent and interdependent construal of self independently predicts choice of treatment site (clinic vs. hospital). A cross-sectional study was conducted at hospitals in urban areas in Japan. One hundred and forty-five consecutive patients who were admitted with AMI within 72 h of the onset of symptoms were interviewed using the modified response to symptoms questionnaire and the independent and interdependent construal of self scale. The interdependent construal of self scores were significantly associated with prehospital delay time, controlling for demographics, medical history, and symptoms (p<.001). However, the relationship between independent and interdependent self and prehospital delay times was not mediated by cognitive or emotional responses. In multiple logistic regression analysis, patients with high independent construal of self were more likely to seek care at a hospital rather than a clinic compared to those with lower independent construal of self. In conclusion, cultural variation within this Japanese group was observed and was associated with prehospital delay time.

White matter hyperintensities on MRI in high-altitude U-2 pilots.

PubMed

McGuire, Stephen; Sherman, Paul; Profenna, Leonardo; Grogan, Patrick; Sladky, John; Brown, Anthony; Robinson, Andrew; Rowland, Laura; Hong, Elliot; Patel, Beenish; Tate, David; Kawano, Elaine S; Fox, Peter; Kochunov, Peter

2013-08-20

To demonstrate that U-2 pilot occupational exposure to hypobaria leads to increased incidence of white matter hyperintensities (WMH) with a more uniform distribution throughout the brain irrespective of clinical neurologic decompression sickness history. We evaluated imaging findings in 102 U-2 pilots and 91 controls matched for age, health, and education levels. Three-dimensional, T2-weighted, high-resolution (1-mm isotropic) imaging data were collected using fluid-attenuated inversion recovery sequence on a 3-tesla MRI scanner. Whole-brain and regional WMH volume and number were compared between groups using a 2-tailed Wilcoxon rank sum test. U-2 pilots demonstrated an increase in volume (394%; p = 0.004) and number (295%; p < 0.001) of WMH. Analysis of regional distribution demonstrated WMH more uniformly distributed throughout the brain in U-2 pilots compared with mainly frontal distribution in controls. Pilots with occupational exposure to hypobaria showed a significant increase in WMH lesion volume and number. Unlike the healthy controls with predominantly WMH in the frontal white matter, WMH in pilots were more uniformly distributed throughout the brain. This is consistent with our hypothesized pattern of damage produced by interaction between microemboli and cerebral tissue, leading to thrombosis, coagulation, inflammation, and/or activation of innate immune response, although further studies will be necessary to clarify the pathologic mechanisms responsible.

White matter hyperintensities on MRI in high-altitude U-2 pilots

PubMed Central

Sherman, Paul; Profenna, Leonardo; Grogan, Patrick; Sladky, John; Brown, Anthony; Robinson, Andrew; Rowland, Laura; Hong, Elliot; Patel, Beenish; Tate, David; Kawano, Elaine S.; Fox, Peter; Kochunov, Peter

2013-01-01

Objective: To demonstrate that U-2 pilot occupational exposure to hypobaria leads to increased incidence of white matter hyperintensities (WMH) with a more uniform distribution throughout the brain irrespective of clinical neurologic decompression sickness history. Methods: We evaluated imaging findings in 102 U-2 pilots and 91 controls matched for age, health, and education levels. Three-dimensional, T2-weighted, high-resolution (1-mm isotropic) imaging data were collected using fluid-attenuated inversion recovery sequence on a 3-tesla MRI scanner. Whole-brain and regional WMH volume and number were compared between groups using a 2-tailed Wilcoxon rank sum test. Results: U-2 pilots demonstrated an increase in volume (394%; p = 0.004) and number (295%; p < 0.001) of WMH. Analysis of regional distribution demonstrated WMH more uniformly distributed throughout the brain in U-2 pilots compared with mainly frontal distribution in controls. Conclusion: Pilots with occupational exposure to hypobaria showed a significant increase in WMH lesion volume and number. Unlike the healthy controls with predominantly WMH in the frontal white matter, WMH in pilots were more uniformly distributed throughout the brain. This is consistent with our hypothesized pattern of damage produced by interaction between microemboli and cerebral tissue, leading to thrombosis, coagulation, inflammation, and/or activation of innate immune response, although further studies will be necessary to clarify the pathologic mechanisms responsible. PMID:23960192

Adaptive Fading Memory H∞ Filter Design for Compensation of Delayed Components in Self Powered Flux Detectors

NASA Astrophysics Data System (ADS)

Tamboli, Prakash Kumar; Duttagupta, Siddhartha P.; Roy, Kallol

2015-08-01

The paper deals with dynamic compensation of delayed Self Powered Flux Detectors (SPFDs) using discrete time H∞ filtering method for improving the response of SPFDs with significant delayed components such as Platinum and Vanadium SPFD. We also present a comparative study between the Linear Matrix Inequality (LMI) based H∞ filtering and Algebraic Riccati Equation (ARE) based Kalman filtering methods with respect to their delay compensation capabilities. Finally an improved recursive H∞ filter based on the adaptive fading memory technique is proposed which provides an improved performance over existing methods. The existing delay compensation algorithms do not account for the rate of change in the signal for determining the filter gain and therefore add significant noise during the delay compensation process. The proposed adaptive fading memory H∞ filter minimizes the overall noise very effectively at the same time keeps the response time at minimum values. The recursive algorithm is easy to implement in real time as compared to the LMI (or ARE) based solutions.

Coded acoustic wave sensors and system using time diversity

NASA Technical Reports Server (NTRS)

Solie, Leland P. (Inventor); Hines, Jacqueline H. (Inventor)

2012-01-01

An apparatus and method for distinguishing between sensors that are to be wirelessly detected is provided. An interrogator device uses different, distinct time delays in the sensing signals when interrogating the sensors. The sensors are provided with different distinct pedestal delays. Sensors that have the same pedestal delay as the delay selected by the interrogator are detected by the interrogator whereas other sensors with different pedestal delays are not sensed. Multiple sensors with a given pedestal delay are provided with different codes so as to be distinguished from one another by the interrogator. The interrogator uses a signal that is transmitted to the sensor and returned by the sensor for combination and integration with the reference signal that has been processed by a function. The sensor may be a surface acoustic wave device having a differential impulse response with a power spectral density consisting of lobes. The power spectral density of the differential response is used to determine the value of the sensed parameter or parameters.

How effectively do horizontal and vertical response strategies of long-finned pilot whales reduce sound exposure from naval sonar?

PubMed

Wensveen, Paul J; von Benda-Beckmann, Alexander M; Ainslie, Michael A; Lam, Frans-Peter A; Kvadsheim, Petter H; Tyack, Peter L; Miller, Patrick J O

2015-05-01

The behaviour of a marine mammal near a noise source can modulate the sound exposure it receives. We demonstrate that two long-finned pilot whales both surfaced in synchrony with consecutive arrivals of multiple sonar pulses. We then assess the effect of surfacing and other behavioural response strategies on the received cumulative sound exposure levels and maximum sound pressure levels (SPLs) by modelling realistic spatiotemporal interactions of a pilot whale with an approaching source. Under the propagation conditions of our model, some response strategies observed in the wild were effective in reducing received levels (e.g. movement perpendicular to the source's line of approach), but others were not (e.g. switching from deep to shallow diving; synchronous surfacing after maximum SPLs). Our study exemplifies how simulations of source-whale interactions guided by detailed observational data can improve our understanding about motivations behind behaviour responses observed in the wild (e.g., reducing sound exposure, prey movement). Copyright © 2015 Elsevier Ltd. All rights reserved.

A New Method for a Virtue-Based Responsible Conduct of Research Curriculum: Pilot Test Results.

PubMed

Berling, Eric; McLeskey, Chet; O'Rourke, Michael; Pennock, Robert T

2018-02-03

Drawing on Pennock's theory of scientific virtues, we are developing an alternative curriculum for training scientists in the responsible conduct of research (RCR) that emphasizes internal values rather than externally imposed rules. This approach focuses on the virtuous characteristics of scientists that lead to responsible and exemplary behavior. We have been pilot-testing one element of such a virtue-based approach to RCR training by conducting dialogue sessions, modeled upon the approach developed by Toolbox Dialogue Initiative, that focus on a specific virtue, e.g., curiosity and objectivity. During these structured discussions, small groups of scientists explore the roles they think the focus virtue plays and should play in the practice of science. Preliminary results have shown that participants strongly prefer this virtue-based model over traditional methods of RCR training. While we cannot yet definitively say that participation in these RCR sessions contributes to responsible conduct, these pilot results are encouraging and warrant continued development of this virtue-based approach to RCR training.

Understanding delayed T-cell priming, lung recruitment, and airway luminal T-cell responses in host defense against pulmonary tuberculosis.

PubMed

Shaler, Christopher R; Horvath, Carly; Lai, Rocky; Xing, Zhou

2012-01-01

Mycobacterium tuberculosis (M.tb), the causative bacterium of pulmonary tuberculosis (TB), is a serious global health concern. Central to M.tb effective immune avoidance is its ability to modulate the early innate inflammatory response and prevent the establishment of adaptive T-cell immunity for nearly three weeks. When compared with other intracellular bacterial lung pathogens, such as Legionella pneumophila, or even closely related mycobacterial species such as M. smegmatis, this delay is astonishing. Customarily, the alveolar macrophage (AM) acts as a sentinel, detecting and alerting surrounding cells to the presence of an invader. However, in the case of M.tb, this may be impaired, thus delaying the recruitment of antigen-presenting cells (APCs) to the lung. Upon uptake by APC populations, M.tb is able to subvert and delay the processing of antigen, MHC class II loading, and the priming of effector T cell populations. This delay ultimately results in the deferred recruitment of effector T cells to not only the lung interstitium but also the airway lumen. Therefore, it is of upmost importance to dissect the mechanisms that contribute to the delayed onset of immune responses following M.tb infection. Such knowledge will help design the most effective vaccination strategies against pulmonary TB.

The effects of physical activity on impulsive choice: Influence of sensitivity to reinforcement amount and delay

PubMed Central

Strickland, Justin C.; Feinstein, Max A.; Lacy, Ryan T.; Smith, Mark A.

2016-01-01

Impulsive choice is a diagnostic feature and/or complicating factor for several psychological disorders and may be examined in the laboratory using delay-discounting procedures. Recent investigators have proposed using quantitative measures of analysis to examine the behavioral processes contributing to impulsive choice. The purpose of this study was to examine the effects of physical activity (i.e., wheel running) on impulsive choice in a single-response, discrete-trial procedure using two quantitative methods of analysis. To this end, rats were assigned to physical activity or sedentary groups and trained to respond in a delay-discounting procedure. In this procedure, one lever always produced one food pellet immediately, whereas a second lever produced three food pellets after a 0, 10, 20, 40, or 80-second delay. Estimates of sensitivity to reinforcement amount and sensitivity to reinforcement delay were determined using (1) a simple linear analysis and (2) an analysis of logarithmically transformed response ratios. Both analyses revealed that physical activity decreased sensitivity to reinforcement amount and sensitivity to reinforcement delay. These findings indicate that (1) physical activity has significant but functionally opposing effects on the behavioral processes that contribute to impulsive choice and (2) both quantitative methods of analysis are appropriate for use in single-response, discrete-trial procedures. PMID:26964905

Urban sprawl and delayed ambulance arrival in the U.S.

PubMed

Trowbridge, Matthew J; Gurka, Matthew J; O'Connor, Robert E

2009-11-01

Minimizing emergency medical service (EMS) response time is a central objective of prehospital care, yet the potential influence of built environment features such as urban sprawl on EMS system performance is often not considered. This study measures the association between urban sprawl and EMS response time to test the hypothesis that features of sprawling development increase the probability of delayed ambulance arrival. In 2008, EMS response times for 43,424 motor-vehicle crashes were obtained from the Fatal Analysis Reporting System, a national census of crashes involving > or =1 fatality. Sprawl at each crash location was measured using a continuous county-level index previously developed by Ewing et al. The association between sprawl and the probability of a delayed ambulance arrival (> or =8 minutes) was then measured using generalized linear mixed modeling to account for correlation among crashes from the same county. Urban sprawl is significantly associated with increased EMS response time and a higher probability of delayed ambulance arrival (p=0.03). This probability increases quadratically as the severity of sprawl increases while controlling for nighttime crash occurrence, road conditions, and presence of construction. For example, in sprawling counties (e.g., Fayette County GA), the probability of a delayed ambulance arrival for daytime crashes in dry conditions without construction was 69% (95% CI=66%, 72%) compared with 31% (95% CI=28%, 35%) in counties with prominent smart-growth characteristics (e.g., Delaware County PA). Urban sprawl is significantly associated with increased EMS response time and a higher probability of delayed ambulance arrival following motor-vehicle crashes in the U.S. The results of this study suggest that promotion of community design and development that follows smart-growth principles and regulates urban sprawl may improve EMS performance and reliability.

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.

Effect of Interocular Delay on Disparity-Selective V1 Neurons: Relationship to Stereoacuity and the Pulfrich Effect

PubMed Central

Read, Jenny C. A.; Cumming, Bruce G.

2006-01-01

The temporal properties of disparity-sensitive neurons place important temporal constraints on stereo matching. We examined these constraints by measuring the responses of disparity-selective neurons in striate cortex of awake behaving monkeys to random-dot stereograms that contained interocular delays. Disparity selectivity was gradually abolished by increasing interocular delay (when the delay exceeds the integration time, the inputs from the 2 eyes become uncorrelated). The amplitude of the disparity-selective response was a Gaussian function of interocular delay, with a mean of 16 ms (±5 ms, SD). Psychophysical measures of stereoacuity, in both monkey and human observers, showed a closely similar dependency on time, suggesting that temporal integration in V1 neurons is what determines psychophysical matching constraints over time. There was a slight but consistent asymmetry in the neuronal responses, as if the optimum stimulus is one in which the right stimulus leads by about 4 ms. Because all recordings were made in the left hemisphere, this probably reflects nasotemporal differences in conduction times; psychophysical data are compatible with this interpretation. In only a few neurons (5/72), interocular delay caused a change in the preferred disparity. Such tilted disparity/delay profiles have been invoked previously to explain depth perception in the stroboscopic version of the Pulfrich effect (and other variants). However, the great majority of the neurons did not show tilted disparity/delay profiles. This suggests that either the activity of these neurons is ignored when viewing Pulfrich stimuli, or that current theories relating neuronal properties to perception in the Pulfrich effect need to be reevaluated. PMID:15788521

Flight testing and frequency domain analysis for rotorcraft handling qualities characteristics

NASA Technical Reports Server (NTRS)

Ham, Johnnie A.; Gardner, Charles K.; Tischler, Mark B.

1993-01-01

A demonstration of frequency domain flight testing techniques and analyses was performed on a U.S. Army OH-58D helicopter in support of the OH-58D Airworthiness and Flight Characteristics Evaluation and the Army's development and ongoing review of Aeronautical Design Standard 33C, Handling Qualities Requirements for Military Rotorcraft. Hover and forward flight (60 knots) tests were conducted in 1 flight hour by Army experimental test pilots. Further processing of the hover data generated a complete database of velocity, angular rate, and acceleration frequency responses to control inputs. A joint effort was then undertaken by the Airworthiness Qualification Test Directorate (AQTD) and the U.S. Army Aeroflightdynamics Directorate (AFDD) to derive handling qualities information from the frequency response database. A significant amount of information could be extracted from the frequency domain database using a variety of approaches. This report documents numerous results that have been obtained from the simple frequency domain tests; in many areas, these results provide more insight into the aircraft dynamics that affect handling qualities than to traditional flight tests. The handling qualities results include ADS-33C bandwidth and phase delay calculations, vibration spectral determinations, transfer function models to examine single axis results, and a six degree of freedom fully coupled state space model. The ability of this model to accurately predict aircraft responses was verified using data from pulse inputs. This report also documents the frequency-sweep flight test technique and data analysis used to support the tests.

Time delay measurement in the frequency domain

DOE PAGES

Durbin, Stephen M.; Liu, Shih -Chieh; Dufresne, Eric M.; ...

2015-08-06

Pump–probe studies at synchrotrons using X-ray and laser pulses require accurate determination of the time delay between pulses. This becomes especially important when observing ultrafast responses with lifetimes approaching or even less than the X-ray pulse duration (~100 ps). The standard approach of inspecting the time response of a detector sensitive to both types of pulses can have limitations due to dissimilar pulse profiles and other experimental factors. Here, a simple alternative is presented, where the frequency response of the detector is monitored versus time delay. Measurements readily demonstrate a time resolution of ~1 ps. Improved precision is possible bymore » simply extending the data acquisition time.« less

Increasing the vocal responses of children with autism and developmental disabilities using manual sign mand training and prompt delay.

PubMed

Carbone, Vincent J; Sweeney-Kerwin, Emily J; Attanasio, Vivian; Kasper, Tamara

2010-01-01

The purpose of this study was to determine the effect of manual sign mand training combined with prompt delay and vocal prompting on the production of vocal responses in nonvocal children with developmental disabilities. A multiple baseline design across participants verified the effectiveness of this intervention. All participants showed increases in vocal responses following the implementation of the independent variables.

Analysis of general aviation single-pilot IFR incident data obtained from the NASA Aviation Safety Reporting System

NASA Technical Reports Server (NTRS)

Bergeron, H. P.

1983-01-01

An analysis of incident data obtained from the NASA Aviation Safety Reporting System (ASRS) has been made to determine the problem areas in general aviation single-pilot IFR (SPIFR) operations. The Aviation Safety Reporting System data base is a compilation of voluntary reports of incidents from any person who has observed or been involved in an occurrence which was believed to have posed a threat to flight safety. This paper examines only those reported incidents specifically related to general aviation single-pilot IFR operations. The frequency of occurrence of factors related to the incidents was the criterion used to define significant problem areas and, hence, to suggest where research is needed. The data was cataloged into one of five major problem areas: (1) controller judgment and response problems, (2) pilot judgment and response problems, (3) air traffic control (ATC) intrafacility and interfacility conflicts, (4) ATC and pilot communication problems, and (5) IFR-VFR conflicts. In addition, several points common to all or most of the problems were observed and reported. These included human error, communications, procedures and rules, and work load.

Topographical gradients of semantics and phonology revealed by temporal lobe stimulation.

PubMed

Miozzo, Michele; Williams, Alicia C; McKhann, Guy M; Hamberger, Marla J

2017-02-01

Word retrieval is a fundamental component of oral communication, and it is well established that this function is supported by left temporal cortex. Nevertheless, the specific temporal areas mediating word retrieval and the particular linguistic processes these regions support have not been well delineated. Toward this end, we analyzed over 1000 naming errors induced by left temporal cortical stimulation in epilepsy surgery patients. Errors were primarily semantic (lemon → "pear"), phonological (horn → "corn"), non-responses, and delayed responses (correct responses after a delay), and each error type appeared predominantly in a specific region: semantic errors in mid-middle temporal gyrus (TG), phonological errors and delayed responses in middle and posterior superior TG, and non-responses in anterior inferior TG. To the extent that semantic errors, phonological errors and delayed responses reflect disruptions in different processes, our results imply topographical specialization of semantic and phonological processing. Specifically, results revealed an inferior-to-superior gradient, with more superior regions associated with phonological processing. Further, errors were increasingly semantically related to targets toward posterior temporal cortex. We speculate that detailed semantic input is needed to support phonological retrieval, and thus, the specificity of semantic input increases progressively toward posterior temporal regions implicated in phonological processing. Hum Brain Mapp 38:688-703, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Pilots' Information Needs and Strategies for Operating in Icing Conditions

NASA Technical Reports Server (NTRS)

Vigeant-Langlois, Laurence N.; Hansman, R. John

2003-01-01

Pilot current use of icing information, pilot encounters and strategies for dealing with in-flight aircraft structural icing situations, and desired attributes of new icing information systems were investigated through a survey of pilots of several operational categories. The survey identified important information elements and fiequently used information paths for obtaining icing-related information. Free- response questions solicited descriptions of significant , icing encounters, and probed key icing-related decision and information criteria. Results indicated the information needs for the horizontal and vertical location of icing conditions and the identification of icing-free zones.

Baseline Behavior of Pilot Whales and their Responses to Playback of Anthropogenic and Natural Sounds

DTIC Science & Technology

2014-09-30

Minvielle- Sebastia, L. and Guinet, C. (2008b). Diet of the social groups of long-finned pilot whales (Globicephala melas ) in the Strait of Gibraltar. Marine...structure of long-finned pilot whales (Globicephala melas ) in the Strait of Gibraltar. Acta Ethologica 11, 81-94. DeRuiter, S. L., Boyd, I. L...Aoki Kagari A, Lam F-Pa, Kvadsheim PH, Huisman J, Tyack PL (2014): The social contect of individual foraging behaviour in long-finned pilot whales (Globicephala melas ). Behaviour 151: 1453-77. [published, refereed

Cardiac responses to long duration and high magnitude +Gz exposure in pilots: an observational study.

PubMed

Öztürk, Cengiz; İlbasmış, M Savaş; Akın, Ahmet

2012-12-01

In military aviation, high performance aircraft pilots are exposed to +Gz acceleration at longer durations and higher magnitude than transport/helicopter pilots. The purpose of this study was to reveal the negative or positive cardiac responses to this occupational high +Gz exposure. Our study design was cross-sectional and observational. We have evaluated 21 echocardiographic parameters of 63 pilots who applied for aircrew periodic medical examination. Of 63 pilots, 33 were grouped as high performance aircraft pilots group (Group A) and 30 were grouped as control group (Group B) whose aircraft type was transport or helicopter. Means of demographic and echocardiography parameters between two groups were compared statistically with Student's t-test, Mann- Whitney U or Chi-square test as appropriate. Among all echocardiographic parameters, mean TV A (tricuspid valve peak velocity during late diastolic filling) was significantly higher and TV E (peak velocity during early diastolic filling)/ A ratio was significantly lower for Group A pilots (p<0.05). In Group A pilots, mean TV A and TV E/A ratio were (52.12 ± 13.85) and (1.36 ± 0.30) respectively. In Group B pilots, mean TV A and TV E/A ratio were (42.61 ± 6.42) and (1.53 ± 0.20) respectively (p=0.001 for TVA and p=0.005 for TV E/A). Mean pulmonary artery pressure (PAP) of Group A pilots (32.04 ± 9.09) was higher than Group B pilots (28.76 ± 7.9) but it was not statistically significant (p>0.05). We conclude that according to the results of our study, long term +Gz exposure has no effects on cardiac morphologic and systolic functions but has effects on right ventricular diastolic functions. We have considered that these effects may be a result of chronic +Gz adaptation or high PAP levels.

An Evaluation of Detect and Avoid (DAA) Displays for Unmanned Aircraft Systems: The Effect of Information Level and Display Location on Pilot Performance

NASA Technical Reports Server (NTRS)

Fern, Lisa; Rorie, R. Conrad; Pack, Jessica S.; Shively, R. Jay; Draper, Mark H.

2015-01-01

A consortium of government, industry and academia is currently working to establish minimum operational performance standards for Detect and Avoid (DAA) and Control and Communications (C2) systems in order to enable broader integration of Unmanned Aircraft Systems (UAS) into the National Airspace System (NAS). One subset of these performance standards will need to address the DAA display requirements that support an acceptable level of pilot performance. From a pilot's perspective, the DAA task is the maintenance of self separation and collision avoidance from other aircraft, utilizing the available information and controls within the Ground Control Station (GCS), including the DAA display. The pilot-in-the-loop DAA task requires the pilot to carry out three major functions: 1) detect a potential threat, 2) determine an appropriate resolution maneuver, and 3) execute that resolution maneuver via the GCS control and navigation interface(s). The purpose of the present study was to examine two main questions with respect to DAA display considerations that could impact pilots' ability to maintain well clear from other aircraft. First, what is the effect of a minimum (or basic) information display compared to an advanced information display on pilot performance? Second, what is the effect of display location on UAS pilot performance? Two levels of information level (basic, advanced) were compared across two levels of display location (standalone, integrated), for a total of four displays. The authors propose an eight-stage pilot-DAA interaction timeline from which several pilot response time metrics can be extracted. These metrics were compared across the four display conditions. The results indicate that the advanced displays had faster overall response times compared to the basic displays, however, there were no significant differences between the standalone and integrated displays. Implications of the findings on understanding pilot performance on the DAA task, the development of DAA display performance standards, as well as the need for future research are discussed.

Hormonal responses of pilots flying high-performance aircraft during seven repetitive flight missions.

PubMed

Tarui, H; Nakamura, A

1991-12-01

Hormonal responses during seven repetitive flight missions (7RFM) were evaluated on F-4EJ fighter pilots. The following biochemical constituents were measured: 1) cortisol in saliva; 2) 17-OHCS; 3) unbound cortisol; 4) catecholamines in urine; and 5) electrolytes in urine. Samples were collected at about 30 min before the mission, 20 min after each flight, and in a nonflight day for control. The levels of saliva and urine corticosteroids slightly increased during 7RFM when compared with controls. The concentrations of urine catecholamines during 7RFM were significantly higher than those of preflight and control. These data suggest that flight stresses were moderate for the pilots flying 7RFM.

How Usability Testing Resulted in Improvements to Ground Collision Software for General Aviation: Improved Ground Collision Avoidance System (IGCAS)

NASA Technical Reports Server (NTRS)

Lamarr, Michael; Chinske, Chris; Williams, Ethan; Law, Cameron; Skoog, Mark; Sorokowski, Paul

2016-01-01

The NASA improved Ground Collision Avoidance System (iGCAS) team conducted an onsite usability study at Experimental Aircraft Association (EAA) Air Venture in Oshkosh, Wisconsin from July 19 through July 26, 2015. EAA Air Venture had approximately 550,000 attendees from which the sample pool of pilots were selected. The objectives of this study were to assess the overall appropriateness and acceptability of iGCAS as a warning system for General Aviation aircraft, usability of the iGCAS displays and audio cues, test terrain avoidance characteristics, performance, functionality, pilot response time, and correlate terrain avoidance performance and pilot response time data.

Music therapy assessment for severely emotionally disturbed children: a pilot study.

PubMed

Layman, Deborah L; Hussey, David L; Laing, Sarah J

2002-01-01

The purpose of this study was to pilot a music therapy assessment instrument for severely emotionally disturbed children. The subjects in this pilot were 20 children, 13 male and 7 female, at a residential treatment center in Cleveland, Ohio. After conducting an extensive literature review, the authors developed a music therapy assessment instrument measuring 4 relevant domains: behavioral/social functioning, emotional responsiveness, language/communication abilities, and music skills. Responses were coded into 3 categories: defensive/withdrawn, target behavior, and disruptive/intrusive. Results demonstrated that subjects displayed significantly more behaviors in the disruptive/intrusive domain. High inter-rater reliability scores of 91.5% for percent agreement and .808 for Cohen's kappa were achieved utilizing this assessment instrument.

Relevance of I-BMIPP delayed scintigraphic imaging for patients with angina pectoris - a pilot study.

PubMed

Koyama, Kohei; Akashi, Yoshihiro J; Kida, Keisuke; Suzuki, Kengo; Ishibashi, Yuki; Musha, Haruki; Banach, Maciej

2011-06-01

The study was designed to clarify the role of (123)I-β-methyl-iodophenylpentadecanoic acid ((123)I-BMIPP) in the evaluation of myocardial fatty acid metabolism in patients with stable angina pectoris (AP) before and after percutaneous coronary intervention (PCI). TEN CONTROLS (MEAN AGE: 70.4 ±10.5 years) and 12 patients with AP (mean age: 67.4 ±11.6 years) and single vessel coronary artery disease participated in the radionuclide cardiac study. Scintigraphic images were acquired at 30 min and at 4 h after (123)I-BMIPP injection to determine early and delayed BMIPP uptake, respectively. The heart-to-mediastinum (H/M) ratio and the washout rate (WR) were calculated from the planar images. All patients underwent scintigraphy one day before PCI and again 1 month after successful PCI. NO SIGNIFICANT DIFFERENCES IN THE EARLY OR DELAYED H/M RATIOS WERE OBSERVED BETWEEN THE PATIENTS AND THE CONTROLS BEFORE PCI (EARLY: 2.70 ±0.36 vs. 2.73 ±0.57; delayed: 2.26 ±0.33 vs. 2.40 ±0.43; p > 0.2 for both). The early and delayed H/M ratios remained unchanged with the comparison with before PCI (early: 2.72 ±0.27, delayed: 2.23 ±0.22; p > 0.2 for both). The global WR before PCI was significantly higher in the patients than in the control group (36.7 ±9.3%, vs. 28.1 ±8.2%, p = 0.02). However, the WR after PCI did not significantly differ between the patients and the controls (34.3 ±7.8% vs. 28.1 ±8.2%, p = 0.1). These data may suggest that the WR of (123)I-BMIPP determined from the planar images enhances the presence of myocardial ischaemia.

Impact characteristics for high-pressure large-flow water-based emulsion pilot operated check valve reverse opening

NASA Astrophysics Data System (ADS)

Liu, Lei; Huang, Chuanhui; Yu, Ping; Zhang, Lei

2017-10-01

To improve the dynamic characteristics and cavitation characteristics of large-flow pilot operated check valve, consider the pilot poppet as the research object, analyses working principle and design three different kinds of pilot poppets. The vibration characteristics and impact characteristics are analyzed. The simulation model is established through flow field simulation software. The cavitation characteristics of large-flow pilot operated check valve are studied and discussed. On this basis, high-pressure large-flow impact experimental system is used for impact experiment, and the cavitation index is discussed. Then optimal structure is obtained. Simulation results indicate that the increase of pilot poppet half cone angle can effectively reduce the cavitation area, reducing the generation of cavitation. Experimental results show that the pressure impact is not decreasing with increasing of pilot poppet half cone angle in process of unloading, but the unloading capacity, response speed and pilot poppet half cone angle are positively correlated. The impact characteristics of 60° pilot poppet, and its cavitation index is lesser, which indicates 60° pilot poppet is the optimal structure, with the theory results are basically identical.

High temperature and performance in a flight task simulator.

DOT National Transportation Integrated Search

1972-05-01

The effects of high cockpit temperature on physiological responses and performance were determined on pilots in a general aviation simulator. The pilots (all instrument rated) 'flew' an instrument flight while exposed to each of three cockpit tempera...

Ground-vehicle operator training using a low-cost simulator

DOT National Transportation Integrated Search

2006-05-01

Pilots, controllers, and ground-vehicle operators all have an important role in runway safety. Their actions, either individually or collectively can cause or avert a runway incursion. The roles and responsibilities of pilots and controllers in this ...

Sensitivity of bandpass filters using recirculating delay-line structures

NASA Astrophysics Data System (ADS)

Heyde, Eric C.

1996-12-01

Recirculating delay lines have value notably as sensors and optical signal processors. Most useful applications depend on a high-finesse response from a network. A proof that, with given response parameters, more complex systems can produce behavior that is more stable to the effects of nonidealities than a single recirculating loop is presented.

The Effects of Short Interval Delay of Reinforcement Upon Human Discrimination Learning. IMRID Papers and Reports Vol. 4 No. 12.

ERIC Educational Resources Information Center

Kral, Paul A.; And Others

Investigates the effect of delay of reinforcement upon human discrimination learning with particular emphasis on the form of the gradient within the first few seconds of delay. In previous studies subjects are usually required to make an instrumental response to a stimulus, this is followed by the delay interval, and finally, the reinforcement…

Noun and predicate comprehension/production and gestures in extremely preterm children at two years of age: Are they delayed?

PubMed

Sansavini, Alessandra; Bello, Arianna; Guarini, Annalisa; Savini, Silvia; Alessandroni, Rosina; Faldella, Giacomo; Caselli, Cristina

2015-01-01

Extremely low gestational age (ELGA, GA<28 weeks) preterm children are at high risk for linguistic impairments; however, their lexical comprehension and production as well as lexical categories in their early language acquisition have not been specifically examined via direct tools. Our study examines lexical comprehension and production as well as gestural production in ELGA children by focusing on noun and predicate acquisition. Forty monolingual ELGA children (mean GA of 26.7 weeks) and 40 full-term (FT) children were assessed at two years of corrected chronological age (CCA) using a test of noun and predicate comprehension and production (PiNG) and the Italian MB-CDI. Noun comprehension and production were delayed in ELGA compared with FT children, as documented by the low number of correct responses and the large number of errors, i.e., incorrect responses and no-response items, and by the types of incorrect responses, i.e., fewer semantically related responses, in noun production. Regarding predicate comprehension and production, a higher frequency of no responses was reported by ELGA children and these children also presented a lower frequency of bimodal spoken-gestural responses in predicate production than FT children. A delayed vocabulary size as demonstrated by the MB-CDI, was exhibited by one-fourth of the ELGA children, who were also unable to complete the predicate subtest. These findings highlight that noun comprehension and production are delayed in ELGA children at two years of CCA and are the most important indexes for the direct evaluation of their lexical abilities and delay. The types of incorrect responses and bimodal spoken-gestural responses were proven to be useful indexes for evaluating the noun and predicate level of acquisition and to plan early focused interventions. After reading this manuscript, the reader will understand (a) the differences in noun and predicate comprehension and production between ELGA and FT children and the indexes of lexical delays exhibited by ELGA children at 2;0 (CCA); (b) the relevance of evaluating errors (incorrect response and no response), the types of incorrect responses (semantically related and unrelated) and the modality of the responses (unimodal spoken and bimodal spoken-gestural) in noun and predicate production to understand the difficulties experienced by ELGA children in representing and expressing meanings; and (c) the need to plan specific interventions to support spoken and gestural modalities in lexical comprehension and production in ELGA children by focusing on noun and predicate acquisition. Copyright © 2015 Elsevier Inc. All rights reserved.

Short-term memory for responses: the "choose-small" effect.

PubMed Central

Fetterman, J G; MacEwen, D

1989-01-01

Pigeons' short-term memory for fixed-ratio requirements was assessed using a delayed symbolic matching-to-sample procedure. Different choices were reinforced after fixed-ratio 10 and fixed-ratio 40 requirements, and delays of 0, 5, or 20 s were sometimes placed between sample ratios and choice. All birds made disproportionate numbers of responses to the small-ratio choice alternative when delays were interposed between ratios and choice, and this bias increased as a function of delay. Preference for the small fixed-ratio alternative was also observed on "no-sample" trials, during which the choice alternatives were presented without a prior sample ratio. This "choose-small" bias is analogous to results obtained by Spetch and Wilkie (1983) with event duration as the discriminative stimulus. The choose-small bias was attenuated when the houselight was turned on during delays, but overall accuracy was not influenced systematically by the houselight manipulation. PMID:2584917

Burner ignition system

DOEpatents

Carignan, Forest J.

1986-01-21

An electronic ignition system for a gas burner is battery operated. The battery voltage is applied through a DC-DC chopper to a step-up transformer to charge a capacitor which provides the ignition spark. The step-up transformer has a significant leakage reactance in order to limit current flow from the battery during initial charging of the capacitor. A tank circuit at the input of the transformer returns magnetizing current resulting from the leakage reactance to the primary in succeeding cycles. An SCR in the output circuit is gated through a voltage divider which senses current flow through a flame. Once the flame is sensed, further sparks are precluded. The same flame sensor enables a thermopile driven main valve actuating circuit. A safety valve in series with the main gas valve responds to a control pressure thermostatically applied through a diaphragm. The valve closes after a predetermined delay determined by a time delay orifice if the pilot gas is not ignited.

Mechanisms of motor recovery after subtotal spinal cord injury: insights from the study of mice carrying a mutation (WldS) that delays cellular responses to injury.

PubMed

Zhang, Z; Guth, L; Steward, O

1998-01-01

Partial lesions of the mammalian spinal cord result in an immediate motor impairment that recovers gradually over time; however, the cellular mechanisms responsible for the transient nature of this paralysis have not been defined. A unique opportunity to identify those injury-induced cellular responses that mediate the recovery of function has arisen from the discovery of a unique mutant strain of mice in which the onset of Wallerian degeneration is dramatically delayed. In this strain of mice (designated WldS for Wallerian degeneration, slow), many of the cellular responses to spinal cord injury are also delayed. We have used this experimental animal model to evaluate possible causal relationships between these delayed cellular responses and the onset of functional recovery. For this purpose, we have compared the time course of locomotor recovery in C57BL/6 (control) mice and in WldS (mutant) mice by hemisecting the spinal cord at T8 and evaluating locomotor function at daily postoperative intervals. The time course of locomotor recovery (as determined by the Tarlov open-field walking procedure) was substantially delayed in mice carrying the WldS mutation: C57BL/6 control mice began to stand and walk within 6 days (mean Tarlov score of 4), whereas mutant mice did not exhibit comparable locomotor function until 16 days postoperatively. (a) The rapid return of locomotor function in the C57BL/6 mice suggests that the recovery resulted from processes of functional plasticity rather than from regeneration or collateral sprouting of nerve fibers. (b) The marked delay in the return of locomotor function in WldS mice indicates that the processes of neuroplasticity are induced by degenerative changes in the damaged neurons. (c) These strains of mice can be effectively used in future studies to elucidate the specific biochemical and physiological alterations responsible for inducing functional plasticity and restoring locomotor function after spinal cord injury.

The Overseas Service Veteran At Home Pilot: How Choice of Care May Affect Use of Nursing Home Beds and Waiting Lists. Brief Report

ERIC Educational Resources Information Center

Pedlar, David; Walker, John

2004-01-01

In 1999 Veterans Affairs Canada (VAC) implemented the Overseas Service Veterans (OSV) At Home Pilot Project in response to the problem that a growing number of clients were on waiting lists for beds in long-term care facilities. The At Home pilot offered certain clients on waiting lists, who met nursing-level care and military-service…

3S2: Behavioral Response Studies of Cetaceans to Navy Sonar Signals in Norwegian Waters

DTIC Science & Technology

2013-09-30

exposures of killer (Orcinus orca), long-finned pilot (Globicephala melas ), and sperm whales (Physeter macrocephalus) to naval sonar. Aquatic Mammals 38...pilot whales (Globicephala melas ). Marine Mammal Science. [in review, refereed] 8 Kvadsheim, PH, Miller, PJO, Tyack, P, Sivle, LD, Lam, FPA, and...killer (Orcinus orca), long-finned pilot (Globicephala melas ), and sperm whales (Physeter macrocephalus) to naval sonar. Aquatic Mammals 38: 362-401

An Examination of the Perceived Importance of Technical Competence in Acquisition Project Management

DTIC Science & Technology

1991-09-01

Develop (First Draft) Instructions Critique (Revision) Answerability Pilot Test (Second Draft) Analysis Response Mode Revision Useability Preparation...appropriate questionnaire items. Initially, the set of questions developed for the study reflected a few shortcomings. A pilot test of the first draft among...resulted. First, feedback from the pilot test indicated a need to reduce the completion time. Because the multiple choice format required several

Classification of response-types for single-pilot NOE helicopter combat tasks

NASA Technical Reports Server (NTRS)

Mitchell, David G.; Hoh, Roger H.; Atencio, Adolph, Jr.

1987-01-01

Two piloted simulations have recently been conducted to evaluate both workload and handling qualities requirements for operation of a helicopter by a single pilot in a nap-of-the-earth combat environment. An advanced cockpit, including a moving-map display and an interactive touchpad screen, provided aircraft mission, status, and position information to the pilot. The results of the simulations are reviewed, and the impact of these results on the development of a revised helicopter handling qualities specification is discussed. Rate command is preferred over attitude command in pitch and roll, and attitude hold over groundspeed hold, for low-speed precision pointing tasks. Position hold is necessary for Level 1 handling qualities in hover when the pilot is required to perform secondary tasks. Addition of a second crew member improves pilot ratings.

Prediction of pilot-aircraft stability boundaries and performance contours

NASA Technical Reports Server (NTRS)

Stengel, R. F.; Broussard, J. R.

1977-01-01

Control-theoretic pilot models can provide important new insights regarding the stability and performance characteristics of the pilot-aircraft system. Optimal-control pilot models can be formed for a wide range of flight conditions, suggesting that the human pilot can maintain stability if he adapts his control strategy to the aircraft's changing dynamics. Of particular concern is the effect of sub-optimal pilot adaptation as an aircraft transitions from low to high angle-of-attack during rapid maneuvering, as the changes in aircraft stability and control response can be extreme. This paper examines the effects of optimal and sub-optimal effort during a typical 'high-g' maneuver, and it introduces the concept of minimum-control effort (MCE) adaptation. Limited experimental results tend to support the MCE adaptation concept.

Research on computer aided testing of pilot response to critical in-flight events

NASA Technical Reports Server (NTRS)

Giffin, W. C.; Rockwell, T. H.; Smith, P. J.

1984-01-01

Experiments on pilot decision making are described. The development of models of pilot decision making in critical in flight events (CIFE) are emphasized. The following tests are reported on the development of: (1) a frame system representation describing how pilots use their knowledge in a fault diagnosis task; (2) assessment of script norms, distance measures, and Markov models developed from computer aided testing (CAT) data; and (3) performance ranking of subject data. It is demonstrated that interactive computer aided testing either by touch CRT's or personal computers is a useful research and training device for measuring pilot information management in diagnosing system failures in simulated flight situations. Performance is dictated by knowledge of aircraft sybsystems, initial pilot structuring of the failure symptoms and efficient testing of plausible causal hypotheses.

Neuronal activity during a cued strategy task: Comparison of dorsolateral, orbital and polar prefrontal cortex

PubMed Central

Tsujimoto, Satoshi; Genovesio, Aldo; Wise, Steven P.

2012-01-01

We compared neuronal activity in the dorsolateral (PFdl), orbital (PFo) and polar (PFp) prefrontal cortex as monkeys performed three tasks. In two tasks, a cue instructed one of two strategies: stay with the previous response or shift to the alternative. Visual stimuli served as cues in one of these tasks; in the other, fluid rewards did so. In the third task, visuospatial cues instructed each response. A delay period followed each cue. As reported previously, PFdl encoded strategies (stay or shift) and responses (left or right) during the cue and delay periods, while PFo encoded strategies and PFp encoded neither strategies nor responses; during the feedback period, all three areas encoded responses, not strategies. Four novel findings emerged from the present analysis. (1) The strategy encoded by PFdl and PFo cells during the cue and delay periods was modality specific. (2) The response encoded by PFdl cells was task- and modality specific during the cue period, but during the delay and feedback periods it became task- and modality general. (3) Although some PFdl and PFo cells responded to or anticipated rewards, we could rule out reward effects for most strategy-and response-related activity. (4) Immediately before feedback, only PFp signaled responses that were correct according to the cued strategy; after feedback, only PFo signaled the response that had been made, whether correct or incorrect. These signals support a role in generating responses by PFdl, assigning outcomes to choices by PFo, and assigning outcomes to cognitive processes by PFp. PMID:22875935

Effects on motor development of kicking and stepping exercise in preterm infants with periventricular brain injury: a pilot study.

PubMed

Campbell, Suzann K; Gaebler-Spira, Deborah; Zawacki, Laura; Clark, April; Boynewicz, Kara; deRegnier, Raye-Ann; Kuroda, Maxine M; Bhat, Rama; Yu, Jinsheng; Campise-Luther, Rose; Kale, Dipti; Bulanda, Michelle; Zhou, Xiaohong Joe

2012-01-01

Preterm infants with periventricular brain injury (PBI) have a high incidence of atypical development and leg movements. Determine whether kicking and treadmill stepping intervention beginning at 2 months corrected age (CA) in children with PBI improves motor function at 12 months CA when compared with control subjects. In a multi-center pilot study for a controlled clinical trial, sixteen infants with PBI were randomly assigned to home exercise consisting of kicking and treadmill stepping or a no-training control condition. Development was assessed at 2, 4, 6, 10, and 12 months CA with the Alberta Infant Motor Scale (AIMS). At 12 months children were classified as normal, delayed, or with cerebral palsy (CP). At 12 months CA 3 of 7 (43%) of the exercise group children walked alone or with one hand held versus 1 of 9 (11%) in the control group (p=0.262), but no significant differences in AIMS scores were found at any age. Half of the subjects had CP or delay; the outcomes of these infants were not improved by exercise. Compliance with the home program was lower than requested and may have affected results. Although not statistically significant with a small sample size, self-produced kicking and treadmill exercise may lower age at walking in infants with normal development following PBI, but improvements of the protocol to increase and document compliance are needed before a larger study is implemented.

Effects on Motor Development of Kicking and Stepping Exercise in Preterm Infants with Periventricular Brain Injury: A Pilot Study

PubMed Central

Campbell, Suzann K.; Gaebler-Spira, Deborah; Zawacki, Laura; Clark, April; Boynewicz, Kara; deRegnier, Raye-Ann; Kuroda, Maxine M.; Bhat, Rama; Yu, Jinsheng; Campise-Luther, Rose; Kale, Dipti; Bulanda, Michelle; Zhou, Xiaohong Joe

2013-01-01

Background Preterm infants with periventricular brain injury (PBI) have a high incidence of atypical development and leg movements. Objective Determine whether kicking and treadmill stepping intervention beginning at 2 months corrected age (CA) in children with PBI improves motor function at 12 months CA when compared with control subjects. Method In a multi-center pilot study for a controlled clinical trial, sixteen infants with PBI were randomly assigned to home exercise consisting of kicking and treadmill stepping or a no-training control condition. Development was assessed at 2, 4, 6, 10, and 12 months CA with the Alberta Infant Motor Scale (AIMS). At 12 months children were classified as normal, delayed, or with cerebral palsy (CP). Results At 12 months CA 3 of 7 (43%) of the exercise group children walked alone or with one hand held versus 1 of 9 (11%) in the control group (p=.262), but no significant differences in AIMS scores were found at any age. Half of the subjects had CP or delay; the outcomes of these infants were not improved by exercise. Compliance with the home program was lower than requested and may have affected results. Conclusion Although not statistically significant with a small sample size, self-produced kicking and treadmill exercise may lower age at walking in infants with normal development following PBI, but improvements of the protocol to increase and document compliance are needed before a larger study is implemented. PMID:22543889

Pilot study on verification of effectiveness on operability of assistance system for robotic tele-surgery using simulation.

PubMed

Kawamura, Kazuya; Kobayashi, Yo; Fujie, Masakatsu G

2010-01-01

Tele-surgery enables medical care even in remote regions, and has been accomplished in clinical cases by means of dedicated communication lines. To make tele-surgery a more widespread method of providing medical care, a surgical environment needs to be made available using public lines of communication, such as the Internet. Moreover, a support system during surgery is required, as the use of surgical tools is performed in an environment subject to delay. In our research, we focus on the operability of specific tasks conducted by surgeons during a medical procedure, with the aim of clarifying, by means of a simulation, the optimum environment for robotic tele-surgery. In the study, we set up experimental systems using our proposed simulation system. In addition, we investigate the mental workloads on subjects and verify the effect of visual-assistance information as a pilot study. The operability of the task of gripping soft tissue was evaluated using a subjective workload assessment tool, the NASA Task Load Index. Results show that the tasks were completed, but the workload did not improve to less than 300ms and 400ms in the simulated environment. Verifying the effect of the support system was an important task under a more-than 200ms delay using this experiment, and future studies will evaluate the operability of the system under varying conditions of comfort. In addition, an intra-operative assistance system will be constructed using a simulation.

Work stressors, perseverative cognition and objective sleep quality: a longitudinal study among Dutch Helicopter Emergency Medical Service (HEMS) Pilots.

PubMed

Radstaak, Mirjam; Geurts, Sabine A E; Beckers, Debby G J; Brosschot, Jos F; Kompier, Michiel A J

2014-01-01

This longitudinal study examined the associations between work stressors, perseverative cognition and subjective and objective sleep quality. We hypothesized work stressors to be associated with (i) poor nocturnal sleep quality and (ii) higher levels of perseverative cognition during a free evening. We further hypothesized (iii) perseverative cognition to be associated with poor nocturnal sleep quality and (iv) the association between work stressors and sleep quality to be mediated by perseverative cognition. The participants were 24 pilots working for the Dutch Helicopter Emergency Medical Service (HEMS). They completed six questionnaires: at the end of three consecutive day shifts and each morning following the shifts. The questionnaires addressed work stressors (workload, distressing shifts and work-related conflicts), subjective sleep quality and perseverative cognition. Participants wore actigraphs to assess sleep onset latency, total sleep time and number of awakenings. Correlation analysis revealed that (i) distressing shifts were related to delayed sleep onset (r=0.50, p=0.026) and that workload was related to impaired sleep quality (e.g., subjective sleep quality: r=-0.42, p=0.044). Moreover, (ii) distressing shifts were positively related to perseverative cognition (r=0.62, p=0.002), (iii) perseverative cognition delayed sleep onset (r=0.74, p<0.001) and (iv) mediated the association between distressing shifts and sleep onset latency. Perseverative cognition may be an explanatory mechanism in the association between work stressors and poor sleep.

Autogenic Feedback Training Exercise and pilot performance: enhanced functioning under search-and-rescue flying conditions.

PubMed

Cowings, P S; Kellar, M A; Folen, R A; Toscano, W B; Burge, J D

2001-01-01

Studies have shown that autonomous mode behavior is one cause of aircraft fatalities due to pilot error. In such cases, the pilot is in a high state of psychological and physiological arousal and tends to focus on one problem, while ignoring more critical information. This study examined the effect of training in physiological self-recognition and regulation, as a means of improving crew cockpit performance. Seventeen pilots were assigned to the treatment and control groups matched for accumulated flight hours. The treatment group contained 4 pilots from HC-130 Hercules aircraft and 4 HH-65 Dolphin helicopter pilots; the control group contained 3 pilots of HC-130s and 6 helicopter pilots. During an initial flight, physiological data were recorded on each crewmember and an instructor pilot rated individual crew performance. Eight crewmembers were then taught to regulate their own physiological response levels using Autogenic-Feedback Training Exercise (AFTE). The remaining participants received no training. During a second flight, treatment participants showed significant improvement in performance (rated by the same instructor pilot as in pretests) while controls did not improve. The results indicate that AFTE management of high states of physiological arousal may improve pilot performance during emergency flying conditions.

Autogenic Feedback Training Exercise and pilot performance: enhanced functioning under search-and-rescue flying conditions

NASA Technical Reports Server (NTRS)

Cowings, P. S.; Kellar, M. A.; Folen, R. A.; Toscano, W. B.; Burge, J. D.

2001-01-01

Studies have shown that autonomous mode behavior is one cause of aircraft fatalities due to pilot error. In such cases, the pilot is in a high state of psychological and physiological arousal and tends to focus on one problem, while ignoring more critical information. This study examined the effect of training in physiological self-recognition and regulation, as a means of improving crew cockpit performance. Seventeen pilots were assigned to the treatment and control groups matched for accumulated flight hours. The treatment group contained 4 pilots from HC-130 Hercules aircraft and 4 HH-65 Dolphin helicopter pilots; the control group contained 3 pilots of HC-130s and 6 helicopter pilots. During an initial flight, physiological data were recorded on each crewmember and an instructor pilot rated individual crew performance. Eight crewmembers were then taught to regulate their own physiological response levels using Autogenic-Feedback Training Exercise (AFTE). The remaining participants received no training. During a second flight, treatment participants showed significant improvement in performance (rated by the same instructor pilot as in pretests) while controls did not improve. The results indicate that AFTE management of high states of physiological arousal may improve pilot performance during emergency flying conditions.

14 CFR 417.221 - Time delay analysis.

Code of Federal Regulations, 2012 CFR

2012-01-01

... occurs; (2) A flight safety official's decision and reaction time, including variation in human response... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Time delay analysis. 417.221 Section 417... OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.221 Time delay analysis. (a...

14 CFR 417.221 - Time delay analysis.

Code of Federal Regulations, 2014 CFR

2014-01-01

... occurs; (2) A flight safety official's decision and reaction time, including variation in human response... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Time delay analysis. 417.221 Section 417... OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.221 Time delay analysis. (a...

14 CFR 417.221 - Time delay analysis.

Code of Federal Regulations, 2013 CFR

2013-01-01

... occurs; (2) A flight safety official's decision and reaction time, including variation in human response... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Time delay analysis. 417.221 Section 417... OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.221 Time delay analysis. (a...

Maritime Evaluation of Aerosol Fire Knock Down Tools. Part 2: Toxicity and Corrosion Potential

DTIC Science & Technology

2014-02-01

determined using paramagnetic sensor technology, while CO and CO2 concentrations were measured, respectively, via gas filter correlation and single...time response of each sensor in the unit. Since it is important to account for this delay in response during analysis and interpretation of measured...within, the compartment as well as confinement and extinguishment of the fire. 1 The initial response of the NOx analyzer and delay in sensor

Physiological responses of low-time private pilots to cross-country flying.

DOT National Transportation Integrated Search

1971-04-01

Various physiological, biochemical, and psychophysiological measurements were made on low-time private pilots who each flew three cross-country flights. The round-trip flights were 320, 520, and 960 NM in length. Heart rate was recorded continuously ...

Ceteacean Social Behavioral Response to Sonar

DTIC Science & Technology

2014-09-30

Kvadsheim PH, Huisman J and Tyack PL (in review). The social context of individual foraging behaviour in long-finned pilot whales (Globicephala melas ...of behavioral changes observed during experimental exposures of killer (Orcinus orca), long-finned pilot whale (Globicephala melas ), and sperm whale

Ceteacean Social Behavioral Response to Sonar

DTIC Science & Technology

2013-09-30

review). The social context of individual foraging behaviour in long-finned pilot whales (Globicephala melas ). Aoki K, Sakai M, Miller JO, Visser F...during 8 experimental exposures of killer (Orcinus orca), long-finned pilot whale (Globicephala melas ), and sperm whale (Physeter macrocephalus

Simulator fidelity considerations for training and evaluation of today's airline pilots

DOT National Transportation Integrated Search

2001-03-05

Regulatory changes in response to today's airline pilot training and evaluation needs push the twin issues of effectiveness and affordability of flight simulators for use by U.S. airlines to the forefront. The Federal Aviation Administration (FAA) is...

Association of postmortem blood hemoglobin A1c levels with diabetic conditions in aviation accident pilot fatalities.

DOT National Transportation Integrated Search

2001-07-01

Purpose. The Federal Aviation Administration's (FAA's) Office of Aerospace Medicine evaluates present and proposed medical certification standards for pilots. Under this responsibility, the FAA Civil Aerospace Medical Institute investigates the role ...

Automatic recording of mediating behavior in delayed matching- and nonmatching-to-position procedures in rats.

PubMed

Panlilio, Leigh V; Yasar, Sevil; Thorndike, Eric B; Goldberg, Steven R; Schindler, Charles W

2011-03-01

Delayed matching-to-position and nonmatching-to-position procedures are widely used to model working memory in rodents. Mediating behavior-which enhances performance but is not explicitly required by the task-is generally considered an obstacle to the measurement of memory, but often occurs despite attempts to prevent it. The ubiquitous nature of mediating behavior suggests it might be analogous to rehearsal, an important component of learning and memory in humans. The aim was to study an easily recordable, rehearsal-like mediating response in rats under baseline conditions and after treatment with amnestic drugs [scopolamine (0.1-0.3 mg/kg) and delta-9-tetrahydrocannabinol (THC; 1-5.6 mg/kg)]. Lighted nosepoke holes were used to present position cues and record delayed matching or nonmatching responses. Performance of a distractor task was required to prevent simply waiting at the correct choice, but the nosepoke holes were left accessible during the delay. Each rat trained with the nonmatching task exhibited one of two mediating "strategies" that increased the odds of a correct choice: responding in the to-be-correct hole during the delay or responding in the opposite hole during the delay. Rats trained with the matching task all showed the former strategy. Treatment with scopolamine disrupted performance of the mediating response. Scopolamine and THC both decreased the effectiveness of the mediating response, increasing errors even on trials when the "appropriate" mediating behavior did occur. The procedures and data analysis approach used here provide an objective, automated means of measuring mediating behavior, which might be useful as an animal model of memory rehearsal.