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Sample records for 30-min time intervals

  1. Physiological and metabolic responses of triathletes to a simulated 30-min time-trial in cycling at self-selected intensity.

    PubMed

    Perrey, S; Grappe, F; Girard, A; Bringard, A; Groslambert, A; Bertucci, W; Rouillon, J D

    2003-02-01

    The aim of this study was to investigate the metabolic and physiological responses to a laboratory-based simulated 30-min individual time-trial (ITT 30 ) in cycling at a self-selected intensity. Twelve experienced triathletes (n = 4 women) performed a progressive incremental exercise test on a cycle ergometer to determine .VO2max (52 +/- 5 ml x min -1 x kg -1), maximum power output (300 +/- 12 W), and the second ventilatory threshold. Then, the subjects completed an ITT30 at self-selected work intensity on a stationary ergometer equipped with the SRM Training System. In all subjects, during the ITT30, heart rate and minute ventilation increased (p < 0.05) progressively whereas oxygen consumption and power output remained unchanged. Triathletes rode at consistent pacing corresponding to their highest steady state of blood lactate concentration that increased by no more than 1.0 mmol x l -1 during the final 20-min of ITT30. The self-selected intensity of triathletes during ITT30 represented 88 +/- 5 % (mean +/- SD) of .VO2max and was not significantly different to the energy demand corresponding to the second ventilatory threshold (84 +/- 5 % of .VO2max). Our data suggest that ITT 30 at a self-selected intensity is a good predictor of individual endurance capacity and may be used to estimate racing pace for training purposes. This performance test for the identification of the exercise intensity that demarcate "steady state" is less troublesome than some of the traditional methods, limiting testing to a single session. PMID:12669261

  2. VARIABLE TIME-INTERVAL GENERATOR

    DOEpatents

    Gross, J.E.

    1959-10-31

    This patent relates to a pulse generator and more particularly to a time interval generator wherein the time interval between pulses is precisely determined. The variable time generator comprises two oscillators with one having a variable frequency output and the other a fixed frequency output. A frequency divider is connected to the variable oscillator for dividing its frequency by a selected factor and a counter is used for counting the periods of the fixed oscillator occurring during a cycle of the divided frequency of the variable oscillator. This defines the period of the variable oscillator in terms of that of the fixed oscillator. A circuit is provided for selecting as a time interval a predetermined number of periods of the variable oscillator. The output of the generator consists of a first pulse produced by a trigger circuit at the start of the time interval and a second pulse marking the end of the time interval produced by the same trigger circuit.

  3. TIME-INTERVAL MEASURING DEVICE

    DOEpatents

    Gross, J.E.

    1958-04-15

    An electronic device for measuring the time interval between two control pulses is presented. The device incorporates part of a previous approach for time measurement, in that pulses from a constant-frequency oscillator are counted during the interval between the control pulses. To reduce the possible error in counting caused by the operation of the counter gating circuit at various points in the pulse cycle, the described device provides means for successively delaying the pulses for a fraction of the pulse period so that a final delay of one period is obtained and means for counting the pulses before and after each stage of delay during the time interval whereby a plurality of totals is obtained which may be averaged and multplied by the pulse period to obtain an accurate time- Interval measurement.

  4. High resolution time interval meter

    DOEpatents

    Martin, A.D.

    1986-05-09

    Method and apparatus are provided for measuring the time interval between two events to a higher resolution than reliability available from conventional circuits and component. An internal clock pulse is provided at a frequency compatible with conventional component operating frequencies for reliable operation. Lumped constant delay circuits are provided for generating outputs at delay intervals corresponding to the desired high resolution. An initiation START pulse is input to generate first high resolution data. A termination STOP pulse is input to generate second high resolution data. Internal counters count at the low frequency internal clock pulse rate between the START and STOP pulses. The first and second high resolution data are logically combined to directly provide high resolution data to one counter and correct the count in the low resolution counter to obtain a high resolution time interval measurement.

  5. High resolution time interval counter

    DOEpatents

    Condreva, Kenneth J.

    1994-01-01

    A high resolution counter circuit measures the time interval between the occurrence of an initial and a subsequent electrical pulse to two nanoseconds resolution using an eight megahertz clock. The circuit includes a main counter for receiving electrical pulses and generating a binary word--a measure of the number of eight megahertz clock pulses occurring between the signals. A pair of first and second pulse stretchers receive the signal and generate a pair of output signals whose widths are approximately sixty-four times the time between the receipt of the signals by the respective pulse stretchers and the receipt by the respective pulse stretchers of a second subsequent clock pulse. Output signals are thereafter supplied to a pair of start and stop counters operable to generate a pair of binary output words representative of the measure of the width of the pulses to a resolution of two nanoseconds. Errors associated with the pulse stretchers are corrected by providing calibration data to both stretcher circuits, and recording start and stop counter values. Stretched initial and subsequent signals are combined with autocalibration data and supplied to an arithmetic logic unit to determine the time interval in nanoseconds between the pair of electrical pulses being measured.

  6. High resolution time interval counter

    DOEpatents

    Condreva, K.J.

    1994-07-26

    A high resolution counter circuit measures the time interval between the occurrence of an initial and a subsequent electrical pulse to two nanoseconds resolution using an eight megahertz clock. The circuit includes a main counter for receiving electrical pulses and generating a binary word--a measure of the number of eight megahertz clock pulses occurring between the signals. A pair of first and second pulse stretchers receive the signal and generate a pair of output signals whose widths are approximately sixty-four times the time between the receipt of the signals by the respective pulse stretchers and the receipt by the respective pulse stretchers of a second subsequent clock pulse. Output signals are thereafter supplied to a pair of start and stop counters operable to generate a pair of binary output words representative of the measure of the width of the pulses to a resolution of two nanoseconds. Errors associated with the pulse stretchers are corrected by providing calibration data to both stretcher circuits, and recording start and stop counter values. Stretched initial and subsequent signals are combined with autocalibration data and supplied to an arithmetic logic unit to determine the time interval in nanoseconds between the pair of electrical pulses being measured. 3 figs.

  7. Effect of 30-min +3 Gz centrifugation on vestibular and autonomic cardiovascular function

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.; Wood, Scott J.; Brown, Troy E.; Harm, Deborah L.; Rupert, A. H.

    2003-01-01

    INTRODUCTION: Repeated exposure to increased +Gz enhances human baroreflex responsiveness and improves tolerance to cardiovascular stress. However, it is not known whether such enhancements might also result from a single, more prolonged exposure to increased +Gz. Our study was designed to investigate whether baroreflex function and orthostatic tolerance are acutely improved by a single prolonged exposure to +3 Gz, and moreover, whether changes in autonomic cardiovascular function resulting from exposure to increased +Gz are correlated with changes in otolith function. METHODS: We exposed 15 healthy human subjects to +3 Gz centrifugation for up to 30 min or until symptoms of incipient G-induced loss of consciousness (G-LOC) ensued. Tests of autonomic cardiovascular function both before and after centrifugation included: 1) power spectral determinations of beat-to-beat R-R intervals and arterial pressures; 2) carotid-cardiac baroreflex tests; 3) Valsalva tests; and 4) 30-min head-up tilt tests. Otolith function was assessed during centrifugation by the linear vestibulo-ocular reflex and both before and after centrifugation by measurements of ocular counter-rolling and dynamic posturography. RESULTS: Of the 15 subjects who underwent prolonged +3 Gz, 4 were intolerant to 30 min of head-up tilt before centrifugation but became tolerant to such tilt after centrifugation. The Valsalva-related baroreflex as well as a measure of the carotid-cardiac baroreflex were also enhanced after centrifugation. No significant vestibular-autonomic relationships were detected beyond a vestibular-cerebrovascular interaction reported earlier in a subset of seven participants. CONCLUSIONS: A single prolonged exposure to +3 Gz centrifugation acutely improves baroreflex function and orthostatic tolerance.

  8. Does the time interval after bleaching influence the adhesion of orthodontic brackets?

    PubMed Central

    Nascimento, Glaucia Cristina Rodrigues; de Miranda, Cyndi Albuquerque; Machado, Sissy Maria Mendes; Brandão, Gustavo Antonio Martins; de Almeida, Haroldo Amorim

    2013-01-01

    Objective To test the null hypothesis that no difference exists between the effects of at-home bleaching and in-office bleaching on shear bond strength (SBS) with bracket bonding at 4 different time intervals after dental bleaching. Methods Ninety extracted human premolars were randomly divided into 9 groups (n = 10) according to the bleaching methods used (at-home bleaching and in-office bleaching) and the storage time in artificial saliva (30 min, 1 day, 2 weeks, and 3 weeks before bonding). The control group was stored in artificial saliva for 7 days. Brackets were bonded with the Transbond XT adhesive system, and SBS testing was performed. The adhesive remnant index (ARI) was used to assess the amount of resin remaining on the enamel surfaces after debonding. The SBS data were analyzed by analysis of variance (ANOVA) and the Tukey test. For the ARI, the Kruskal-Wallis test was performed. Significance for all statistical tests was predetermined to be p < 0.05. Results The SBS of the unbleached group was significantly higher (p < 0.05) than that of the bleached groups (except for the group bonded 30 min after at-home bleaching). Conclusions The null hypothesis was not totally rejected. All bleaching groups tested had decreased SBS of the brackets to the enamel, except for the group bonded 30 min after at-home bleaching. The SBS returned to values close to those of the unbleached enamel within 3 weeks following bleaching. PMID:24228239

  9. Intact Interval Timing in Circadian CLOCK Mutants

    PubMed Central

    Cordes, Sara; Gallistel, C. R.

    2008-01-01

    While progress has been made in determining the molecular basis for the circadian clock, the mechanism by which mammalian brains time intervals measured in seconds to minutes remains a mystery. An obvious question is whether the interval timing mechanism shares molecular machinery with the circadian timing mechanism. In the current study, we trained circadian CLOCK +/− and −/− mutant male mice in a peak-interval procedure with 10 and 20-s criteria. The mutant mice were more active than their wild-type littermates, but there were no reliable deficits in the accuracy or precision of their timing as compared with wild-type littermates. This suggests that expression of the CLOCK protein is not necessary for normal interval timing. PMID:18602902

  10. Systolic Time Intervals and New Measurement Methods.

    PubMed

    Tavakolian, Kouhyar

    2016-06-01

    Systolic time intervals have been used to detect and quantify the directional changes of left ventricular function. New methods of recording these cardiac timings, which are less cumbersome, have been recently developed and this has created a renewed interest and novel applications for these cardiac timings. This manuscript reviews these new methods and addresses the potential for the application of these cardiac timings for the diagnosis and prognosis of different cardiac diseases. PMID:27048269

  11. Sunspot Time Series: Passive and Active Intervals

    NASA Astrophysics Data System (ADS)

    Zięba, S.; Nieckarz, Z.

    2014-07-01

    Solar activity slowly and irregularly decreases from the first spotless day (FSD) in the declining phase of the old sunspot cycle and systematically, but also in an irregular way, increases to the new cycle maximum after the last spotless day (LSD). The time interval between the first and the last spotless day can be called the passive interval (PI), while the time interval from the last spotless day to the first one after the new cycle maximum is the related active interval (AI). Minima of solar cycles are inside PIs, while maxima are inside AIs. In this article, we study the properties of passive and active intervals to determine the relation between them. We have found that some properties of PIs, and related AIs, differ significantly between two group of solar cycles; this has allowed us to classify Cycles 8 - 15 as passive cycles, and Cycles 17 - 23 as active ones. We conclude that the solar activity in the PI declining phase (a descending phase of the previous cycle) determines the strength of the approaching maximum in the case of active cycles, while the activity of the PI rising phase (a phase of the ongoing cycle early growth) determines the strength of passive cycles. This can have implications for solar dynamo models. Our approach indicates the important role of solar activity during the declining and the rising phases of the solar-cycle minimum.

  12. Evidence of a major fault zone along the California-Nevada state line 35 deg 30 min to 36 deg 30 min north latitude

    NASA Technical Reports Server (NTRS)

    Liggett, M. A.; Childs, J. F.

    1973-01-01

    The author has identified the following significant results. Geologic reconnaissance guided by analysis of ERTS-1 and Apollo-9 satellite imagery and intermediate scale photography from X-15 and U-2 aircraft has confirmed the presence of a major fault zone along the California-Nevada state line, between 35 deg 30 min and 36 deg 30 min north latitude. The name Pahrump Fault Zone has been suggested for this feature after the valley in which it is best exposed. Field reconnaissance has indicated the existence of previously unreported faults cutting bedrock along range fronts, and displacing Tertiary and Quaternary basin sediments. Gravity data support the interpretation of regional structural discontinuity along this zone. Individual fault traces within the Pahrump Fault Zone form generally left-stepping en echelon patterns. These fault patterns, the apparent offset of a Laramide age thrust fault, and possible drag folding along a major fault break suggest a component of right lateral displacement. The trend and postulated movement of the Pahrump Fault Zone are similar to the adjacent Las Vegas Shear Zone and Death Valley-Furnace Creek Faults, which are parts of a regional strike slip system in the southern Basin-Range Province.

  13. Precise time and time interval data handling and reduction

    NASA Technical Reports Server (NTRS)

    Fisher, L. C.

    1973-01-01

    In the past year, the increase in Precise Time And Time Interval data to be reduced to the U.S. Naval Observatory Master Clock and the requirement for its quick dissemination has necessitated development of more efficient methods of data handling and reduction. An outline of the data involved and of the Time Service computerization of these functions is presented.

  14. Magnetic resonance imaging of extradural blood patches: appearances from 30 min to 18 h.

    PubMed

    Beards, S C; Jackson, A; Griffiths, A G; Horsman, E L

    1993-08-01

    We have used magnetic resonance imaging to examine five patients treated with extradural blood patches for persistent post lumbar puncture headache. Images were obtained between 30 min and 18 h after patching. Extradural blood patch injection produced a focal haematoma mass around the injection site which initially compressed the thecal sac and nerve roots. The main bulk of the extradural clot extended only three to five spinal segments from the injection site, although small amounts of blood spread more distally. Spread from the injection site was principally cephalad. Mass effect was present at 30 min and 3 h, but clot resolution had occurred by 7 h, leaving a thick layer of mature clot over the dorsal part of the thecal sac. Eighteen hours after injection only small widely distributed clots, adherent to the thecal sac, were demonstrated. Extensive leakage of blood from the injection site into the subcutaneous tissues was present in all patients. PMID:8123389

  15. Working memory for time intervals in auditory rhythmic sequences

    PubMed Central

    Teki, Sundeep; Griffiths, Timothy D.

    2014-01-01

    The brain can hold information about multiple objects in working memory. It is not known, however, whether intervals of time can be stored in memory as distinct items. Here, we developed a novel paradigm to examine temporal memory where listeners were required to reproduce the duration of a single probed interval from a sequence of intervals. We demonstrate that memory performance significantly varies as a function of temporal structure (better memory in regular vs. irregular sequences), interval size (better memory for sub- vs. supra-second intervals), and memory load (poor memory for higher load). In contrast memory performance is invariant to attentional cueing. Our data represent the first systematic investigation of temporal memory in sequences that goes beyond previous work based on single intervals. The results support the emerging hypothesis that time intervals are allocated a working memory resource that varies with the amount of other temporal information in a sequence. PMID:25477849

  16. Introduction to the neurobiology of interval timing.

    PubMed

    Merchant, Hugo; de Lafuente, Victor

    2014-01-01

    Time is a fundamental variable that organisms must quantify in order to survive. In humans, for example, the gradual development of the sense of duration and rhythm is an essential skill in many facets of social behavior such as speaking, dancing to-, listening to- or playing music, performing a wide variety of sports, and driving a car (Merchant H, Harrington DL, Meck WH. Annu Rev Neurosci. 36:313-36, 2013). During the last 10 years there has been a rapid growth of research on the neural underpinnings of timing in the subsecond and suprasecond scales, using a variety of methodological approaches in the human being, as well as in varied animal and theoretical models. In this introductory chapter we attempt to give a conceptual framework that defines time processing as a family of different phenomena. The brain circuits and neural underpinnings of temporal quantification seem to largely depend on its time scale and the sensorimotor nature of specific behaviors. Therefore, we describe the main time scales and their associated behaviors and show how the perception and execution of timing events in the subsecond and second scales may depend on similar or different neural mechanisms. PMID:25358702

  17. Precise time and time interval applications to electric power systems

    NASA Technical Reports Server (NTRS)

    Wilson, Robert E.

    1992-01-01

    There are many applications of precise time and time interval (frequency) in operating modern electric power systems. Many generators and customer loads are operated in parallel. The reliable transfer of electrical power to the consumer partly depends on measuring power system frequency consistently in many locations. The internal oscillators in the widely dispersed frequency measuring units must be syntonized. Elaborate protection and control systems guard the high voltage equipment from short and open circuits. For the highest reliability of electric service, engineers need to study all control system operations. Precise timekeeping networks aid in the analysis of power system operations by synchronizing the clocks on recording instruments. Utility engineers want to reproduce events that caused loss of service to customers. Precise timekeeping networks can synchronize protective relay test-sets. For dependable electrical service, all generators and large motors must remain close to speed synchronism. The stable response of a power system to perturbations is critical to continuity of electrical service. Research shows that measurement of the power system state vector can aid in the monitoring and control of system stability. If power system operators know that a lightning storm is approaching a critical transmission line or transformer, they can modify operating strategies. Knowledge of the location of a short circuit fault can speed the re-energizing of a transmission line. One fault location technique requires clocks synchronized to one microsecond. Current research seeks to find out if one microsecond timekeeping can aid and improve power system control and operation.

  18. Interval timing in Siamese fighting fish (Betta splendens).

    PubMed

    Higa, J J; Simm, L A

    2004-11-30

    The present study evaluated the temporal performance of Siamese fighting fish (Betta splendens) given short-term exposure to four fixed interval (FI) schedules of reinforcement, FI 30, 60, 120, and 240 s, during which a reinforcer (mirror image) was given for the first response (swimming through a hoop) after the interval requirement had elapsed. Response levels were generally low early in an interval and increased as the interval elapsed; wait times and break points in an interval increased with increases in the FI requirement. The results were similar to that obtained with other species and different types of responses and reinforcers, and demonstrate that the procedure is a feasible method for studying interval timing in fish. PMID:15518999

  19. Sustained AS160 and TBC1D1 phosphorylations in human skeletal muscle 30 min after a single bout of exercise

    PubMed Central

    Vendelbo, M. H.; Møller, A. B.; Treebak, J. T.; Gormsen, L. C.; Goodyear, L. J.; Wojtaszewski, J. F. P.; Jørgensen, J. O. L.; Møller, N.

    2014-01-01

    Background: phosphorylation of AS160 and TBC1D1 plays an important role for GLUT4 mobilization to the cell surface. The phosphorylation of AS160 and TBC1D1 in humans in response to acute exercise is not fully characterized. Objective: to study AS160 and TBC1D1 phosphorylation in human skeletal muscle after aerobic exercise followed by a hyperinsulinemic euglycemic clamp. Design: eight healthy men were studied on two occasions: 1) in the resting state and 2) in the hours after a 1-h bout of ergometer cycling. A hyperinsulinemic euglycemic clamp was initiated 240 min after exercise and in a time-matched nonexercised control condition. We obtained muscle biopsies 30 min after exercise and in a time-matched nonexercised control condition (t = 30) and after 30 min of insulin stimulation (t = 270) and investigated site-specific phosphorylation of AS160 and TBC1D1. Results: phosphorylation on AS160 and TBC1D1 was increased 30 min after the exercise bout, whereas phosphorylation of the putative upstream kinases, Akt and AMPK, was unchanged compared with resting control condition. Exercise augmented insulin-stimulated phosphorylation on AS160 at Ser341 and Ser704 270 min after exercise. No additional exercise effects were observed on insulin-stimulated phosphorylation of Thr642 and Ser588 on AS160 or Ser237 and Thr596 on TBC1D1. Conclusions: AS160 and TBC1D1 phosphorylations were evident 30 min after exercise without simultaneously increased Akt and AMPK phosphorylation. Unlike TBC1D1, insulin-stimulated site-specific AS160 phosphorylation is modified by prior exercise, but these sites do not include Thr642 and Ser588. Together, these data provide new insights into phosphorylation of key regulators of glucose transport in human skeletal muscle. PMID:24876356

  20. Atomic temporal interval relations in branching time: calculation and application

    NASA Astrophysics Data System (ADS)

    Anger, Frank D.; Ladkin, Peter B.; Rodriguez, Rita V.

    1991-03-01

    A practical method of reasoning about intervals in a branching-time model which is dense, unbounded, future-branching, without rejoining branches is presented. The discussion is based on heuristic constraint- propagation techniques using the relation algebra of binary temporal relations among the intervals over the branching-time model. This technique has been applied with success to models of intervals over linear time by Allen and others, and is of cubic-time complexity. To extend it to branding-time models, it is necessary to calculate compositions of the relations; thus, the table of compositions for the 'atomic' relations is computed, enabling the rapid determination of the composition of arbitrary relations, expressed as disjunctions or unions of the atomic relations.

  1. Unwinding the Molecular Basis of Interval and Circadian Timing

    PubMed Central

    Agostino, Patricia V.; Golombek, Diego A.; Meck, Warren H.

    2011-01-01

    Neural timing mechanisms range from the millisecond to diurnal, and possibly annual, frequencies. Two of the main processes under study are the interval timer (seconds-to-minute range) and the circadian clock. The molecular basis of these two mechanisms is the subject of intense research, as well as their possible relationship. This article summarizes data from studies investigating a possible interaction between interval and circadian timing and reviews the molecular basis of both mechanisms, including the discussion of the contribution from studies of genetically modified animal models. While there is currently no common neurochemical substrate for timing mechanisms in the brain, circadian modulation of interval timing suggests an interaction of different frequencies in cerebral temporal processes. PMID:22022309

  2. A model of interval timing by neural integration

    PubMed Central

    Simen, Patrick; Balci, Fuat; deSouza, Laura; Cohen, Jonathan D.; Holmes, Philip

    2011-01-01

    We show that simple assumptions about neural processing lead to a model of interval timing as a temporal integration process, in which a noisy firing-rate representation of time rises linearly on average toward a response threshold over the course of an interval. Our assumptions include: that neural spike trains are approximately independent Poisson processes; that correlations among them can be largely cancelled by balancing excitation and inhibition; that neural populations can act as integrators; and that the objective of timed behavior is maximal accuracy and minimal variance. The model accounts for a variety of physiological and behavioral findings in rodents, monkeys and humans, including ramping firing rates between the onset of reward-predicting cues and the receipt of delayed rewards, and universally scale-invariant response time distributions in interval timing tasks. It furthermore makes specific, well-supported predictions about the skewness of these distributions, a feature of timing data that is usually ignored. The model also incorporates a rapid (potentially one-shot) duration-learning procedure. Human behavioral data support the learning rule’s predictions regarding learning speed in sequences of timed responses. These results suggest that simple, integration-based models should play as prominent a role in interval timing theory as they do in theories of perceptual decision making, and that a common neural mechanism may underlie both types of behavior. PMID:21697374

  3. Motor and Executive Control in Repetitive Timing of Brief Intervals

    ERIC Educational Resources Information Center

    Holm, Linus; Ullen, Fredrik; Madison, Guy

    2013-01-01

    We investigated the causal role of executive control functions in the production of brief time intervals by means of a concurrent task paradigm. To isolate the influence of executive functions on timing from motor coordination effects, we dissociated executive load from the number of effectors used in the dual task situation. In 3 experiments,…

  4. Specifying real-time systems with interval logic

    NASA Technical Reports Server (NTRS)

    Rushby, John

    1988-01-01

    Pure temporal logic makes no reference to time. An interval temporal logic and an extension to that logic which includes real time constraints are described. The application of this logic by giving a specification for the well-known lift (elevator) example is demonstrated. It is shown how interval logic can be extended to include a notion of process. How the specification language and verification environment of EHDM could be enhanced to support this logic is described. A specification of the alternating bit protocol in this extended version of the specification language of EHDM is given.

  5. Systolic time interval data acquisition system. Specialized cardiovascular studies

    NASA Technical Reports Server (NTRS)

    Baker, J. T.

    1976-01-01

    The development of a data acquisition system for noninvasive measurement of systolic time intervals is described. R-R interval from the ECG determines instantaneous heart rate prior to the beat to be measured. Total electromechanical systole (Q-S2) is measured from the onset of the ECG Q-wave to the onset of the second heart sound (S2). Ejection time (ET or LVET) is measured from the onset of carotid upstroke to the incisure. Pre-ejection period (PEP) is computed by subtracting ET from Q-S2. PEP/ET ratio is computed directly.

  6. Time Interval Errors of a Flicker-noise Generator

    NASA Technical Reports Server (NTRS)

    Greenhall, C. A.

    1984-01-01

    Time interval error (TIE) is the error of a clock at time t after it is synchronized and syntonized at time zero. Previous simulations of Flicker FM noise yielded a mean-square TIE proportional to sq t. It is shown that the order of growth is actually sq t log t. The earlier sq t result is explained and a modified version of the Barnes-Jarvis simulation algorithm is given.

  7. Department of Defense Precise Time and Time Interval program improvement plan

    NASA Technical Reports Server (NTRS)

    Bowser, J. R.

    1981-01-01

    The United States Naval Observatory is responsible for ensuring uniformity in precise time and time interval operations including measurements, the establishment of overall DOD requirements for time and time interval, and the accomplishment of objectives requiring precise time and time interval with minimum cost. An overview of the objectives, the approach to the problem, the schedule, and a status report, including significant findings relative to organizational relationships, current directives, principal PTTI users, and future requirements as currently identified by the users are presented.

  8. The Behavioral Economics of Choice and Interval Timing

    PubMed Central

    Jozefowiez, J.; Staddon, J. E. R.; Cerutti, D. T.

    2009-01-01

    We propose a simple behavioral economic model (BEM) describing how reinforcement and interval timing interact. The model assumes a Weber-law-compliant logarithmic representation of time. Associated with each represented time value are the payoffs that have been obtained for each possible response. At a given real time, the response with the highest payoff is emitted. The model accounts for a wide range of data from procedures such as simple bisection, metacognition in animals, economic effects in free-operant psychophysical procedures and paradoxical choice in double-bisection procedures. Although it assumes logarithmic time representation, it can also account for data from the time-left procedure usually cited in support of linear time representation. It encounters some difficulties in complex free-operant choice procedures, such as concurrent mixed fixed-interval schedules as well as some of the data on double bisection, that may involve additional processes. Overall, BEM provides a theoretical framework for understanding how reinforcement and interval timing work together to determine choice between temporally differentiated reinforcers. PMID:19618985

  9. Versatile all-digital time interval measuring system

    NASA Astrophysics Data System (ADS)

    Vyhlidal, David; Cech, Miroslav

    2011-06-01

    This paper describes a design and performance of a versatile all-digital time interval measuring system. The measurement method is based on an interpolation principle. In this principle the time interval is first roughly digitized by a coarse counter driven by a high stability reference clock and the fractions between the clock periods are measured by two Time-to-Digital Converter chips TDC-GPX manufactured by Acam messelectronic. Control circuits allow programmable customization of the system to satisfy many applications such as laser range finding, event counting, or time-of-flight measurements in various physics experiments. The system has two reference clocks inputs and two independent channels for measuring start and stop events. Only one 40 MHz reference is required for the measurement. The second reference can be, for example, 1 PPS (Pulse per Second) signal from a GPS (Global Positioning System) to time tag events. Time intervals are measured using the highest resolution mode of the TDC-GPX chips. The resolution of each chip is software programmable and is PLL (Phase Locked Loop) stabilized against temperature and voltage variations. The system can achieve a timing resolution better than 15 ps rms with up to 90 kHz repetition rate. The time interval measurement range is from 0 ps up to 1 second. The power consumption of the whole system is 18 W including an embedded computer board and an LCD (Liquid Crystal Display) screen. The embedded computer controls the whole system, collects and evaluates measurement data and with the display provides a user interface. The system is implemented using commercially available components.

  10. Individual variability in cardiac biomarker release after 30 min of high-intensity rowing in elite and amateur athletes.

    PubMed

    Legaz-Arrese, Alejandro; López-Laval, Isaac; George, Keith; Puente-Lanzarote, Juan José; Moliner-Urdiales, Diego; Ayala-Tajuelo, Vicente Javier; Mayolas-Pi, Carmen; Reverter-Masià, Joaquín

    2015-09-01

    This study had two objectives: (i) to examine individual variation in the pattern of cardiac troponin I (cTnI) and N-terminal pro-brain natriuretic peptide (NT-proBNP) release in response to high-intensity rowing exercise, and (ii) to establish whether individual heterogeneity in biomarker appearance was influenced by athletic status (elite vs. amateur). We examined cTnI and NT-proBNP in 18 elite and 14 amateur rowers before and 5 min, 1, 3, 6, 12, and 24 h after a 30-min maximal rowing test. Compared with pre-exercise levels, peak postexercise cTnI (pre: 0.014 ± 0.030 μg·L(-1); peak post: 0.058 ± 0.091 μg·L(-1); p = 0.000) and NT-proBNP (pre: 15 ± 11 ng·L(-1); peak post: 31 ± 19 ng·L(-1); p = 0.000) were elevated. Substantial individual heterogeneity in peak and time-course data was noted for cTnI. Peak cTnI exceeded the upper reference limit (URL) in 9 elite and 3 amateur rowers. No rower exceeded the URL for NT-proBNP. Elite rowers had higher baseline (0.019 ± 0.038 vs. 0.008 ± 0.015 μg·L(-1); p = 0.003) and peak postexercise cTnI (0.080 ± 0.115 vs. 0.030 ± 0.029 μg·L(-1); p = 0.022) than amateur rowers, but the change with exercise was similar between groups. There were no significant differences in baseline and peak postexercise NT-proBNP between groups. In summary, marked individuality in the cTnI response to a short but high-intensity rowing bout was observed. Athletic status did not seem to affect the change in cardiac biomarkers in response to high-intensity exercise. PMID:26307519

  11. Systolic time intervals after a seven-day orbital flight

    NASA Astrophysics Data System (ADS)

    Groza, P.; Vrâncianu, R.; Lazǎr, M.; Baevski, R. M.; Funtova, V. L.

    Heart rate, systolic time intervals (pre-ejection period, left ventricular ejection time), ejection fraction, stroke volume and QT interval of two cosmonauts (Leonid Popov - L.P. and Dumitru Prunariu - D.P.) were studied before, during, and after an ergometric bicycle exercise test performed before and after the seven-day Soviet-Romanian orbital flight on the Soyuz 40 - Salyut 6 Complex in May 1981. For this purpose one precordial electrocardiogram (ecg) and the ear photodensitogram (den) were recorded stimulaneously. The method used permitted recording even during exercise, Ecg and den signals were stored on magnetic tape, processed in an analogue device and in a digital computer. The data obtained after landing suggest a slight cardiac deconditioning in L.P., demonstrated especially by augmentation of the pre-ejection period, which was unchanged in D.P. corresponding to a sympathoadrenergic hypertonia. The seven-day orbital flight has not produced important cardiovascular changes.

  12. Total ozone change estimations for different time intervals

    NASA Technical Reports Server (NTRS)

    Fioletov, Vitali E.

    1994-01-01

    To investigate total ozone behavior in different time intervals for the 40 deg - 52 deg N and 53 deg - 64 deg N latitudinal bands sliding 11 year linear trends with the first interval from 1959 to 1969 and the final one from 1980 to 1990 were computed. The most recent 11-year trends are negative and have larger absolute values than in the past. The trend values in the period from 1980 to 1990 in the 53 deg - 64 deg N band are minus 4.3 percent (winter), minus 3.2 percent (summer), and minus 3.8 percent (annual) per decade, and in the 40 deg - 52 deg N band they are minus 5.9 percent (winter), minus 2.7 percent (summer), and minus 3.6 percent (annual) per decade.

  13. Proceedings of the Eleventh Annual Precise Time and Time Interval (PTTI) Application and Planning Meeting. [conference

    NASA Technical Reports Server (NTRS)

    Wardrip, S. C. (Editor)

    1979-01-01

    Thirty eight papers are presented addressing various aspects of precise time and time interval applications. Areas discussed include: past accomplishments; state of the art systems; new and useful applications, procedures, and techniques; and fruitful directions for research efforts.

  14. Central tendency effects in time interval reproduction in autism

    PubMed Central

    Karaminis, Themelis; Cicchini, Guido Marco; Neil, Louise; Cappagli, Giulia; Aagten-Murphy, David; Burr, David; Pellicano, Elizabeth

    2016-01-01

    Central tendency, the tendency of judgements of quantities (lengths, durations etc.) to gravitate towards their mean, is one of the most robust perceptual effects. A Bayesian account has recently suggested that central tendency reflects the integration of noisy sensory estimates with prior knowledge representations of a mean stimulus, serving to improve performance. The process is flexible, so prior knowledge is weighted more heavily when sensory estimates are imprecise, requiring more integration to reduce noise. In this study we measure central tendency in autism to evaluate a recent theoretical hypothesis suggesting that autistic perception relies less on prior knowledge representations than typical perception. If true, autistic children should show reduced central tendency than theoretically predicted from their temporal resolution. We tested autistic and age- and ability-matched typical children in two child-friendly tasks: (1) a time interval reproduction task, measuring central tendency in the temporal domain; and (2) a time discrimination task, assessing temporal resolution. Central tendency reduced with age in typical development, while temporal resolution improved. Autistic children performed far worse in temporal discrimination than the matched controls. Computational simulations suggested that central tendency was much less in autistic children than predicted by theoretical modelling, given their poor temporal resolution. PMID:27349722

  15. Central tendency effects in time interval reproduction in autism.

    PubMed

    Karaminis, Themelis; Cicchini, Guido Marco; Neil, Louise; Cappagli, Giulia; Aagten-Murphy, David; Burr, David; Pellicano, Elizabeth

    2016-01-01

    Central tendency, the tendency of judgements of quantities (lengths, durations etc.) to gravitate towards their mean, is one of the most robust perceptual effects. A Bayesian account has recently suggested that central tendency reflects the integration of noisy sensory estimates with prior knowledge representations of a mean stimulus, serving to improve performance. The process is flexible, so prior knowledge is weighted more heavily when sensory estimates are imprecise, requiring more integration to reduce noise. In this study we measure central tendency in autism to evaluate a recent theoretical hypothesis suggesting that autistic perception relies less on prior knowledge representations than typical perception. If true, autistic children should show reduced central tendency than theoretically predicted from their temporal resolution. We tested autistic and age- and ability-matched typical children in two child-friendly tasks: (1) a time interval reproduction task, measuring central tendency in the temporal domain; and (2) a time discrimination task, assessing temporal resolution. Central tendency reduced with age in typical development, while temporal resolution improved. Autistic children performed far worse in temporal discrimination than the matched controls. Computational simulations suggested that central tendency was much less in autistic children than predicted by theoretical modelling, given their poor temporal resolution. PMID:27349722

  16. Optical timing receiver for the NASA laser ranging system. Part 2: High precision time interval digitizer

    NASA Technical Reports Server (NTRS)

    Leskovar, B.; Turko, B.

    1977-01-01

    The development of a high precision time interval digitizer is described. The time digitizer is a 10 psec resolution stop watch covering a range of up to 340 msec. The measured time interval is determined as a separation between leading edges of a pair of pulses applied externally to the start input and the stop input of the digitizer. Employing an interpolation techniques and a 50 MHz high precision master oscillator, the equivalent of a 100 GHz clock frequency standard is achieved. Absolute accuracy and stability of the digitizer are determined by the external 50 MHz master oscillator, which serves as a standard time marker. The start and stop pulses are fast 1 nsec rise time signals, according to the Nuclear Instrument means of tunnel diode discriminators. Firing level of the discriminator define start and stop points between which the time interval is digitized.

  17. Proceedings of the Fourth Precise Time and Time Interval Planning Meeting

    NASA Technical Reports Server (NTRS)

    Acrivos, H. N. (Compiler); Wardrip, S. C. (Compiler)

    1972-01-01

    The proceedings of a conference on Precise Time and Time Interval Planning are presented. The subjects discussed include the following: (1) satellite timing techniques, precision frequency sources, and very long baseline interferometry, (2) frequency stabilities and communications, and (3) very low frequency and ultrahigh frequency propagation and use. Emphasis is placed on the accuracy of time discrimination obtained with time measuring equipment and specific applications of time measurement to military operations and civilian research projects.

  18. On selection of the optimal data time interval for real-time hydrological forecasting

    NASA Astrophysics Data System (ADS)

    Liu, J.; Han, D.

    2013-09-01

    With the advancement in modern telemetry and communication technologies, hydrological data can be collected with an increasingly higher sampling rate. An important issue deserving attention from the hydrological community is which suitable time interval of the model input data should be chosen in hydrological forecasting. Such a problem has long been recognised in the control engineering community but is a largely ignored topic in operational applications of hydrological forecasting. In this study, the intrinsic properties of rainfall-runoff data with different time intervals are first investigated from the perspectives of the sampling theorem and the information loss using the discrete wavelet transform tool. It is found that rainfall signals with very high sampling rates may not always improve the accuracy of rainfall-runoff modelling due to the catchment low-pass-filtering effect. To further investigate the impact of a data time interval in real-time forecasting, a real-time forecasting system is constructed by incorporating the probability distributed model (PDM) with a real-time updating scheme, the autoregressive moving-average (ARMA) model. Case studies are then carried out on four UK catchments with different concentration times for real-time flow forecasting using data with different time intervals of 15, 30, 45, 60, 90 and 120 min. A positive relation is found between the forecast lead time and the optimal choice of the data time interval, which is also highly dependent on the catchment concentration time. Finally, based on the conclusions from the case studies, a hypothetical pattern is proposed in three-dimensional coordinates to describe the general impact of the data time interval and to provide implications of the selection of the optimal time interval in real-time hydrological forecasting. Although nowadays most operational hydrological systems still have low data sampling rates (daily or hourly), the future is that higher sampling rates will become

  19. Assessment of histological changes in antemortem gingival tissues fixed at various time intervals: A method of estimation of postmortem interval

    PubMed Central

    Mahalakshmi, V.; Gururaj, N.; Sathya, R.; Sabarinath, T. R.; Sivapathasundharam, B.; Kalaiselvan, S.

    2016-01-01

    Introduction: Conventional methods to estimate the time of death are adequate, but a histological method is yet unavailable to assess postmortem interval (PMI). The autolytic changes that occur in an unfixed antemortem gingival tissue which reflects histologically at an early stage are similar to changes that occur in postmortem tissue. These histological changes can be used and applied in a postmortem tissue as a method to assess PMI. Aims: The aim of the study is to assess the histological changes in a gingival tissue left unfixed for various time intervals and to correlate the findings with duration. Materials and Methods: Sixty gingival tissues obtained from patients following therapeutic extractions, impactions, gingivectomy and crown lengthening procedures were used. Each tissue obtained was divided into two pieces and labeled as “A”, the control group and “ B” the study group. Tissues labeled “A” were fixed in 10% formalin immediately and tissues labeled“B” were placed in closed containers and fixed after 15, 30, 45 min, 1, 2, and 4 h time interval. Of the sixty tissues in the study group “ B”, ten tissues were used for each time interval under investigation. All the fixed tissues were processed, stained, assessed, and analyzed statistically using Pearson correlation and regression analysis. Results: Histological changes appear at 15 min in an unfixed antemortem tissue. At 2 h interval, all layers with few cells in basal cell layer are involved. At 4 h interval, loss of stratification and complete homogenization of cells in the superficial layers with prominent changes in basal layer is evident. There was a positive correlation (<1.0) between the time interval and the appearance of the histological changes. Conclusion: Histological changes such as complete homogenization of cells in superficial layers and loss of epithelial architecture at 4 h in unfixed antemortem tissue may be used as a criterion to estimate PMI, after further studies

  20. The 26th Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting

    NASA Technical Reports Server (NTRS)

    Sydnor, Richard (Editor)

    1995-01-01

    This document is a compilation of technical papers presented at the 26th Annual PTTI Applications and Planning Meeting. Papers are in the following categories: (1) Recent developments in rubidium, cesium, and hydrogen-based frequency standards, and in cryogenic and trapped-ion technology; (2) International and transnational applications of Precise Time and Time Interval technology with emphasis on satellite laser tracking, GLONASS timing, intercomparison of national time scales and international telecommunications; (3) Applications of Precise Time and Time Interval technology to the telecommunications, power distribution, platform positioning, and geophysical survey industries; (4) Applications of PTTI technology to evolving military communications and navigation systems; and (5) Dissemination of precise time and frequency by means of GPS, GLONASS, MILSTAR, LORAN, and synchronous communications satellites.

  1. Time and memory: towards a pacemaker-free theory of interval timing.

    PubMed Central

    Staddon, J E; Higa, J J

    1999-01-01

    A popular view of interval timing in animals is that it is driven by a discrete pacemaker-accumulator mechanism that yields a linear scale for encoded time. But these mechanisms are fundamentally at odds with the Weber law property of interval timing, and experiments that support linear encoded time can be interpreted in other ways. We argue that the dominant pacemaker-accumulator theory, scalar expectancy theory (SET), fails to explain some basic properties of operant behavior on interval-timing procedures and can only accommodate a number of discrepancies by modifications and elaborations that raise questions about the entire theory. We propose an alternative that is based on principles of memory dynamics derived from the multiple-time-scale (MTS) model of habituation. The MTS timing model can account for data from a wide variety of time-related experiments: proportional and Weber law temporal discrimination, transient as well as persistent effects of reinforcement omission and reinforcement magnitude, bisection, the discrimination of relative as well as absolute duration, and the choose-short effect and its analogue in number-discrimination experiments. Resemblances between timing and counting are an automatic consequence of the model. We also argue that the transient and persistent effects of drugs on time estimates can be interpreted as well within MTS theory as in SET. Recent real-time physiological data conform in surprising detail to the assumptions of the MTS habituation model. Comparisons between the two views suggest a number of novel experiments. PMID:10220931

  2. Interresponse Time Structures in Variable-Ratio and Variable-Interval Schedules

    ERIC Educational Resources Information Center

    Bowers, Matthew T.; Hill, Jade; Palya, William L.

    2008-01-01

    The interresponse-time structures of pigeon key pecking were examined under variable-ratio, variable-interval, and variable-interval plus linear feedback schedules. Whereas the variable-ratio and variable-interval plus linear feedback schedules generally resulted in a distinct group of short interresponse times and a broad distribution of longer…

  3. The 25th Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting

    NASA Technical Reports Server (NTRS)

    Sydnor, Richard L. (Editor)

    1994-01-01

    Papers in the following categories are presented: recent developments in rubidium, cesium, and hydrogen-based frequency standards, and in cryogenic and trapped-ion technology; international and transnational applications of precise time and time interval (PTTI) technology with emphasis on satellite laser tracking networks, GLONASS timing, intercomparison of national time scales and international telecommunication; applications of PTTI technology to the telecommunications, power distribution, platform positioning, and geophysical survey industries; application of PTTI technology to evolving military communications and navigation systems; and dissemination of precise time and frequency by means of GPS, GLONASS, MILSTAR, LORAN, and synchronous communications satellites.

  4. The 22nd Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting

    NASA Technical Reports Server (NTRS)

    Sydnor, Richard L. (Editor)

    1990-01-01

    Papers presented at the 22nd Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting are compiled. The following subject areas are covered: Rb, Cs, and H-based frequency standards and cryogenic and trapped-ion technology; satellite laser tracking networks, GLONASS timing, intercomparison of national time scales and international telecommunications; telecommunications, power distribution, platform positioning, and geophysical survey industries; military communications and navigation systems; and dissemination of precise time and frequency by means of GPS, GLONASS, MILSTAR, LORAN, and synchronous communication satellites.

  5. The 22nd Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting

    SciTech Connect

    Sydnor, R.L.

    1990-05-01

    Papers presented at the 22nd Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting are compiled. The following subject areas are covered: Rb, Cs, and H-based frequency standards and cryogenic and trapped-ion technology; satellite laser tracking networks, GLONASS timing, intercomparison of national time scales and international telecommunications; telecommunications, power distribution, platform positioning, and geophysical survey industries; military communications and navigation systems; and dissemination of precise time and frequency by means of GPS, GLONASS, MIL<550>STAR, LORAN, and synchronous communication satellites.

  6. Proceedings of the Thirteenth Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting

    NASA Technical Reports Server (NTRS)

    Wardrip, S. C.

    1982-01-01

    Proceedings of an annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting are summarized. A transparent view of the state-of-the-art, an opportunity to express needs, a view of important future trends, and a review of relevant past accomplishments were considered for PTTI managers, systems engineers, and program planner. Specific aims were: to provide PTTI users with new and useful applications, procedures, and techniques; to allow the PTTI researcher to better assess fruitful directions for research efforts.

  7. MK-801 and memantine act differently on short-term memory tested with different time-intervals in the Morris water maze test.

    PubMed

    Duda, Weronika; Wesierska, Malgorzata; Ostaszewski, Pawel; Vales, Karel; Nekovarova, Tereza; Stuchlik, Ales

    2016-09-15

    N-methyl-d-aspartate receptors (NMDARs) play a crucial role in spatial memory formation. In neuropharmacological studies their functioning strongly depends on testing conditions and the dosage of NMDAR antagonists. The aim of this study was to assess the immediate effects of NMDAR block by (+)MK-801 or memantine on short-term allothetic memory. Memory was tested in a working memory version of the Morris water maze test. In our version of the test, rats underwent one day of training with 8 trials, and then three experimental days when rats were injected intraperitoneally with low- 5 (MeL), high - 20 (MeH) mg/kg memantine, 0.1mg/kg MK-801 or 1ml/kg saline (SAL) 30min before testing, for three consecutive days. On each experimental day there was just one acquisition and one test trial, with an inter-trial interval of 5 or 15min. During training the hidden platform was relocated after each trial and during the experiment after each day. The follow-up effect was assessed on day 9. Intact rats improved their spatial memory across the one training day. With a 5min interval MeH rats had longer latency then all rats during retrieval. With a 15min interval the MeH rats presented worse working memory measured as retrieval minus acquisition trial for path than SAL and MeL and for latency than MeL rats. MK-801 rats had longer latency than SAL during retrieval. Thus, the high dose of memantine, contrary to low dose of MK-801 disrupts short-term memory independent on the time interval between acquisition and retrieval. This shows that short-term memory tested in a working memory version of water maze is sensitive to several parameters: i.e., NMDA receptor antagonist type, dosage and the time interval between learning and testing. PMID:27180167

  8. Relationship between the Initial Systolic Time Interval and RR-interval during an exercise stimulus measured with Impedance Cardiography

    NASA Astrophysics Data System (ADS)

    Hoekstra, Femke; Habers, Esther; Janssen, Thomas W. J.; Verdaasdonk, Rudolf M.; Meijer, Jan H.

    2010-04-01

    The Initial Systolic Time Interval (ISTI), obtained from the electrocardiogram and impedance cardiogram, is considered to be a measure for the time delay between the electrical and mechanical activity of the heart and reflects an active period of the heart cycle. The relationship between ISTI and the total heart cycle (RR-interval) was studied in three groups of young, healthy volunteers: low, moderately and highly trained subjects. The three groups were exposed to an exercise stimulus on a cycle ergometer with an increasing work load to increase the heart rate. ISTI was decreased with decreasing RR-interval. However, the relative proportion of ISTI, ISTI/RR, was found to increase with decreasing RR-interval. This relationship was found to be inversely proportional. The rate of this increase in ISTI/RR was significantly higher in highly trained subjects. Also, over the whole range of heart rates ISTI was longer in these subjects. It is concluded that ISTI can be used to evaluate cardiac performance during physical exercise non-invasively and in an extramural setting.

  9. Proceedings of the 7th Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The Proceedings contain the papers presented at the Seventh Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting and the edited record of the discussion period following each paper. This meeting provided a forum to promote more effective, efficient, economical and skillful applications of PTTI technology to the many problem areas to which PTTI offers solutions. Specifically the purpose of the meeting is to: disseminate, coordinate, and exchange practical information associated with precise time and frequency; acquaint systems engineers, technicians and managers with precise time and frequency technology and its applications; and review present and future requirements for PTTI.

  10. Effects of a reduced time-out interval on compliance with the time-out instruction.

    PubMed

    Donaldson, Jeanne M; Vollmer, Timothy R; Yakich, Theresa M; Van Camp, Carole

    2013-01-01

    Time-out is a negative punishment procedure that parents and teachers commonly use to reduce problem behavior; however, specific time-out parameters have not been evaluated adequately. One parameter that has received relatively little attention in the literature is the mode of administration (verbal or physical) of time-out. In this study, we evaluated a procedure designed to reduce problem behavior and increase compliance with the verbal instruction to go to time-out. Specifically, we reduced the time-out interval contingent on compliance with the time-out instruction. Six preschool-aged boys participated in the study. Time-out effectively reduced the problem behavior of all 6 participants, and the procedure to increase compliance with the time-out instruction was effective for 4 of 6 participants. PMID:24114153

  11. Proceedings of the 23rd Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting

    SciTech Connect

    Sydnor, R.L.

    1992-07-01

    A compilation of technical papers, from the 23rd annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting, is presented. Papers were given in the following categories: (1) developments in rubidium, cesium, and hydrogen-based frequency standards, and in cryogenic and trapped-ion technology; (2) international and transnational applications of PTTI technology with emphasis on satellite laser tracking networks, GLONASS timing, comparison of national time scales and international communications; (3) applications of PTTI technology to the telecommunications, power distribution, platform positioning, and geophysical survey industries; (4) applications of PTTI technology to evolving military communications and navigation systems; and (5) dissemination of precise time and frequency by means of GPS, GLONASS, MILSTAR, Loran, and synchronous communications satellites.

  12. Proceedings of the 30th Annual Precise Time and Time Interval (PTTI) Systems and Applications Meeting

    NASA Technical Reports Server (NTRS)

    Breakiron, Lee A. (Editor)

    1999-01-01

    This document is a compilation of technical papers presented at the 30th Annual Precise Time and Time Interval (PTTI) Systems and Applications Meeting held 1-3 December 1998 at the Hyatt Regency Hotel at Reston Town Center, Reston, Virginia. Papers are in the following categories: 1) Recent developments in rubidium, cesium, and hydrogen-based atomic frequency standards, and in trapped-ion and space clock technology; 2) National and international applications of PTTI technology with emphasis on GPS and GLONASS timing, atomic time scales, and telecommunications; 3) Applications of PTTI technology to evolving military navigation and communication systems; geodesy; aviation; and pulsars; and 4) Dissemination of precise time and frequency by means of GPS, geosynchronous communication satellites, computer networks, WAAS, and LORAN.

  13. Proceedings of the 23rd Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting

    NASA Technical Reports Server (NTRS)

    Sydnor, Richard L. (Editor)

    1992-01-01

    A compilation of technical papers, from the 23rd annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting, is presented. Papers were given in the following categories: (1) developments in rubidium, cesium, and hydrogen-based frequency standards, and in cryogenic and trapped-ion technology; (2) international and transnational applications of PTTI technology with emphasis on satellite laser tracking networks, GLONASS timing, comparison of national time scales and international communications; (3) applications of PTTI technology to the telecommunications, power distribution, platform positioning, and geophysical survey industries; (4) applications of PTTI technology to evolving military communications and navigation systems; and (5) dissemination of precise time and frequency by means of GPS, GLONASS, MILSTAR, Loran, and synchronous communications satellites.

  14. The 24th Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting

    NASA Technical Reports Server (NTRS)

    Sydnor, Richard L.

    1993-01-01

    A compilation of technical papers presented at the 24th Precise Time and Time Interval (PTTI) Applications and Planning Meeting held in Dec. 1992 is presented. Papers are in the following categories: recent developments in rubidium, cesium, and hydrogen-based frequency standards, and in cryogenic and trapped-ion technology; international and transnational applications of PTTI technology with emphasis on satellite laser tracking networks, GLONASS timing, intercomparison of national time scales, and international telecommunications; applications of PTTI technology to the telecommunications, power distribution, and platform positioning, and geophysical survey industries; applications of PTTI technology to evolving military communications and navigation systems; and dissemination of precise time and frequency by means of GPS, GLONASS, MILSTAR, Loran, and synchronous communications satellites.

  15. 27th Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting

    NASA Technical Reports Server (NTRS)

    Sydnor, Richard L. (Editor)

    1996-01-01

    This document is a compilation of technical papers presented at the 27th Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting, held November 29 - December 1, 1995 at San Diego, CA. Papers are in the following categories: Recent developments in rubidium, cesium, and hydrogen-based frequency standards; and in cryogenic and trapped-ion technology; International and transnational applications of PTTI technology with emphasis on satellite laser tracking, GLONASS timing, intercomparison of national time scales and international telecommunications; Applications of PTTI technology to the telecommunications, power distribution, platform positioning, and geophysical survey industries; Applications of PTTI technology to evolving military communications and navigation systems; and Dissemination of precise time and frequency by means of Global Positioning System (GPS), Global Satellite Navigation System (GLONASS), MILSTAR, LORAN, and synchronous communications satellites.

  16. Brain Bases of Working Memory for Time Intervals in Rhythmic Sequences.

    PubMed

    Teki, Sundeep; Griffiths, Timothy D

    2016-01-01

    Perception of auditory time intervals is critical for accurate comprehension of natural sounds like speech and music. However, the neural substrates and mechanisms underlying the representation of time intervals in working memory are poorly understood. In this study, we investigate the brain bases of working memory for time intervals in rhythmic sequences using functional magnetic resonance imaging. We used a novel behavioral paradigm to investigate time-interval representation in working memory as a function of the temporal jitter and memory load of the sequences containing those time intervals. Human participants were presented with a sequence of intervals and required to reproduce the duration of a particular probed interval. We found that perceptual timing areas including the cerebellum and the striatum were more or less active as a function of increasing and decreasing jitter of the intervals held in working memory respectively whilst the activity of the inferior parietal cortex is modulated as a function of memory load. Additionally, we also analyzed structural correlations between gray and white matter density and behavior and found significant correlations in the cerebellum and the striatum, mirroring the functional results. Our data demonstrate neural substrates of working memory for time intervals and suggest that the cerebellum and the striatum represent core areas for representing temporal information in working memory. PMID:27313506

  17. Brain Bases of Working Memory for Time Intervals in Rhythmic Sequences

    PubMed Central

    Teki, Sundeep; Griffiths, Timothy D.

    2016-01-01

    Perception of auditory time intervals is critical for accurate comprehension of natural sounds like speech and music. However, the neural substrates and mechanisms underlying the representation of time intervals in working memory are poorly understood. In this study, we investigate the brain bases of working memory for time intervals in rhythmic sequences using functional magnetic resonance imaging. We used a novel behavioral paradigm to investigate time-interval representation in working memory as a function of the temporal jitter and memory load of the sequences containing those time intervals. Human participants were presented with a sequence of intervals and required to reproduce the duration of a particular probed interval. We found that perceptual timing areas including the cerebellum and the striatum were more or less active as a function of increasing and decreasing jitter of the intervals held in working memory respectively whilst the activity of the inferior parietal cortex is modulated as a function of memory load. Additionally, we also analyzed structural correlations between gray and white matter density and behavior and found significant correlations in the cerebellum and the striatum, mirroring the functional results. Our data demonstrate neural substrates of working memory for time intervals and suggest that the cerebellum and the striatum represent core areas for representing temporal information in working memory. PMID:27313506

  18. Revisiting the Effect of Nicotine on Interval Timing

    PubMed Central

    Daniels, Carter W.; Watterson, Elizabeth; Garcia, Raul; Mazur, Gabriel J.; Brackney, Ryan J.; Sanabria, Federico

    2015-01-01

    This paper reviews the evidence for nicotine-induced acceleration of the internal clock when timing in the seconds-to-minutes timescale, and proposes an alternative explanation to this evidence: that nicotine reduces the threshold for responses that result in more reinforcement. These two hypotheses were tested in male Wistar rats using a novel timing task. In this task, rats were trained to seek food at one location after 8 s since trial onset and at a different location after 16 s. Some rats received the same reward at both times (group SAME); some received a larger reward at 16 s (group DIFF). Steady baseline performance was followed by 3 days of subcutaneous nicotine administration (0.3 mg/kg), baseline recovery, and an antagonist challenge (mecamylamine, 1.0 mg/kg). Nicotine induced a larger, immediate reduction in latencies to switch (LTS) in group DIFF than in group SAME. This effect was sustained throughout nicotine administration. Mecamylamine administration and discontinuation of nicotine rapidly recovered baseline performance. These results support a response-threshold account of nicotinic disruption of timing performance, possibly mediated by nicotinic acetylcholine receptors. A detailed analysis of the distribution of LTSs suggests that anomalous effects of nicotine on LTS dispersion may be due to loss of temporal control of behavior. PMID:25637907

  19. Improvements in Interval Time Tracking and Effects on Reading Achievement

    ERIC Educational Resources Information Center

    Taub, Gordon E.; McGrew, Kevin S.; Keith, Timothy Z.

    2007-01-01

    This study examined the effect of improvements in timing/rhythmicity on students' reading achievement. 86 participants completed pre- and post-test measures of reading achievement (i.e., Woodcock-Johnson III, Comprehensive Test of Phonological Processing, Test of Word Reading Efficiency, and Test of Silent Word Reading Fluency). Students in the…

  20. Accuracy in Recalling Interest Inventory Information at Three Time Intervals

    ERIC Educational Resources Information Center

    Swanson, Jane L.; Gore, Paul A., Jr.; Leuwerke, Wade; D'Achiardi, Catalina; Edwards, Jorie Hitch; Edwards, Jared

    2006-01-01

    Rates of accurate recall of the Strong Interest Inventory (SII; L. W. Harmon, J. C. Hansen, F. H. Borgen, & A. L. Hammer, 1994) profile information varied with the amount of time elapsed since the interpretation, the type of SII scale, and whether immediate recall was elicited, but rates did not vary with the strategy used to provide the…

  1. Improved confidence intervals when the sample is counted an integer times longer than the blank.

    PubMed

    Potter, William Edward; Strzelczyk, Jadwiga Jodi

    2011-05-01

    Past computer solutions for confidence intervals in paired counting are extended to the case where the ratio of the sample count time to the blank count time is taken to be an integer, IRR. Previously, confidence intervals have been named Neyman-Pearson confidence intervals; more correctly they should have been named Neyman confidence intervals or simply confidence intervals. The technique utilized mimics a technique used by Pearson and Hartley to tabulate confidence intervals for the expected value of the discrete Poisson and Binomial distributions. The blank count and the contribution of the sample to the gross count are assumed to be Poisson distributed. The expected value of the blank count, in the sample count time, is assumed known. The net count, OC, is taken to be the gross count minus the product of IRR with the blank count. The probability density function (PDF) for the net count can be determined in a straightforward manner. PMID:21451310

  2. Time-Interval Measurement of Stuttering: Systematic Replication of Ingham, Cordes, and Gow (1993).

    ERIC Educational Resources Information Center

    Ingham, Roger J.; And Others

    1993-01-01

    This replication study of time-interval judgments of stuttering found higher interjudge agreement than previously reported for event-based analyses of stuttering judgments or time-interval analyses of event judgments. Judges with high intrajudge agreement levels also showed higher interjudge agreement levels than did judges with low intrajudge…

  3. Proceedings of the 8th Precise Time and Time Interval (PTTI) Applications and Planning Meeting

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The Proceedings contain the papers presented at the Eight Annual Precise Time and Tme Interval PTTI Applications and Planning Meeting. The edited record of the discussions following the papers and the panel discussions are also included. This meeting provided a forum for the exchange of information on precise time and frequency technology among members of the scientific community and persons with program applications. The 282 registered attendees came from various U.S. Government agencies, private industry, universities and a number of foreign countries were represented. In this meeting, papers were presented that emphasized: (1) definitions and international regulations of precise time sources and users, (2) the scientific foundations of Hydrogen Maser standards, the current developments in this field and the application experience, and (3) how to measure the stability performance properties of precise standards. As in the previous meetings, update and new papers were presented on system applications with past, present and future requirements identified.

  4. Representation of interval timing by temporally scalable firing patterns in rat prefrontal cortex

    PubMed Central

    Xu, Min; Zhang, Si-yu; Dan, Yang; Poo, Mu-ming

    2014-01-01

    Perception of time interval on the order of seconds is an essential component of cognition, but the underlying neural mechanism remains largely unknown. In rats trained to estimate time intervals, we found that many neurons in the medial prefrontal cortex (PFC) exhibited sustained spiking activity with diverse temporal profiles of firing-rate modulation during the time-estimation period. Interestingly, in tasks involving different intervals, each neuron exhibited firing-rate modulation with the same profile that was temporally scaled by a factor linearly proportional to the instructed intervals. The behavioral variability across trials within each task also correlated with the intertrial variability of the temporal scaling factor. Local cooling of the medial PFC, which affects neural circuit dynamics, significantly delayed behavioral responses. Thus, PFC neuronal activity contributes to time perception, and temporally scalable firing-rate modulation may reflect a general mechanism for neural representation of interval timing. PMID:24367075

  5. Representation of interval timing by temporally scalable firing patterns in rat prefrontal cortex.

    PubMed

    Xu, Min; Zhang, Si-yu; Dan, Yang; Poo, Mu-ming

    2014-01-01

    Perception of time interval on the order of seconds is an essential component of cognition, but the underlying neural mechanism remains largely unknown. In rats trained to estimate time intervals, we found that many neurons in the medial prefrontal cortex (PFC) exhibited sustained spiking activity with diverse temporal profiles of firing-rate modulation during the time-estimation period. Interestingly, in tasks involving different intervals, each neuron exhibited firing-rate modulation with the same profile that was temporally scaled by a factor linearly proportional to the instructed intervals. The behavioral variability across trials within each task also correlated with the intertrial variability of the temporal scaling factor. Local cooling of the medial PFC, which affects neural circuit dynamics, significantly delayed behavioral responses. Thus, PFC neuronal activity contributes to time perception, and temporally scalable firing-rate modulation may reflect a general mechanism for neural representation of interval timing. PMID:24367075

  6. Postprandial hyperglycemia was ameliorated by taking metformin 30 min before a meal than taking metformin with a meal; a randomized, open-label, crossover pilot study.

    PubMed

    Hashimoto, Yoshitaka; Tanaka, Muhei; Okada, Hiroshi; Mistuhashi, Kazuteru; Kimura, Toshihiro; Kitagawa, Noriyuki; Fukuda, Takuya; Majima, Saori; Fukuda, Yukiko; Tanaka, Yoshimitsu; Yamada, Shunji; Senmaru, Takafumi; Hamaguchi, Masahide; Asano, Mai; Yamazaki, Masahiro; Oda, Yohei; Hasegawa, Goji; Nakamura, Naoto; Fukui, Michiaki

    2016-05-01

    Taking metformin with a meal has been shown to decrease bioavailability of metformin. We hypothesized that taking metformin 30 min before a meal improves glucose metabolism. As an animal model, 18 Zucker-rats were divided into three groups as follows: no medication (Control), metformin (600 mg/kg) with meal (Met), and metformin 10 min before meal (pre-Met). In addition, five diabetic patients were recruited and randomized to take metformin (1000 mg) either 30 min before a meal (pre-Met protocol) or with a meal (Met protocol). In the animal model, the peak glucose level of pre-Met (7.8 ± 1.5 mmol/L) was lower than that of Control (12.6 ± 2.5 mmol/L, P = 0.010) or Met (14.1 ± 2.9 mmol/L, P = 0.020). Although there was no statistical difference among the three groups, total GLP-1 level at t = 0 min of pre-Met (7.4 ± 2.7 pmol/L) tended to be higher than that of Control (3.7 ± 2.0 pmol/L, P = 0.030) or Met (3.9 ± 1.2 pmol/L, P = 0.020). In diabetic patients, the peak glucose level of pre-Met protocol (7.0 ± 0.4 mmol/L) was lower than that of Met protocol (8.5 ± 0.9 mmol/L, P = 0.021). Total GLP-1 level at t = 30 min of pre-Met protocol (11.0 ± 6.1 pmol/L) was higher than that of Met protocol (6.7 ± 3.9 pmol/L, P = 0.033). Taking metformin 30 min before a meal ameliorated postprandial hyperglycemia. This promises to be a novel approach for postprandial hyperglycemia. PMID:26518190

  7. Dichotomy in perceptual learning of interval timing: calibration of mean accuracy and precision differ in specificity and time course.

    PubMed

    Sohn, Hansem; Lee, Sang-Hun

    2013-01-01

    Our brain is inexorably confronted with a dynamic environment in which it has to fine-tune spatiotemporal representations of incoming sensory stimuli and commit to a decision accordingly. Among those representations needing constant calibration is interval timing, which plays a pivotal role in various cognitive and motor tasks. To investigate how perceived time interval is adjusted by experience, we conducted a human psychophysical experiment using an implicit interval-timing task in which observers responded to an invisible bar drifting at a constant speed. We tracked daily changes in distributions of response times for a range of physical time intervals over multiple days of training with two major types of timing performance, mean accuracy and precision. We found a decoupled dynamics of mean accuracy and precision in terms of their time course and specificity of perceptual learning. Mean accuracy showed feedback-driven instantaneous calibration evidenced by a partial transfer around the time interval trained with feedback, while timing precision exhibited a long-term slow improvement with no evident specificity. We found that a Bayesian observer model, in which a subjective time interval is determined jointly by a prior and likelihood function for timing, captures the dissociative temporal dynamics of the two types of timing measures simultaneously. Finally, the model suggested that the width of the prior, not the likelihoods, gradually shrinks over sessions, substantiating the important role of prior knowledge in perceptual learning of interval timing. PMID:23076112

  8. Algorithmic recognition of anomalous time intervals in sea-level observations

    NASA Astrophysics Data System (ADS)

    Getmanov, V. G.; Gvishiani, A. D.; Kamaev, D. A.; Kornilov, A. S.

    2016-03-01

    The problem of the algorithmic recognition of anomalous time intervals in the time series of the sea-level observations conducted by the Russian Tsunami Warning Survey (RTWS) is considered. The normal and anomalous sea-level observations are described. The polyharmonic models describing the sea-level fluctuations on the short time intervals are constructed, and sea-level forecasting based on these models is suggested. The algorithm for the recognition of anomalous time intervals is developed and its work is tested on the real RTWS data.

  9. Auditory Time-Interval Perception as Causal Inference on Sound Sources

    PubMed Central

    Sawai, Ken-ichi; Sato, Yoshiyuki; Aihara, Kazuyuki

    2012-01-01

    Perception of a temporal pattern in a sub-second time scale is fundamental to conversation, music perception, and other kinds of sound communication. However, its mechanism is not fully understood. A simple example is hearing three successive sounds with short time intervals. The following misperception of the latter interval is known: underestimation of the latter interval when the former is a little shorter or much longer than the latter, and overestimation of the latter when the former is a little longer or much shorter than the latter. Although this misperception of auditory time intervals for simple stimuli might be a cue to understanding the mechanism of time-interval perception, there exists no model that comprehensively explains it. Considering a previous experiment demonstrating that illusory perception does not occur for stimulus sounds with different frequencies, it might be plausible to think that the underlying mechanism of time-interval perception involves a causal inference on sound sources: herein, different frequencies provide cues for different causes. We construct a Bayesian observer model of this time-interval perception. We introduce a probabilistic variable representing the causality of sounds in the model. As prior knowledge, the observer assumes that a single sound source produces periodic and short time intervals, which is consistent with several previous works. We conducted numerical simulations and confirmed that our model can reproduce the misperception of auditory time intervals. A similar phenomenon has also been reported in visual and tactile modalities, though the time ranges for these are wider. This suggests the existence of a common mechanism for temporal pattern perception over modalities. This is because these different properties can be interpreted as a difference in time resolutions, given that the time resolutions for vision and touch are lower than those for audition. PMID:23226136

  10. Time dependent modeling at Mt. Etna volcano: an application to the 2005-2013 time interval

    NASA Astrophysics Data System (ADS)

    Cannavo', Flavio; McCaffrey, Robert; Palano, Mimmo

    2015-04-01

    Following the 2004-05 eruption, Mt. Etna activity has been characterized by the occurrence of a number of eruptive episodes (2006, 2008 and 2012) and more than 35 paroxysmal events (mainly during the 2011-2012 time interval). In addition, continuous downslope motion of its eastern flank has affected the volcano. This seaward motion has been characterized by some episodic phases combined with the occurrence of multiple slow slip events (SSEs). In order to obtain a comprehensive view of the time evolution of these observed features and thus provide new insight into the ground deformation pattern of Mt. Etna, here we use time-dependent modeling of the three-component daily time series of all GNSS continuous stations installed on the volcanic edifice. All GNSS data spanning the 2005-2013 time interval were processed using the GAMIT/GLOBK software (Herring et al. 2010) following the strategy described in Gonzalez and Palano (2014). Estimated GNSS daily time series were referred to the "Etn@ref" reference frame (a local reference frame computed to isolate the Mt. Etna volcanic deformation from the background tectonic pattern; Palano et al. 2010). Using these daily time series as input we performed a time-dependent, non-linear inversion using the TDEFNODE code (McCaffrey, 2009). We used TDEFNODE to invert the time series to model simultaneously the steady tectonic kinematics plus the transient volcanic and tectonic sources, thus obtaining a realistic model of the complex area. Preliminary results allow us to track, over the considered time interval, the volume changes associated to the activity of a magmatic reservoir located at a depth of about 5 km b.s.l. beneath the upper western flank of the volcano, as well as the location and associated magnitude of four SSEs below the eastern flank. In addition, we attempted a preliminary subdivision of the southern and eastern flanks of Mt. Etna into four tectonic blocks which provide a reasonable representation of the observed

  11. Chronic Treatment with Haloperidol Induces Deficits in Working Memory and Feedback Effects of Interval Timing

    ERIC Educational Resources Information Center

    Lustig, C.; Meck, W.H.

    2005-01-01

    Normal participants (n=5) having no experience with antipsychotic drugs and medicated participants (n=5) with clinical experience with chronic low doses of haloperidol (3-10mg/day for 2-4 months) in the treatment of neuroses were evaluated for the effects of inter-trial interval (ITI) feedback on a discrete-trials peak-interval timing procedure.…

  12. Interval timing behavior in Pallas's long-tongued bat (Glossophaga soricina).

    PubMed

    Toelch, Ulf; Winter, York

    2013-11-01

    Timing behavior in animals and its underlying mechanisms have been investigated extensively in the peak procedure, a variant of fixed interval procedures. In such experiments, individuals typically start responding with high frequency after an initial inactive time interval and continue their responses after peak time if rewards are omitted. This begs the so far unexplored question as to how timing behavior is influenced when such continuous responses are suppressed. Here, we present results from a nectar-feeding bat species, Glossophaga soricina, that was tested in a modified version of the peak procedure at three fixed time intervals (5 s, 11 s, 20 s). In contrast to standard peak procedures we imposed metabolic costs on individual responses which effectively suppressed trains of rapid responses during trials. Under this manipulation, bats' aggregated responses showed clear peaks around the peak time in the 5-s and 11-s schedules. Bats' responses in the 20-s schedule, however, did not peak around the fixed interval time. Crucially, an analysis of time intervals between successive revisits in all schedules revealed that bats revisited feeders at accurately timed intervals in all three conditions. The individual within trial behavioral responses showed clear oscillatory patterns throughout nonrewarded trials. These findings follow predictions from mechanistic timing models, like the striatal beat frequency model, and are discussed with regard to these models. PMID:23875922

  13. Timing Rhythms: Perceived Duration Increases with a Predictable Temporal Structure of Short Interval Fillers

    PubMed Central

    Horr, Ninja K.; Di Luca, Massimiliano

    2015-01-01

    Variations in the temporal structure of an interval can lead to remarkable differences in perceived duration. For example, it has previously been shown that isochronous intervals, that is, intervals filled with temporally regular stimuli, are perceived to last longer than intervals left empty or filled with randomly timed stimuli. Characterizing the extent of such distortions is crucial to understanding how duration perception works. One account to explain effects of temporal structure is a non-linear accumulator-counter mechanism reset at the beginning of every subinterval. An alternative explanation based on entrainment to regular stimulation posits that the neural response to each filler stimulus in an isochronous sequence is amplified and a higher neural response may lead to an overestimation of duration. If entrainment is the key that generates response amplification and the distortions in perceived duration, then any form of predictability in the temporal structure of interval fillers should lead to the perception of an interval that lasts longer than a randomly filled one. The present experiments confirm that intervals filled with fully predictable rhythmically grouped stimuli lead to longer perceived duration than anisochronous intervals. No general over- or underestimation is registered for rhythmically grouped compared to isochronous intervals. However, we find that the number of stimuli in each group composing the rhythm also influences perceived duration. Implications of these findings for a non-linear clock model as well as a neural response magnitude account of perceived duration are discussed. PMID:26474047

  14. Monitoring molecular interactions using photon arrival-time interval distribution analysis

    DOEpatents

    Laurence, Ted A.; Weiss, Shimon

    2009-10-06

    A method for analyzing/monitoring the properties of species that are labeled with fluorophores. A detector is used to detect photons emitted from species that are labeled with one or more fluorophores and located in a confocal detection volume. The arrival time of each of the photons is determined. The interval of time between various photon pairs is then determined to provide photon pair intervals. The number of photons that have arrival times within the photon pair intervals is also determined. The photon pair intervals are then used in combination with the corresponding counts of intervening photons to analyze properties and interactions of the molecules including brightness, concentration, coincidence and transit time. The method can be used for analyzing single photon streams and multiple photon streams.

  15. Characterization of cardiac time intervals in healthy bonnet macaques (Macaca radiata) by using an electronic stethoscope.

    PubMed

    Kamran, Haroon; Salciccioli, Louis; Pushilin, Sergei; Kumar, Paraag; Carter, John; Kuo, John; Novotney, Carol; Lazar, Jason M

    2011-03-01

    Nonhuman primates are used frequently in cardiovascular research. Cardiac time intervals derived by phonocardiography have long been used to assess left ventricular function. Electronic stethoscopes are simple low-cost systems that display heart sound signals. We assessed the use of an electronic stethoscope to measure cardiac time intervals in 48 healthy bonnet macaques (age, 8±5 y) based on recorded heart sounds. Technically adequate recordings were obtained from all animals and required 1.5±1.3 min. The following cardiac time intervals were determined by simultaneously recording acoustic and single-lead electrocardiographic data: electromechanical activation time (QS1), electromechanical systole (QS2), the time interval between the first and second heart sounds (S1S2), and the time interval between the second and first sounds (S2S1). QS2 was correlated with heart rate, mean arterial pressure, diastolic blood pressure, and left ventricular ejection time determined by using echocardiography. S1S2 correlated with heart rate, mean arterial pressure, diastolic blood pressure, left ventricular ejection time, and age. S2S1 correlated with heart rate, mean arterial pressure, diastolic blood pressure, systolic blood pressure, and left ventricular ejection time. QS1 did not correlate with any anthropometric or echocardiographic parameter. The relation S1S2/S2S1 correlated with systolic blood pressure. On multivariate analyses, heart rate was the only independent predictor of QS2, S1S2, and S2S1. In conclusion, determination of cardiac time intervals is feasible and reproducible by using an electrical stethoscope in nonhuman primates. Heart rate is a major determinant of QS2, S1S2, and S2S1 but not QS1; regression equations for reference values for cardiac time intervals in bonnet macaques are provided. PMID:21439218

  16. Involvement of dopamine signaling in the circadian modulation of interval timing.

    PubMed

    Bussi, Ivana L; Levín, Gloria; Golombek, Diego A; Agostino, Patricia V

    2014-07-01

    Duration discrimination within the seconds-to-minutes range, known as interval timing, involves the interaction of cortico-striatal circuits via dopaminergic-glutamatergic pathways. Besides interval timing, most (if not all) organisms exhibit circadian rhythms in physiological, metabolic and behavioral functions with periods close to 24 h. We have previously reported that both circadian disruption and desynchronization impaired interval timing in mice. In this work we studied the involvement of dopamine (DA) signaling in the interaction between circadian and interval timing. We report that daily injections of levodopa improved timing performance in the peak-interval procedure in C57BL/6 mice with circadian disruptions, suggesting that a daily increase of DA is necessary for an accurate performance in the timing task. Moreover, striatal DA levels measured by reverse-phase high-pressure liquid chromatography indicated a daily rhythm under light/dark conditions. This daily variation was affected by inducing circadian disruption under constant light (LL). We also demonstrated a daily oscillation in tyrosine hydroxylase levels, DA turnover (3,4-dihydroxyphenylacetic acid/DA levels), and both mRNA and protein levels of the circadian component Period2 (Per2) in the striatum and substantia nigra, two brain areas relevant for interval timing. None of these oscillations persisted under LL conditions. We suggest that the lack of DA rhythmicity in the striatum under LL - probably regulated by Per2 - could be responsible for impaired performance in the timing task. Our findings add further support to the notion that circadian and interval timing share some common processes, interacting at the level of the dopaminergic system. PMID:24689904

  17. Dissociations between interval timing and intertemporal choice following administration of fluoxetine, cocaine, or methamphetamine.

    PubMed

    Heilbronner, Sarah R; Meck, Warren H

    2014-01-01

    The goal of our study was to characterize the relationship between intertemporal choice and interval timing, including determining how drugs that modulate brain serotonin and dopamine levels influence these two processes. In Experiment 1, rats were tested on a standard 40-s peak-interval procedure following administration of fluoxetine (3, 5, or 8 mg/kg) or vehicle to assess basic effects on interval timing. In Experiment 2, rats were tested in a novel behavioral paradigm intended to simultaneously examine interval timing and impulsivity. Rats performed a variant of the bi-peak procedure using 10-s and 40-s target durations with an additional "defection" lever that provided the possibility of a small, immediate reward. Timing functions remained relatively intact, and 'patience' across subjects correlated with peak times, indicating a negative relationship between 'patience' and clock speed. We next examined the effects of fluoxetine (5 mg/kg), cocaine (15 mg/kg), or methamphetamine (1 mg/kg) on task performance. Fluoxetine reduced impulsivity as measured by defection time without corresponding changes in clock speed. In contrast, cocaine and methamphetamine both increased impulsivity and clock speed. Thus, variations in timing may mediate intertemporal choice via dopaminergic inputs. However, a separate, serotonergic system can affect intertemporal choice without affecting interval timing directly. This article is part of a Special Issue entitled: Associative and Temporal Learning. PMID:24135569

  18. Minimum Capacity of NaS Battery according to Capacity of PV System in a Microgrid under 30 min Power Balancing Control

    NASA Astrophysics Data System (ADS)

    Shimakage, Toyonari; Sone, Akihito; Sumita, Jiro; Kato, Takeyoshi; Suzuoki, Yasuo

    On constructing a microgrid, it is essential to design capacity of photovoltaic power generation (PV) systems and storage batteries in accordance with a control target. In this study, we constructed a simulation model of energy control system in the microgrid used in the demonstration project. By using this model, we investigated the minimum capacity of NaS battery for different PV system capacities for keeping the target power imbalance within ±3% over 30 min. The main results are as follows. The microgrid involving 330-kW PV systems (corresponding to the actual system) needs a NaS battery capacity of at least approximately ±20kW, and PV systems with a capacity up to about 890kW can be integrated in the microgrid with a NaS battery capacity of ±500kW (corresponding to the actual system). We estimated the minimum capacity of NaS battery for different PV system capacities and clarified that the output behavior of the NaS battery and PAFC when supply and demand power imbalance over 30 min. exceeds the ±3% limit. We suggested the improved control model and showed that it is effective in decreasing the minimum capacity of NaS battery, although it has negative effects on the reduction of short-period power flow fluctuation at the grid-connection point.

  19. Systolic and diastolic time intervals in pulsus alternans - Significance of alternating isovolumic relaxation

    NASA Technical Reports Server (NTRS)

    Spodick, D. H.; Quarry, V. M.; Khan, A. H.

    1974-01-01

    Systolic and diastolic time intervals in 14 cardiac patients with pulsus alternans revealed significant alternation of preinjection period (PEP), isovolumic contraction time (IVCT), left ventricular ejection time (LVET), ejection time index (ETI), PEP/LVET, and carotid dD/dt with better functional values in the strong beats. Cycle length, duration of electromechanical systole (EMS) and total diastole, i.e., isovolumic relaxation period (IRP) and diastolic filling period (DFP) occurred in 7 out of 8 patients. These diastolic intervals alternated reciprocally such that the IRP of the strong beats encroached upon the DFP of the next (weak) beats.

  20. Time intervals in the treatment of fractured femurs as indicators of the quality of trauma systems

    PubMed Central

    Elliott, Iain; Marmor, Meir; Caldwell, Amber; Coughlin, Richard; Gosselin, Richard A

    2014-01-01

    Abstract Objective To investigate the use of time intervals in the treatment of fractured femurs as indicators of the quality of trauma systems. Methods Time intervals from injury to admission, admission to surgery and surgery to discharge for patients with isolated femur fractures in four low- and middle-income countries were compared with the corresponding values from one German hospital, an Israeli hospital and the National Trauma Data Bank of the United States of America by means of Student’s t-tests. The correlations between the time intervals recorded in a country and that country’s expenditure on health and gross domestic product (GDP) were also evaluated using Pearson’s product moment correlation coefficient. Findings Relative to patients from high-income countries, those from low- and middle-income countries were significantly more likely to be male and to have been treated by open femoral nailing, and their intervals from injury to admission, admission to surgery and surgery to discharge were significantly longer. Strong negative correlations were detected between the interval from injury to admission and government expenditure on health, and between the interval from admission to surgery and the per capita values for total expenditure on health, government expenditure on health and GDP. Strong positive correlations were detected between the interval from surgery to discharge and general government expenditure on health. Conclusion The time intervals for the treatment of femur fractures are relatively long in low- and middle-income countries, can easily be measured, and are highly correlated with accessible and quantifiable country data on health and economics. PMID:24391299

  1. Estimation of the Optimal Statistical Quality Control Sampling Time Intervals Using a Residual Risk Measure

    PubMed Central

    Hatjimihail, Aristides T.

    2009-01-01

    Background An open problem in clinical chemistry is the estimation of the optimal sampling time intervals for the application of statistical quality control (QC) procedures that are based on the measurement of control materials. This is a probabilistic risk assessment problem that requires reliability analysis of the analytical system, and the estimation of the risk caused by the measurement error. Methodology/Principal Findings Assuming that the states of the analytical system are the reliability state, the maintenance state, the critical-failure modes and their combinations, we can define risk functions based on the mean time of the states, their measurement error and the medically acceptable measurement error. Consequently, a residual risk measure rr can be defined for each sampling time interval. The rr depends on the state probability vectors of the analytical system, the state transition probability matrices before and after each application of the QC procedure and the state mean time matrices. As optimal sampling time intervals can be defined those minimizing a QC related cost measure while the rr is acceptable. I developed an algorithm that estimates the rr for any QC sampling time interval of a QC procedure applied to analytical systems with an arbitrary number of critical-failure modes, assuming any failure time and measurement error probability density function for each mode. Furthermore, given the acceptable rr, it can estimate the optimal QC sampling time intervals. Conclusions/Significance It is possible to rationally estimate the optimal QC sampling time intervals of an analytical system to sustain an acceptable residual risk with the minimum QC related cost. For the optimization the reliability analysis of the analytical system and the risk analysis of the measurement error are needed. PMID:19513124

  2. An Integrated Theory of Prospective Time Interval Estimation: The Role of Cognition, Attention, and Learning

    ERIC Educational Resources Information Center

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

    2007-01-01

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

  3. The Impact of Various Time Intervals on the Supragingival Plaque Dynamic Core Microbiome

    PubMed Central

    Gao, Li; He, Zhi-yan; Zhu, Cai-lian; Ma, Rui; Huang, Zheng-wei

    2015-01-01

    Objective The aim of this study was to examine the influence of various time intervals on the composition of the supragingival plaque microbiome, especially the dynamic core microbiome, and to find a suitable observation interval for further studies on oral microbiota. Methods and Materials Eight qualified volunteers whose respective age ranges from 25 to 28 years participated in the present study. The supragingival plaque was collected from the buccogingival surface of the maxillary first molar at eight time slots with different intervals (day 0, 1 day, 3 days, 1 week, 2 weeks, 3 weeks, 1 month, and 3 months). Bioinformatic analyses was performed based on 16S rDNA pyrosequencing (454 sequencing platform) targeting at the hypervariable V4–V5 region, in order to assess the diversity and variation of the supragingival plaque microbiome. Results A total of 359,565 qualified reads for 64 samples were generated for subsequent analyses, which represents 8,452 operational taxonomic units identified at 3% dissimilarity. The dynamic core microbiome detected in the current study included five phyla, 12 genera and 13 species. At the genus level, the relative abundance of bacterial communities under the “1 day,” “1 month,” and “3 months” intervals was clustered into sub-category. At the species level, the number of overlapping species remained stable between the “1 month” and “3 months” intervals, whereas the number of dynamic core species became stable within only 1 week. Conclusions This study emphasized the impact of different time intervals (days, weeks and months) on the composition, commonality and diversity of the supragingival microbiome. The analyses found that for various types of studies, the time interval of a month is more suitable for observing the general composition of the supragingival microbiome, and that a week is better for observing the dynamic core microbiome. PMID:25942317

  4. USSR national time unit keeping over long interval using an ensemble of H-masers

    NASA Technical Reports Server (NTRS)

    Koshelyaevsky, N. B.; Pushkin, S. B.

    1990-01-01

    The U.S.S.R. State Time and Frequency Service (STFS) is discussed. The STFS is responsible for time and frequency measurement unification both in the field of atomic, TA(SU) and UTC(SU) and universal time UT1(SU) over the whole territory of the U.S.S.R. The U.S.S.R. national time unit keeping over long interval using an ensemble of H-masers is also discussed.

  5. Evaluating the Time Interval for Presenting the Signs of Hypocalcaemia after Thyroidectomy

    PubMed Central

    Hosseini, Mostafa; Otaghvar, Hamidreza Alizadeh; Shabestanipour, Ghazaal; Vahid, Parichehr Atef

    2016-01-01

    Introduction Thyroidectomy is one of the most prevalent treatments for thyroid malignancies. It has very low rate of complications except the hypocalcaemia. Only a small number of studies have evaluated the clinical signs of hypocalcaemia but no study have reported the time interval between the procedure and signs of hypocalcaemia. Aim The aim of this study was to determine that time interval in those patients. Materials and Methods Medical files of a group of patients who underwent thyroidectomy were reviewed. Demographic characteristics of the patients and the time interval to hypocalcaemia were recorded and analysed by SPSS software. p-value <0.05 was considered significant. Results One hundred and eight patients, 65 women (60.2%) and 43 men (39.8%) with a mean age of 42.6+12.2 years were included. Perioral numbness was reported in 30 (27.8%) patients while 29 (26.8%) patients had lip numbness. Numbness in extremities and muscle spasm were found in 19 (17.6%) and 13 (12%) patients respectively. Seizure was reported in 3 (2.8%) patients. The Trousseau and Chvostek signs were found in 17 (15.7%) and 9 (8.3%) patients respectively. Only the Trousseau sign was different between the two surgical groups. The mean time interval was 41.25±11.5 hours postoperatively. However the time interval was shorter for the total thyroidectomy. Conclusion Physical examination is useful for diagnosing hypocalcaemia due to the presentation of sings during the first 48 hours of thyroidectomy. Total thyroidectomy is associated with shorter time interval. PMID:27134928

  6. Method and circuit for controlling the evolution time interval of a laser output pulse

    NASA Technical Reports Server (NTRS)

    Barnes, Norman P. (Inventor)

    1992-01-01

    The invention is a method and circuit for controlling the evolution time interval of a laser output pulse used for making precise spectral measurements. It comprises the means for pumping a laser medium in a resonator that includes a Q-switch and polarizer that act in combination to control the loss in the resonator. A photodiode senses the resulting fluorescence which is applied to a two level Q-switch and polarizer from high to intermediate to substantially zero loss states to control the evolution time interval of the resulting laser output pulse.

  7. Selective activation of a putative reinforcement signal conditions cued interval timing in primary visual cortex

    PubMed Central

    Liu, Cheng-Hang; Coleman, Jason E.; Davoudi, Heydar; Zhang, Kechen; Hussain Shuler, Marshall G.

    2015-01-01

    Summary As a consequence of conditioning visual cues with delayed reward, cue-evoked neural activity that predicts the time of expected future reward emerges in the primary visual cortex (V1). We hypothesized that this reward timing activity is engendered by a reinforcement signal conveying reward acquisition to V1. In lieu of behavioral conditioning, we assessed in vivo whether selective activation of either basal forebrain (BF) or cholinergic innervation is sufficient to condition cued interval timing activity. Substituting for actual reward, optogenetic activation of BF or cholinergic input within V1 at fixed delays following visual stimulation entrains neural responses that mimic behaviorally-conditioned reward timing activity. Optogenetically-conditioned neural responses express cue-evoked temporal intervals that correspond to the conditioning intervals, are bidirectionally modifiable, display experience-dependent refinement, and exhibit a scale invariance to the encoded delay. Our results demonstrate that the activation of BF or cholinergic input within V1is sufficient to encode cued interval timing activity, and indicate that V1 itself is a substrate for associative learning that may inform the timing of visually-cued behaviors. PMID:26004763

  8. Apparatus for using a time interval counter to measure frequency stability

    NASA Technical Reports Server (NTRS)

    Greenhall, Charles A. (Inventor)

    1989-01-01

    An apparatus for measuring the relative stability of two signals is disclosed comprising a means for mixing the two signals down to a beat note sine wave and for producing a beat note square wave whose upcrossings are the same as the sine wave. A source of reference frequency is supplied to a clock divider and interval counter to synchronize them and to generate a picket fence for providing a time reference grid of period shorter than the beat period. An interval counter is employed to make a preliminary measurement between successive upcrossings of the beat note square wave for providing an approximate time interval therebetween as a reference. The beat note square wave and the picket fence are then provided to the interval counter to provide an output consisting of the time difference between the upcrossing of each beat note square wave cycle and the next picket fence pulse such that the counter is ready for each upcrossing and dead time is avoided. A computer containing an algorithm for calculating the exact times of the beat note upcrossings then computes the upcrossing times.

  9. Opposite Distortions in Interval Timing Perception for Visual and Auditory Stimuli with Temporal Modulations

    PubMed Central

    Yuasa, Kenichi; Yotsumoto, Yuko

    2015-01-01

    When an object is presented visually and moves or flickers, the perception of its duration tends to be overestimated. Such an overestimation is called time dilation. Perceived time can also be distorted when a stimulus is presented aurally as an auditory flutter, but the mechanisms and their relationship to visual processing remains unclear. In the present study, we measured interval timing perception while modulating the temporal characteristics of visual and auditory stimuli, and investigated whether the interval times of visually and aurally presented objects shared a common mechanism. In these experiments, participants compared the durations of flickering or fluttering stimuli to standard stimuli, which were presented continuously. Perceived durations for auditory flutters were underestimated, while perceived durations of visual flickers were overestimated. When auditory flutters and visual flickers were presented simultaneously, these distortion effects were cancelled out. When auditory flutters were presented with a constantly presented visual stimulus, the interval timing perception of the visual stimulus was affected by the auditory flutters. These results indicate that interval timing perception is governed by independent mechanisms for visual and auditory processing, and that there are some interactions between the two processing systems. PMID:26292285

  10. Density-dependent state-space model for population-abundance data with unequal time intervals.

    PubMed

    Dennis, Brian; Ponciano, José Miguel

    2014-08-01

    The Gompertz state-space (GSS) model is a stochastic model for analyzing time-series observations of population abundances. The GSS model combines density dependence, environmental process noise, and observation error toward estimating quantities of interest in biological monitoring and population viability analysis. However, existing methods for estimating the model parameters apply only to population data with equal time intervals between observations. In the present paper, we extend the GSS model to data with unequal time intervals, by embedding it within a state-space version of the Ornstein-Uhlenbeck process, a continuous-time model of an equilibrating stochastic system. Maximum likelihood and restricted maximum likelihood calculations for the Ornstein-Uhlenbeck state-space model involve only numerical maximization of an explicit multivariate normal likelihood, and so the extension allows for easy bootstrapping, yielding confidence intervals for model parameters, statistical hypothesis testing of density dependence, and selection among sub-models using information criteria. Ecologists and managers previously drawn to models lacking density dependence or observation error because such models accommodated unequal time intervals (for example, due to missing data) now have an alternative analysis framework incorporating density dependence, process noise, and observation error. PMID:25230459

  11. Density dependent state space model for population abundance data with unequal time intervals

    PubMed Central

    Dennis, Brian; Ponciano, José Miguel

    2014-01-01

    The Gompertz state-space (GSS) model is a stochastic model for analyzing time series observations of population abundances. The GSS model combines density dependence, environmental process noise, and observation error toward estimating quantities of interest in biological monitoring and population viability analysis. However, existing methods for estimating the model parameters apply only to population data with equal time intervals between observations. In the present paper, we extend the GSS model to data with unequal time intervals, by embedding it within a state-space version of the Ornstein-Uhlenbeck process, a continuous-time model of an equilibrating stochastic system. Maximum likelihood and restricted maximum likelihood calculations for the Ornstein-Uhlenbeck state-space model involve only numerical maximization of an explicit multivariate normal likelihood, and so the extension allows for easy bootstrapping, yielding confidence intervals for model parameters, statistical hypothesis testing of density dependence, and selection among sub-models using information criteria. Ecologists and managers previously drawn to models lacking density dependence or observation error because such models accommodated unequal time intervals (for example, due to missing data) now have an alternative analysis framework incorporating density dependence, process noise and observation error. PMID:25230459

  12. Internal Representations of Temporal Statistics and Feedback Calibrate Motor-Sensory Interval Timing

    PubMed Central

    Acerbi, Luigi; Wolpert, Daniel M.; Vijayakumar, Sethu

    2012-01-01

    Humans have been shown to adapt to the temporal statistics of timing tasks so as to optimize the accuracy of their responses, in agreement with the predictions of Bayesian integration. This suggests that they build an internal representation of both the experimentally imposed distribution of time intervals (the prior) and of the error (the loss function). The responses of a Bayesian ideal observer depend crucially on these internal representations, which have only been previously studied for simple distributions. To study the nature of these representations we asked subjects to reproduce time intervals drawn from underlying temporal distributions of varying complexity, from uniform to highly skewed or bimodal while also varying the error mapping that determined the performance feedback. Interval reproduction times were affected by both the distribution and feedback, in good agreement with a performance-optimizing Bayesian observer and actor model. Bayesian model comparison highlighted that subjects were integrating the provided feedback and represented the experimental distribution with a smoothed approximation. A nonparametric reconstruction of the subjective priors from the data shows that they are generally in agreement with the true distributions up to third-order moments, but with systematically heavier tails. In particular, higher-order statistical features (kurtosis, multimodality) seem much harder to acquire. Our findings suggest that humans have only minor constraints on learning lower-order statistical properties of unimodal (including peaked and skewed) distributions of time intervals under the guidance of corrective feedback, and that their behavior is well explained by Bayesian decision theory. PMID:23209386

  13. Time Interval between Trauma and Arthroscopic Meniscal Repair Has No Influence on Clinical Survival.

    PubMed

    van der Wal, Robert J P; Thomassen, Bregje J W; Swen, Jan-Willem A; van Arkel, Ewoud R A

    2016-07-01

    Arthroscopic meniscal repair is the gold standard for longitudinal peripheral meniscal tears. The time interval between trauma and meniscal repair remains controversial. The aim of this study was to evaluate failure rates and clinical outcome of arthroscopic meniscal repair in relation to chronicity of injury. A total of 238 meniscal repairs were performed in 234 patients. Anterior cruciate ligament (ACL) was reconstructed in almost all ACL-deficient knees (130 out of 133). Time interval between injury and repair was divided into acute (< 2 weeks), subacute (> 2 to < 12 weeks), and chronic (> 12 weeks). Patients completed postal questionnaires to evaluate clinical outcome and failure rates. Study instruments included Lysholm, Knee injury and Osteoarthritis Outcome Score (KOOS), and Tegner scoring systems. At a median follow-up of 41 months (interquartile range [IQR], 34-53 months) 55 medial and 10 lateral meniscal repairs failed (overall failure rate, 27%). There was a significant higher failure rate for medial meniscal repair (p < 0.05) and ACL-deficient knees without ACL reconstruction. Functional outcome scores showed only significant differences on the KOOS subscale "function in daily living" (95% confidence interval, 1.05-15.27, p < 0.05). No significant difference was found for any interval between trauma and repair. The interval between trauma and arthroscopic meniscal repair has no influence on the failure rate. Differences in survival rate of meniscal repair are more dependent on location of the lesion and ACL status, rather than chronicity of injury. PMID:26516071

  14. A model of multisecond timing behaviour under peak-interval procedures.

    PubMed

    Hasegawa, Takayuki; Sakata, Shogo

    2015-04-01

    In this study, the authors developed a fundamental theory of interval timing behaviour, inspired by the learning-to-time (LeT) model and the scalar expectancy theory (SET) model, and based on quantitative analyses of such timing behaviour. Our experiments used the peak-interval procedure with rats. The proposed model of timing behaviour comprises clocks, a regulator, a mixer, a response, and memory. Using our model, we calculated the basic clock speeds indicated by the subjects' behaviour under such peak procedures. In this model, the scalar property can be defined as a kind of transposition, which can then be measured quantitatively. The Akaike information criterion (AIC) values indicated that the current model fit the data slightly better than did the SET model. Our model may therefore provide a useful addition to SET for the analysis of timing behaviour. PMID:25539685

  15. A Comparison of Momentary Time Sampling and Partial-Interval Recording for Evaluating Functional Relations

    ERIC Educational Resources Information Center

    Meany-Daboul, Maeve G.; Roscoe, Eileen M.; Bourret, Jason C.; Ahearn, William H.

    2007-01-01

    In the current study, momentary time sampling (MTS) and partial-interval recording (PIR) were compared to continuous-duration recording of stereotypy and to the frequency of self-injury during a treatment analysis to determine whether the recording method affected data interpretation. Five previously conducted treatment analysis data sets were…

  16. New delay dependent stability criteria for recurrent neural networks with interval time-varying delay.

    PubMed

    Yang, Qiongfen; Ren, Quanhong; Xie, Xuemei

    2014-07-01

    This paper is concerned with the delay dependent stability criteria for a class of static recurrent neural networks with interval time-varying delay. By choosing an appropriate Lyapunov-Krasovskii functional and employing a delay partitioning method, the less conservative condition is obtained. Furthermore, the LMIs-based condition depend on the lower and upper bounds of time delay. Finally, a numerical example is also designated to verify the reduced conservatism of developed criteria. PMID:24908560

  17. Modeling circadian and sleep-homeostatic effects on short-term interval timing

    PubMed Central

    Späti, Jakub; Aritake, Sayaka; Meyer, Andrea H.; Kitamura, Shingo; Hida, Akiko; Higuchi, Shigekazu; Moriguchi, Yoshiya; Mishima, Kazuo

    2015-01-01

    Short-term interval timing i.e., perception and action relating to durations in the seconds range, has been suggested to display time-of-day as well as wake dependent fluctuations due to circadian and sleep-homeostatic changes to the rate at which an underlying pacemaker emits pulses; pertinent human data being relatively sparse and lacking in consistency however, the phenomenon remains elusive and its mechanism poorly understood. To better characterize the putative circadian and sleep-homeostatic effects on interval timing and to assess the ability of a pacemaker-based mechanism to account for the data, we measured timing performance in eighteen young healthy male subjects across two epochs of sustained wakefulness of 38.67 h each, conducted prior to (under entrained conditions) and following (under free-running conditions) a 28 h sleep-wake schedule, using the methods of duration estimation and duration production on target intervals of 10 and 40 s. Our findings of opposing oscillatory time courses across both epochs of sustained wakefulness that combine with increasing and, respectively, decreasing, saturating exponential change for the tasks of estimation and production are consistent with the hypothesis that a pacemaker emitting pulses at a rate controlled by the circadian oscillator and increasing with time awake determines human short-term interval timing; the duration-specificity of this pattern is interpreted as reflecting challenges to maintaining stable attention to the task that progressively increase with stimulus magnitude and thereby moderate the effects of pacemaker-rate changes on overt behavior. PMID:25741253

  18. Efficiency of time-lapse intervals and simple baits for camera surveys of wild pigs

    USGS Publications Warehouse

    Williams, B.L.; Holtfreter, R.W.; Ditchkoff, S.S.; Grand, J.B.

    2011-01-01

    Growing concerns surrounding established and expanding populations of wild pigs (Sus scrofa) have created the need for rapid and accurate surveys of these populations. We conducted surveys of a portion of the wild pig population on Fort Benning, Georgia, to determine if a longer time-lapse interval than had been previously used in surveys of wild pigs would generate similar detection results. We concurrently examined whether use of soured corn at camera sites affected the time necessary for pigs to locate a new camera site or the time pigs remained at a site. Our results suggest that a 9-min time-lapse interval generated dependable detection results for pigs and that soured corn neither attracted pigs to a site any quicker than plain, dry, whole-kernel corn, nor held them at a site longer. Maximization of time-lapse interval should decrease data and processing loads, and use of a simple, available bait should decrease cost and effort associated with more complicated baits; combination of these concepts should increase efficiency of wild pig surveys. ?? 2011 The Wildlife Society.

  19. Discrete time interval measurement system: fundamentals, resolution and errors in the measurement of angular vibrations

    NASA Astrophysics Data System (ADS)

    Gómez de León, F. C.; Meroño Pérez, P. A.

    2010-07-01

    The traditional method for measuring the velocity and the angular vibration in the shaft of rotating machines using incremental encoders is based on counting the pulses at given time intervals. This method is generically called the time interval measurement system (TIMS). A variant of this method that we have developed in this work consists of measuring the corresponding time of each pulse from the encoder and sampling the signal by means of an A/D converter as if it were an analog signal, that is to say, in discrete time. For this reason, we have denominated this method as the discrete time interval measurement system (DTIMS). This measurement system provides a substantial improvement in the precision and frequency resolution compared with the traditional method of counting pulses. In addition, this method permits modification of the width of some pulses in order to obtain a mark-phase on every lap. This paper explains the theoretical fundamentals of the DTIMS and its application for measuring the angular vibrations of rotating machines. It also displays the required relationship between the sampling rate of the signal, the number of pulses of the encoder and the rotating velocity in order to obtain the required resolution and to delimit the methodological errors in the measurement.

  20. Do Longer Intervals between Challenges Reduce the Risk of Adverse Reactions in Oral Wheat Challenges?

    PubMed Central

    Yanagida, Noriyuki; Imai, Takanori; Sato, Sakura; Ebisawa, Motohiro

    2015-01-01

    Background The use of oral food challenges (OFCs) in clinics is limited because they are complicated and associated with anaphylactic symptoms. To increase their use, it is necessary to develop novel, effective, and safe methods. However, the effectiveness of different OFCs has not been compared. Objective To investigate the effect of ingestion methods on wheat allergy symptoms and treatment during OFCs. Method Without changing the total challenge dose, we changed the administration method from a 5-installment dose titration every 15 min (15-min interval method) to 3 installments every 30 min (30-min interval method). We retrospectively reviewed and compared the results of 65 positive 15-min interval wheat challenge tests conducted between July 2005 and February 2008 and 87 positive 30-min interval tests conducted between March 2008 and December 2009. Results A history of immediate symptoms was more common for the 30-min interval method; however, no difference between methods was observed in other background parameters. Switching from the 15-min to the 30-min interval method did not increase symptoms or require treatment. The rate of cardiovascular symptoms (p = 0.032), and adrenaline use (p = 0.017) was significantly lower with the 30-min interval method. The results did not change after adjusting for the effects of immediate symptom history in multivariate analysis. Conclusion This study suggests that the 30-min interval method reduces the risk of adverse events, compared to the 15-min interval method. PMID:26624006

  1. H∞ control problem for Hopfield neural networks with interval time-varying delay

    NASA Astrophysics Data System (ADS)

    Emharuethai, Chanikan

    2016-02-01

    In this paper, we consider H∞ control problem for a class Hopfield neural networks with interval time-varying delay. The time delay is a continuous function belonging to a given interval, but not necessariry differentiable. The stabilizing controllers to be designed must satisfy some exponential stability constraints on the closed-loop poles. Based on the construction of improved Lyapunov-Krasovskii functionals combined with Newton-Leibniz formula. H∞ controller is designed via memoryless state feedback control and new sufficient conditions for the existence of the H∞ state-feedback for the system are given in terms of linear matrix inequalities (LMIs). Numerical examples are given to illustrate the effectiveness of the obtained result.

  2. Proceedings of the 14th Annual Precise Time and Time Interval (PTTI) Applications Planning Meeting

    NASA Technical Reports Server (NTRS)

    Wardrip, S. C. (Editor)

    1983-01-01

    Developments and applications in the field of frequency and time are addressed. Specific topics include rubidium frequency standards, future timing requirements, noise and atomic standards, hydrogen maser technology, synchronization, and quartz technology.

  3. Loran-C expansion: Impact on precise time/time interval

    NASA Technical Reports Server (NTRS)

    Roeber, J. F., Jr.

    1974-01-01

    On 16 May 1974, it was announced that Loran-C was chosen as the navigation system to serve the U. S. Coastal Confluence Zone. At the present time, reliable CONUS Loran-C groundwave timing coverage extends westward only about as far as Boulder, CO. The groundwave hyperbolic and timing coverage which will result from the planned CONUS expansion are illustrated. Time frames are provided. A status report on the planned reduction in Loran-C PTTI tolerances is presented.

  4. Adaptation to visual or auditory time intervals modulates the perception of visual apparent motion

    PubMed Central

    Zhang, Huihui; Chen, Lihan; Zhou, Xiaolin

    2012-01-01

    It is debated whether sub-second timing is subserved by a centralized mechanism or by the intrinsic properties of task-related neural activity in specific modalities (Ivry and Schlerf, 2008). By using a temporal adaptation task, we investigated whether adapting to different time intervals conveyed through stimuli in different modalities (i.e., frames of a visual Ternus display, visual blinking discs, or auditory beeps) would affect the subsequent implicit perception of visual timing, i.e., inter-stimulus interval (ISI) between two frames in a Ternus display. The Ternus display can induce two percepts of apparent motion (AM), depending on the ISI between the two frames: “element motion” for short ISIs, in which the endmost disc is seen as moving back and forth while the middle disc at the overlapping or central position remains stationary; “group motion” for longer ISIs, in which both discs appear to move in a manner of lateral displacement as a whole. In Experiment 1, participants adapted to either the typical “element motion” (ISI = 50 ms) or the typical “group motion” (ISI = 200 ms). In Experiments 2 and 3, participants adapted to a time interval of 50 or 200 ms through observing a series of two paired blinking discs at the center of the screen (Experiment 2) or hearing a sequence of two paired beeps (with pitch 1000 Hz). In Experiment 4, participants adapted to sequences of paired beeps with either low pitches (500 Hz) or high pitches (5000 Hz). After adaptation in each trial, participants were presented with a Ternus probe in which the ISI between the two frames was equal to the transitional threshold of the two types of motions, as determined by a pretest. Results showed that adapting to the short time interval in all the situations led to more reports of “group motion” in the subsequent Ternus probes; adapting to the long time interval, however, caused no aftereffect for visual adaptation but significantly more reports of group motion for

  5. Effects of a Reduced Time-Out Interval on Compliance with the Time-Out Instruction

    ERIC Educational Resources Information Center

    Donaldson, Jeanne M.; Vollmer, Timothy R.; Yakich, Theresa M.; Van Camp, Carole

    2013-01-01

    Time-out is a negative punishment procedure that parents and teachers commonly use to reduce problem behavior; however, specific time-out parameters have not been evaluated adequately. One parameter that has received relatively little attention in the literature is the mode of administration (verbal or physical) of time-out. In this study, we…

  6. Proceedings of the Sixteenth Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The effects of ionospheric and tropospheric propagation on time and frequency transfer, advances in the generation of precise time and frequency, time transfer techniques and filtering and modeling were among the topics emphasized. Rubidium and cesium frequency standard, crystal oscillators, masers, Kalman filters, and atomic clocks were discussed.

  7. The Initial Systolic Time Interval in patients with spinal cord injury measured with impedance cardiography

    NASA Astrophysics Data System (ADS)

    Hoekstra, Femke; Martinsen, Ørjan G.; Verdaasdonk, Rudolf M.; Janssen, Thomas W. J.; Meijer, Jan H.

    2012-12-01

    The Initial Systolic Time Interval (ISTI), obtained from the electrocardiogram and impedance cardiogram, is considered to be a measure for the time delay between the electrical and mechanical activity of the heart. This time delay is influenced by the sympathetic nerve system. Therefore, an observational study was performed in a group of patients (SCI) with spinal cord injuries. The relationship between the ISTI and the total heart cycle (RR-interval) was established by varying the RR-interval using an exercise stimulus to increase the heart rate. The slope of this relationship was observed to be significantly higher in the SCI-group as compared with a control group, although there was no difference in ISTI in the range of common heart rates during the test between the groups. This slope and the ISTI was observed to be significantly different in an acute patient having a recent spinal cord injury at a high level. Because of the variety in injury levels and incompleteness of the injuries further, more specific research is necessary to draw decisive conclusions with respect to the contribution of autonomic nervous control on the ISTI in SCI, although the present observations are notable.

  8. Time on timing: Dissociating premature responding from interval sensitivity in Parkinson's disease

    PubMed Central

    Nombela, Cristina; Wolpe, Noham; Barker, Roger A.; Rowe, James B.

    2016-01-01

    ABSTRACT Background Parkinson's disease (PD) can cause impulsivity with premature responses, but there are several potential mechanisms. We proposed a distinction between poor decision‐making and the distortion of temporal perception. Both effects may be present and interact, but with different clinical and pharmacological correlates. Objectives This study assessed premature responding during time perception in PD. Methods In this study, 18 PD patients and 19 age‐matched controls completed 2 temporal discrimination tasks (bisection and trisection) and a baseline reaction‐time task. Timing sensitivity and decision‐making processes were quantified by response and response time. An extended version of the modified difference model was used to examine the precision of time representation and the modulation of response time by stimulus ambiguity. Results In the bisection task, patients had a lower bisection point (P < .05) and reduced timing sensitivity when compared with controls (P < .001). In the trisection task, patients showed lower sensitivity in discriminating between short and medium standards (P < .05). The impairment in timing sensitivity correlated positively with patients' levodopa dose equivalent (P < .05). Critically, patients had disproportionately faster response times when compared with controls in more ambiguous conditions, and the degree of acceleration of response time increased with disease severity (P < .05). Computational modeling indicated that patients had poorer precision in time representation and stronger modulation of response time by task ambiguity, leading to smaller scaling of the decision latency (P < .05). Conclusions These findings suggest that timing deficits in PD cannot be solely attributed to perceptual distortions, but are also associated with impulsive decision strategies that bias patients toward premature responses. © 2016 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on

  9. Model for the respiratory modulation of the heart beat-to-beat time interval series

    NASA Astrophysics Data System (ADS)

    Capurro, Alberto; Diambra, Luis; Malta, C. P.

    2005-09-01

    In this study we present a model for the respiratory modulation of the heart beat-to-beat interval series. The model consists of a set of differential equations used to simulate the membrane potential of a single rabbit sinoatrial node cell, excited with a periodic input signal with added correlated noise. This signal, which simulates the input from the autonomous nervous system to the sinoatrial node, was included in the pacemaker equations as a modulation of the iNaK current pump and the potassium current iK. We focus at modeling the heart beat-to-beat time interval series from normal subjects during meditation of the Kundalini Yoga and Chi techniques. The analysis of the experimental data indicates that while the embedding of pre-meditation and control cases have a roughly circular shape, it acquires a polygonal shape during meditation, triangular for the Kundalini Yoga data and quadrangular in the case of Chi data. The model was used to assess the waveshape of the respiratory signals needed to reproduce the trajectory of the experimental data in the phase space. The embedding of the Chi data could be reproduced using a periodic signal obtained by smoothing a square wave. In the case of Kundalini Yoga data, the embedding was reproduced with a periodic signal obtained by smoothing a triangular wave having a rising branch of longer duration than the decreasing branch. Our study provides an estimation of the respiratory signal using only the heart beat-to-beat time interval series.

  10. The time lag and interval of discharge with a spring actuated fuel injection pump

    NASA Technical Reports Server (NTRS)

    Matthews, Robertson; Gardiner, A W

    1923-01-01

    Discussed here is research on a spring activated fuel pump for solid or airless injection with small, high speed internal combustion engines. The pump characteristics under investigation were the interval of fuel injection in terms of degrees of crank travel and in absolute time, the lag between the time the injection pump plunger begins its stroke and the appearance of the jet at the orifice, and the manner in which the fuel spray builds up to a maximum when the fuel valve is opened, and then diminishes.

  11. Automatic identification of fetal breathing movements in fetal RR interval time series.

    PubMed

    Van Leeuwen, Peter; Voss, Anna; Cysarz, Dirk; Edelhäuser, Friedrich; Grönemeyer, Dietrich

    2012-03-01

    Fetal breathing movements are associated with respiratory sinus arrhythmia (RSA). We present an algorithm which processes RR interval time series in the time and frequency domain, identifying spectral peaks with characteristics consistent with fetal RSA. Tested on 50 data sets from the second and third trimester, the algorithm had a sensitivity of 96.1%, false positive rate 35.7%, false negative rate 3.9%. The characteristics of automatically and visually identified episodes were very similar and corresponded the expected changes over gestation. The method is suited for easy and reliable identification of fetal breathing movements. PMID:21621759

  12. Time interval moderates the relationship between psyching-up and actual sprint performance.

    PubMed

    Hammoudi-Nassib, Sarra; Chtara, Moktar; Nassib, Sabri; Briki, Walid; Hammoudi-Riahi, Sabra; Tod, David; Chamari, Karim

    2014-11-01

    This study attempted to test whether the strongest effect of psyching-up (PU) strategy on actual sprint performance can be observed when the strategy is used immediately (or almost) before performance compared with when there is a delay between PU and performance. To do so, 16 male sprinters (age, 20.6 ± 1.3 years; body mass, 77.5 ± 7.1 kg; height, 180.8 ± 5.6 cm) were enrolled in a counterbalanced experimental design in which participants were randomly assigned to 10 sessions (2 [Experimental Condition: imagery vs. distraction] × 5 [Time Intervals: no interval, 1 minute, 2 minutes, 3 minutes, and 5 minutes]). Before performing the experimental tasks, participants rated: (a) the Hooper index, (b) their degree of self-confidence, and (c) after the completion of the experimental test; they rated their perceived effort. Findings showed that the imagery significantly improved sprint performance. Specifically, the imagery enhanced performance on the phase of acceleration (0-10 m) and on the overall sprint (0-30 m) when used immediately before performance and at 1- and 2-minute intervals but not for 3- and 5-minute intervals. These findings support the hypothesis that the potential effect of the PU strategy on performance vanishes over time. The pre-experimental task Hooper and self-efficacy indexes did not change across the 10 experimental sessions, reinforcing the view that the observed performance changes were directly caused by the experimental manipulation and not through any altered status of the athletes (self-efficacy, fatigue/recovery, and stress). The potential mechanisms underlying such a process and practical applications are discussed. PMID:25029002

  13. A BiCMOS time interval digitizer based on fully-differential, current-steering circuits

    SciTech Connect

    Loinaz, M.J.; Wooley, B.A. . Center for Integrated Systems)

    1994-06-01

    A time interval digitizer cell with a 0--16 ns input range and a nominal LSB width of 1.0 ns has been integrated in a 2-[mu]m BiCMOS technology. The circuit exhibits both integral and differential nonlinearity below 0.15 LSB and a timing error of 0.32 ns RMS. Logic gate propagation delays are used as time measurement units, and the nominal value of the delays is set by an on-chip phase-locked loop (PLL). Fully-differential, current-steering circuits with low voltage swings are used to implement the time interval digitizer so as to generate minimal switching noise. The cell is to be used in the monolithic, multi-channel realization of a high-sensitivity, mixed-signal data acquisition front-end. By virtue of the time digitization architecture used, the average power dissipation of the cell is only 19.8 mW, despite the use of circuits that dissipate static power, and the layout area is a compact 448 [mu]m x 634 [mu]m.

  14. Time and again: effects of repetition and retention interval on 2 year olds' event recall.

    PubMed

    Fivush, R; Hamond, N R

    1989-04-01

    How and what very young children remember is a central question for understanding the course of memory development. In this research, we examined the effects of two factors on 2-year-old children's ability to recall novel events: repetition of the experience and time since experience. Twenty 24-month-old and twenty 28-month-old children participated in unusual laboratory play events. Half of the children returned after a 2-week delay and again after a 3-month delay (repeated experience condition); the remaining children returned only after 3 months (single experience condition). Memory was assessed by asking children to reenact the events. Recall was generally accurate, and there were no significant effects of age. All children recalled more information about the activities associated with the event than about the objects. Surprisingly, children in the repeated experience condition recalled as much about the events at the 3-month retention interval as at the 2-week retention interval. Further, children in this condition recalled more information at the 3-month retention interval than children in the single experience condition, suggesting that reexperiencing an event may guard against long-term forgetting. PMID:2703807

  15. Effect of Variations in IRU Integration Time Interval On Accuracy of Aqua Attitude Estimation

    NASA Technical Reports Server (NTRS)

    Natanson, G. A.; Tracewell, Dave

    2003-01-01

    During Aqua launch support, attitude analysts noticed several anomalies in Onboard Computer (OBC) rates and in rates computed by the ground Attitude Determination System (ADS). These included: 1) periodic jumps in the OBC pitch rate every 2 minutes; 2) spikes in ADS pitch rate every 4 minutes; 3) close agreement between pitch rates computed by ADS and those derived from telemetered OBC quaternions (in contrast to the step-wise pattern observed for telemetered OBC rates); 4) spikes of +/- 10 milliseconds in telemetered IRU integration time every 4 minutes (despite the fact that telemetered time tags of any two sequential IRU measurements were always 1 second apart from each other). An analysis presented in the paper explains this anomalous behavior by a small average offset of about 0.5 +/- 0.05 microsec in the time interval between two sequential accumulated angle measurements. It is shown that errors in the estimated pitch angle due to neglecting the aforementioned variations in the integration time interval by the OBC is within +/- 2 arcseconds. Ground attitude solutions are found to be accurate enough to see the effect of the variations on the accuracy of the estimated pitch angle.

  16. Combination of equiprobable symbolization and time reversal asymmetry for heartbeat interval series analysis

    NASA Astrophysics Data System (ADS)

    Hou, Fengzhen; Huang, Xiaolin; Chen, Ying; Huo, Chengyu; Liu, Hongxing; Ning, Xinbao

    2013-01-01

    Symbolic dynamics method and time reversal asymmetry analysis are both important approaches in the study of heartbeat interval series. However, there is limited research work reported on combining these two methods. We provide a method of time reversal asymmetry analysis which focuses on the differences between the forward and backward embedding “m words” after the operation of equiprobable symbolization. To investigate the total amplitude as well as the distribution features of the difference, four indices are proposed. Based on the application to simulation series, we found that these measures can successfully detect time reversal asymmetry in chaos series. With application to human heartbeat interval series (RR series), it is suggested that the distribution features of the forward-backward difference can sensitively capture the dynamical changes caused by diseases or aging. In particular, the index ED, which reflects the random degree of the forward-backward difference distribution, can significantly discriminate healthy subjects from diseased ones. We conclude that RR series from healthy subjects show more asymmetry in temporal structure on the original time scale from the perspective of equiprobable symbolization, whereas diseases account for loss of this asymmetry.

  17. The delayed reproduction of long time intervals defined by innocuous thermal sensation.

    PubMed

    Khoshnejad, Mina; Martinu, Kristina; Grondin, Simon; Rainville, Pierre

    2016-04-01

    The presence of discrete events during an interval to be estimated generally causes a dilation of perceived duration (event-filling effect). Here, we investigated this phenomenon in the thermal modality using multi-seconds (19 s) innocuous cool stimuli that were either constant (continuous interval) or fluctuating to create three discrete sensory events (segmented interval). Moreover, we introduced a delay following stimulus offset, before the reproduction phase, to allow for a direct comparison with our recent study showing an underestimation of duration in a delayed reproduction task of heat pain sensations (Khoshnejad et al. in Pain 155:581-590, 2014. doi: 10.1016/j.pain.2013.12.015 ). The event-filling effect was tested by comparing the delayed reproduction of the segmented and the continuous stimuli in experimental conditions asking participants to (1) reproduce the dynamics of the sensation (i.e., changes in sensory intensity over time) or (2) reproduce only the interval duration (i.e., sensation onset-to-offset). A perceptual (control) condition required participants to report changes in sensation concurrently with the stimulus. Results of the dynamic task confirmed the underestimation of duration in the delayed reproduction task, but this effect was only found with the continuous and not with the segmented stimulus. This implies that the dilation of duration produced by segmentation might compensate for the underestimation of duration in this delayed reproduction task. However, this temporal dilation effect was only observed when participants were required to attend and reproduce the dynamics of sensation. These results suggest that the event-filling effect can be observed in the thermal sensory modality and that attention directed toward changes in sensory intensity might contribute to this effect. PMID:26724930

  18. The impact of different sampling rates and calculation time intervals on ROTI values

    NASA Astrophysics Data System (ADS)

    Jacobsen, Knut Stanley

    2014-11-01

    The ROTI (Rate of TEC index) is a commonly used measure of ionospheric irregularities level. The algorithm to calculate ROTI is easily implemented, and is the same from paper to paper. However, the sample rate of the GNSS data used, and the time interval over which a value of ROTI is calculated, varies from paper to paper. When comparing ROTI values from different studies, this must be taken into account. This paper aims to show what these differences are, to increase the awareness of this issue. We have investigated the effect of different parameters for the calculation of ROTI values, using one year of data from 8 receivers at latitudes ranging from 59° N to 79° N. We have found that the ROTI values calculated using different parameter choices are strongly positively correlated. However, the ROTI values are quite different. The effect of a lower sample rate is to lower the ROTI value, due to the loss of high-frequency parts of the ROT spectrum, while the effect of a longer calculation time interval is to remove or reduce short-lived peaks due to the inherent smoothing effect. The ratio of ROTI values based on data of different sampling rate is examined in relation to the ROT power spectrum. Of relevance to statistical studies, we find that the median level of ROTI depends strongly on sample rate, strongly on latitude at auroral latitudes, and weakly on time interval. Thus, a baseline "quiet" or "noisy" level for one location or choice or parameters may not be valid for another location or choice of parameters.

  19. Dimensional regularization of the path integral in curved space on an infinite time interval

    NASA Astrophysics Data System (ADS)

    Bastianelli, F.; Corradini, O.; van Nieuwenhuizen, P.

    2000-09-01

    We use dimensional regularization to evaluate quantum mechanical path integrals in arbitrary curved spaces on an infinite time interval. We perform 3-loop calculations in Riemann normal coordinates, and 2-loop calculations in general coordinates. It is shown that one only needs a covariant two-loop counterterm (VDR=ℏ2/8R) to obtain the same results as obtained earlier in other regularization schemes. It is also shown that the mass term needed in order to avoid infrared divergences explicitly breaks general covariance in the final result.

  20. [Fetal systolic time intervals in threatened premature labor and their relation to therapeutic efforts].

    PubMed

    Ruckhäberle, K E; Vogtmann, C; Forberg, J; Viehweg, B; Chaikha, S

    1989-01-01

    In a total of 113 single pregnancies we determined foetal systolic time intervals (pre-ejection period, left ventricular ejection time, a quotient of both) in order to investigate the impact of threatened premature labour and the different therapeutic regimen (betamimetics, maternal O2-inhalation, maternal transcutaneous dorsal nerve stimulation) on the myocardial performance capacity. Prolonged systolic time intervals (significant for pre-ejection period) in threatened premature labour (compared with control) supplement the concept of a chronic respiratory impairment of the foe-to-materno-placental relationships. Therapeutic prolongation of the pregnancy by betamimetics led to further impairment of the myocardial contractility while additional oxygen inhalation brought about a positive effect. As indicated by "no changes" after transcutaneous dorsal nerve stimulation, the decisive effect apparently seems not to be in the improvement of the uteroplacental perfusion but more on the direct influence of the raised O2-provision on the foetal myocardium. Non-demonstrable obvious relations to the cardiotocographic findings, such as to the postnatal evaluation criteria, speak against a serious threat to the foetus as the advantages of a reasonable prolongation of the gestational period by betamimetics preponderate. More than that the foetal myocardial impairments are to be favourably influenced by additional O2-therapy. PMID:2669398

  1. Comparative evaluation of nickel discharge from brackets in artificial saliva at different time intervals

    PubMed Central

    Jithesh, C.; Venkataramana, V.; Penumatsa, Narendravarma; Reddy, S. N.; Poornima, K. Y.; Rajasigamani, K.

    2015-01-01

    Objectives: To determine and compare the potential difference of nickel release from three different orthodontic brackets, in different artificial pH, in different time intervals. Materials and Methods: Twenty-seven samples of three different orthodontic brackets were selected and grouped as 1, 2, and 3. Each group was divided into three subgroups depending on the type of orthodontic brackets, salivary pH and the time interval. The Nickel release from each subgroup were analyzed by using inductively coupled plasma-Atomic Emission Spectrophotometer (Perkin Elmer, Optima 2100 DV, USA) model. Quantitative analysis of nickel was performed three times, and the mean value was used as result. ANOVA (F-test) was used to test the significant difference among the groups at 0.05 level of significance (P < 0.05). The descriptive method of statistics was used to calculate the mean, standard deviation, minimum and maximum. SPSS 18 software ((SPSS.Ltd, Quarry bay, Hong Kong, PASW-statistics 18) was used to analyze the study. Result: The analysis shows a significant difference between three groups. The study shows that the nickel releases from the recycled stainless steel brackets have the highest at all 4.2 pH except in 120 h. Conclusion: The study result shows that the nickel release from the recycled stainless steel brackets is highest. Metal slot ceramic bracket release significantly less nickel. So, recycled stainless steel brackets should not be used for nickel allergic patients. Metal slot ceramic brackets are advisable. PMID:26538924

  2. Assessing the Impact of Different Measurement Time Intervals on Observed Long-Term Wind Speed Trends

    NASA Astrophysics Data System (ADS)

    Azorin-Molina, C.; Vicente-Serrano, S. M.; McVicar, T.; Jerez, S.; Revuelto, J.; López Moreno, J. I.

    2014-12-01

    During the last two decades climate studies have reported a tendency toward a decline in measured near-surface wind speed in some regions of Europe, North America, Asia and Australia. This weakening in observed wind speed has been recently termed "global stilling", showing a worldwide average trend of -0.140 m s-1 dec-1 during last 50-years. The precise cause of the "global stilling" remains largely uncertain and has been hypothetically attributed to several factors, mainly related to: (i) an increasing surface roughness (i.e. forest growth, land use changes, and urbanization); (ii) a slowdown in large-scale atmospheric circulation; (iii) instrumental drifts and technological improvements, maintenance, and shifts in measurements sites and calibration issues; (iv) sunlight dimming due to air pollution; and (v) astronomical changes. This study proposed a novel investigation aimed at analyzing how different measurement time intervals used to calculate a wind speed series can affect the sign and magnitude of long-term wind speed trends. For instance, National Weather Services across the globe estimate daily average wind speed using different time intervals and formulae that may affect the trend results. Firstly, we carried out a comprehensive review of wind studies reporting the sign and magnitude of wind speed trend and the sampling intervals used. Secondly, we analyzed near-surface wind speed trends recorded at 59 land-based stations across Spain comparing monthly mean wind speed series obtained from: (a) daily mean wind speed data averaged from standard 10-min mean observations at 0000, 0700, 1300 and 1800 UTC; and (b) average wind speed of 24 hourly measurements (i.e., wind run measurements) from 0000 to 2400 UTC. Thirdly and finally, we quantified the impact of anemometer drift (i.e. bearing malfunction) by presenting preliminary results (1-year of paired measurements) from a comparison of one new anemometer sensor against one malfunctioned anenometer sensor due

  3. Time interval measurement device based on surface acoustic wave filter excitation, providing 1 ps precision and stability

    NASA Astrophysics Data System (ADS)

    Panek, Petr; Prochazka, Ivan

    2007-09-01

    This article deals with the time interval measurement device, which is based on a surface acoustic wave (SAW) filter as a time interpolator. The operating principle is based on the fact that a transversal SAW filter excited by a short pulse can generate a finite signal with highly suppressed spectra outside a narrow frequency band. If the responses to two excitations are sampled at clock ticks, they can be precisely reconstructed from a finite number of samples and then compared so as to determine the time interval between the two excitations. We have designed and constructed a two-channel time interval measurement device which allows independent timing of two events and evaluation of the time interval between them. The device has been constructed using commercially available components. The experimental results proved the concept. We have assessed the single-shot time interval measurement precision of 1.3ps rms that corresponds to the time of arrival precision of 0.9ps rms in each channel. The temperature drift of the measured time interval on temperature is lower than 0.5ps/K, and the long term stability is better than ±0.2ps/h. These are to our knowledge the best values reported for the time interval measurement device. The results are in good agreement with the error budget based on the theoretical analysis.

  4. Time interval measurement device based on surface acoustic wave filter excitation, providing 1 ps precision and stability.

    PubMed

    Panek, Petr; Prochazka, Ivan

    2007-09-01

    This article deals with the time interval measurement device, which is based on a surface acoustic wave (SAW) filter as a time interpolator. The operating principle is based on the fact that a transversal SAW filter excited by a short pulse can generate a finite signal with highly suppressed spectra outside a narrow frequency band. If the responses to two excitations are sampled at clock ticks, they can be precisely reconstructed from a finite number of samples and then compared so as to determine the time interval between the two excitations. We have designed and constructed a two-channel time interval measurement device which allows independent timing of two events and evaluation of the time interval between them. The device has been constructed using commercially available components. The experimental results proved the concept. We have assessed the single-shot time interval measurement precision of 1.3 ps rms that corresponds to the time of arrival precision of 0.9 ps rms in each channel. The temperature drift of the measured time interval on temperature is lower than 0.5 ps/K, and the long term stability is better than +/-0.2 ps/h. These are to our knowledge the best values reported for the time interval measurement device. The results are in good agreement with the error budget based on the theoretical analysis. PMID:17902964

  5. Measurements of systolic time intervals using a transoesophageal pulsed echo-Doppler.

    PubMed

    Tournadre, J P; Muchada, R; Lansiaux, S; Chassard, D

    1999-10-01

    Measurement of systolic time intervals (STI), an index of left ventricular (LV) systolic function, is usually labour intensive and requires considerable expertise to perform accurately. We have evaluated the accuracy of an automated, continuous and non-invasive STI measurement technique using a descending aortic blood velocity Doppler signal obtained using a transoesophageal echo-Doppler system (TEDS) and an ECG signal. STI were measured in adult pigs using a transoesophageal probe (4 x 4 mm pulsed wave Doppler transducer, 5-MHz frequency and a 3 x 3 mm echo transducer, 10-MHz frequency) associated with an ECG recorder. Measurements were performed at baseline and after injection of esmolol and dobutamine. TEDS data were compared with those obtained by one-line recordings of the electrocardiogram and the central aortic arterial pressure wave. Similar mean values were observed for pre-ejection period (PEPI), LV ejection time (LVET) and PEP/LVET with the two methods. Agreement between the methods (Bland and Altman's test) was excellent with 95% confidence intervals for PEP, LVET and PEP/LVET of -7.17 to +1.37 ms, -12.64 to +0.24 ms and -0.033 to +0.028, respectively. We conclude that the combination of descending aorta blood velocity Doppler and ECG signal is an alternative technique for non-invasive and objective measurement of STI, allowing continuous monitoring of LV systolic function. PMID:10673883

  6. One-Year Real-Time Operational Prediction Intervals for Direct Normal Irradiance

    NASA Astrophysics Data System (ADS)

    Chu, Y.; Carreira Pedro, H. T.; Coimbra, C. F.

    2015-12-01

    This work describes an algorithm to generate intra-hour prediction intervals (PIs) for the highly-variable direct normal irradiance, which is the energy source for the concentrated solar power technologies. The prediction intervals are generated using a Multi-layer Stochastic-Learning Model (MSLM), which is developed based on methods such as: sky imaging techniques, support vector machine and artificial neural network. The MSLM is trained using one year of co-located, high-quality irradiance and sky image recording in Folsom, California. In addition to being validated with historical data, the algorithm has been generating operational PI forecasts in real-time for that observatory since July 1st 2014. In the real-time scenario, without re-training or significant maintenance, the hybrid model consistently provides valid PI (PICP > 92%) and outperforms the reference persistence model (PICP ~ 85%) regardless of weather condition. This work has great impact in the field of solar energy to potentially facilitate the level of solar penetration in the grid with significantly reduced integration costs.

  7. Detection of abnormal item based on time intervals for recommender systems.

    PubMed

    Gao, Min; Yuan, Quan; Ling, Bin; Xiong, Qingyu

    2014-01-01

    With the rapid development of e-business, personalized recommendation has become core competence for enterprises to gain profits and improve customer satisfaction. Although collaborative filtering is the most successful approach for building a recommender system, it suffers from "shilling" attacks. In recent years, the research on shilling attacks has been greatly improved. However, the approaches suffer from serious problem in attack model dependency and high computational cost. To solve the problem, an approach for the detection of abnormal item is proposed in this paper. In the paper, two common features of all attack models are analyzed at first. A revised bottom-up discretized approach is then proposed based on time intervals and the features for the detection. The distributions of ratings in different time intervals are compared to detect anomaly based on the calculation of chi square distribution (χ(2)). We evaluated our approach on four types of items which are defined according to the life cycles of these items. The experimental results show that the proposed approach achieves a high detection rate with low computational cost when the number of attack profiles is more than 15. It improves the efficiency in shilling attacks detection by narrowing down the suspicious users. PMID:24693248

  8. Pre- and postflight systolic time intervals during LBNP: the second manned Skylab mission.

    PubMed

    Bergman, S A; Hoffler, G W; Johnson, R L; Wolthuis, R A

    1976-04-01

    After space flight of 59 d, Skylab 3 astronauts were stressed with lower body negative pressure (LBNP). During this stress procedure vectorcardiograms, pneumograms, phonocardiograms, and carotid pulse tracings were monitored and recorded onto analog tape. Accepted techniques were used to measure the intervals of systole. The postflight results were compared to multiple preflight tests and each of the three crewmen served as his own control. Immediately postflight, there were elevations in heart rate and blood pressure in response to a fixed level (-50 mm Hg) of LBNP. Total electromechanical systole, (Q-S2) I, was unchanged. Ejection time index (ETI) was depressed at rest and during stress, while pre-ejection period was elevated compared with preflight values. Systolic time intervals (STI) were within preflight limits after 1 month on earth in all crewmen. Resting STI returned sooner than did stressed STI. The magnitude and direction of STI in the postflight period were similar to those obtained from patients with moderate heart disease, although signs and symptoms were absent in the astronauts. However, the abnormality of the stressed STI persisted after both blood volume repletion and lowered afterload. These findings suggest a compromise in cardiac function, peripheral circulatory integrity, or both after exposure to long-duration space flight, and are consistent with findings reported after 3 weeks of absolute bedrest. PMID:1275822

  9. Detection of Abnormal Item Based on Time Intervals for Recommender Systems

    PubMed Central

    Yuan, Quan; Ling, Bin; Xiong, Qingyu

    2014-01-01

    With the rapid development of e-business, personalized recommendation has become core competence for enterprises to gain profits and improve customer satisfaction. Although collaborative filtering is the most successful approach for building a recommender system, it suffers from “shilling” attacks. In recent years, the research on shilling attacks has been greatly improved. However, the approaches suffer from serious problem in attack model dependency and high computational cost. To solve the problem, an approach for the detection of abnormal item is proposed in this paper. In the paper, two common features of all attack models are analyzed at first. A revised bottom-up discretized approach is then proposed based on time intervals and the features for the detection. The distributions of ratings in different time intervals are compared to detect anomaly based on the calculation of chi square distribution (χ2). We evaluated our approach on four types of items which are defined according to the life cycles of these items. The experimental results show that the proposed approach achieves a high detection rate with low computational cost when the number of attack profiles is more than 15. It improves the efficiency in shilling attacks detection by narrowing down the suspicious users. PMID:24693248

  10. Amphetamine affects the start of responding in the peak interval timing task.

    PubMed

    Taylor, Kathleen M; Horvitz, Jon C; Balsam, Peter D

    2007-02-22

    In this paper we investigate how amphetamine affects performance in a PI task by comparing two analyses of responding during peak trials. After training on 24 s fixed interval (FI-24) with 96 s peak trials, rats were given amphetamine for 4 consecutive days at doses of .5 and 1.0 mg/kg. Responses during peak trials were fitted with a Gaussian distribution to estimate the expected time of reinforcement from the peak time. A single trials analysis was also performed to determine the start time and stop time of the transition into and out of a high rate of responding on each peak trial. Amphetamine significantly decreased peak times as measured with the Gaussian curve fitting. However, in the single trials analysis, animals initiated responding significantly earlier, but did not stop responding earlier. Thus, fitting a Gaussian to the average performance across trials sometimes provides a different characterization of the timing process than does analyzing the start and stop of responding on individual trials. In the current experiment, the latter approach provided a more precise characterization of the effects of amphetamine on response timing. PMID:17222991

  11. First-in-human, phase I study of elisidepsin (PM02734) administered as a 30-min or as a 3-hour intravenous infusion every three weeks in patients with advanced solid tumors.

    PubMed

    Ratain, Mark J; Geary, David; Undevia, Samir D; Coronado, Cinthya; Alfaro, Vicente; Iglesias, Jorge L; Schilsky, Richard L; Miguel-Lillo, Bernardo

    2015-08-01

    This first-in-human, phase I clinical trial was designed to determine the dose-limiting toxicities (DLTs) and the dose for phase II trials (P2D) of elisidepsin (PM02734) administered as a 30-min or as a 3-h intravenous infusion every 3 weeks (q3wk). Between March 2006 and April 2011, 53 patients with advanced malignant solid tumors were enrolled and treated with elisidepsin on the two different q3wk infusion schedules: 22 (30-min) and 31 (3-h), respectively. Doses evaluated ranged from 0.1 to 1.6 mg/m(2) (30-min q3wk) and from 2.0 to 11.0 mg flat dose (FD) (3-h q3wk). In the 30-min q3wk schedule, transient grade 3/4 increases in hepatic transaminases were the DLT, which appeared at the highest doses tested (from 1.1 to 1.6 mg/m(2)). No DLTs were observed on the 3-h schedule at doses up to 11.0 mg q3wk. Common adverse events were grade 1/2 pruritus, nausea, fatigue and hypersensitivity. Of note, myelotoxicity was not observed. Plasma maximum concentration and total drug exposure increased linearly with dose. Prolonged (≥3 months) disease stabilization was observed in pretreated patients with pleural mesothelioma (n = 1) in the 30-min q3wk arm, and with colorectal adenocarcinoma (n = 3), esophagus adenocarcinoma, endometrium adenocarcinoma, pleural mesothelioma, and head and neck carcinoma (n = 1 each) in the 3-h q3wk arm. In conclusion, elisidepsin doses of 1.1 mg/m(2) (equivalent to a FD of 2.0 mg) and 11.0 mg FD are the dose levels achieved for further phase II trials testing the 30-min q3wk and 3-h q3wk schedules, respectively. PMID:25947566

  12. First passage time distribution of a modified fractional diffusion equation in the semi-infinite interval

    NASA Astrophysics Data System (ADS)

    Guo, Gang; Chen, Bin; Zhao, Xinjun; Zhao, Fang; Wang, Quanmin

    2015-09-01

    We investigate the first passage time (FPT) distribution for accelerating subdiffusion governed by the modified fractional diffusion equation which has a secondary fractional time derivative acting on a diffusion operator. For the FPT problem subject to absorbing barrier condition, we obtain exact analytical expressions for the FPT distribution as well as its Laplace transform in the semi-infinite interval. Most of the results have been derived by using the Laplace transform, the Fourier Cosine transform, the Mellin transform and the properties of the Fox H-function. In contrast to the Laplace transform of the FPT distribution which can be expressed elegantly and neatly, the exact solution for the FPT distribution requires an infinite series of Fox H-functions instead of a single Fox H-function. Numerical result reveals that the crossover between the two distinct scaling regimes is apparent only when the discrepancy between the two diffusion exponents becomes more pronounced.

  13. Pigeons' wait-time responses to transitions in interfood-interval duration: Another look at cyclic schedule performance

    PubMed Central

    Higa, Jennifer J.; Thaw, Jean M.; Staddon, John E. R.

    1993-01-01

    Recent developments reveal that animals can rapidly learn about intervals of time. We studied the nature of this fast-acting process in two experiments. In Experiment 1 pigeons were exposed to a modified fixed-time schedule, in which the time between food rewards (interfood interval) changed at an unpredictable point in each session, either decreasing from 15 to 5 s (step-down) or increasing from 15 to 45 s (step-up). The birds were able to track under both conditions by producing postreinforcement wait times proportional to the preceding interfood-interval duration. However, the time course of responding differed: Tracking was apparently more gradual in the step-up condition. Experiment 2 studied the effect of having both kinds of transitions within the same session by exposing pigeons to a repeating (cyclic) sequence of the interfood-interval values used in Experiment 1. Pigeons detected changes in the input sequence of interfood intervals, but only for a few sessions—discrimination worsened with further training. The dynamic effects we observed do not support a linear waiting process of time discrimination, but instead point to a timing mechanism based on the frequency and recency of prior interfood intervals and not the preceding interfood interval alone. PMID:16812693

  14. Continuous-time interval model identification of blood glucose dynamics for type 1 diabetes

    NASA Astrophysics Data System (ADS)

    Kirchsteiger, Harald; Johansson, Rolf; Renard, Eric; del Re, Luigi

    2014-07-01

    While good physiological models of the glucose metabolism in type 1 diabetic patients are well known, their parameterisation is difficult. The high intra-patient variability observed is a further major obstacle. This holds for data-based models too, so that no good patient-specific models are available. Against this background, this paper proposes the use of interval models to cover the different metabolic conditions. The control-oriented models contain a carbohydrate and insulin sensitivity factor to be used for insulin bolus calculators directly. Available clinical measurements were sampled on an irregular schedule which prompts the use of continuous-time identification, also for the direct estimation of the clinically interpretable factors mentioned above. An identification method is derived and applied to real data from 28 diabetic patients. Model estimation was done on a clinical data-set, whereas validation results shown were done on an out-of-clinic, everyday life data-set. The results show that the interval model approach allows a much more regular estimation of the parameters and avoids physiologically incompatible parameter estimates.

  15. Cumulative Instructional Time and Relative Effectiveness Conclusions: Extending Research on Response Intervals, Learning, and Measurement Scale.

    PubMed

    Black, Michelle P; Skinner, Christopher H; Forbes, Bethany E; McCurdy, Merilee; Coleman, Mari Beth; Davis, Kristie; Gettelfinger, Maripat

    2016-03-01

    Adapted alternating treatments designs were used to evaluate three computer-based flashcard reading interventions (1-s, 3-s, or 5-s response intervals) across two students with disabilities. When learning was plotted with cumulative instructional sessions on the horizontal axis, the session-series graphs suggest that the interventions were similarly effective. When the same data were plotted as a function of cumulative instructional seconds, time-series graphs suggest that the 1-s intervention caused the most rapid learning for one student. Discussion focuses on applied implications of comparative effectiveness studies and why measures of cumulative instructional time are needed to identify the most effective intervention(s).Comparative effectiveness studies may not identify the intervention which causes the most rapid learning.Session-series repeated measures are not the same as time-series repeated measures.Measuring the time students spend in each intervention (i.e., cumulative instructional seconds) allows practitioners to identify interventions that enhance learning most rapidly.Student time spent working under interventions is critical for drawing applied conclusions. PMID:27606240

  16. On the gap and time interval between the first two maxima of long continuous time random walks

    NASA Astrophysics Data System (ADS)

    Mounaix, Philippe; Schehr, Grégory; Majumdar, Satya N.

    2016-01-01

    We consider a one-dimensional continuous time random walk (CTRW) on a fixed time interval T where at each time step the walker waits a random time τ, before performing a jump drawn from a symmetric continuous probability distribution function (PDF) f(η ) , of Lévy index 0<μ ≤slant 2 . Our study includes the case where the waiting time PDF \\Psi(τ ) has a power law tail, \\Psi(τ )\\propto {τ-1-γ} , with 0<γ <1 , such that the average time between two consecutive jumps is infinite. The random motion is sub-diffusive if γ <μ /2 (and super-diffusive if γ >μ /2 ). We investigate the joint PDF of the gap g between the first two highest positions of the CTRW and the time t separating these two maxima. We show that this PDF reaches a stationary limiting joint distribution p(g, t) in the limit of long CTRW, T\\to ∞ . Our exact analytical results show a very rich behavior of this joint PDF in the (γ,μ ) plane, which we study in great detail. Our main results are verified by numerical simulations. This work provides a non trivial extension to CTRWs of the recent study in the discrete time setting by Majumdar et al (2014 J. Stat. Mech. P09013).

  17. Robust reliable guaranteed cost control of positive interval systems with multiple time delays and actuator failure

    NASA Astrophysics Data System (ADS)

    Zhang, Ji-Shi; Wang, Yan-Wu; Xiao, Jiang-Wen; Chen, Yang

    2016-03-01

    This paper addresses the robust reliable guaranteed cost control problem of positive interval systems with multiple time delays and actuator failure for a given quadratic cost function. Through constructing a Lyapunov-Krasovskii functional, a sufficient condition for the existence of robust reliable guaranteed cost controllers is established such that the closed-loop system is positive and asymptotically stable, and the cost function is guaranteed to be no more than a certain upper bound. Based on the linear matrix inequality method, a criterion for the design of robust reliable guaranteed cost controllers is derived which can tolerate all admissible uncertainties as well as actuator failure. Moreover, a convex optimisation problem with linear matrix inequality constraints is formulated to design the optimal robust reliable guaranteed cost controller which minimises the upper bound of the closed-loop system cost. A numerical example is given to show the effectiveness of the proposed methods.

  18. Variable interval time/temperature (VITT) defrost-control-system evaluation

    SciTech Connect

    1980-08-12

    Two variable-interval-time/temperature (VITT) heat pump defrost control systems are analyzed to determine if systems manufactured by Honeywell and Ranco qualify for credit for heat pumps with demand defrost control. The operation of the systems is described. VITT controls are not demand defrost control systems but utilize demand defrost control as backup systems in most Ranco models and all Honeywell models. The evaluations and results, intended to provide DOE information in making its determinations regarding credits for the control systems are discussed. The evaluation methodology utilizes a modified version of the Heat Pump Seasonal Performance Model (HPSPM) and the important modifications are discussed in Appendix A. Appendix B contains a detailed listing and discussion of the HPSPM output. (MCW)

  19. A novel implementation of homodyne time interval analysis method for primary vibration calibration

    NASA Astrophysics Data System (ADS)

    Sun, Qiao; Zhou, Ling; Cai, Chenguang; Hu, Hongbo

    2011-12-01

    In this paper, the shortcomings and their causes of the conventional homodyne time interval analysis (TIA) method is described with respect to its software algorithm and hardware implementation, based on which a simplified TIA method is proposed with the help of virtual instrument technology. Equipped with an ordinary Michelson interferometer and dual channel synchronous data acquisition card, the primary vibration calibration system using the simplified method can perform measurements of complex sensitivity of accelerometers accurately, meeting the uncertainty requirements laid down in pertaining ISO standard. The validity and accuracy of the simplified TIA method is verified by simulation and comparison experiments with its performance analyzed. This simplified method is recommended to apply in national metrology institute of developing countries and industrial primary vibration calibration labs for its simplified algorithm and low requirements on hardware.

  20. A sediment budget for southern Lake Michigan: source and sink models for different time intervals

    USGS Publications Warehouse

    Colman, Steven M.; Foster, D.S.

    1994-01-01

    Two terms dominate the modern sediment-budget equation: (1) bluff erosion, which is an order of magnitude larger than either rivers or aerosols as a source, and (2) deposition in the deep basin, which is more than two orders of magnitude greater as a sink than suspended sediment transport out of the basin. The attempt to reconstruct sediment budgets for time intervals of 100, 5000, and 10 000 years leads to important insights about erosion and sedimentation processes. Bluff erosion is the dominant source of both sand and mud in the basin. The deep lake floor is the primary sink for mud, whereas both the deep lake and nearshore areas are important sinks for sand. -from Authors

  1. Optimal time interval between capecitabine intake and radiotherapy in preoperative chemoradiation for locally advanced rectal cancer

    SciTech Connect

    Yu, Chang Sik; Kim, Tae Won; Kim, Jong Hoon . E-mail: jhkim2@amc.seoul.kr; Choi, Won Sik; Kim, Hee Cheol; Chang, Heung Moon; Ryu, Min Hee; Jang, Se Jin; Ahn, Seung Do; Lee, Sang-wook; Shin, Seong Soo; Choi, Eun Kyung; Kim, Jin Cheon

    2007-03-15

    Purpose: Capecitabine and its metabolites reach peak plasma concentrations 1 to 2 hours after a single oral administration, and concentrations rapidly decrease thereafter. We performed a retrospective analysis to find the optimal time interval between capecitabine administration and radiotherapy for rectal cancer. Methods and Materials: The time interval between capecitabine intake and radiotherapy was measured in patients who were treated with preoperative radiotherapy and concurrent capecitabine for rectal cancer. Patients were classified into the following groups. Group A1 included patients who took capecitabine 1 hour before radiotherapy, and Group B1 included all other patients. Group B1 was then subdivided into Group A2 (patients who took capecitabine 2 hours before radiotherapy) and Group B2. Group B2 was further divided into Group A3 and Group B3 with the same method. Total mesorectal excision was performed 6 weeks after completion of chemoradiation and the pathologic response was evaluated. Results: A total of 200 patients were enrolled in this study. Pathologic examination showed that Group A1 had higher rates of complete regression of primary tumors in the rectum (23.5% vs. 9.6%, p = 0.01), good response (44.7% vs. 25.2%, p = 0.006), and lower T stages (p = 0.021) compared with Group B1; however, Groups A2 and A3 did not show any improvement compared with Groups B2 and B3. Multivariate analysis showed that increases in primary tumors in the rectum and good response were only significant when capecitabine was administered 1 hour before radiotherapy. Conclusion: In preoperative chemoradiotherapy for rectal cancer, the pathologic response could be improved by administering capecitabine 1 hour before radiotherapy.

  2. Protein supplementation during a short-interval prostaglandin-based protocol for timed AI in sheep.

    PubMed

    Fierro, S; Gil, J; Viñoles, C; Soca, F; Banchero, G; Olivera-Muzante, J

    2014-10-01

    The aim of this experiment was to improve the reproductive performance of a short-interval prostaglandin (PG)-based protocol for timed artificial insemination in sheep, using a short-term nutritional treatment. During the breeding season (March-April), 132 multiparous and 61 nulliparous Corriedale ewes grazing natural pastures (600 kg DM/ha, 8.5% CP), were allocated to two groups: 1, Control group (n=100) two injections of D-Cloprostenol (75 μg per dose, 7d apart: Synchrovine(®) protocol); and 2, Supplemented group (n=93) ewes in which stage of the oestrous cycle was synchronised with Synchrovine(®) protocol plus focus feeding of a protein supplement (33.8% CP) between PG doses (Day -7 to -2). Cervical AI was performed at fixed time (Day 0), 46 ± 1.0 h after the second PG injection using 150 million sperm per ewe. Ovulation rate (Day 10), pregnancy rate, prolificacy and fecundity at Day 69 were evaluated by ultrasonography. Ovulation rate at Day 10 (1.20 ± 0.05 vs. 1.22 ± 0.05), pregnancy (46 ± 0.05 vs. 56 ± 0.05), prolificacy (1.09 ± 0.04 vs. 1.06 ± 0.05), and fecundity (0.49 ± 0.06 vs. 0.59 ± 0.06) at Day 69, were similar between groups (P>0.05; Control and Supplemented group respectively). It is concluded that focus feeding for 6d with protein supplementation during a short-interval PG-based protocol (Synchrovine(®)) did not improve the reproductive outcome associated with this protocol. PMID:25129637

  3. Reasoning about real-time systems with temporal interval logic constraints on multi-state automata

    NASA Technical Reports Server (NTRS)

    Gabrielian, Armen

    1991-01-01

    Models of real-time systems using a single paradigm often turn out to be inadequate, whether the paradigm is based on states, rules, event sequences, or logic. A model-based approach to reasoning about real-time systems is presented in which a temporal interval logic called TIL is employed to define constraints on a new type of high level automata. The combination, called hierarchical multi-state (HMS) machines, can be used to model formally a real-time system, a dynamic set of requirements, the environment, heuristic knowledge about planning-related problem solving, and the computational states of the reasoning mechanism. In this framework, mathematical techniques were developed for: (1) proving the correctness of a representation; (2) planning of concurrent tasks to achieve goals; and (3) scheduling of plans to satisfy complex temporal constraints. HMS machines allow reasoning about a real-time system from a model of how truth arises instead of merely depending of what is true in a system.

  4. An Efficient Format for Nearly Constant-Time Access to Arbitrary Time Intervals in Large Trace Files

    DOE PAGESBeta

    Chan, Anthony; Gropp, William; Lusk, Ewing

    2008-01-01

    A powerful method to aid in understanding the performance of parallel applications uses log or trace files containing time-stamped events and states (pairs of events). These trace files can be very large, often hundreds or even thousands of megabytes. Because of the cost of accessing and displaying such files, other methods are often used that reduce the size of the tracefiles at the cost of sacrificing detail or other information. This paper describes a hierarchical trace file format that provides for display of an arbitrary time window in a time independent of the total size of the file andmore » roughly proportional to the number of events within the time window. This format eliminates the need to sacrifice data to achieve a smaller trace file size (since storage is inexpensive, it is necessary only to make efficient use of bandwidth to that storage). The format can be used to organize a trace file or to create a separate file of annotations that may be used with conventional trace files. We present an analysis of the time to access all of the events relevant to an interval of time and we describe experiments demonstrating the performance of this file format.« less

  5. Initial Systolic Time Interval (ISTI) as a Predictor of Intradialytic Hypotension (IDH)

    NASA Astrophysics Data System (ADS)

    Biesheuvel, J. D.; Vervloet, M. G.; Verdaasdonk, R. M.; Meijer, J. H.

    2013-04-01

    In haemodialysis treatment the clearance and volume control by the kidneys of a patient are partially replaced by intermittent haemodialysis. Because this artificial process is performed on a limited time scale, unphysiological imbalances in the fluid compartments of the body occur, that can lead to intradialytic hypotensions (IDH). An IDH endangers the efficacy of the haemodialysis session and is associated with dismal clinical endpoints, including mortality. A diagnostic method that predicts the occurrence of these drops in blood pressure could facilitate timely measures for the prevention of IDH. The present study investigates whether the Initial Systolic Time Interval (ISTI) can provide such a diagnostic method. The ISTI is defined as the time difference between the R-peak in the electrocardiogram (ECG) and the C-wave in the impedance cardiogram (ICG) and is considered to be a non-invasive assessment of the time delay between the electrical and mechanical activity of the heart. This time delay has previously been found to depend on autonomic nervous function as well as preload of the heart. Therefore, it can be expected that ISTI may predict an imminent IDH caused by a low circulating blood volume. This ongoing observational clinical study investigates the relationship between changes in ISTI and subsequent drops in blood pressure during haemodialysis. A registration of a complicated dialysis showed a significant correlation between a drop in blood pressure, a decrease in relative blood volume and a substantial increase in ISTI. An uncomplicated dialysis, in which also a considerable amount of fluid was removed, showed no correlations. Both, blood pressure and ISTI remained stable. In conclusion, the preliminary results of the present study show a substantial response of ISTI to haemodynamic instability, indicating an application in optimization and individualisation of the dialysis process.

  6. Probability distributions for quantum stress tensors measured in a finite time interval

    NASA Astrophysics Data System (ADS)

    Fewster, Christopher J.; Ford, L. H.

    2015-11-01

    A meaningful probability distribution for measurements of a quantum stress tensor operator can only be obtained if the operator is averaged in time or in spacetime. This averaging can be regarded as a description of the measurement process. Realistic measurements can be expected to begin and end at finite times, which means that they are described by functions with compact support, which we will also take to be smooth. Here we study the probability distributions for stress tensor operators averaged with such functions of time, in the vacuum state of a massless free field. Our primary aim is to understand the asymptotic form of the distribution which describes the probability of large vacuum fluctuations. Our approach involves asymptotic estimates for the high moments of the distribution. These estimates in turn may be used to obtain estimates for the asymptotic form of the probability distribution. Our results show that averaging over a finite interval results in a probability distribution which falls more slowly than for the case of Lorentzian averaging, and both fall more slowly than exponentially. This indicates that vacuum fluctuations effects can dominate over thermal fluctuations in some circumstances.

  7. Individual Case Analysis of Postmortem Interval Time on Brain Tissue Preservation

    PubMed Central

    Blair, Jeffrey A.; Wang, Chunyu; Hernandez, Damarys; Siedlak, Sandra L.; Rodgers, Mark S.; Achar, Rojan K.; Fahmy, Lara M.; Torres, Sandy L.; Petersen, Robert B.; Zhu, Xiongwei; Casadesus, Gemma; Lee, Hyoung-gon

    2016-01-01

    At autopsy, the time that has elapsed since the time of death is routinely documented and noted as the postmortem interval (PMI). The PMI of human tissue samples is a parameter often reported in research studies and comparable PMI is preferred when comparing different populations, i.e., disease versus control patients. In theory, a short PMI may alleviate non-experimental protein denaturation, enzyme activity, and other chemical changes such as the pH, which could affect protein and nucleic acid integrity. Previous studies have compared PMI en masse by looking at many different individual cases each with one unique PMI, which may be affected by individual variance. To overcome this obstacle, in this study human hippocampal segments from the same individuals were sampled at different time points after autopsy creating a series of PMIs for each case. Frozen and fixed tissue was then examined by Western blot, RT-PCR, and immunohistochemistry to evaluate the effect of extended PMI on proteins, nucleic acids, and tissue morphology. In our results, immunostaining profiles for most proteins remained unchanged even after PMI of over 50 h, yet by Western blot distinctive degradation patterns were observed in different protein species. Finally, RNA integrity was lower after extended PMI; however, RNA preservation was variable among cases suggesting antemortem factors may play a larger role than PMI in protein and nucleic acid integrity. PMID:26982086

  8. A new algorithm for segmentation of cardiac quiescent phases and cardiac time intervals using seismocardiography

    NASA Astrophysics Data System (ADS)

    Jafari Tadi, Mojtaba; Koivisto, Tero; Pänkäälä, Mikko; Paasio, Ari; Knuutila, Timo; Teräs, Mika; Hänninen, Pekka

    2015-03-01

    Systolic time intervals (STI) have significant diagnostic values for a clinical assessment of the left ventricle in adults. This study was conducted to explore the feasibility of using seismocardiography (SCG) to measure the systolic timings of the cardiac cycle accurately. An algorithm was developed for the automatic localization of the cardiac events (e.g. the opening and closing moments of the aortic and mitral valves). Synchronously acquired SCG and electrocardiography (ECG) enabled an accurate beat to beat estimation of the electromechanical systole (QS2), pre-ejection period (PEP) index and left ventricular ejection time (LVET) index. The performance of the algorithm was evaluated on a healthy test group with no evidence of cardiovascular disease (CVD). STI values were corrected based on Weissler's regression method in order to assess the correlation between the heart rate and STIs. One can see from the results that STIs correlate poorly with the heart rate (HR) on this test group. An algorithm was developed to visualize the quiescent phases of the cardiac cycle. A color map displaying the magnitude of SCG accelerations for multiple heartbeats visualizes the average cardiac motions and thereby helps to identify quiescent phases. High correlation between the heart rate and the duration of the cardiac quiescent phases was observed.

  9. Individual Case Analysis of Postmortem Interval Time on Brain Tissue Preservation.

    PubMed

    Blair, Jeffrey A; Wang, Chunyu; Hernandez, Damarys; Siedlak, Sandra L; Rodgers, Mark S; Achar, Rojan K; Fahmy, Lara M; Torres, Sandy L; Petersen, Robert B; Zhu, Xiongwei; Casadesus, Gemma; Lee, Hyoung-Gon

    2016-01-01

    At autopsy, the time that has elapsed since the time of death is routinely documented and noted as the postmortem interval (PMI). The PMI of human tissue samples is a parameter often reported in research studies and comparable PMI is preferred when comparing different populations, i.e., disease versus control patients. In theory, a short PMI may alleviate non-experimental protein denaturation, enzyme activity, and other chemical changes such as the pH, which could affect protein and nucleic acid integrity. Previous studies have compared PMI en masse by looking at many different individual cases each with one unique PMI, which may be affected by individual variance. To overcome this obstacle, in this study human hippocampal segments from the same individuals were sampled at different time points after autopsy creating a series of PMIs for each case. Frozen and fixed tissue was then examined by Western blot, RT-PCR, and immunohistochemistry to evaluate the effect of extended PMI on proteins, nucleic acids, and tissue morphology. In our results, immunostaining profiles for most proteins remained unchanged even after PMI of over 50 h, yet by Western blot distinctive degradation patterns were observed in different protein species. Finally, RNA integrity was lower after extended PMI; however, RNA preservation was variable among cases suggesting antemortem factors may play a larger role than PMI in protein and nucleic acid integrity. PMID:26982086

  10. Brain response during the M170 time interval is sensitive to socially relevant information.

    PubMed

    Arviv, Oshrit; Goldstein, Abraham; Weeting, Janine C; Becker, Eni S; Lange, Wolf-Gero; Gilboa-Schechtman, Eva

    2015-11-01

    Deciphering the social meaning of facial displays is a highly complex neurological process. The M170, an event related field component of MEG recording, like its EEG counterpart N170, was repeatedly shown to be associated with structural encoding of faces. However, the scope of information encoded during the M170 time window is still being debated. We investigated the neuronal origin of facial processing of integrated social rank cues (SRCs) and emotional facial expressions (EFEs) during the M170 time interval. Participants viewed integrated facial displays of emotion (happy, angry, neutral) and SRCs (indicated by upward, downward, or straight head tilts). We found that the activity during the M170 time window is sensitive to both EFEs and SRCs. Specifically, highly prominent activation was observed in response to SRC connoting dominance as compared to submissive or egalitarian head cues. Interestingly, the processing of EFEs and SRCs appeared to rely on different circuitry. Our findings suggest that vertical head tilts are processed not only for their sheer structural variance, but as social information. Exploring the temporal unfolding and brain localization of non-verbal cues processing may assist in understanding the functioning of the social rank biobehavioral system. PMID:26423664

  11. Determination of short-term error caused by the reference clock in precision time-interval measurement and generation

    NASA Astrophysics Data System (ADS)

    Kalisz, Jozef

    1988-06-01

    A simple analysis based on the randomized clock cycle T(o) yields a useful formula on its variance in terms of the Allan variance. The short-term uncertainty of the measured or generated time interval t is expressed by the standard deviation in an approximate form as a function of the Allen variance. The estimates obtained are useful for determining the measurement uncertainty of time intervals within the approximate range of 10 ms-100 s.

  12. Effects of variable sequences of food availability on interval time-place learning by pigeons.

    PubMed

    García-Gallardo, Daniel; Carpio, Claudio

    2016-09-01

    The effects of within session variability of the sequences of food availability in a 16 period Time Place Learning (TPL) task on the performance of pigeons were assessed. Two groups of birds were exposed to two conditions. For group 1 (N=3), the first condition consisted of a TPL task in which food could be obtained according to a Random Interval (RI) 25s schedule of reinforcement in one of four feeders, the correct feeder changed every 3min. The same sequence was repeated four times within every training session (Fixed Sequence). The second condition was exactly the same as the first one with the exception that the sequence in which the correct feeder changed was randomized, yielding a total of four randomized sequences of food availability each session (Variable Sequence). An Open Hopper Test (OHT) was conducted at the end of each condition. Birds in group 2 (N=3) experienced the same conditions but in the reverse order. Results showed high percent correct responses for both group of birds under both conditions. However, birds were able to time the availability period's duration only under the Fixed Sequence condition, as shown by anticipation, anticipation of depletion and persistence of visiting patterns on the OHT. The implications of these results to Gallistels (1990) tripartite time-place-event memory code model are discussed, pointing out that these results are in line with previous findings about the important role that spatial parameters of a TPL task can play, for accurate timing was precluded when a variable sequence was employed. PMID:27425658

  13. Distribution of Seismicity Before the Larger Earthquakes in Italy in the Time Interval 1994-2004

    NASA Astrophysics Data System (ADS)

    Gentili, S.

    2010-08-01

    The Region-Time-Length (RTL) algorithm has been applied to different instrumental catalogues to detect seismic quiescence before medium-to-large earthquakes in Italy in the last two decades. RTL performances are sensitive to the choice of spatial and temporal parameters. The method for automatic parameters selection developed by Chen and Wu has been applied to twelve Italian earthquakes with magnitude greater than 5. The limits of the method in constructing maps of seismic quiescence before the earthquake are demonstrated, and a simple improvement is proposed. Then a new technique, namely RTLsurv, is proposed for routine surveys of the Italian seismicity. RTLsurv has been applied to all the earthquakes with magnitude greater than 4 in the Italian area in the time interval 1994-2004; four different sub-areas have been identified, with different characteristics in the level of recorded seismicity. One subarea—Tyrrhenian Sea—was characterized by a too low level of recorded seismicity for the application of the method. In the other three subareas a seismic quiescence was detected before at least the 66% of the earthquakes with magnitude greater or equal to 4 and all the earthquakes with magnitude greater than 5.

  14. Salt marsh mapping based on a short-time interval NDVI time-series from HJ-1 CCD imagery

    NASA Astrophysics Data System (ADS)

    SUN, C.

    2015-12-01

    Salt marshes are regard as one of the most dynamic and valuable ecosystems in coastal zone. It is crucial to obtain accurate information on the species composition and spatial distribution of salt marshes in time since they are experiencing tremendous replacement and disappearance. However, discriminating various types of salt marshes is a rather difficult task because of the strong spectral similarities. In previous studies, salt marsh mappings were mainly focused on high-spatial and hyperspectral resolution imageries combined with auxiliary information but this method can hardly extend to a large region. With high temporal and moderate spatial resolutions, Chinese HJ-1 CCD imagery would not only allow monitoring phenological changes of salt marsh vegetation in short-time intervals, but also cover large areas of salt marshes. Taking the middle coast of Jiangsu (east China) as an example, our study first constructed a monthly NDVI time-series to classify various types of salt marshes. Then, we tested the idea of compressed time-series continuously to broaden the applicability and portability of this particular approach. The results showed that (1) the overall accuracy of salt marsh mapping based on the monthly NDVI time-series reached 90.3%, which increased approximately 16.0% in contrast with a single-phase classification strategy; (2) a compressed time-series, including NDVI from six key months (April, June to September, and November) demonstrated very little decline (2.3%) in overall accuracy but led to obvious improvements in unstable regions; (3) Spartina alterniflora identification could be achieved with only a scene NDVI image from November, which could provide an effective way to regularly monitor its distribution. Besides, by comparing the calibrated performance between HJ-1 CCD and other sensors (i.e., Landsat TM/ETM+, OLI), we certified the reliability of HJ-1 CCD imagery, which is expected to pave the way for laws expansibility from this imagery.

  15. Induction of mycobacterial proteins during phagocytosis and heat shock: a time interval analysis.

    PubMed

    Alavi, M R; Affronti, L F

    1994-05-01

    Mycobacterium tuberculosis survives macrophage bactericidal activities by mechanisms that may include induction of stress proteins. We sought to determine whether the synthesis of any mycobacterial proteins is increased during phagocytosis and whether any of these proteins are also up-regulated during heat shock. Protein synthesis by M. tuberculosis H37Ra during phagocytosis by the mouse macrophage cell line IC-21, and during heat shock at 45 and 48 degrees C, was monitored at various time intervals using 35S-labeled methionine/cysteine and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Our data suggest the existence of certain common elements in the stress response of mycobacteria to the three stress stimuli. This apparent similarity was best characterized by the up-regulation of a 25-kDa protein after exposure to each of the stress conditions. Furthermore, this 25-kDa protein and a 37-kDa protein that was also synthesized during phagocytosis appeared to be extracellular because they were preferentially solubilized when infected macrophages were lysed with 0.5% NP-40. PMID:8182341

  16. Cardiac systolic time intervals in fetal monkeys: pre-ejection period.

    PubMed

    Murata, Y; Martin, C B; Ikenoue, T; Petrie, R H

    1978-10-01

    The systolic time intervals of the fetal cardiac cycle were studied by means of simultaneous recordings of electrocardiogram (ECG) and ultrasound Doppler cardiogram (DCG) in chronic preparations of fetal rhesus monkeys. Recordings were made under physiologic conditions as well as during various experimental stresses. The pre-ejection period (PEP) showed no significant relationship with heart rate in the unstressed fetuses, but the acceleration of heart rate induced by epinephrine was accompanied by shortening of PEP. The PEP increased with advancing fetal age. The PEP was inversely correlated with left ventricular end-diastolic pressure and arterial pulse pressure, but showed a positive correlation with both systolic and diastolic arterial blood pressure. The PEP also exhibited strong negative correlation with arterial blood pH. the prolongation was essentially the same whether acidosis was of respiratory or metabolic origin. The PEP increased slightly but significantly during nonacidemic hypoxemia; however, there was no correlation between Pao2 and PEP Epinephrine shortened the PEP significantly, whereas the effect of atropine was inconsistent. Alteration of the plasma glucose level by injection of insulin or glucose did not affect PEP. These findings demonstrate that the PEP may be a useful indicator of fetal cardiac performance, reflecting both myocardial contractility and the hemodynamic state of the cardiovascular system. PMID:30282

  17. Behavioral adaptation to fixed-interval and fixed-time food delivery in golden hamsters1

    PubMed Central

    Anderson, Merrill C.; Shettleworth, Sara J.

    1977-01-01

    Food-deprived golden hamsters in a large enclosure received food every 30 sec contingent on lever pressing, or free while their behavior was continuously recorded in terms of an exhaustive classification of motor patterns. As with other species in other situations, behavior became organized into two main classes. One (terminal behaviors) increased in probability throughout interfood intervals; the other (interim behaviors) peaked earlier in interfood intervals. Which class an activity belonged to was independent of whether food was contingent on lever pressing. When food was omitted on some of the intervals (thwarting), the terminal activities began sooner in the next interval, and different interim activities changed in different ways. The interim activities did not appear to be schedule-induced in the usual sense. Rather, the hamsters left the area of the feeder when food was not due and engaged in activities they would normally perform in the experimental environment. PMID:16811980

  18. Corticostriatal Field Potentials Are Modulated at Delta and Theta Frequencies during Interval-Timing Task in Rodents

    PubMed Central

    Emmons, Eric B.; Ruggiero, Rafael N.; Kelley, Ryan M.; Parker, Krystal L.; Narayanan, Nandakumar S.

    2016-01-01

    Organizing movements in time is a critical and highly conserved feature of mammalian behavior. Temporal control of action requires corticostriatal networks. We investigate these networks in rodents using a two-interval timing task while recording LFPs in medial frontal cortex (MFC) or dorsomedial striatum. Consistent with prior work, we found cue-triggered delta (1–4 Hz) and theta activity (4–8 Hz) primarily in rodent MFC. We observed delta activity across temporal intervals in MFC and dorsomedial striatum. Rewarded responses were associated with increased delta activity in MFC. Activity in theta bands in MFC and delta bands in the striatum was linked with the timing of responses. These data suggest both delta and theta activity in frontostriatal networks are modulated during interval timing and that activity in these bands may be involved in the temporal control of action. PMID:27092091

  19. Lethal pedestrian--passenger car collisions in Berlin. Changed injury patterns in two different time intervals.

    PubMed

    Ehrlich, Edwin; Tischer, Anja; Maxeiner, H

    2009-04-01

    To expand the passive safety of automobiles protecting traffic participants technological innovations were done in the last decades. Objective of our retrospective analysis was to examine if these technical modifications led to a clearly changed pattern of injuries of pedestrians whose death was caused by the accidents. Another reduction concerns the exclusion of injured car passengers--only pedestrians walking or standing at the moment of collision were included. We selected time intervals 1975-1985 and 1991-2004 (=years of construction of the involved passenger cars). The cars were classified depending on their frontal construction in types as presented by Schindler et al. [Schindler V, Kühn M, Weber S, Siegler H, Heinrich T. Verletzungsmechanismen und Wirkabschätzungen der Fahrzegfrontgestaltung bei Pkw-Fussgänger-Kollisionen. Abschlussbericht im Auftrag der Deutschen Versicherungswirtschaft e.V. TU-Berlin Fachgebiet Kraftfahrzeuge (GDV) 2004:36-40]. In both periods more than 90% of all cars were from the usual types small/medium/large class. Hundred and thirty-four autopsy records of such cases from Department of Forensic Medicine (Charité Berlin) data were analysed. The data included technical information of the accidents and vehicles and the external and internal injuries of the victims. The comparison of the two periods showed a decrease of serious head injuries and femoral fractures but an increase of chest-, abdominal and pelvic injuries. This situation could be explained by an increased occurrence of soft-face-constructions and changed front design of modern passenger cars, resulting in a favourable effects concerning head impact to the car during accident. Otherwise the same kinetic energy was transferred to the (complete) victim - but because of a displacement of main focus of impact the pattern of injuries modified (went distally). PMID:19261507

  20. An Assessment of Fixed Interval Timing in Free-Flying Honey Bees (Apis mellifera ligustica): An Analysis of Individual Performance

    PubMed Central

    Craig, David Philip Arthur; Varnon, Christopher A.; Sokolowski, Michel B. C.; Wells, Harrington; Abramson, Charles I.

    2014-01-01

    Interval timing is a key element of foraging theory, models of predator avoidance, and competitive interactions. Although interval timing is well documented in vertebrate species, it is virtually unstudied in invertebrates. In the present experiment, we used free-flying honey bees (Apis mellifera ligustica) as a model for timing behaviors. Subjects were trained to enter a hole in an automated artificial flower to receive a nectar reinforcer (i.e. reward). Responses were continuously reinforced prior to exposure to either a fixed interval (FI) 15-sec, FI 30-sec, FI 60-sec, or FI 120-sec reinforcement schedule. We measured response rate and post-reinforcement pause within each fixed interval trial between reinforcers. Honey bees responded at higher frequencies earlier in the fixed interval suggesting subject responding did not come under traditional forms of temporal control. Response rates were lower during FI conditions compared to performance on continuous reinforcement schedules, and responding was more resistant to extinction when previously reinforced on FI schedules. However, no “scalloped” or “break-and-run” patterns of group or individual responses reinforced on FI schedules were observed; no traditional evidence of temporal control was found. Finally, longer FI schedules eventually caused all subjects to cease returning to the operant chamber indicating subjects did not tolerate the longer FI schedules. PMID:24983960

  1. Decision to delivery interval: a retrospective study of 1,000 emergency caesarean sections.

    PubMed

    Livermore, L J; Cochrane, R M

    2006-05-01

    The monitoring of the time interval from decision to operate to delivery of the fetus (DDI) for emergency caesarean sections has become an important part of an obstetric department's continuous auditing and clinical governance. The accepted standard is that the DDI for emergency caesarean sections should be 30 minutes. Previous authors have questioned whether this 30-min benchmark is a realistic target for obstetric units. This study, the largest of its kind with 1000 subjects, shows that it is not feasible for busy obstetric units to reach this target in all emergency caesarean sections. Explanations for lengthy DDI and possible improvements are proposed. PMID:16753678

  2. Influence of Forecast Accuracy of Photovoltaic Power Output on Facility Planning and Operation of Microgrid under 30 min Power Balancing Control

    NASA Astrophysics Data System (ADS)

    Kato, Takeyoshi; Sone, Akihito; Shimakage, Toyonari; Suzuoki, Yasuo

    A microgrid (MG) is one of the measures for enhancing the high penetration of renewable energy (RE)-based distributed generators (DGs). For constructing a MG economically, the capacity optimization of controllable DGs against RE-based DGs is essential. By using a numerical simulation model developed based on the demonstrative studies on a MG using PAFC and NaS battery as controllable DGs and photovoltaic power generation system (PVS) as a RE-based DG, this study discusses the influence of forecast accuracy of PVS output on the capacity optimization and daily operation evaluated with the cost. The main results are as follows. The required capacity of NaS battery must be increased by 10-40% against the ideal situation without the forecast error of PVS power output. The influence of forecast error on the received grid electricity would not be so significant on annual basis because the positive and negative forecast error varies with days. The annual total cost of facility and operation increases by 2-7% due to the forecast error applied in this study. The impact of forecast error on the facility optimization and operation optimization is almost the same each other at a few percentages, implying that the forecast accuracy should be improved in terms of both the number of times with large forecast error and the average error.

  3. CONTINUOUS NONINVASIVE MONITORING OF LEFT VENTRICULAR FUNCTION DURING EXERCISE BY THORACIC IMPEDANCE CARDIOGRAPHY AUTOMATED DERIVATION OF SYSTOLIC TIME INTERVALS

    EPA Science Inventory

    Systolic time intervals (ST) obtained during exercise are useful as a method of estimating global left ventricular function. The conventional method, however, which requires a carotid pulse tracing as well as a phonocardiogram of high quality, is technically difficult under condi...

  4. A Comparison of Momentary Time Sampling and Partial-Interval Recording for Assessment of Effects of Social Skills Training

    ERIC Educational Resources Information Center

    Radley, Keith C.; O'Handley, Roderick D.; Labrot, Zachary C.

    2015-01-01

    Assessment in social skills training often utilizes procedures such as partial-interval recording (PIR) and momentary time sampling (MTS) to estimate changes in duration in social engagements due to intervention. Although previous research suggests PIR to be more inaccurate than MTS in estimating levels of behavior, treatment analysis decisions…

  5. Passivity and robust synchronisation of switched interval coupled neural networks with time delay

    NASA Astrophysics Data System (ADS)

    Li, Ning; Cao, Jinde

    2016-09-01

    This paper is concerned with passivity and robust synchronisation of switched coupled neural networks with uncertain parameters. First, the mathematical model of switched coupled neural networks with interval uncertain parameters is established, which consists of L modes and switches from one mode to another according to the switching rule. Second, by employing passivity theory and linear matrix inequality techniques, delay-independent and delay-dependent conditions are derived to guarantee the passivity of switched interval coupled neural networks. Moreover, based on the proposed passivity results, global synchronisation criteria can be obtained for switched coupled neural networks with or without uncertain parameters. Finally, an illustrative example is provided to demonstrate the effectiveness of the obtained results.

  6. An experimental evaluation of electrical skin conductivity changes in postmortem interval and its assessment for time of death estimation.

    PubMed

    Cantürk, İsmail; Karabiber, Fethullah; Çelik, Safa; Şahin, M Feyzi; Yağmur, Fatih; Kara, Sadık

    2016-02-01

    In forensic medicine, estimation of the time of death (ToD) is one of the most important and challenging medico-legal problems. Despite the partial accomplishments in ToD estimations to date, the error margin of ToD estimation is still too large. In this study, electrical conductivity changes were experimentally investigated in the postmortem interval in human cases. Electrical conductivity measurements give some promising clues about the postmortem interval. A living human has a natural electrical conductivity; in the postmortem interval, intracellular fluids gradually leak out of cells. These leaked fluids combine with extra-cellular fluids in tissues and since both fluids are electrolytic, intracellular fluids help increase conductivity. Thus, the level of electrical conductivity is expected to increase with increased time after death. In this study, electrical conductivity tests were applied for six hours. The electrical conductivity of the cases exponentially increased during the tested time period, indicating a positive relationship between electrical conductivity and the postmortem interval. PMID:26751404

  7. Time interval between successive trading in foreign currency market: from microscopic to macroscopic

    NASA Astrophysics Data System (ADS)

    Sato, Aki-Hiro

    2004-12-01

    Recently, it has been shown that inter-transaction interval (ITI) distribution of foreign currency rates has a fat tail. In order to understand the statistical property of the ITI dealer model with N interactive agents is proposed. From numerical simulations it is confirmed that the ITI distribution of the dealer model has a power law tail. The random multiplicative process (RMP) can be approximately derived from the ITI of the dealer model. Consequently, we conclude that the power law tail of the ITI distribution of the dealer model is a result of the RMP.

  8. Polyandry Depends on Postmating Time Interval in the Dengue Vector Aedes aegypti

    PubMed Central

    Degner, Ethan C.; Harrington, Laura C.

    2016-01-01

    Aedes aegypti is the primary vector of the dengue and chikungunya viruses. After mating, male seminal fluid molecules cause females to become unreceptive to a subsequent mating. This response is often assumed to be immediate and complete, but a growing body of evidence suggests that some females do mate more than once. It is unknown how quickly a female becomes unreceptive to a second mating. Furthermore, the degree to which she remains monandrous after laying several batches of eggs has not been rigorously tested. Therefore, we assessed the rates of polyandry in two sets of experiments using wild-type males and those with fluorescent sperm. The first experiment tested the likelihood of polyandry after postmating intervals of various durations. Most females became refractory to a second mating within 2 hours after mating, and rates of polyandry ranged from 24% immediately after mating to 3% at 20 hours after mating. The second experiment tested whether females were polyandrous after cycles of blood meals and oviposition. No re-insemination was found after one, three, or five such cycles. This study is the first to demonstrate that polyandrous behavior depends on the postmating interval. Our results will inform future applications that depend on an accurate knowledge of Ae. aegypti mating behavior, including models of gene flow, investigations of molecules that drive female mating behavior, and control strategies that deploy genetically modified mosquitoes into the field. PMID:26880776

  9. Towards a bipolar layer-counted ice-core chronology for the 41-75 ka time interval

    NASA Astrophysics Data System (ADS)

    Svensson, Anders; Bigler, Matthias; Blunier, Thomas; Dahl-Jensen, Dorthe; Fischer, Hubertus; Kipfstuhl, Sepp; Rasmussen, Sune; Schwander, Jakob; Seierstad, Inger; Steffensen, Jørgen Peder; Vallelonga, Paul; Vinther, Bo; Wegner, Anna; Wilhelms, Frank; Winstrup, Mai

    2015-04-01

    Precise chronologies have been developed for Greenland and Antarctic ice cores based on counting of annual layers in high-resolution water isotope and impurity profiles. Antarctic ice cores are layer-counted back to 31 ka (WAIS Divide ice core) whereas Greenland ice cores are dated back to 60 ka (NGRIP ice core, GICC05 time scale). Beyond 60 ka, in Marine Isotope Stage 4 (MIS4), annual layers in Greenland are thin (less than 1 cm in NGRIP in the coldest periods) and annual layer counting is more uncertain. In the Antarctic EDML ice core annual layers are somewhat thicker over most of MIS4 although they are still marginal for counting. Greenland and Antarctic ice cores are tightly linked at the Laschamp geomagnetic excursion (41 ka) and at the Toba YTT eruption (74 ka) providing end constrains for the investigated time interval. In this work, annual layer counting has been performed in parallel in the NGRIP and EDML ice cores for the time interval 41-75 ka using high-resolution records of visual stratigraphy, dust concentrations, and continuous chemistry. For NGRIP the GICC05 time scale is adapted for the period 41-60 ka. The NGRIP and EDML ice cores are then synchronized by identifying series of bipolar volcanic eruptions in acidity records of electrolytic conductivity, sulfur concentrations, and electric measurements of the solid ice (ECM and DEP). The synchronization is constrained by the layer counting that provides interval durations between volcanic markers. In some periods, a pattern of several bipolar volcanic events provides robust synchronization, but there are longer intervals for which there are no synchronization due to the lack of unambiguous bipolar markers. Over periods of robust synchronization the North-South phasing of climate (water isotopes) and dust concentrations can be investigated at decadal precision. During MIS4 the resulting time scale shows a North-South phasing somewhat different from that of the modelled AICC2012 time scale.

  10. Modulation of photodynamic activity with Photofrin: effect of dose, time interval, fluence, and delivery system

    NASA Astrophysics Data System (ADS)

    Garbo, Greta M.; Ballard, Jonathan R.; Harrison, Linda T.; Kik, Peter K.; Wieman, T. J.; Fingar, Victor H.

    2005-04-01

    A goal of our laboratory is to accurately define the parameters of light dose and drug dose that contribute to tissue destruction after Photodynamic therapy (PDT). Using Photofrin as sensitizer, we examined a range of drug doses, various intervals between injection and light treatment, and various fluence rates. The effect of Photofrin photosensitizer encapsulated in liposomal delivery vehicle was also studied. Three liposome delivery vehicles were chosen to deliver the photosensitizer in vivo: DPPC/cholesterol, DMPC/HPC and stealth liposomes. Tumor response and microvessel behaviour were examined in tumor and surrounding skin in a mouse model. Under these conditions, better selectivity of tissue damage was seen using some of the treatment. These data might be used to design better clinical protocols for patient care. In memory of Dr. Victor Fingar (Supported by R01 CA51771).

  11. Time dose relationships in endometrial adenocarcinoma: importance of the interval from external pelvic irradiation to surgery

    SciTech Connect

    Wilson, J.F.; Cox, J.D.; Chahbazian, C.M.; del Regato, J.A.

    1980-05-01

    One hundred twenty-one patients with adenocarcinoma of the endometrium received external pelvic irradiation (EPI) as a preoperative surgical adjuvant to total abdominal hysterectomy between March, 1951 and February, 1977. Either 400 KVP x-rays, Cobalt teletherapy or 25 MeV photons were used. In more than one third of the hysterectomy specimens, there was no histopathological evidence of residual cancer. Statistical analysis shows a significant reduction in the proportion of positive specimens as the interval to hysterectomy increased. The data support the concept that adenocarcinomas are not radioresistant but may be slow to regress following irradiation. Caution is advised against making decisions about therapy based on histopathological findings in patients who receive surgery immediately following short course or intracavitary preoperative irradiation.

  12. Delay-dependent passivity criteria for uncertain switched neural networks of neutral type with interval time-varying delay

    NASA Astrophysics Data System (ADS)

    Nagamani, G.; Balasubramaniam, P.

    2012-04-01

    This paper is concerned with the robust passivity analysis of uncertain switched neural networks of neutral type with interval time-varying delay. We first discuss the passivity conditions for the addressed model with norm bounded uncertainties and then extend this result to the case of interval uncertainties. For the neural networks under study, a generalized activation function is considered, where the traditional assumptions on the boundedness, monotonicity and differentiability of the activation functions are removed. Constructing a new Lyapunov-Krasovskii functional with triple integral terms and using a minimal number of free-weighting matrices, some passivity criteria are proposed in terms of linear matrix inequalities, which are dependent on the size of the time delay. Finally, some numerical examples are given to illustrate the effectiveness and merits of the developed techniques.

  13. Identifying new cannabis use with urine creatinine-normalized THCCOOH concentrations and time intervals between specimen collections.

    PubMed

    Smith, Michael L; Barnes, Allan J; Huestis, Marilyn A

    2009-05-01

    A previously recommended method for detecting new cannabis use with creatinine-normalized 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THCCOOH) urine concentrations in periodically collected specimens for treatment, workplace and judicial drug testing applications is refined by considering the time interval between urine collections. All urine specimens were collected from six less-than-daily cannabis users who smoked placebo, 1.75%, and 3.55% THC cigarettes in randomized order, each separated by one week. Ratios (n = 24,322) were calculated by dividing each creatinine-normalized THCCOOH concentration (U2) by that of a previously collected specimen (U1). Maximum, 95% limit, and median U2/U1 ratios with 15 and 6 ng THCCOOH/mL cutoff concentrations, with and without new use between specimens, were calculated for each 24-h interval after smoking up to 168 h and are included in tables. These ratios decreased with increasing interval between collections providing improved decision values for determining new cannabis use. For example, with a 15 ng THCCOOH/mL cutoff concentration and no new use between specimens, the maximum, 95% limit, and median U2/U1 ratios were 3.05, 1.59, and 0.686, respectively, when the collection interval was

  14. Impact of heart disease and calibration interval on accuracy of pulse transit time-based blood pressure estimation.

    PubMed

    Ding, Xiaorong; Zhang, Yuanting; Tsang, Hon Ki

    2016-02-01

    Continuous blood pressure (BP) measurement without a cuff is advantageous for the early detection and prevention of hypertension. The pulse transit time (PTT) method has proven to be promising for continuous cuffless BP measurement. However, the problem of accuracy is one of the most challenging aspects before the large-scale clinical application of this method. Since PTT-based BP estimation relies primarily on the relationship between PTT and BP under certain assumptions, estimation accuracy will be affected by cardiovascular disorders that impair this relationship and by the calibration frequency, which may violate these assumptions. This study sought to examine the impact of heart disease and the calibration interval on the accuracy of PTT-based BP estimation. The accuracy of a PTT-BP algorithm was investigated in 37 healthy subjects and 48 patients with heart disease at different calibration intervals, namely 15 min, 2 weeks, and 1 month after initial calibration. The results showed that the overall accuracy of systolic BP estimation was significantly lower in subjects with heart disease than in healthy subjects, but diastolic BP estimation was more accurate in patients than in healthy subjects. The accuracy of systolic and diastolic BP estimation becomes less reliable with longer calibration intervals. These findings demonstrate that both heart disease and the calibration interval can influence the accuracy of PTT-based BP estimation and should be taken into consideration to improve estimation accuracy. PMID:26767518

  15. High-intensity interval exercise induces 24-h energy expenditure similar to traditional endurance exercise despite reduced time commitment.

    PubMed

    Skelly, Lauren E; Andrews, Patricia C; Gillen, Jenna B; Martin, Brian J; Percival, Michael E; Gibala, Martin J

    2014-07-01

    Subjects performed high-intensity interval training (HIIT) and continuous moderate-intensity training (END) to evaluate 24-h oxygen consumption. Oxygen consumption during HIIT was lower versus END; however, total oxygen consumption over 24 h was similar. These data demonstrate that HIIT and END induce similar 24-h energy expenditure, which may explain the comparable changes in body composition reported despite lower total training volume and time commitment. PMID:24773393

  16. Benzoylphenylurea residues in peppers and zucchinis grown in greenhouses: determination of decline times and pre-harvest intervals by modelling.

    PubMed

    López-López, Trinidad; Martínez-Vidal, José L; Gil-García, María D; Martínez-Galera, María; Rodríguez-Lallena, José A

    2004-02-01

    Residue levels and degradation rates of five benzoylphenylurea insecticides were studied in zucchinis and peppers grown in experimental greenhouses in Almería (Spain). Benzoylphenylurea residues were analyzed by HPLC using on-line post-elution photoirradiation with fluorescence detection. Mathematically defined decline curves were established by determining optimal relationships between benzoylphenylurea residues and time, using different models. The models that best fitted the experimental data were those of first-order for diflubenzuron, triflumuron, hexaflumuron and flufenoxuron in zucchini and RF first-order models for the five insecticides in peppers and for lufenuron in zucchini. Half-life times for the residues on the two vegetables were estimated from the optimal models. In order to guarantee safe consumption of the two vegetables, we have estimated suitable pre-harvest intervals complying with the maximum residue levels established by the Spanish Government. In all cases, such pre-harvest intervals were shorter than those specified by the manufacturers of commercial formulates. Experimental data for the five insecticides in peppers and for lufenuron in zucchini were also fitted to a first-order model. Even though this function was legitimized statistically, estimations of decline times (T/2) and pre-harvest intervals were quite different from those provided by the optimal model. PMID:14971687

  17. Demarcation of diapause development by cold and its relation to time-interval activation of TIME-ATPase in eggs of the silkworm, Bombyx mori.

    PubMed

    Ti, Xiaonan; Tuzuki, Nobuhiko; Tani, Naoki; Morigami, Etsuko; Isobe, Minoru; Kai, Hidenori

    2004-11-01

    We investigated the mode of action of winter cold in the termination of diapause by investigating Time-Interval-Measuring Enzyme (TIME). First, we determined the period of cold required for the completion of diapause development. Synchronously developing egg batches of a pure strain (C108 Bombyx mori silkworm) were used to minimize variations in hatching time. Hatching occurred with only 18 days chilling at 5 degrees C when the incubation at 25 degrees C after the chilling was elongated. The 18-day period was much shorter than we expected; diapause in B. mori is known to terminate completely with about 100 days of chilling. Even in such a short period of chilling, no sporadic hatching occurred. Moreover, we determined that a temperature-insensitive stage, which we called "Neboke", followed the short cold-requiring stage. Thus, the stage of diapause development was demarcated from other stages of diapause. While the length of diapause development was elongated when chilling was delayed after oviposition, the Neboke stage length was invariant. Cold evidently exerts its effect only on diapause development. When TIME was purified from eggs and chilled in test tubes, a transitory burst of its ATPase activity occurred at a time equivalent to shortly before the completion of diapause development; this was an interval-timer activation. The mechanism by which cold activates TIME to measure the time interval may help explain in biochemical terms the insect's adaptation to its seasonal environments. PMID:15607508

  18. Self-Produced Time Intervals Are Perceived as More Variable and/or Shorter Depending on Temporal Context in Subsecond and Suprasecond Ranges

    PubMed Central

    Mitani, Keita; Kashino, Makio

    2016-01-01

    The processing of time intervals is fundamental for sensorimotor and cognitive functions. Perceptual and motor timing are often performed concurrently (e.g., playing a musical instrument). Although previous studies have shown the influence of body movements on time perception, how we perceive self-produced time intervals has remained unclear. Furthermore, it has been suggested that the timing mechanisms are distinct for the sub- and suprasecond ranges. Here, we compared perceptual performances for self-produced and passively presented time intervals in random contexts (i.e., multiple target intervals presented in a session) across the sub- and suprasecond ranges (Experiment 1) and within the sub- (Experiment 2) and suprasecond (Experiment 3) ranges, and in a constant context (i.e., a single target interval presented in a session) in the sub- and suprasecond ranges (Experiment 4). We show that self-produced time intervals were perceived as shorter and more variable across the sub- and suprasecond ranges and within the suprasecond range but not within the subsecond range in a random context. In a constant context, the self-produced time intervals were perceived as more variable in the suprasecond range but not in the subsecond range. The impairing effects indicate that motor timing interferes with perceptual timing. The dependence of impairment on temporal contexts suggests multiple timing mechanisms for the subsecond and suprasecond ranges. In addition, violation of the scalar property (i.e., a constant variability to target interval ratio) was observed between the sub- and suprasecond ranges. The violation was clearer for motor timing than for perceptual timing. This suggests that the multiple timing mechanisms for the sub- and suprasecond ranges overlap more for perception than for motor. Moreover, the central tendency effect (i.e., where shorter base intervals are overestimated and longer base intervals are underestimated) disappeared with motor timing within the

  19. Self-Produced Time Intervals Are Perceived as More Variable and/or Shorter Depending on Temporal Context in Subsecond and Suprasecond Ranges.

    PubMed

    Mitani, Keita; Kashino, Makio

    2016-01-01

    The processing of time intervals is fundamental for sensorimotor and cognitive functions. Perceptual and motor timing are often performed concurrently (e.g., playing a musical instrument). Although previous studies have shown the influence of body movements on time perception, how we perceive self-produced time intervals has remained unclear. Furthermore, it has been suggested that the timing mechanisms are distinct for the sub- and suprasecond ranges. Here, we compared perceptual performances for self-produced and passively presented time intervals in random contexts (i.e., multiple target intervals presented in a session) across the sub- and suprasecond ranges (Experiment 1) and within the sub- (Experiment 2) and suprasecond (Experiment 3) ranges, and in a constant context (i.e., a single target interval presented in a session) in the sub- and suprasecond ranges (Experiment 4). We show that self-produced time intervals were perceived as shorter and more variable across the sub- and suprasecond ranges and within the suprasecond range but not within the subsecond range in a random context. In a constant context, the self-produced time intervals were perceived as more variable in the suprasecond range but not in the subsecond range. The impairing effects indicate that motor timing interferes with perceptual timing. The dependence of impairment on temporal contexts suggests multiple timing mechanisms for the subsecond and suprasecond ranges. In addition, violation of the scalar property (i.e., a constant variability to target interval ratio) was observed between the sub- and suprasecond ranges. The violation was clearer for motor timing than for perceptual timing. This suggests that the multiple timing mechanisms for the sub- and suprasecond ranges overlap more for perception than for motor. Moreover, the central tendency effect (i.e., where shorter base intervals are overestimated and longer base intervals are underestimated) disappeared with motor timing within the

  20. Effects of posture on exercise performance - Measurement by systolic time intervals.

    NASA Technical Reports Server (NTRS)

    Spodick, D. H.; Quarry-Pigott, V. M.

    1973-01-01

    Because posture significantly influences cardiac performance, the effects of moderate supine and upright ergometer exercise were compared on the basis of proportional (+37%) rate increments over resting control. Supine exercise produced significant decreases in left ventricular ejection time (LVET), pre-ejection period (PEP), and isovolumic contraction time (IVCT). Ejection time index (ETI) and corrected ejection time (LVETc) did not change significantly. Upright exercise produced greater decreases in PEP and LVET, but despite the rate increase there was no change in LVET, which resulted in sharp increases in ETI and LVETc. The discordant directional effects on LVET and its rate-correcting indices between the two postures were consistent with hemodynamic studies demonstrating lack of stroke volume change during supine exercise and increased stroke volume over control during light to moderate upright exercise.

  1. The Influence of Pretreatment Characteristics and Radiotherapy Parameters on Time Interval to Development of Radiation-Associated Meningioma

    SciTech Connect

    Paulino, Arnold C.; Ahmed, Irfan M.; Mai, Wei Y.; Teh, Bin S.

    2009-12-01

    Purpose: To identify pretreatment characteristics and radiotherapy parameters which may influence time interval to development of radiation-associated meningioma (RAM). Methods and Materials: A Medline/PUBMED search of articles dealing with RAM yielded 66 studies between 1981 and 2006. Factors analyzed included patient age and gender, type of initial tumor treated, radiotherapy (RT) dose and volume, and time interval from RT to development of RAM. Results: A total of 143 patients with a median age at RT of 12 years form the basis of this report. The most common initial tumors or conditions treated with RT were medulloblastoma (n = 27), pituitary adenoma (n = 20), acute lymphoblastic leukemia (n = 20), low-grade astrocytoma (n = 19), and tinea capitis (n = 14). In the 116 patients whose RT fields were known, 55 (47.4%) had a portion of the brain treated, whereas 32 (27.6%) and 29 (25.0%) had craniospinal and whole-brain fields. The median time from RT to develop a RAM or latent time (LT) was 19 years (range, 1-63 years). Male gender (p = 0.001), initial diagnosis of leukemia (p = 0.001), and use of whole brain or craniospinal field (p <= 0.0001) were associated with a shorter LT, whereas patients who received lower doses of RT had a longer LT (p < 0.0001). Conclusions: The latent time to develop a RAM was related to gender, initial tumor type, radiotherapy volume, and radiotherapy dose.

  2. VALIDATION OF SPRING OPERATED PRESSURE RELIEF VALVE TIME TO FAILURE AND THE IMPORTANCE OF STATISTICALLY SUPPORTED MAINTENANCE INTERVALS

    SciTech Connect

    Gross, R; Stephen Harris, S

    2009-02-18

    The Savannah River Site operates a Relief Valve Repair Shop certified by the National Board of Pressure Vessel Inspectors to NB-23, The National Board Inspection Code. Local maintenance forces perform inspection, testing, and repair of approximately 1200 spring-operated relief valves (SORV) each year as the valves are cycled in from the field. The Site now has over 7000 certified test records in the Computerized Maintenance Management System (CMMS); a summary of that data is presented in this paper. In previous papers, several statistical techniques were used to investigate failure on demand and failure rates including a quantal response method for predicting the failure probability as a function of time in service. The non-conservative failure mode for SORV is commonly termed 'stuck shut'; industry defined as the valve opening at greater than or equal to 1.5 times the cold set pressure. Actual time to failure is typically not known, only that failure occurred some time since the last proof test (censored data). This paper attempts to validate the assumptions underlying the statistical lifetime prediction results using Monte Carlo simulation. It employs an aging model for lift pressure as a function of set pressure, valve manufacturer, and a time-related aging effect. This paper attempts to answer two questions: (1) what is the predicted failure rate over the chosen maintenance/ inspection interval; and do we understand aging sufficient enough to estimate risk when basing proof test intervals on proof test results?

  3. Natural Course of Chlamydia trachomatis Bacterial Load in the Time Interval between Screening and Treatment in Anogenital Samples

    PubMed Central

    Dirks, J. A. M. C.; van Liere, G. A. F. S.; Bogers, S.; Dukers-Muijrers, N. H. T. M.; Wolffs, P. F. G.; Hoebe, C. J. P. A.

    2015-01-01

    Introduction Although Chlamydia trachomatis (CT) is the most common bacterial sexually transmitted infection worldwide, little is known about the natural course of the bacterial load during infection. We investigated the natural course of the bacterial load in the interval between screening and returning for treatment in genital and anorectal CT-infections. Materials & Methods CT-positive patients, visiting our STI-clinic in the Netherlands from June 2011–January 2014, provided a second urogenital and/or anorectal sample when returning for treatment (diagnostic sample = T1; treatment sample = T2). Patient-record provided data about the days between samples and the date of last unsafe sex. Included patients were ≥18 years old, HIV-negative and did not report antibiotic use in the study-interval. CT load was quantified using qPCR. CT load was log-transformed, and a CT load difference (Δ-CT load) of >1 log was deemed clinically relevant. Chi-square test compared load category distributions over time (decrease/equal/increase), between sample types. Results 274 patients provided 296 paired samples. Majority of samples had a stable CT load in the interval T1-T2 (66.3%, 73.1% and 48.6% for vaginal swabs, urine and anorectal swabs resp. p = 0.07). Load decreased in 17–41% of patients, while ±10% of patients showed an increase in CT load. No association between Δ-CT load and the interval T1-T2 was observed. Large variations can be seen in CT load at T1 and over time. Discussion The majority (±90%) of patients have a stable or decreasing CT load in the time interval between screening and returning for treatment. The number of days between sampling was not associated with change in CT load. In the first month after the last unsafe sex, only stable CT loads were seen. Our data seems to indicate that when most patients visit an STI-clinic, recommended 2 weeks after infection, the infection has already been established or is in its downward phase. PMID:26713628

  4. Persistent time intervals between features in solar flare hard X-ray emission

    NASA Astrophysics Data System (ADS)

    Desai, Upendra D.; Kouveliotou, Chryssa; Barat, C.; Hurley, K.; Niel, M.; Talon, R.; Vedrenne, G.

    Several solar hard X-ray events (greater than 100 keV) were observed simultaneously with identical instruments on the Venera 11, 12, 13, 14, and Prognoz spacecraft. High time resolution (= 2 ms) data were stored in memory when a trigger occurred. The observations of modulation are presented with a period of 1.6 s for the event on December 3, 1978. Evidence is also presented for fast time fluctuations from an event on November 6, 1979, observed from Venera 12 and another on September 6, 1981, observed from the Solar Maximum Mission. Power spectrum analysis, epoch folding, and Monte Carlo simulation were used to evaluate the statistical significance of persistent time delays between features. The results are discussed in light of the MHD model proposed by Zaitsev and Stepanov.

  5. Persistent time intervals between features in solar flare hard X-ray emission

    NASA Technical Reports Server (NTRS)

    Desai, Upendra D.; Kouveliotou, Chryssa; Barat, C.; Hurley, K.; Niel, M.; Talon, R.; Vedrenne, G.

    1986-01-01

    Several solar hard X-ray events (greater than 100 keV) were observed simultaneously with identical instruments on the Venera 11, 12, 13, 14, and Prognoz spacecraft. High time resolution (= 2 ms) data were stored in memory when a trigger occurred. The observations of modulation are presented with a period of 1.6 s for the event on December 3, 1978. Evidence is also presented for fast time fluctuations from an event on November 6, 1979, observed from Venera 12 and another on September 6, 1981, observed from the Solar Maximum Mission. Power spectrum analysis, epoch folding, and Monte Carlo simulation were used to evaluate the statistical significance of persistent time delays between features. The results are discussed in light of the MHD model proposed by Zaitsev and Stepanov.

  6. Influence of the dosing interval on prolactin release after remoxipride.

    PubMed Central

    Movin-Osswald, G; Hammarlund-Udenaes, M; Von Bahr, C; Eneroth, P; Walton-Bowen, K

    1995-01-01

    1. The prolactin response following administration of the D2-dopamine receptor antagonist remoxipride was studied in eight healthy male volunteers. The purpose of the study was to investigate the duration of a refractory period of prolactin release following two doses of remoxipride. A further aim was to compare the prolactin response following remoxipride and thyrotropin release hormone (TRH) during the refractory period. The subjects received two 30 min intravenous (i.v.) infusions of remoxipride 50 mg with different time intervals between the two doses, in a randomized six period crossover design. The time intervals between the two remoxipride doses were 2, 8, 12, 24 and 48 h. On one occasion the remoxipride dose was followed by an i.v. injection of TRH after 2 h. 2. The plasma peak prolactin concentrations obtained after the first remoxipride dose correspond to a maximal release of prolactin according to earlier studies. A small second peak of prolactin was observed after 2 h. The release was gradually increased with longer time intervals between the consecutive doses. The refractory period for a second prolactin release similar to the first one after remoxipride was found to be 24 h for most of the subjects. 3. TRH resulted in a faster and higher increase in prolactin response of a shorter duration than after remoxipride administered 2 h after the first dose. PMID:7669486

  7. A Further Assessment of Momentary Time-Sampling across Extended Interval Lengths

    ERIC Educational Resources Information Center

    Alvero, Alicia M.; Rappaport, Eva; Taylor, Matthew A.

    2011-01-01

    The current study compared the estimation of momentary time-sampling (MTS) to actual safety performance of three ergonomic responses: back, shoulder, and feet. Actual safety performance was established for the five participants by measuring the target responses with a continuous procedure. MTS 90, 105, 120, 135, 150, 165, 180, 195, 210, 240, and…

  8. Effects of Improvements in Interval Timing on the Mathematics Achievement of Elementary School Students

    ERIC Educational Resources Information Center

    Taub, Gordon E.; McGrew, Kevin S.; Keith, Timothy Z.

    2015-01-01

    This article examines the effect of improvements in timing/rhythmicity on mathematics achievement. A total of 86 participants attending 1st through 4th grades completed pre- and posttest measures of mathematics achievement from the Woodcock-Johnson III Tests of Achievement. Students in the experimental group participated in a 4-week intervention…

  9. Systolic time intervals as a measure of left ventricular function in viscose rayon workers exposed to carbon disulfide.

    PubMed

    Franco, G; Malamani, T

    1976-06-01

    In a group of viscose rayon workers exposed to carbon disulfide the systolic time intervals were calculated. They were determined from the simultaneous recording of an ECG, a phonocardiogram, and arterial pulse tracings. Results indicate a shortened left ventricular ejection time (lvet) and a prolonged isovolumetric contraction time (ICT), together with an increase in the ratio of ICT to LVET. These alterations, which occurred in the absence of any clinical signs or symptoms of heart disease, are interpreted as a consequence of an impaired left ventricular contractility, comparable to mild coronary dysfunction. Literature data support the hypothesis that the biochemical mechanisms involved in the effect of carbon disulfide on myocardial cells are (a) an interference with energy metabolism from the inadequate availability of thiamine and nicotinamide or a direct inhibition of cytochrome or (b) an interference with catecholamine metabolism and defective hormonal control of the energy utilization process. Impaired left ventricular function in rayon viscose workers exposed to carbon disulfide represents an early and highly sensitive sign of carbon disulfide intoxication, and the use of systolic time intervals as a noninvasive measure of myocardial performance may be a useful method for monitoring carbon disulfide exposed people. PMID:959790

  10. Decision makers calibrate behavioral persistence on the basis of time-interval experience

    PubMed Central

    McGuire, Joseph T.; Kable, Joseph W.

    2012-01-01

    A central question in intertemporal decision making is why people reverse their own past choices. Someone who initially prefers a long-run outcome might fail to maintain that preference for long enough to see the outcome realized. Such behavior is usually understood as reflecting preference instability or self-control failure. However, if a decision maker is unsure exactly how long an awaited outcome will be delayed, a reversal can constitute the rational, utility-maximizing course of action. In the present behavioral experiments, we placed participants in timing environments where persistence toward delayed rewards was either productive or counterproductive. Our results show that human decision makers are responsive to statistical timing cues, modulating their level of persistence according to the distribution of delay durations they encounter. We conclude that temporal expectations act as a powerful and adaptive influence on people’s tendency to sustain patient decisions. PMID:22533999

  11. Theory of the determination of systolic time intervals by impedance cardiography.

    PubMed

    Visser, K R; Mook, G A; van der Wall, E; Zijlstra, W G

    1993-08-01

    It is possible to accurately measure the left ventricular ejection time from the dZ/dt signal of impedance cardiography. The pre-ejection period can be measured from simultaneous recordings of ECG and dZ/dt. The thoracic admittance (reciprocal value of thoracic impedance) is the sum of a constant tissue admittance and a varying blood conductance Gb (reciprocal value of the blood resistance). dZ/dt represents the changes in Gb. The notches of the dZ/dt signal, corresponding to opening and closing of the aortic valve, are due to conductivity changes of blood caused by changes in orientation of erythrocytes; near zero-velocity the first derivative with respect to time of these conductivity changes approaches infinity. Therefore, these notches coincide with the actual opening and closing of the valve, although different vessels, including the aorta, contribute to dZ/dt. Comparison of ejection times, simultaneously measured by impedance cardiography and aortic pressure recording, showed excellent agreement for the whole range of measured heart rates (maximum heart rate = 140 beats min-1, n = 70, r = 0.986). PMID:8218623

  12. Estimating the Time Interval Between Exposure to the World Trade Center Disaster and Incident Diagnoses of Obstructive Airway Disease

    PubMed Central

    Glaser, Michelle S.; Webber, Mayris P.; Zeig-Owens, Rachel; Weakley, Jessica; Liu, Xiaoxue; Ye, Fen; Cohen, Hillel W.; Aldrich, Thomas K.; Kelly, Kerry J.; Nolan, Anna; Weiden, Michael D.; Prezant, David J.; Hall, Charles B.

    2014-01-01

    Respiratory disorders are associated with occupational and environmental exposures. The latency period between exposure and disease onset remains uncertain. The World Trade Center (WTC) disaster presents a unique opportunity to describe the latency period for obstructive airway disease (OAD) diagnoses. This prospective cohort study of New York City firefighters compared the timing and incidence of physician-diagnosed OAD relative to WTC exposure. Exposure was categorized by WTC arrival time as high (on the morning of September 11, 2001), moderate (after noon on September 11, 2001, or on September 12, 2001), or low (during September 13–24, 2001). We modeled relative rates and 95% confidence intervals of OAD incidence by exposure over the first 5 years after September 11, 2001, estimating the times of change in the relative rate with change point models. We observed a change point at 15 months after September 11, 2001. Before 15 months, the relative rate for the high- versus low-exposure group was 3.96 (95% confidence interval: 2.51, 6.26) and thereafter, it was 1.76 (95% confidence interval: 1.26, 2.46). Incident OAD was associated with WTC exposure for at least 5 years after September 11, 2001. There were higher rates of new-onset OAD among the high-exposure group during the first 15 months and, to a lesser extent, throughout follow-up. This difference in relative rate by exposure occurred despite full and free access to health care for all WTC-exposed firefighters, demonstrating the persistence of WTC-associated OAD risk. PMID:24980522

  13. Estimating the time interval between exposure to the World Trade Center disaster and incident diagnoses of obstructive airway disease.

    PubMed

    Glaser, Michelle S; Webber, Mayris P; Zeig-Owens, Rachel; Weakley, Jessica; Liu, Xiaoxue; Ye, Fen; Cohen, Hillel W; Aldrich, Thomas K; Kelly, Kerry J; Nolan, Anna; Weiden, Michael D; Prezant, David J; Hall, Charles B

    2014-08-01

    Respiratory disorders are associated with occupational and environmental exposures. The latency period between exposure and disease onset remains uncertain. The World Trade Center (WTC) disaster presents a unique opportunity to describe the latency period for obstructive airway disease (OAD) diagnoses. This prospective cohort study of New York City firefighters compared the timing and incidence of physician-diagnosed OAD relative to WTC exposure. Exposure was categorized by WTC arrival time as high (on the morning of September 11, 2001), moderate (after noon on September 11, 2001, or on September 12, 2001), or low (during September 13-24, 2001). We modeled relative rates and 95% confidence intervals of OAD incidence by exposure over the first 5 years after September 11, 2001, estimating the times of change in the relative rate with change point models. We observed a change point at 15 months after September 11, 2001. Before 15 months, the relative rate for the high- versus low-exposure group was 3.96 (95% confidence interval: 2.51, 6.26) and thereafter, it was 1.76 (95% confidence interval: 1.26, 2.46). Incident OAD was associated with WTC exposure for at least 5 years after September 11, 2001. There were higher rates of new-onset OAD among the high-exposure group during the first 15 months and, to a lesser extent, throughout follow-up. This difference in relative rate by exposure occurred despite full and free access to health care for all WTC-exposed firefighters, demonstrating the persistence of WTC-associated OAD risk. PMID:24980522

  14. Systolic time intervals: a review of the method in the non-invasive investigation of cardiac function in health, disease and clinical pharmacology.

    PubMed Central

    Hassan, S.; Turner, P.

    1983-01-01

    Measurement of systolic time intervals is a valuable, non-invasive procedure to assess left ventricular performance, particularly when influenced by drugs. In this review, we discuss various factors affecting systolic time intervals, the therapeutic implications of the technique and its place among other non-invasive tests of cardiac function. PMID:6353394

  15. Rank-based inference for the accelerated failure time model in the presence of interval censored data

    NASA Astrophysics Data System (ADS)

    Karimi, Mostafa; Ibrahim, Noor Akma; Bakar, Mohd. Rizam Abu; Arasan, Jayanthi

    2016-06-01

    Semiparametric analysis and rank-based inference for the accelerated failure time model are complicated in the presence of interval censored data. The main difficulty with the existing rank-based methods is that they involve estimating functions with the possibility of multiple roots. In this paper a class of asymptotically normal rank estimators is developed which can be aquired via linear programming for estimating the parameters of the model, and a two-step iterative algorithm is introduce for solving the estimating equations. The proposed inference procedures are assessed through a real example.

  16. Delay-dependent exponential stability for uncertain neutral stochastic neural networks with interval time-varying delay

    NASA Astrophysics Data System (ADS)

    Chen, Huabin; Zhao, Yang

    2015-10-01

    This paper is mainly concerned with the problem for the robustly exponential stability in mean square moment of uncertain neutral stochastic neural networks with interval time-varying delay. With an appropriate augmented Lyapunov-Krasovskii functional (LKF) formulated, the convex combination method is utilised to estimate the derivative of the LKF. Some new delay-dependent exponential stability criteria for such systems are obtained in terms of linear matrix inequalities, which involve fewer matrix variables and have less conservatism. Finally, two illustrative numerical examples are given to show the effectiveness of our obtained results.

  17. Global robust dissipativity of interval recurrent neural networks with time-varying delay and discontinuous activations.

    PubMed

    Duan, Lian; Huang, Lihong; Guo, Zhenyuan

    2016-07-01

    In this paper, the problems of robust dissipativity and robust exponential dissipativity are discussed for a class of recurrent neural networks with time-varying delay and discontinuous activations. We extend an invariance principle for the study of the dissipativity problem of delay systems to the discontinuous case. Based on the developed theory, some novel criteria for checking the global robust dissipativity and global robust exponential dissipativity of the addressed neural network model are established by constructing appropriate Lyapunov functionals and employing the theory of Filippov systems and matrix inequality techniques. The effectiveness of the theoretical results is shown by two examples with numerical simulations. PMID:27475061

  18. Global robust dissipativity of interval recurrent neural networks with time-varying delay and discontinuous activations

    NASA Astrophysics Data System (ADS)

    Duan, Lian; Huang, Lihong; Guo, Zhenyuan

    2016-07-01

    In this paper, the problems of robust dissipativity and robust exponential dissipativity are discussed for a class of recurrent neural networks with time-varying delay and discontinuous activations. We extend an invariance principle for the study of the dissipativity problem of delay systems to the discontinuous case. Based on the developed theory, some novel criteria for checking the global robust dissipativity and global robust exponential dissipativity of the addressed neural network model are established by constructing appropriate Lyapunov functionals and employing the theory of Filippov systems and matrix inequality techniques. The effectiveness of the theoretical results is shown by two examples with numerical simulations.

  19. Infusion of D1 Dopamine Receptor Agonist into Medial Frontal Cortex Disrupts Neural Correlates of Interval Timing

    PubMed Central

    Parker, Krystal L.; Ruggiero, Rafael N.; Narayanan, Nandakumar S.

    2015-01-01

    Medial frontal cortical (MFC) dopamine is essential for the organization of behavior in time. Our prior work indicates that blocking D1 dopamine receptors (D1DR) attenuates temporal processing and low-frequency oscillations by MFC neuronal networks. Here we investigate the effects of focal infusion of the D1DR agonist SKF82958 into MFC during interval timing. MFC D1DR agonist infusion impaired interval timing performance without changing overall firing rates of MFC neurons. MFC ramping patterns of neuronal activity that reflect temporal processing were attenuated following infusion of MFC D1DR agonist. MFC D1DR agonist infusion also altered MFC field potentials by enhancing delta activity between 1 and 4 Hz and attenuating alpha activity between 8 and 15 Hz. These data support the idea that the influence of D1-dopamine signals on frontal neuronal activity adheres to a U-shaped curve, and that cognition requires optimal levels of dopamine in frontal cortex. PMID:26617499

  20. Online Doppler Effect Elimination Based on Unequal Time Interval Sampling for Wayside Acoustic Bearing Fault Detecting System

    PubMed Central

    Ouyang, Kesai; Lu, Siliang; Zhang, Shangbin; Zhang, Haibin; He, Qingbo; Kong, Fanrang

    2015-01-01

    The railway occupies a fairly important position in transportation due to its high speed and strong transportation capability. As a consequence, it is a key issue to guarantee continuous running and transportation safety of trains. Meanwhile, time consumption of the diagnosis procedure is of extreme importance for the detecting system. However, most of the current adopted techniques in the wayside acoustic defective bearing detector system (ADBD) are offline strategies, which means that the signal is analyzed after the sampling process. This would result in unavoidable time latency. Besides, the acquired acoustic signal would be corrupted by the Doppler effect because of high relative speed between the train and the data acquisition system (DAS). Thus, it is difficult to effectively diagnose the bearing defects immediately. In this paper, a new strategy called online Doppler effect elimination (ODEE) is proposed to remove the Doppler distortion online by the introduced unequal interval sampling scheme. The steps of proposed strategy are as follows: The essential parameters are acquired in advance. Then, the introduced unequal time interval sampling strategy is used to restore the Doppler distortion signal, and the amplitude of the signal is demodulated as well. Thus, the restored Doppler-free signal is obtained online. The proposed ODEE method has been employed in simulation analysis. Ultimately, the ODEE method is implemented in the embedded system for fault diagnosis of the train bearing. The results are in good accordance with the bearing defects, which verifies the good performance of the proposed strategy. PMID:26343657

  1. Online Doppler Effect Elimination Based on Unequal Time Interval Sampling for Wayside Acoustic Bearing Fault Detecting System.

    PubMed

    Ouyang, Kesai; Lu, Siliang; Zhang, Shangbin; Zhang, Haibin; He, Qingbo; Kong, Fanrang

    2015-01-01

    The railway occupies a fairly important position in transportation due to its high speed and strong transportation capability. As a consequence, it is a key issue to guarantee continuous running and transportation safety of trains. Meanwhile, time consumption of the diagnosis procedure is of extreme importance for the detecting system. However, most of the current adopted techniques in the wayside acoustic defective bearing detector system (ADBD) are offline strategies, which means that the signal is analyzed after the sampling process. This would result in unavoidable time latency. Besides, the acquired acoustic signal would be corrupted by the Doppler effect because of high relative speed between the train and the data acquisition system (DAS). Thus, it is difficult to effectively diagnose the bearing defects immediately. In this paper, a new strategy called online Doppler effect elimination (ODEE) is proposed to remove the Doppler distortion online by the introduced unequal interval sampling scheme. The steps of proposed strategy are as follows: The essential parameters are acquired in advance. Then, the introduced unequal time interval sampling strategy is used to restore the Doppler distortion signal, and the amplitude of the signal is demodulated as well. Thus, the restored Doppler-free signal is obtained online. The proposed ODEE method has been employed in simulation analysis. Ultimately, the ODEE method is implemented in the embedded system for fault diagnosis of the train bearing. The results are in good accordance with the bearing defects, which verifies the good performance of the proposed strategy. PMID:26343657

  2. The duration of uncertain times: audiovisual information about intervals is integrated in a statistically optimal fashion.

    PubMed

    Hartcher-O'Brien, Jess; Di Luca, Massimiliano; Ernst, Marc O

    2014-01-01

    Often multisensory information is integrated in a statistically optimal fashion where each sensory source is weighted according to its precision. This integration scheme isstatistically optimal because it theoretically results in unbiased perceptual estimates with the highest precisionpossible.There is a current lack of consensus about how the nervous system processes multiple sensory cues to elapsed time.In order to shed light upon this, we adopt a computational approach to pinpoint the integration strategy underlying duration estimationof audio/visual stimuli. One of the assumptions of our computational approach is that the multisensory signals redundantly specify the same stimulus property. Our results clearly show that despite claims to the contrary, perceived duration is the result of an optimal weighting process, similar to that adopted for estimates of space. That is, participants weight the audio and visual information to arrive at the most precise, single duration estimate possible. The work also disentangles how different integration strategies - i.e. consideringthe time of onset/offset ofsignals - might alter the final estimate. As such we provide the first concrete evidence of an optimal integration strategy in human duration estimates. PMID:24594578

  3. Short time interval for condensation of high-temperature silicates in the solar accretion disk.

    PubMed

    Luu, Tu-Han; Young, Edward D; Gounelle, Matthieu; Chaussidon, Marc

    2015-02-01

    Chondritic meteorites are made of primitive components that record the first steps of formation of solids in our Solar System. Chondrules are the major component of chondrites, yet little is known about their formation mechanisms and history within the solar protoplanetary disk (SPD). We use the reconstructed concentrations of short-lived (26)Al in chondrules to constrain the timing of formation of their precursors in the SPD. High-precision bulk magnesium isotopic measurements of 14 chondrules from the Allende chondrite define a (26)Al isochron with (26)Al/(27)Al = 1.2(±0.2) × 10(-5) for this subset of Allende chondrules. This can be considered to be the minimum bulk chondrule (26)Al isochron because all chondrules analyzed so far with high precision (∼50 chondrules from CV and ordinary chondrites) have an inferred minimum bulk initial ((26)Al/(27)Al) ≥ 1.2 × 10(-5). In addition, mineral (26)Al isochrons determined on the same chondrules show that their formation (i.e., fusion of their precursors by energetic events) took place from 0 Myr to ∼2 Myr after the formation of their precursors, thus showing in some cases a clear decoupling in time between the two events. The finding of a minimum bulk chondrule (26)Al isochron is used to constrain the astrophysical settings for chondrule formation. Either the temperature of the condensation zone dropped below the condensation temperature of chondrule precursors at ∼1.5 My after the start of the Solar System or the transport of precursors from the condensation zone to potential storage sites stopped after 1.5 My, possibly due to a drop in the disk accretion rate. PMID:25605942

  4. Short time interval for condensation of high-temperature silicates in the solar accretion disk

    PubMed Central

    Luu, Tu-Han; Young, Edward D.; Gounelle, Matthieu; Chaussidon, Marc

    2015-01-01

    Chondritic meteorites are made of primitive components that record the first steps of formation of solids in our Solar System. Chondrules are the major component of chondrites, yet little is known about their formation mechanisms and history within the solar protoplanetary disk (SPD). We use the reconstructed concentrations of short-lived 26Al in chondrules to constrain the timing of formation of their precursors in the SPD. High-precision bulk magnesium isotopic measurements of 14 chondrules from the Allende chondrite define a 26Al isochron with 26Al/27Al = 1.2(±0.2) × 10−5 for this subset of Allende chondrules. This can be considered to be the minimum bulk chondrule 26Al isochron because all chondrules analyzed so far with high precision (∼50 chondrules from CV and ordinary chondrites) have an inferred minimum bulk initial (26Al/27Al) ≥ 1.2 × 10−5. In addition, mineral 26Al isochrons determined on the same chondrules show that their formation (i.e., fusion of their precursors by energetic events) took place from 0 Myr to ∼2 Myr after the formation of their precursors, thus showing in some cases a clear decoupling in time between the two events. The finding of a minimum bulk chondrule 26Al isochron is used to constrain the astrophysical settings for chondrule formation. Either the temperature of the condensation zone dropped below the condensation temperature of chondrule precursors at ∼1.5 My after the start of the Solar System or the transport of precursors from the condensation zone to potential storage sites stopped after 1.5 My, possibly due to a drop in the disk accretion rate. PMID:25605942

  5. Reference intervals for coagulation times using two point-of-care analysers in healthy pet rabbits (Oryctolagus cuniculus).

    PubMed

    Mentré, V; Bulliot, C; Linsart, A; Ronot, P

    2014-06-28

    The purpose of this study was to establish reference intervals for prothrombin time (PT) and activated partial prothrombin time (aPTT) in healthy rabbits using two different point-of-care analysers (Idexx Coag DX and MS Quick Vet Coag Combo). These intervals would be useful in the diagnosis of coagulopathies and in the determination of coagulation status in critical patients. We are unaware of reports of coagulation values in pet rabbits. Blood samples were analysed from 81 clinically healthy pet rabbits under three years of age (49 females and 32 males). The reference intervals were as follows (non-parametric method for the MS Quick Vet Coag Combo and Box-Cox Robust method for the Idexx Coag DX, p<0.05 limit for statistical significance): PT (MS Quick Vet Coag Combo)=N=33, 17.2-28.5; PT (Idexx Coag DX)=N=48, 10.0-14.8, aPTT (MS Quick Vet Coag Combo)=N=33, 103.2-159.2 and aPTT (Idexx Coag DX)=N=48, 104.2-159.1. PT was significantly longer using the MS Quick Vet Coag Combo. aPTT was significantly shorter with the MS Quick Vet Coag Combo. On each type of analyser, there was no significant difference between sexes and blood sampling sites. A significant difference was present for the use or not of anaesthesia with the MS Quick Vet Coag Combo analyser. This study on healthy pet rabbits will be useful in point-of-care diagnosis of coagulopathies. PMID:24722233

  6. Time-interval for integration of stabilizing haptic and visual information in subjects balancing under static and dynamic conditions

    PubMed Central

    Honeine, Jean-Louis; Schieppati, Marco

    2014-01-01

    Maintaining equilibrium is basically a sensorimotor integration task. The central nervous system (CNS) continually and selectively weights and rapidly integrates sensory inputs from multiple sources, and coordinates multiple outputs. The weighting process is based on the availability and accuracy of afferent signals at a given instant, on the time-period required to process each input, and possibly on the plasticity of the relevant pathways. The likelihood that sensory inflow changes while balancing under static or dynamic conditions is high, because subjects can pass from a dark to a well-lit environment or from a tactile-guided stabilization to loss of haptic inflow. This review article presents recent data on the temporal events accompanying sensory transition, on which basic information is fragmentary. The processing time from sensory shift to reaching a new steady state includes the time to (a) subtract or integrate sensory inputs; (b) move from allocentric to egocentric reference or vice versa; and (c) adjust the calibration of motor activity in time and amplitude to the new sensory set. We present examples of processes of integration of posture-stabilizing information, and of the respective sensorimotor time-intervals while allowing or occluding vision or adding or subtracting tactile information. These intervals are short, in the order of 1–2 s for different postural conditions, modalities and deliberate or passive shift. They are just longer for haptic than visual shift, just shorter on withdrawal than on addition of stabilizing input, and on deliberate than unexpected mode. The delays are the shortest (for haptic shift) in blind subjects. Since automatic balance stabilization may be vulnerable to sensory-integration delays and to interference from concurrent cognitive tasks in patients with sensorimotor problems, insight into the processing time for balance control represents a critical step in the design of new balance- and locomotion training devices

  7. Time-interval for integration of stabilizing haptic and visual information in subjects balancing under static and dynamic conditions.

    PubMed

    Honeine, Jean-Louis; Schieppati, Marco

    2014-01-01

    Maintaining equilibrium is basically a sensorimotor integration task. The central nervous system (CNS) continually and selectively weights and rapidly integrates sensory inputs from multiple sources, and coordinates multiple outputs. The weighting process is based on the availability and accuracy of afferent signals at a given instant, on the time-period required to process each input, and possibly on the plasticity of the relevant pathways. The likelihood that sensory inflow changes while balancing under static or dynamic conditions is high, because subjects can pass from a dark to a well-lit environment or from a tactile-guided stabilization to loss of haptic inflow. This review article presents recent data on the temporal events accompanying sensory transition, on which basic information is fragmentary. The processing time from sensory shift to reaching a new steady state includes the time to (a) subtract or integrate sensory inputs; (b) move from allocentric to egocentric reference or vice versa; and (c) adjust the calibration of motor activity in time and amplitude to the new sensory set. We present examples of processes of integration of posture-stabilizing information, and of the respective sensorimotor time-intervals while allowing or occluding vision or adding or subtracting tactile information. These intervals are short, in the order of 1-2 s for different postural conditions, modalities and deliberate or passive shift. They are just longer for haptic than visual shift, just shorter on withdrawal than on addition of stabilizing input, and on deliberate than unexpected mode. The delays are the shortest (for haptic shift) in blind subjects. Since automatic balance stabilization may be vulnerable to sensory-integration delays and to interference from concurrent cognitive tasks in patients with sensorimotor problems, insight into the processing time for balance control represents a critical step in the design of new balance- and locomotion training devices

  8. Precise time and Time Interval (PTTI) measurements from the navigation technology satellites and the GPS NAVSTAR-4 satellite

    NASA Technical Reports Server (NTRS)

    Buisson, J. A.; Mccaskill, T., B.; Oaks, O. J.; Jeffries, M. M.; Stebbins, S. B.

    1979-01-01

    A time domain estimate for the NAVSTAR-4 SV clock offset was obtained for each SV pass over the GPS monitor sites, using a smoothed reference ephemeris, with corrections for ionospheric delay, tropospheric delay, earth rotation and relativistic effects. Conversion from the time domain to the frequency domain was made using the two sample Allan Variance; sigma-tau plots used to identify the noise processes. Estimates of flicker and white frequency noise for the NAVSTAR-4 rubidium frequency standard were obtained. The contribution of the reference ground clocks and other error sources to the frequency stability estimates were also considered.

  9. Effect of sintering temperature and time intervals on morphological and hardness behaviour of Al-20 vol% Sn matrix composites

    NASA Astrophysics Data System (ADS)

    Badarulzaman, N. A.; Karim, S. R.; Lajis, M. A.

    2015-05-01

    Aluminium (Al) alloys are widely used in various industries, such as automotive and aerospace. The production processes in these sectors create large amount of Al residues. In this paper, a new method of recycling Al chip is presented. Metal matrix composite (MMCs) of Al-20 vol% Sn was prepared by using solid state direct conversion method of recycled Al 6061 alloy. Constant pressure (10 ton) was used to implement the cold forging process. The differences of sintering temperature (200 °C, 250 °C, 300 °C and 350 °C) and time intervals (1h, 2h, 3h, 4h and 5h) were studied to obtain the optimum hardness, strength and surface integrity of Al-20 vol% Sn. The results showed that, hardness and strength of Al-20 vol% Sn was decreased by additional temperature and increase with time interval of sintering. Sintering temperature at 350 °C produces better morphology structure of Al-Sn composites.

  10. Blind synchronization of the OFDM signals in multipath channels on the basis of the time and frequency protection intervals

    NASA Astrophysics Data System (ADS)

    Bochkov, G. N.; Gorokhov, K. V.; Kolobkov, A. V.

    2013-08-01

    New methods of symbol-timing and carrier-frequency blind synchronization of an OFDM-signal receiver are developed and studied. They generalize the well-known methods which use either the protection interval in time in the cyclic prefix form or the protection interval with respect to frequency in the form of virtual subcarriers, and are based on their joint application. To reduce the computational complexity, approximate algorithms which are based on the approximation of the optimal rules, but, according to the study results, have almost the same characteristics of parameter-estimation accuracy and the reception bit-error-rate performance are proposed. It is shown that in terms of the parameter-estimation accuracy and the reception bit-error-rate performance, the proposed methods are superior to the well-known methods of synchronization by the cyclic prefix and the virtual subcarriers in the two-path Rayleigh-fading channel. For incoherent systems with the differential phase shift keying variants, using such methods makes it possible to rule out the necessity of accurate synchronization and, due to insignificant redundancy of the system band and the cyclic prefix length, closely approach the reception bit-error-rate performance for perfect synchronization.

  11. A delay-dependent approach to robust control for neutral uncertain neural networks with mixed interval time-varying delays

    NASA Astrophysics Data System (ADS)

    Lu, Chien-Yu

    2011-04-01

    This paper considers the problem of delay-dependent global robust stabilization for discrete, distributed and neutral interval time-varying delayed neural networks described by nonlinear delay differential equations of the neutral type. The parameter uncertainties are norm bounded. The activation functions are assumed to be bounded and globally Lipschitz continuous. Using a Lyapunov functional approach and linear matrix inequality (LMI) techniques, the stability criteria for the uncertain neutral neural networks with interval time-varying delays are established in the form of LMIs, which can be readily verified using the standard numerical software. An important feature of the result reported is that all the stability conditions are dependent on the upper and lower bounds of the delays. Another feature of the results lies in that it involves fewer free weighting matrix strategy, and upper bounds of the inner product between two vectors are not introduced to reduce the conservatism of the criteria. Two illustrative examples are provided to demonstrate the effectiveness and the reduced conservatism of the proposed method.

  12. High-intensity interval training (HIT) for effective and time-efficient pre-surgical exercise interventions.

    PubMed

    Weston, Matthew; Weston, Kathryn L; Prentis, James M; Snowden, Chris P

    2016-01-01

    The advancement of perioperative medicine is leading to greater diversity in development of pre-surgical interventions, implemented to reduce patient surgical risk and enhance post-surgical recovery. Of these interventions, the prescription of pre-operative exercise training is gathering momentum as a realistic means for enhancing patient surgical outcome. Indeed, the general benefits of exercise training have the potential to pre-operatively optimise several pre-surgical risks factors, including cardiorespiratory function, frailty and cognitive function. Any exercise programme incorporated into the pre-operative pathway of care needs to be effective and time efficient in that any fitness gains are achievable in the limited period between the decision for surgery and operation (e.g. 4 weeks). Fortunately, there is a large volume of research describing effective and time-efficient exercise training programmes within the discipline of sports science. Accordingly, the objective of our commentary is to synthesise contemporary exercise training research, both from non-clinical and clinical populations, with the overarching aim of informing the development of effective and time-efficient pre-surgical exercise training programmes. The development of such exercise training programmes requires the careful consideration of several key principles, namely frequency, intensity, time, type and progression of exercise. Therefore, in light of more recent evidence demonstrating the effectiveness and time efficiency of high-intensity interval training-which involves brief bouts of intense exercise interspersed with longer recovery periods-the principles of exercise training programme design will be discussed mainly in the context of such high-intensity interval training programmes. Other issues pertinent to the development, implementation and evaluation of pre-operative exercise training programmes, such as individual exercise prescription, training session monitoring and potential

  13. Joint timing and frequency synchronization based on weighted CAZAC sequences for reduced-guard-interval CO-OFDM systems.

    PubMed

    Omomukuyo, Oluyemi; Chang, Deyuan; Zhu, Jingwen; Dobre, Octavia; Venkatesan, Ramachandran; Ngatched, Telex; Rumbolt, Chuck

    2015-03-01

    A novel joint symbol timing and carrier frequency offset (CFO) estimation algorithm is proposed for reduced-guard-interval coherent optical orthogonal frequency-division multiplexing (RGI-CO-OFDM) systems. The proposed algorithm is based on a constant amplitude zero autocorrelation (CAZAC) sequence weighted by a pseudo-random noise (PN) sequence. The symbol timing is accomplished by using only one training symbol of two identical halves, with the weighting applied to the second half. The special structure of the training symbol is also utilized in estimating the CFO. The performance of the proposed algorithm is demonstrated by means of numerical simulations in a 115.8-Gb/s 16-QAM RGI-CO-OFDM system. PMID:25836807

  14. Fourth-grade Children’s Dietary Recall Accuracy is Influenced by Retention Interval (Target Period and Interview Time)

    PubMed Central

    Hardin, James W.; Guinn, Caroline H.; Royer, Julie A.; Mackelprang, Alyssa J.; Smith, Albert F.

    2009-01-01

    Background For a 24-hour dietary recall, two possible target periods are the prior 24 hours (24 hours immediately preceding the interview time) and previous day (midnight to midnight of the day before the interview), and three possible interview times are morning, afternoon, and evening. Target period and interview time determine the retention interval (elapsed time between to-be-reported meals and the interview), which, along with intervening meals, can influence reporting accuracy. Objective The effects of target period and interview time on children’s accuracy for reporting school meals during 24-hour dietary recalls were investigated. Design and subjects/setting During the 2004–05, 2005–06, and 2006–07 school years in (city), (state), each of 374 randomly selected fourth-grade children (96% Black) was observed eating two consecutive school meals (breakfast, lunch) and interviewed to obtain a 24-hour dietary recall using one of six conditions defined by crossing two target periods with three interview times. Each condition had 62 or 64 children (half boys). Main outcome measures Accuracy for reporting school meals was quantified by calculating rates for omissions (food items observed eaten but unreported) and intrusions (food items reported eaten but unobserved); a measure of total inaccuracy combined errors for reporting food items and amounts. Statistical analyses performed For each accuracy measure, analysis of variance was conducted with target period, interview time, their interaction, sex, interviewer, and school year in the model. Results There was a target-period effect and a target-period by interview-time interaction on omission rates, intrusion rates, and total inaccuracy (six P values <0.004). For prior-24-hour recalls compared to previous-day recalls, and for prior-24-hour recalls in the afternoon and evening compared to previous-day recalls in the afternoon and evening, omission rates were better by one-third, intrusion rates were better by

  15. Priority effects of time of arrival of plant functional groups override sowing interval or density effects: a grassland experiment.

    PubMed

    von Gillhaussen, Philipp; Rascher, Uwe; Jablonowski, Nicolai D; Plückers, Christine; Beierkuhnlein, Carl; Temperton, Vicky M

    2014-01-01

    Priority effects occur when species that arrive first in a habitat significantly affect the establishment, growth, or reproduction of species arriving later and thus affect functioning of communities. However, we know little about how the timing of arrival of functionally different species may alter structure and function during assembly. Even less is known about how plant density might interact with initial assembly. In a greenhouse experiment legumes, grasses or forbs were sown a number of weeks before the other two plant functional types were sown (PFT) in combination with a sowing density treatment. Legumes, grasses or non-legume forbs were sown first at three different density levels followed by sowing of the remaining PFTs after three or six-weeks. We found that the order of arrival of different plant functional types had a much stronger influence on aboveground productivity than sowing density or interval between the sowing events. The sowing of legumes before the other PFTs produced the highest aboveground biomass. The larger sowing interval led to higher asymmetric competition, with highest dominance of the PFT sown first. It seems that legumes were better able to get a head-start and be productive before the later groups arrived, but that their traits allowed for better subsequent establishment of non-legume PFTs. Our study indicates that the manipulation of the order of arrival can create priority effects which favour functional groups of plants differently and thus induce different assembly routes and affect community composition and functioning. PMID:24497995

  16. Eliminating livelock by assigning the same priority state to each message that is inputted into a flushable routing system during N time intervals

    DOEpatents

    Faber, Vance

    1994-01-01

    Livelock-free message routing is provided in a network of interconnected nodes that is flushable in time T. An input message processor generates sequences of at least N time intervals, each of duration T. An input register provides for receiving and holding each input message, where the message is assigned a priority state p during an nth one of the N time intervals. At each of the network nodes a message processor reads the assigned priority state and awards priority to messages with priority state (p-1) during an nth time interval and to messages with priority state p during an (n+1) th time interval. The messages that are awarded priority are output on an output path toward the addressed output message processor. Thus, no message remains in the network for a time longer than T.

  17. Eliminating livelock by assigning the same priority state to each message that is input into a flushable routing system during N time intervals

    DOEpatents

    Faber, V.

    1994-11-29

    Livelock-free message routing is provided in a network of interconnected nodes that is flushable in time T. An input message processor generates sequences of at least N time intervals, each of duration T. An input register provides for receiving and holding each input message, where the message is assigned a priority state p during an nth one of the N time intervals. At each of the network nodes a message processor reads the assigned priority state and awards priority to messages with priority state (p-1) during an nth time interval and to messages with priority state p during an (n+1) th time interval. The messages that are awarded priority are output on an output path toward the addressed output message processor. Thus, no message remains in the network for a time longer than T. 4 figures.

  18. Effect of palady and cup feeding on premature neonates’ weight gain and reaching full oral feeding time interval

    PubMed Central

    Marofi, Maryam; Abedini, Fatemeh; Mohammadizadeh, Majid; Talakoub, Sedigheh

    2016-01-01

    Background: Premature neonates’ feeding is of great importance due to its effective role in their growth. These neonates should reach an independent oral nutrition stage before being discharged from the Neonatal Intensive care Unit. Therefore, the researcher decided to conduct a study on the effect of palady and cup feeding on premature neonates’ weight gain and their reaching full oral feeding time interval. Materials and Methods: This is a clinical trial with a quantitative design conducted on 69 premature infants (gestational age between 29 and 32 weeks) who were assigned to cup (n = 34) and palady (n = 35) feeding groups through random allocation. The first feeding was administrated either by cup or palady method in each shift within seven sequential days (total of 21 cup and palady feedings). Then, the rest of feeding was administrated by gavage. Results: Mean hospitalization time (cup = 39.01 and palady = 30.4; P < 0.001) and mean time interval to reach full oral feeding (cup = 33.7 and palady = 24.1; P < 0.001) were significantly lower in palady group compared to cup group. Mean weight changes of neonates 7 weeks after the intervention compared to those in the beginning of the intervention were significantly more in palady group compared to the cup group (cup = 146.7 and palady = 198.8; P < 0.001). Conclusions: The neonates in palady group reached full oral feeding earlier than those of cup group. Subjects’ weight gain was also higher in palady group compared to the cup group. Premature neonates with over 30 weeks of gestational age and physiological stability can be fed by palady. PMID:27095996

  19. STICK: Spike Time Interval Computational Kernel, a Framework for General Purpose Computation Using Neurons, Precise Timing, Delays, and Synchrony.

    PubMed

    Lagorce, Xavier; Benosman, Ryad

    2015-11-01

    There has been significant research over the past two decades in developing new platforms for spiking neural computation. Current neural computers are primarily developed to mimic biology. They use neural networks, which can be trained to perform specific tasks to mainly solve pattern recognition problems. These machines can do more than simulate biology; they allow us to rethink our current paradigm of computation. The ultimate goal is to develop brain-inspired general purpose computation architectures that can breach the current bottleneck introduced by the von Neumann architecture. This work proposes a new framework for such a machine. We show that the use of neuron-like units with precise timing representation, synaptic diversity, and temporal delays allows us to set a complete, scalable compact computation framework. The framework provides both linear and nonlinear operations, allowing us to represent and solve any function. We show usability in solving real use cases from simple differential equations to sets of nonlinear differential equations leading to chaotic attractors. PMID:26378879

  20. Quantification of left to right shunt in atrial septal defect using systolic time intervals derived from pulsed Doppler velocimetry.

    PubMed Central

    Veyrat, C; Gourtchiglouian, C; Bas, S; Abitbol, G; Kalmanson, D

    1984-01-01

    Systolic time intervals derived from Doppler velocimetry measurements were used instead of direct pulmonary to systemic flow ratio measurements in adults with atrial septal defect to quantify left to right atrial shunts. Thirteen normal subjects and 25 patients with uncomplicated atrial septal defect confirmed by cardiac catheterisation were studied. The pulmonary to systemic flow ratio (Qp:Qs) expressing the shunt size was determined by the Fick method; in normal subjects the Qp:Qs ratio was assumed to be equal to 1.0. The pulsed Doppler analogue velocity recording of flow in the pulmonary artery and the ascending aorta was taken as indicating the ejection time of each ventricle and the Q wave of the electrocardiogram as indicating the onset of systole. From these measurements the ratios of the pre-ejection periods to the ejection times (haemodynamic ratio) were calculated for each ventricle and the ratios of each variable (pre-ejection period, ejection time, and haemodynamic ratio) were calculated for both ventricles. Significant differences were found between the normal subjects and the patients with atrial septal defect for all these ratios. When the Doppler findings and the Fick measurements of Qp:Qs were compared the best linear correlation coefficient was for the left to right haemodynamic ratio. It is concluded that the use of a ratio involving several variables, such as the pre-ejection period and the ejection time for both ventricles, improves the reliability of this method, which appears to be applicable in adults. Images PMID:6239641

  1. Four-dimensional noise reduction using the time series of medical computed tomography datasets with short interval times: a static-phantom study.

    PubMed

    Nishii, Tatsuya; Kono, Atsushi K; Tani, Wakiko; Suehiro, Erina; Negi, Noriyuki; Takahashi, Satoru; Sugimura, Kazuro

    2016-01-01

    Backgrounds. This study examines the hypothesis that four-dimensional noise reduction (4DNR) with short interval times reduces noise in cardiac computed tomography (CCT) using "padding" phases. Furthermore, the capability of reducing the reduction dose in CCT using this post-processing technique was assessed. Methods. Using base and quarter radiation doses for CCT (456 and 114 mAs/rot with 120 kVp), a static phantom was scanned ten times with retrospective electrocardiogram gating, and 4DNR with short interval times (50 ms) was performed using a post-processing technique. Differences in the computed tomography (CT) attenuation, contrast-to-noise ratio (CNR) and spatial resolution with modulation transfer function in each dose image obtained with and without 4DNR were assessed by conducting a Tukey-Kramer's test and non-inferiority test. Results. For the base dose, by using 4DNR, the CNR was improved from 1.18 ± 0.15 to 2.08 ± 0.20 (P = 0.001), while the CT attenuation and spatial resolution of the image of 4DNR did not were significantly inferior to those of reference image (P < 0.001). CNRs of the quarter-dose image in 4DNR also improved to 1.28 ± 0.11, and were not inferior to those of the non-4DNR images of the base dose (P < 0.001). Conclusions. 4DNR with short interval times significantly reduced noise. Furthermore, applying this method to CCT would have the potential of reducing the radiation dose by 75%, while maintaining a similar image noise level. PMID:26893966

  2. Four-dimensional noise reduction using the time series of medical computed tomography datasets with short interval times: a static-phantom study

    PubMed Central

    Kono, Atsushi K.; Tani, Wakiko; Suehiro, Erina; Negi, Noriyuki; Takahashi, Satoru; Sugimura, Kazuro

    2016-01-01

    Backgrounds. This study examines the hypothesis that four-dimensional noise reduction (4DNR) with short interval times reduces noise in cardiac computed tomography (CCT) using “padding” phases. Furthermore, the capability of reducing the reduction dose in CCT using this post-processing technique was assessed. Methods. Using base and quarter radiation doses for CCT (456 and 114 mAs/rot with 120 kVp), a static phantom was scanned ten times with retrospective electrocardiogram gating, and 4DNR with short interval times (50 ms) was performed using a post-processing technique. Differences in the computed tomography (CT) attenuation, contrast-to-noise ratio (CNR) and spatial resolution with modulation transfer function in each dose image obtained with and without 4DNR were assessed by conducting a Tukey–Kramer’s test and non-inferiority test. Results. For the base dose, by using 4DNR, the CNR was improved from 1.18 ± 0.15 to 2.08 ± 0.20 (P = 0.001), while the CT attenuation and spatial resolution of the image of 4DNR did not were significantly inferior to those of reference image (P < 0.001). CNRs of the quarter-dose image in 4DNR also improved to 1.28 ± 0.11, and were not inferior to those of the non-4DNR images of the base dose (P < 0.001). Conclusions. 4DNR with short interval times significantly reduced noise. Furthermore, applying this method to CCT would have the potential of reducing the radiation dose by 75%, while maintaining a similar image noise level. PMID:26893966

  3. Design, development, and fabrication of a electronic analog microminiaturized electronic analog signal to discrete time interval converter

    NASA Technical Reports Server (NTRS)

    Schoenfeld, A. D.; Schuegraf, K. K.

    1973-01-01

    The microminiaturization of an electronic analog signal to discrete time interval converter is presented. Discrete components and integrated circuits comprising the converter were assembled on a thin-film ceramic substrate containing nichrome resistors with gold interconnections. The finished assembly is enclosed in a flat package measuring 3.30 by 4.57 centimeters. The module can be used whenever conversion of analog to digital signals is required, in particular for the purpose of regulation by means of pulse modulation. In conjunction with a precision voltage reference, the module was applied to control the duty cycle of a switching regulator within a temperature range of -55 C to +125 C, and an input voltage range of 10V to 35V. The output-voltage variation was less than + or - 300 parts per million, i.e., less than + or - 3mV for a 10V output.

  4. Real-time temperature control system based on the finite element method for liver radiofrequency ablation: effect of the time interval on control.

    PubMed

    Isobe, Yosuke; Watanabe, Hiroki; Yamazaki, Nozomu; Lu, XiaoWei; Kobayashi, Yo; Miyashita, Tomoyuki; Hashizume, Makoto; Fujie, Masakatsu G

    2013-01-01

    Radiofrequency (RF) ablation is increasingly being used to treat liver cancer because it is minimally invasive. However, it is difficult for operators to control the size of the coagulation zones precisely, because no method has been established to form an adequate and suitable ablation area. To overcome this limitation, we propose a new system that can control the coagulation zone size. The system operates as follows: 1) the liver temperature is estimated using a temperature-distribution simulator to reduce invasiveness; 2) the output power of the RF generator is controlled automatically according to the liver temperature. To use this system in real time, both the time taken to calculate the temperature in the simulation and the control accuracy are important. We therefore investigated the relationship between the time interval required to change the output voltage and temperature control stability in RF ablation. The results revealed that the proposed method can control the temperature at a point away from the electrode needle to obtain the desired ablation size. It was also shown to be necessary to reduce the time interval when small tumors are cauterized to avoid excessive treatment. In contrast, such high frequency feedback control is not required when large tumors are cauterized. PMID:24109706

  5. Deficits in Interval Timing Measured by the Dual-Task Paradigm among Children and Adolescents with Attention-Deficit/Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Hwang, Shoou-Lian; Gau, Susan Shur-Fen; Hsu, Wen-Yau; Wu, Yu-Yu

    2010-01-01

    Background: The underlying mechanism of time perception deficit in long time intervals in attention-deficit/hyperactivity disorder (ADHD) is still unclear. This study used the time reproduction dual task to explore the role of the attentional resource in time perception deficits among children and adolescents with ADHD. Methods: Participants…

  6. Pigeons (Columba livia) associate time intervals with symbols in a touch screen task: evidence for ordinality but not summation.

    PubMed

    Olthof, Anneke; Santi, Angelo

    2007-02-01

    The present experiments examined whether pigeons can sum symbols that are associated with various temporal consequences in a touch screen apparatus. Pigeons were trained to discriminate between two visual symbols that were associated with 0, 1, 2, 3, 4, or 5 s either of delay to 4 s of hopper access (delay group) or duration of hopper access (reward group). In Experiment 1, the pigeons in both groups learned to select the symbol associated with the more favorable outcome, and they successfully transferred this discrimination to novel symbol pairs. However, when tested with 2 pairs of symbols associated with different summed durations, they responded on the basis of a simple response rule rather than the sum of the symbol pair. In Experiment 2, the reward group was presented with four symbols at once and was allowed to successively choose one symbol at a time. All pigeons chose the symbols in order from largest to smallest. This indicates that pigeons formed an ordered representation of symbols associated with different time intervals, even though they did not sum the symbols. PMID:17324078

  7. Robust iterative learning protocols for finite-time consensus of multi-agent systems with interval uncertain topologies

    NASA Astrophysics Data System (ADS)

    Meng, Deyuan; Jia, Yingmin; Du, Junping

    2015-04-01

    This paper is devoted to the robust finite-time output consensus problems of multi-agent systems under directed graphs, where all agents and their communication topologies are subject to interval uncertainties. Distributed protocols are constructed by using iterative learning control (ILC) algorithms, where information is exchanged only at the end of one iteration and learning is used to update the control inputs after each iteration. It is proved that under ILC-based protocols, the finite-time consensus can be achieved with an increasing number of iterations if the communication network of agents is guaranteed to have a spanning tree. Moreover, if the information of any desired terminal output is available to a portion (not necessarily all) of the agents, then the consensus output that all agents finally reach can be enabled to be the desired terminal output. It is also proved that for all ILC-based protocols, gain selections can be provided in terms of bound values, and consensus conditions can be developed associated with bound matrices. Simulation results are given to demonstrate the effectiveness of our theoretical results.

  8. A Prolonged Time Interval Between Trauma and Prophylactic Radiation Therapy Significantly Increases the Risk of Heterotopic Ossification

    SciTech Connect

    Mourad, Waleed F.; Packianathan, Satyaseelan; Shourbaji, Rania A.; Zhang Zhen; Graves, Mathew; Khan, Majid A.; Baird, Michael C.; Russell, George; Vijayakumar, Srinivasan

    2012-03-01

    Purpose: To ascertain whether the time from injury to prophylactic radiation therapy (RT) influences the rate of heterotopic ossification (HO) after operative treatment of displaced acetabular fractures. Methods and Materials: This is a single-institution, retrospective analysis of patients referred for RT for the prevention of HO. Between January 2000 and January 2009, 585 patients with displaced acetabular fractures were treated surgically followed by RT for HO prevention. We analyzed the effect of time from injury on prevention of HO by RT. In all patients, 700 cGy was prescribed in a single fraction and delivered within 72 hours postsurgery. The patients were stratified into five groups according to time interval (in days) from the date of their accident to the date of RT: Groups A {<=}3, B {<=}7, C {<=}14, D {<=}21, and E >21days. Results: Of the 585 patients with displaced acetabular fractures treated with RT, (18%) 106 patients developed HO within the irradiated field. The risk of HO after RT increased from 10% for RT delivered {<=}3 days to 92% for treatment delivered >21 days after the initial injury. Wilcoxon test showed a significant correlation between the risk of HO and the length of time from injury to RT (p < 0.0001). Chi-square test and multiple logistic regression analysis showed no significant association between all other factors and the risk of HO (race, gender, cause and type of fracture, surgical approach, or the use of indomethacin). Conclusions: Our data suggest that there is higher incidence and risk of HO if prophylactic RT is significantly delayed after a displaced acetabular fracture. Thus, RT should be administered as early as clinically possible after the trauma. Patients undergoing RT >3 weeks from their displaced acetabular fracture should be informed of the higher risk (>90%) of developing HO despite prophylaxis.

  9. Exercise-induced hypoalgesia - interval versus continuous mode.

    PubMed

    Kodesh, Einat; Weissman-Fogel, Irit

    2014-07-01

    Aerobic exercise at approximately 70% of maximal aerobic capacity moderately reduces pain sensitivity and attenuates pain, even after a single session. If the analgesic effects depend on exercise intensity, then high-intensity interval exercise at 85% of maximal aerobic capacity should further reduce pain. The aim of this study was to explore the exercise-induced analgesic effects of high-intensity interval aerobic exercise and to compare them with the analgesic effects of moderate continuous aerobic exercise. Twenty-nine young untrained healthy males were randomly assigned to aerobic-continuous (70% heart rate reserve (HRR)) and interval (4 × 4 min at 85% HRR and 2 min at 60% HRR between cycles) exercise modes, each lasting 30 min. Psychophysical pain tests, pressure and heat pain thresholds (HPT), and tonic heat pain (THP) were conducted before and after exercise sessions. Repeated measures ANOVA was used for data analysis. HPT increased (p = 0.056) and THP decreased (p = 0.013) following exercise unrelated to exercise type. However, the main time effect (pre-/postexercise) was a trend of increased HPT (45.6 ± 1.9 °C to 46.2 ± 1.8 °C; p = 0.082) and a significant reduction in THP (from 50.7 ± 25 to 45.9 ± 25.4 numeric pain scale; p = 0.043) following interval exercise. No significant change was found for the pressure pain threshold following either exercise type. In conclusion, interval exercise (85% HRR) has analgesic effects on experimental pain perception. This, in addition to its cardiovascular, muscular, and metabolic advantages may promote its inclusion in pain management programs. PMID:24773287

  10. Effect of denture cleansers on surface hardness of resilient denture liners at various time intervals- an in vitro study

    PubMed Central

    Pahuja, Rasleen Kaur; Bansal, Sanjay

    2013-01-01

    PURPOSE This study was aimed to determine the effect of two chemically distinct denture cleansers and water on the surface hardness of acrylic and silicone based soft denture liners at various time intervals. MATERIALS AND METHODS Two commonly used commercial resilient liner material were selected based on their chemical composition (silicone- and acrylic-based soft liners) for this investigation. 120 cylindrical specimens were made of 15 mm × 10 mm dimensions (according to ASTM: D-2240-64T) in a custom made metal mold. All specimens were stored in artificial saliva throughout the study. Forty specimens were cleansed daily in 0.5% sodium hypochlorite solution; forty were cleansed in sodium perborate and remaining forty specimens were daily rinsed in water. Testing was done at 1 week, 1 month, 3 months and 6 months for surface hardness using a Shore A Durometer. A mean of 3 reading for each sample was subjected to one-way ANOVA, Post Hoc test and pair-t test for statistical analysis. P values of less than 0.05 were taken as statistically significant. RESULTS Surface hardness of all the samples was significantly higher after a period of 6 months irrespective of the cleansing treatment. Minor changes were observed between control, sodium hypochlorite and sodium perborate groups with time. Greater change was observed in surface hardness of acrylic-based soft denture liners as compared to silicone-based soft liners for all groups, as time progressed. CONCLUSION Silicone-based soft denture liners performed significantly better in all cleansing treatments than acrylic-based soft denture liners. PMID:24049568

  11. Bursts shape the NMDA-R mediated spike timing dependent plasticity curve: role of burst interspike interval and GABAergic inhibition.

    PubMed

    Cutsuridis, Vassilis

    2012-10-01

    Spike timing dependent plasticity (STDP) is a synaptic learning rule where the relative timing between the presynaptic and postsynaptic action potentials determines the sign and strength of synaptic plasticity. In its basic form STDP has an asymmetric form which incorporates both persistent increases and persistent decreases in synaptic strength. The basic form of STDP, however, is not a fixed property and depends on the dendritic location. An asymmetric curve is observed in the distal dendrites, whereas a symmetrical one is observed in the proximal ones. A recent computational study has shown that the transition from the asymmetry to symmetry is due to inhibition under certain conditions. Synapses have also been observed to be unreliable at generating plasticity when excitatory postsynaptic potentials and single spikes are paired at low frequencies. Bursts of spikes, however, are reliably signaled because transmitter release is facilitated. This article presents a two-compartment model of the CA1 pyramidal cell. The model is neurophysiologically plausible with its dynamics resulting from the interplay of many ionic and synaptic currents. Plasticity is measured by a deterministic Ca(2+) dynamics model which measures the instantaneous calcium level and its time course in the dendrite and change the strength of the synapse accordingly. The model is validated to match the asymmetrical form of STDP from the pairing of a presynaptic (dendritic) and postsynaptic (somatic) spikes as observed experimentally. With the parameter set unchanged the model investigates how pairing of bursts with single spikes and bursts in the presence or absence of inhibition shapes the STDP curve. The model predicts that inhibition strength and frequency are not the only factors of the asymmetry-to-symmetry switch of the STDP curve. Burst interspike interval is another factor. This study is an important first step towards understanding how STDP is affected under natural firing patterns in vivo

  12. Entropy, pattern entropy, and related methods for the analysis of data on the time intervals between heartbeats from 24-h electrocardiograms

    NASA Astrophysics Data System (ADS)

    Żebrowski, J. J.; Popławska, W.; Baranowski, R.

    1994-11-01

    Sequences of the time intervals between heartbeats-medically termed RR intervals-extracted from 24-h electrocardiogram recordings are examined as three-dimensional return map images. The recordings were made in humans by means of the medically widely used portable electrocardiograph (Holter system). A time window measured in the number of heartbeats is used and different types of behavior are classified. Bifurcations between the types of dynamics of the heart are noted and a form of intermittency is found. An alternative quantitative measure-a form pattern entropy of the return map image-is defined that characterizes the dynamics of the RR interval sequence. It is shown that this is a measure of the degree of ordering of the RR interval sequence and as such it is a good novel medical diagnostic tool for analyzing heart rate variability which distinguishes between illness and health where other diagnostics fail.

  13. Interval Training.

    ERIC Educational Resources Information Center

    President's Council on Physical Fitness and Sports, Washington, DC.

    Regardless of the type of physical activity used, interval training is simply repeated periods of physical stress interspersed with recovery periods during which activity of a reduced intensity is performed. During the recovery periods, the individual usually keeps moving and does not completely recover before the next exercise interval (e.g.,…

  14. The different effects of high intensity interval training and moderate intensity interval training for weightlessness countermeasures

    NASA Astrophysics Data System (ADS)

    Wang, Lin-Jie; Cheng, Tan; Zhi-Li, Li; Hui-juan, Wang; Wen-juan, Chen; Jianfeng, Zhang; Desheng, Wang; Dongbin, Niu; Qi, Zhao; Chengjia, Yang; Yanqing, Wang

    High intensity interval training (HIIT) has been demonstrated to improve performance in a relatively short training period. But the difference between high intensity interval training and moderate intensity interval training (MIIT) in simulated weightlessness still has not been well studied. This study sought to characterize the difference between 6 weeks high intensity interval training and moderate intensity interval training under reduced weight (RW) gait training device and zero-gravity locomotion system (ZLS). Twenty-three subjects (14M/4F, 32.5±4.5 years) volunteered to participate. They were divided into three groups, that were MITT (alternating 2 min at 40% VO _{2} peak and 2 min at 60% VO _{2} peak for 30min, five days per week) RW group (n=8), HITT (alternating 2 min at 40% VO _{2} peak and 2 min at 90% VO _{2} peak for 30min, three days per week) RW group (n=8) and HITT ZLS group (n=7). The Z-axis load used in RW group was 80% body weight (BW) and in ZLS was 100% BW. Cardiopulmonary function was measured before, after 4-week training and after 6-week training. Isokinetic knee extension-flexion test at 60(°) deg/s and 180(°) deg/s were performed before and after the 6-week training, and isometric knee extension-flexion test at 180(°) deg/s was also examined at the same time. It was found that the VO _{2} peaks, metabolic equivalent (MET), Speedmax and respiratory exchange ratio (RER) were significantly increased after 4 and 6-week training in all three groups and no significant group difference were detected. The peak torque at 60(°) deg/s for right knee flexion were significantly increased after 6 week-training in all three groups, and only in HITT RW group the total power at 60(°) deg/s for right knee flexion enhanced. The total power and average power at 60(°) deg/s for right knee extension decreased significantly after 6-week training in all three groups. The peak torque at 60(°) deg/s for right knee extension in MIIT RW group was

  15. Time series and recurrence interval models to predict the vulnerability of streams to episodic acidification in Shenandoah National Park, Virginia

    USGS Publications Warehouse

    Deviney, F.A., Jr.; Rice, K.C.; Hornberger, G.M.

    2006-01-01

    Acid rain affects headwater streams by temporarily reducing the acid-neutralizing capacity (ANC) of the water, a process termed episodic acidification. The increase in acidic components in stream water can have deleterious effects on the aquatic biota. Although acidic deposition is uniform across Shenandoah National Park (SNP) in north central Virginia, the stream water quality response during rain events varies substantially. This response is a function of the catchment's underlying geology and topography. Geologic and topographic data for SNP's 231 catchments are readily available; however, long-term measurements (tens of years) of ANC and accompanying discharge are not and would be prohibitively expensive to collect. Transfer function time series models were developed to predict hourly ANC from discharge for five SNP catchments with long-term water-quality and discharge records. Hourly ANC predictions over short time periods (??? 1 week) were averaged, and distributions of the recurrence intervals of annual water-year minimum ANC values were model-simulated for periods of 6, 24, 72, and 168 hours. The distributions were extrapolated to the rest of the SNP catchments on the basis of catchment geology and topography. On the basis of the models, large numbers of SNP streams have 6- to 168-hour periods of low-ANC values, which may stress resident fish populations. Smaller catchments are more vulnerable to episodic acidification than larger catchments underlain by the same bedrock. Catchments with similar topography and size are more vulnerable if underlain by less basaltic/carbonate bedrock. Many catchments are predicted to have successive years of low-ANC values potentially sufficient to extirpate some species. Copyright 2006 by the American Geophysical Union.

  16. Running interval training and estimated plasma-volume variation.

    PubMed

    Ben Abderrahman, Abderraouf; Prioux, Jacques; Chamari, Karim; Ben Ounis, Omar; Tabka, Zouhair; Zouhal, Hassane

    2013-07-01

    The effect of endurance interval training (IT) on hematocrit (Ht), hemoglobin (Hb), and estimated plasma- volume variation (PVV) in response to maximal exercise was studied in 15 male subjects (21.1 ± 1.1 y; control group n = 6, and training group, n = 9). The training group participated in interval training 3 times a week for 7 wk. A maximal graded test (GXT) was performed to determine maximal aerobic power (MAP) and maximal aerobic speed (MAS) both before and after the training program. To determine Ht, Hb concentration, and lactate concentrations, blood was collected at rest, at the end of GXT, and after 10 and 30 min of recovery. MAP and MAS increased significantly (P < .05) after training only in training group. Hematocrit determined at rest was significantly lower in the training group than in the control group after the training period (P < .05). IT induced a significant increase of estimated PVV at rest for training group (P < .05), whereas there were no changes for control group. Hence, significant relationships were observed after training between PVV deter- mined at the end of the maximal test and MAS (r = .60, P < .05) and MAP (r = .76, P < .05) only for training group. In conclusion, 7 wk of IT led to a significant increase in plasma volume that possibly contributed to the observed increase of aerobic fitness (MAP and MAS). PMID:23113934

  17. RISMA: A Rule-based Interval State Machine Algorithm for Alerts Generation, Performance Analysis and Monitoring Real-Time Data Processing

    NASA Astrophysics Data System (ADS)

    Laban, Shaban; El-Desouky, Aly

    2013-04-01

    The monitoring of real-time systems is a challenging and complicated process. So, there is a continuous need to improve the monitoring process through the use of new intelligent techniques and algorithms for detecting exceptions, anomalous behaviours and generating the necessary alerts during the workflow monitoring of such systems. The interval-based or period-based theorems have been discussed, analysed, and used by many researches in Artificial Intelligence (AI), philosophy, and linguistics. As explained by Allen, there are 13 relations between any two intervals. Also, there have also been many studies of interval-based temporal reasoning and logics over the past decades. Interval-based theorems can be used for monitoring real-time interval-based data processing. However, increasing the number of processed intervals makes the implementation of such theorems a complex and time consuming process as the relationships between such intervals are increasing exponentially. To overcome the previous problem, this paper presents a Rule-based Interval State Machine Algorithm (RISMA) for processing, monitoring, and analysing the behaviour of interval-based data, received from real-time sensors. The proposed intelligent algorithm uses the Interval State Machine (ISM) approach to model any number of interval-based data into well-defined states as well as inferring them. An interval-based state transition model and methodology are presented to identify the relationships between the different states of the proposed algorithm. By using such model, the unlimited number of relationships between similar large numbers of intervals can be reduced to only 18 direct relationships using the proposed well-defined states. For testing the proposed algorithm, necessary inference rules and code have been designed and applied to the continuous data received in near real-time from the stations of International Monitoring System (IMS) by the International Data Centre (IDC) of the Preparatory

  18. Classification mapping and species identification of salt marshes based on a short-time interval NDVI time-series from HJ-1 optical imagery

    NASA Astrophysics Data System (ADS)

    Sun, Chao; Liu, Yongxue; Zhao, Saishuai; Zhou, Minxi; Yang, Yuhao; Li, Feixue

    2016-03-01

    Salt marshes are seen as the most dynamic and valuable ecosystems in coastal zones, and in these areas, it is crucial to obtain accurate remote sensing information on the spatial distributions of species over time. However, discriminating various types of salt marsh is rather difficult because of their strong spectral similarities. Previous salt marsh mapping studies have focused mainly on high spatial and spectral (i.e., hyperspectral) resolution images combined with auxiliary information; however, the results are often limited to small regions. With a high temporal and moderate spatial resolution, the Chinese HuanJing-1 (HJ-1) satellite optical imagery can be used not only to monitor phenological changes of salt marsh vegetation over short-time intervals, but also to obtain coverage of large areas. Here, we apply HJ-1 satellite imagery to the middle coast of Jiangsu in east China to monitor changes in saltmarsh vegetation cover. First, we constructed a monthly NDVI time-series to classify various types of salt marsh and then we tested the possibility of using compressed time-series continuously, to broaden the applicability of this particular approach. Our principal findings are as follows: (1) the overall accuracy of salt marsh mapping based on the monthly NDVI time-series was 90.3%, which was ∼16.0% higher than the single-phase classification strategy; (2) a compressed time-series, including NDVI from six key months (April, June-September, and November), demonstrated very little reduction (2.3%) in overall accuracy but led to obvious improvements in unstable regions; and (3) a simple rule for Spartina alterniflora identification was established using a scene solely from November, which may provide an effective way for regularly monitoring its distribution.

  19. Long-interval facilitation and inhibition are differentially affected by conditioning stimulus intensity over different time courses.

    PubMed

    Vallence, Ann-Maree; Schneider, Luke A; Pitcher, Julia B; Ridding, Michael C

    2014-06-01

    Intracortical facilitatory and inhibitory processes in the primary motor cortex (M1) play an important role in both the preparation and execution of motor tasks. Here we aimed to (1) confirm the existence of, and further characterise, intracortical facilitation at long conditioning-test stimulus intervals at subthreshold conditioning stimulus (CS) intensities and (2) identify the threshold for long-interval intracortical inhibition (LICI) at different inter-stimulus intervals (ISIs). To examine facilitation, stimulus-response curves at ISIs of 100 and 150 ms were obtained using a range of subthreshold CS intensities. LICI stimulus-response curves were also obtained using varying CS intensities at ISIs of 100 (LICI100) and 150 ms (LICI150). Facilitation of the conditioned MEP was observed at subthreshold CS intensities at an ISI of 100 ms. LICI100 was observed at a lower CS intensity than LICI150. First, we provide evidence of a long-interval facilitation and provide some evidence consistent with a cortical origin of this facilitation. Second, the lower threshold for evoking LICI100 than LICI150 suggests an intensity-duration effect whereby a more intense CS results in longer duration LICI. Investigation of the interaction between LICI and long-interval facilitation might help to elucidate the functional importance of these processes. PMID:24704380

  20. Note: Simple calibration of the counting-rate dependence of the timing shift of single photon avalanche diodes by photon interval analysis

    SciTech Connect

    Otosu, Takuhiro; Ishii, Kunihiko; Tahara, Tahei

    2013-03-15

    The counting-rate dependence of the temporal response of single photon avalanche diodes (SPADs) is a critical issue for the accurate determination of the fluorescence lifetime. In this study, the response of SPADs was examined with analyzing the time interval of the detected photons. The results clearly show that the shift of the detection timing causes the counting-rate dependence of the temporal response, and this timing shift is solely determined by the time interval from the preceding photon. We demonstrate that this timing instability is readily calibrated by utilizing the macrotime data taken with the time-tag mode that is implemented in the time-correlated single photon counting modules.

  1. Nitrate Intake Promotes Shift in Muscle Fiber Type Composition during Sprint Interval Training in Hypoxia

    PubMed Central

    De Smet, Stefan; Van Thienen, Ruud; Deldicque, Louise; James, Ruth; Sale, Craig; Bishop, David J.; Hespel, Peter

    2016-01-01

    Purpose: We investigated the effect of sprint interval training (SIT) in normoxia, vs. SIT in hypoxia alone or in conjunction with oral nitrate intake, on buffering capacity of homogenized muscle (βhm) and fiber type distribution, as well as on sprint and endurance performance. Methods: Twenty-seven moderately-trained participants were allocated to one of three experimental groups: SIT in normoxia (20.9% FiO2) + placebo (N), SIT in hypoxia (15% FiO2) + placebo (H), or SIT in hypoxia + nitrate supplementation (HN). All participated in 5 weeks of SIT on a cycle ergometer (30-s sprints interspersed by 4.5 min recovery-intervals, 3 weekly sessions, 4–6 sprints per session). Nitrate (6.45 mmol NaNO3) or placebo capsules were administered 3 h before each session. Before and after SIT participants performed an incremental VO2max-test, a 30-min simulated cycling time-trial, as well as a 30-s cycling sprint test. Muscle biopsies were taken from m. vastus lateralis. Results: SIT decreased the proportion of type IIx muscle fibers in all groups (P < 0.05). The relative number of type IIa fibers increased (P < 0.05) in HN (P < 0.05 vs. H), but not in the other groups. SIT had no significant effect on βhm. Compared with H, SIT tended to enhance 30-s sprint performance more in HN than in H (P = 0.085). VO2max and 30-min time-trial performance increased in all groups to a similar extent. Conclusion: SIT in hypoxia combined with nitrate supplementation increases the proportion of type IIa fibers in muscle, which may be associated with enhanced performance in short maximal exercise. Compared with normoxic training, hypoxic SIT does not alter βhm or endurance and sprinting exercise performance. PMID:27378942

  2. To study the flow property of seven commercially available zinc oxide eugenol impression material at various time intervals after mixing.

    PubMed

    Katna, Vishal; Suresh, S; Vivek, Sharma; Meenakshi, Khandelwal; Ankita, Gaur

    2014-12-01

    Aims and objective of the study was to evaluate the flow property of seven commercially available zinc oxide eugenol impression materials at various time intervals, after mixing 49 samples (seven groups) were fabricated for flow property of the material. The sample were fabricated as equal length of base and accelerator paste of the test materials was taken on the glass slab and mixed with a rigid stainless steel spatula as per manufacturers recommendation till the homogenous mix was obtained. The mix material was loaded in glass syringe and 0.5 ml material was injected on a cellophane sheet placed on marked glass plate. A cellophane sheet and glass plate 70 and 500 g weight was carefully placed on freshly dispensed zinc oxide eugenol impression paste sequentially. The diameter of the mix was noted after 30 s and 1 min of load application and also after the final set of material. The diameter gives the flow of material. The samples were stored at the room temperature. The data of the flow property was analyzed with analysis of variance, Post hoc test and t test. The flow of the zinc oxide eugenol impression paste after 30 s, 1 min and final set of load application for Group A to Group G was noted. Maximum flow was seen for Group G zinc oxide eugenol impression material followed by Group F, D, E, B, C and A in descending order respectively after 30 s, where as the flow property changed after 1 min in the sequence of maximum for Group G followed by Group E, D, B, A, C, and F. Lastly after final set of the impression material the flow maximum for Group G followed by Group E, D, C, F, A and B in descending order. Based on statistical analysis of the results and within in the limitations of this in-vitro study, the following conclusions were drawn that; the flow of zinc oxide eugenol impression material after 30 s, 1 min and that after the final set was maximum for P.S.P. (Group G) and the flow for PYREX (Group A) was minimum. PMID:25489163

  3. Administration of the Phosphodiesterase Type 4 Inhibitor Rolipram into the Amygdala at a Specific Time Interval after Learning Increases Recognition Memory Persistence

    ERIC Educational Resources Information Center

    Werenicz, Aline; Christoff, Raissa R.; Blank, Martina; Jobim, Paulo F. C.; Pedroso, Thiago R.; Reolon, Gustavo K.; Schroder, Nadja; Roesler, Rafael

    2012-01-01

    Here we show that administration of the phosphodiesterase type 4 (PDE4) inhibitor rolipram into the basolateral complex of the amygdala (BLA) at a specific time interval after training enhances memory consolidation and induces memory persistence for novel object recognition (NOR) in rats. Intra-BLA infusion of rolipram immediately, 1.5 h, or 6 h…

  4. Measurement of Trained Speech Patterns in Stuttering: Interjudge and Intrajudge Agreement of Experts by Means of Modified Time-Interval Analysis

    ERIC Educational Resources Information Center

    Alpermann, Anke; Huber, Walter; Natke, Ulrich; Willmes, Klaus

    2010-01-01

    Improved fluency after stuttering therapy is usually measured by the percentage of stuttered syllables. However, outcome studies rarely evaluate the use of trained speech patterns that speakers use to manage stuttering. This study investigated whether the modified time interval analysis can distinguish between trained speech patterns, fluent…

  5. Individualized treatment with infliximab therapy in children with Crohn’s disease support shorter time intervals between infusions

    PubMed Central

    Sommar, M.; Eksborg, S.; Hildebrand, H.; Grahnquist, L.

    2012-01-01

    Objectives To study the effect of an individualized treatment approach with regard to dosage intervals between infliximab infusions on the clinical outcome of pediatric Crohn’s disease (CD). Patients and methods A retrospective analysis of medical records of all pediatric patients with CD who had been treated with infliximab between 1999 and 2007 in two Swedish counties, where an individualized treatment approach had been applied. Results Twenty-nine patients were included in the study. The number of infusions varied from 2 to 47 (median: 8). Nineteen patients received more than 5 infusions and 13 patients received more than 10 infusions. Most of the patients did not stay in remission when the dosage interval was 8 weeks or longer. Conclusions An individualized treatment approach, based on the physician’s desire to treat, resulted in shorter dosage intervals than 8 weeks between infliximab infusions in a majority of pediatric patients with CD. The retrospective design of the study must be taken into account when interpreting the results.

  6. The in vivo study on the radiobiologic effect of prolonged delivery time to tumor control in C57BL mice implanted with Lewis lung cancer

    PubMed Central

    2011-01-01

    Background High-precision radiation therapy techniques such as IMRT or sterotactic radiosurgery, delivers more complex treatment fields than conventional techniques. The increased complexity causes longer dose delivery times for each fraction. The purpose of this work is to explore the radiobiologic effect of prolonged fraction delivery time on tumor response and survival in vivo. Methods 1-cm-diameter Lewis lung cancer tumors growing in the legs of C57BL mice were used. To evaluate effect of dose delivery prolongation, 18 Gy was divided into different subfractions. 48 mice were randomized into 6 groups: the normal control group, the single fraction with 18 Gy group, the two subfractions with 30 min interval group, the seven subfractions with 5 min interval group, the two subfractions with 60 min interval group and the seven subfractions with 10 min interval group. The tumor growth tendency, the tumor growth delay and the mice survival time were analyzed. Results The tumor growth delay of groups with prolonged delivery time was shorter than the group with single fraction of 18 Gy (P < 0.05). The tumor grow delay of groups with prolonged delivery time 30 min was longer than that of groups with prolonged delivery time 60 min P < 0.05). There was no significant difference between groups with same delivery time (P > 0.05). Compared to the group with single fraction of 18 Gy, the groups with prolonged delivery time shorten the mice survival time while there was no significant difference between the groups with prolonged delivery time 30 min and the groups with prolonged delivery time 60 min. Conclusions The prolonged delivery time with same radiation dose shorten the tumor growth delay and survival time in the mice implanted with Lewis lung cancer. The anti-tumor effect decreased with elongation of the total interfractional time. PMID:21226899

  7. Interbirth intervals

    PubMed Central

    Haig, David

    2014-01-01

    Background and objectives: Interbirth intervals (IBIs) mediate a trade-off between child number and child survival. Life history theory predicts that the evolutionarily optimal IBI differs for different individuals whose fitness is affected by how closely a mother spaces her children. The objective of the article is to clarify these conflicts and explore their implications for public health. Methodology: Simple models of inclusive fitness and kin conflict address the evolution of human birth-spacing. Results: Genes of infants generally favor longer intervals than genes of mothers, and infant genes of paternal origin generally favor longer IBIs than genes of maternal origin. Conclusions and implications: The colonization of maternal bodies by offspring cells (fetal microchimerism) raises the possibility that cells of older offspring could extend IBIs by interfering with the implantation of subsequent embryos. PMID:24480612

  8. Defibrillation time intervals and outcomes of cardiac arrest in hospital: retrospective cohort study from Get With The Guidelines-Resuscitation registry

    PubMed Central

    Liu, Wenhui; Chan, Paul S; Nallamothu, Brahmajee K; Grunwald, Gary K; Self, Alyssa; Sasson, Comilla; Varosy, Paul D; Anderson, Monique L; Schneider, Preston M; Ho, P Michael

    2016-01-01

    Objective To describe temporal trends in the time interval between first and second attempts at defibrillation and the association between this time interval and outcomes in patients with persistent ventricular tachycardia or ventricular fibrillation (VT/VF) arrest in hospital. Design Retrospective cohort study Setting 172 hospitals in the United States participating in the Get With The Guidelines-Resuscitation registry, 2004-12. Participants Adults who received a second defibrillation attempt for persistent VT/VF arrest within three minutes of a first attempt. Interventions Second defibrillation attempts categorized as early (time interval of up to and including one minute between first and second defibrillation attempts) or deferred (time interval of more than one minute between first and second defibrillation attempts). Main outcome measure Survival to hospital discharge. Results Among 2733 patients with persistent VT/VF after the first defibrillation attempt, 1121 (41%) received a deferred second attempt. Deferred second defibrillation for persistent VT/VF increased from 26% in 2004 to 57% in 2012 (P<0.001 for trend). Compared with early second defibrillation, unadjusted patient outcomes were significantly worse with deferred second defibrillation (57.4% v 62.5% for return of spontaneous circulation, 38.4% v 43.6% for survival to 24 hours, and 24.7% v 30.8% for survival to hospital discharge; P<0.01 for all comparisons). After risk adjustment, deferred second defibrillation was not associated with survival to hospital discharge (propensity weighting adjusted risk ratio 0.89, 95% confidence interval 0.78 to 1.01; P=0.08; hierarchical regression adjusted 0.92, 0.83 to 1.02; P=0.1). Conclusions Since 2004, the use of deferred second defibrillation for persistent VT/VF in hospital has doubled. Deferred second defibrillation was not associated with improved survival. PMID:27052620

  9. Evaluation of the Effects of Light Intensity and Time Interval After the Start of Scotophase on the Female Flight Propensity of Asian Gypsy Moth (Lepidoptera: Erebidae).

    PubMed

    Chen, Fang; Shi, Juan; Keena, Melody

    2016-04-01

    Asian gypsy moth, Lymantria dispar L. (Lepidoptera: Erebidae), females are capable of flight, but little is known about what causes the variation in flight propensity that has been observed. The female flight propensity and capability of Asian gypsy moth from seven geographic populations (three from China, two from Russia, one from Japan, and one from Korea) were compared under all combinations of three light intensities (0.05, 0.10, and 0.40 lux) and during three time intervals after the start of scotophase. A total of 567 females were flight tested. Female flight propensity, time to initiate walking, fanning, and flying, and duration of fanning differed significantly among geographic populations. Females were less likely to voluntarily fly during the 0-1-h time interval after the start of scotophase than during the later time intervals (1-2 and 2-3 h), suggesting that the light intensity cue has to occur at the correct time after the expected start of scotophase for flight initiation. Light intensity did not significantly affect the proportion of females that voluntarily flew, but did impact the timing of the walking and fanning preflight behaviors. The interaction between light intensity and time interval after the start of scotophase had a significant effect on the proportion of females that fanned. The proportion of females with sustained flight capability varied among the populations evaluated. These results may aid in determining the risk of Asian gypsy moth dispersal, but further work is needed to assess other factors that play a role in flight propensity. PMID:26748672

  10. Low-jitter wide-range integrated time interval/delay generator based on combination of period counting and capacitor charging

    NASA Astrophysics Data System (ADS)

    Klepacki, K.; Pawłowski, M.; Szplet, R.

    2015-02-01

    We present the design, operation, and test results of a new time interval/delay generator that provides the resolution of 0.3 ps, jitter below 10 ps (rms), and wide delay range of 10 s. The wide range has been achieved by counting periods of a reference clock while the high resolution and low jitter have been obtained through the two-time use of inner interpolation. This interpolation, based on charging of a single capacitor, provides both the precise external trigger synchronization and accurate generation of residual time interval. A combination of both processes virtually eliminates triggering indeterminacy. The jitter between the trigger and output is below 1 ps, which ensures a high performance delay. The generator is integrated in a single application specific integrated circuit chip using a standard cost-effective 0.35 μm CMOS process.

  11. Stability criteria for T-S fuzzy systems with interval time-varying delays and nonlinear perturbations based on geometric progression delay partitioning method.

    PubMed

    Chen, Hao; Zhong, Shouming; Li, Min; Liu, Xingwen; Adu-Gyamfi, Fehrs

    2016-07-01

    In this paper, a novel delay partitioning method is proposed by introducing the theory of geometric progression for the stability analysis of T-S fuzzy systems with interval time-varying delays and nonlinear perturbations. Based on the common ratio α, the delay interval is unequally separated into multiple subintervals. A newly modified Lyapunov-Krasovskii functional (LKF) is established which includes triple-integral terms and augmented factors with respect to the length of every related proportional subintervals. In addition, a recently developed free-matrix-based integral inequality is employed to avoid the overabundance of the enlargement when dealing with the derivative of the LKF. This innovative development can dramatically enhance the efficiency of obtaining the maximum upper bound of the time delay. Finally, much less conservative stability criteria are presented. Numerical examples are conducted to demonstrate the significant improvements of this proposed approach. PMID:27138648

  12. Evaluation of colour stability of provisional restorative materials exposed to different mouth rinses at varying time intervals: an in vitro study.

    PubMed

    Prasad, D Krishna; Alva, Harshitha; Shetty, Manoj

    2014-03-01

    The most important factor affecting esthetics is colour. Whether a definitive prosthesis or a provisional restoration, maintenance of esthetics is of prime concern along with restoration of function. Colour stability of provisional prosthesis is affected by various factors and various studies are documented in the literature on this. The purpose of this study was to evaluate the colour stability of provisional restorative materials exposed to different mouth rinses at varying time intervals. 120 discs, each of self cure tooth moulding material, Protemp 4 and Revotek LC were prepared and immersed in two mouth rinses, hexidine and periogard and evaluated for their colour stability after 1 week, 1 and 3 months. The data obtained was statistically analysed using ANOVA and Tukey's post hoc analysis. The results indicate that there is a significant difference in the colour variation of various materials in two different mouth rinses at different time intervals. Revotek LC was found to be the most colour stable material and periogard had the least staining potential at varying time intervals. PMID:24605003

  13. Recovery from exercise at varying work loads - Time course of responses of heart rate and systolic intervals

    NASA Technical Reports Server (NTRS)

    Nandi, P. S.; Spodick, D. H.

    1977-01-01

    The time course of the recovery period was characterized by noninvasive measurements after 4 minute bicycle exercise at 3 separate work loads in volunteers with normal peak responses. Most responses started immediately to return toward resting control values. Left ventricular ejection time and stroke volume change are discussed. Changes in pre-ejection period were determined by changes in isovolume contraction time, and factors affecting the degree and rate of return are considered. The rates of change in the ejection time index and in the ratio pre-ejection period/left ventricular ejection time were virtually independent of load throughout most of recovery.

  14. The relationship between adjunctive drinking, blood ethanol concentration and plasma corticosterone across fixed-time intervals of food delivery in two inbred mouse strains

    PubMed Central

    Ford, Matthew M.; Steele, Andrea M.; McCracken, Aubrey D.; Finn, Deborah A.; Grant, Kathleen A.

    2013-01-01

    Summary Schedules of intermittent food delivery induce excessive fluid intake, termed schedule-induced polydipsia (SIP), and hypothalamic-pituitary-adrenal (HPA) axis activation is important for the expression and maintenance of this adjunctive behavior. Previous work has focused of examining the relationship between water intake and plasma corticosterone (CORT) in rats at a single or a limited range of fixed time (FT) intervals. However, little remains known regarding SIP and the corresponding stress response 1) across the bitonic function that epitomizes adjunctive behavior, 2) when ethanol is the available fluid, and 3) when a species other than rat or multiple strains are studied. Here we report the findings from ethanol-preferring C57BL/6J (B6) and non-preferring DBA/2J (D2) mice serially exposed to progressively larger FT intervals (0 → 60 min) and given access to either water or a 5% v/v ethanol solution. Following 2 weeks of experience with each schedule, blood samples were collected at the conclusion of the last 60-min session to evaluate CORT and the blood ethanol concentration (BEC) achieved. While both strains exhibited a bitonic function of ethanol intake and BEC that peaked at or near a 5-min interval, only D2 mice showed a similar response with water. In contrast, CORT levels rose monotonically with incremental increases in the FT interval regardless of the strain examined or fluid type offered, indicating that glucocorticoid release likely reflects the aversive aspects of increasing intervals between reinforcement rather than engagement in adjunctive behavior. These findings also caution against the use of a single intensity stressor to evaluate the relationship between stress and ethanol intake, as the magnitude of stress appears to affect ethanol consumption in a non-linear fashion. PMID:23827168

  15. Generalized additive models with interval-censored data and time-varying covariates: application to human immunodeficiency virus infection in hemophiliacs.

    PubMed

    Bacchetti, Peter; Quale, Christopher

    2002-06-01

    We describe a method for extending smooth nonparametric modeling methods to time-to-event data where the event may be known only to lie within a window of time. Maximum penalized likelihood is used to fit a discrete proportional hazards model that also models the baseline hazard, and left-truncation and time-varying covariates are accommodated. The implementation follows generalized additive modeling conventions, allowing both parametric and smooth terms and specifying the amount of smoothness in terms of the effective degrees of freedom. We illustrate the method on a well-known interval-censored data set on time of human immunodeficiency virus infection in a multicenter study of hemophiliacs. The ability to examine time-varying covariates, not available with previous methods, allows detection and modeling of nonproportional hazards and use of a time-varying covariate that fits the data better and is more plausible than a fixed alternative. PMID:12071419

  16. Cardiac Time Intervals by Tissue Doppler Imaging M-Mode: Normal Values and Association with Established Echocardiographic and Invasive Measures of Systolic and Diastolic Function

    PubMed Central

    Mogelvang, Rasmus; de Knegt, Martina Chantal; Olsen, Flemming Javier; Galatius, Søren; Jensen, Jan Skov

    2016-01-01

    Purpose To define normal values of the cardiac time intervals obtained by tissue Doppler imaging (TDI) M-mode through the mitral valve (MV). Furthermore, to evaluate the association of the myocardial performance index (MPI) obtained by TDI M-mode (MPITDI) and the conventional method of obtaining MPI (MPIConv), with established echocardiographic and invasive measures of systolic and diastolic function. Methods In a large community based population study (n = 974), where all are free of any cardiovascular disease and cardiovascular risk factors, cardiac time intervals, including isovolumic relaxation time (IVRT), isovolumic contraction time (IVCT), and ejection time (ET) were obtained by TDI M-mode through the MV. IVCT/ET, IVRT/ET and the MPI ((IVRT+IVCT)/ET) were calculated. We also included a validation population (n = 44) of patients who underwent left heart catheterization and had the MPITDI and MPIConv measured. Results IVRT, IVRT/ET and MPI all increased significantly with increasing age in both genders (p<0.001 for all). IVCT, ET, IVRT/ET, and MPI differed significantly between males and females, displaying that women, in general exhibit better cardiac function. MPITDI was significantly associated with invasive (dP/dt max) and echocardiographic measures of systolic (LVEF, global longitudinal strain and global strainrate s) and diastolic function (e’, global strainrate e)(p<0.05 for all), whereas MPIConv was significantly associated with LVEF, e’ and global strainrate e (p<0.05 for all). Conclusion Normal values of cardiac time intervals differed between genders and deteriorated with increasing age. The MPITDI (but not MPIConv) is associated with most invasive and established echocardiographic measures of systolic and diastolic function. PMID:27093636

  17. Wait Times Experienced by Lung Cancer Patients in the BC Southern Interior to Obtain Oncologic Care: Exploration of the Intervals from First Abnormal Imaging to Oncologic Treatment

    PubMed Central

    Chowdhury, Rezwan; Boyce, Andrew; Halperin, Ross

    2015-01-01

    Background: Lung cancer is associated with rapid disease progression, which can significantly progress over a duration of four to eight weeks. This study examines the time interval lung cancer patients from the interior of British Columbia (BC) experience while undergoing diagnostic evaluation, biopsy, staging, and preparation for treatment. Methods: A chart review of lung cancer patients (n=231) referred to the BC Cancer Agency Centre for the Southern Interior between January 1, 2010 and December 31, 2011 was performed. Time zero was defined as the date of the first abnormal chest imaging. Time intervals, expressed as median averages, to specialist consult, biopsy, oncologic referral, initial oncology consultation, and commencement of oncologic treatment were obtained. Results: The median time interval from first abnormal chest imaging to a specialist consultation was 18 days (interquartile range, IQR, 7-36). An additional nine days elapsed prior to biopsy in the form of bronchoscopy, CT-guided biopsy, or sputum cytology (median; IQR, 3-21); if lobectomy was required, 18 days elapsed (median; IQR, 9-28). Eight days were required for pathologic diagnosis and subsequent referral to the cancer centre (median; IQR, 3-16.5). Once referral was received, 10 days elapsed prior to consultation with either a medical or radiation oncologist (median, IQR 5-18). Finally, eight days was required for initiation of radiation and/or chemotherapy (median; IQR, 1-15). The median wait time from detection of lung cancer on imaging to oncologic treatment in the form of radiation and/or chemotherapy was 65.5 days (IQR, 41.5-104.3).  Interpretation: Patients in the BC Southern Interior experience considerable delays in accessing lung cancer care. During this time, the disease has the potential to significantly progress and it is possible that a subset of patients may lose their opportunity for curative intent treatment. PMID:26543688

  18. Distortion of time interval reproduction in an epileptic patient with a focal lesion in the right anterior insular/inferior frontal cortices.

    PubMed

    Monfort, Vincent; Pfeuty, Micha; Klein, Madelyne; Collé, Steffie; Brissart, Hélène; Jonas, Jacques; Maillard, Louis

    2014-11-01

    This case report on an epileptic patient suffering from a focal lesion at the junction of the right anterior insular cortex (AIC) and the adjacent inferior frontal cortex (IFC) provides the first evidence that damage to this brain region impairs temporal performance in a visual time reproduction task in which participants had to reproduce the presentation duration (3, 5 and 7s) of emotionally-neutral and -negative pictures. Strikingly, as compared to a group of healthy subjects, the AIC/IFC case considerably overestimated reproduction times despite normal variability. The effect was obtained in all duration and emotion conditions. Such a distortion in time reproduction was not observed in four other epileptic patients without insular or inferior frontal damage. Importantly, the absolute extent of temporal over-reproduction increased in proportion to the magnitude of the target durations, which concurs with the scalar property of interval timing, and points to an impairment of time-specific rather than of non temporal (such as motor) mechanisms. Our data suggest that the disability in temporal reproduction of the AIC/IFC case would result from a distorted memory representation of the encoded duration, occurring during the process of storage and/or of recovery from memory and leading to a deviation of the temporal judgment during the reproduction task. These findings support the recent proposal that the anterior insular/inferior frontal cortices would be involved in time interval representation. PMID:25223467

  19. Delay-dependent stability and stabilization criteria for T-S fuzzy singular systems with interval time-varying delay by improved delay partitioning approach.

    PubMed

    Sun, Chao; Wang, Fuli; He, Xiqin

    2016-01-01

    This paper deals with the stability analysis and fuzzy stabilizing controller design for a class of Takagi-Sugeno fuzzy singular systems with interval time-varying delay and linear fractional uncertainties. By decomposing the delay interval into two unequal subintervals and seeking a appropriate ρ, a new Lyapunov-Krasovskii functional is constructed to develop the improved delay-dependent stability criteria, which ensures the considered system to be regular, impulse-free and stable. Furthermore, the desired fuzzy controller gains are also presented by solving a set of strict linear matrix inequalities. Compared with some existing results, the obtained ones give the result with less conservatism. Finally, some examples are given to show the improvement and the effectiveness of the proposed method. PMID:27066363

  20. Tracking time interval changes of pulmonary nodules on follow-up 3D CT images via image-based risk score of lung cancer

    NASA Astrophysics Data System (ADS)

    Kawata, Y.; Niki, N.; Ohmatsu, H.; Kusumoto, M.; Tsuchida, T.; Eguchi, K.; Kaneko, M.; Moriyama, N.

    2013-03-01

    In this paper, we present a computer-aided follow-up (CAF) scheme to support physicians to track interval changes of pulmonary nodules on three dimensional (3D) CT images and to decide the treatment strategies without making any under or over treatment. Our scheme involves analyzing CT histograms to evaluate the volumetric distribution of CT values within pulmonary nodules. A variational Bayesian mixture modeling framework translates the image-derived features into an image-based risk score for predicting the patient recurrence-free survival. Through applying our scheme to follow-up 3D CT images of pulmonary nodules, we demonstrate the potential usefulness of the CAF scheme which can provide the trajectories that can characterize time interval changes of pulmonary nodules.

  1. Time Interval From Breast-Conserving Surgery to Breast Irradiation in Early Stage Node-Negative Breast Cancer: 17-Year Follow-Up Results and Patterns of Recurrence

    SciTech Connect

    Vujovic, Olga; Yu, Edward; Cherian, Anil; Dar, A. Rashid; Stitt, Larry; Perera, Francisco

    2015-02-01

    Purpose: A retrospectivechart review was conducted to determine whether the time interval from breast-conserving surgery to breast irradiation (surgery-radiation therapy interval) in early stage node-negative breast cancer had any detrimental effects on recurrence rates. Methods and Materials: There were 566 patients with T1 to T3, N0 breast cancer treated with breast-conserving surgery and breast irradiation and without adjuvant systemic treatment between 1985 and 1992. The surgery-to-radiation therapy intervals used for analysis were 0 to 8 weeks (201 patients), >8 to 12 weeks (233 patients), >12 to 16 weeks (91 patients), and >16 weeks (41 patients). Kaplan-Meier estimates of time to local recurrence, disease-free survival, distant disease-free survival, cause-specific survival, and overall survival rates were calculated. Results: Median follow-up was 17.4 years. Patients in all 4 time intervals were similar in terms of characteristics and pathologic features. There were no statistically significant differences among the 4 time groups in local recurrence (P=.67) or disease-free survival (P=.82). The local recurrence rates at 5, 10, and 15 years were 4.9%, 11.5%, and 15.0%, respectively. The distant disease relapse rates at 5, 10, and 15 years were 10.6%, 15.4%, and 18.5%, respectively. The disease-free failure rates at 5, 10, and 15 years were 20%, 32.3%, and 39.8%, respectively. Cause-specific survival rates at 5, 10, and 15 years were 92%, 84.6%, and 79.8%, respectively. The overall survival rates at 5, 10, and 15 years were 89.3%, 79.2%, and 66.9%, respectively. Conclusions: Surgery-radiation therapy intervals up to 16 weeks from breast-conserving surgery are not associated with any increased risk of recurrence in early stage node-negative breast cancer. There is a steady local recurrence rate of 1% per year with adjuvant radiation alone.

  2. Two locations, two times, and the element set. [applicable to orbit determination of artificial satellites

    NASA Technical Reports Server (NTRS)

    Taff, L. G.; Randall, P. M. S.

    1985-01-01

    A robust analytical formulation is developed to apply classical initial orbital determination to artificial satellites whose locations are uncertain to about 1 cu km and separated in time by no more than 30 min. An analytical simplification reduces Gauss's method, iteration on the semilatus rectum, iteration on the true anomaly, and the Lambert-Euler technique, to the solution of a single equation in one unknown, instead of the usual coupled triplet of three equations in three unknowns. The method is demonstrated for all common artificial satellite orbits over a variety of time intervals between the two location vectors, and for a varied set of position and distance errors.

  3. Multiscale entropy and detrended fluctuation analysis of QT interval and heart rate variability during normal pregnancy.

    PubMed

    Baumert, Mathias; Javorka, Michal; Seeck, Andrea; Faber, Renaldo; Sanders, Prashanthan; Voss, Andreas

    2012-03-01

    Pregnancy leads to physiological changes in various parameters of the cardiovascular system. The aim of this study was to investigate longitudinal changes in the structure and complexity of heart rate variability (HRV) and QT interval variability during the second half of normal gestation. We analysed 30-min high-resolution ECGs recorded monthly in 32 pregnant women, starting from the 20th week of gestation. Heart rate and QT variability were quantified using multiscale entropy (MSE) and detrended fluctuation analyses (DFA). DFA of HRV showed significantly higher scaling exponents towards the end of gestation (p<0.0001). MSE analysis showed a significant decrease in sample entropy of HRV with progressing gestation on scales 1-4 (p<0.05). MSE analysis and DFA of QT interval time series revealed structures significantly different from those of HRV with no significant alteration during the second half of gestation. In conclusion, pregnancy is associated with increases in long-term correlations and regularity of HRV, but it does not affect QT variability. The structure of QT time series is significantly different from that of RR time series, despite its close physiological dependence. PMID:21530956

  4. Proper Interval Vertex Deletion

    NASA Astrophysics Data System (ADS)

    Villanger, Yngve

    Deleting a minimum number of vertices from a graph to obtain a proper interval graph is an NP-complete problem. At WG 2010 van Bevern et al. gave an O((14k + 14) k + 1 kn 6) time algorithm by combining iterative compression, branching, and a greedy algorithm. We show that there exists a simple greedy O(n + m) time algorithm that solves the Proper Interval Vertex Deletion problem on \\{claw,net,allowbreak tent,allowbreak C_4,C_5,C_6\\}-free graphs. Combining this with branching on the forbidden structures claw,net,tent,allowbreak C_4,C_5, and C 6 enables us to get an O(kn 6 6 k ) time algorithm for Proper Interval Vertex Deletion, where k is the number of deleted vertices.

  5. [Effect of ergonovine and the cold stress test on time intervals of left ventricular systole and their significance for the diagnosis of coronary heart disease].

    PubMed

    Gawor, Z; Markiewicz, K; Cholewa, M

    1988-08-15

    In 20 healthy test persons and 44 patients with a coronary heart disease without stenocardia at rest the ergonovine and the cold pressure test were performed. During the tests the ECG in 12 standard leads and the mechanocardiogrammes were registered, from which the time intervals of the left-ventricular systole were calculated. From the analysis of the pectanginous complaints and/or from the changes of the ST segment for the diagnosis of the coronary heart disease a sensitiveness of the ergonovine test of 40% was obtained, whereas the sensitiveness of the cold tolerance test was only 10%. In healthy test persons during the ergonovine test a shortening of Q-1, a decrease of the quotient PEP/LVET and a prolongation of LVETI were established. Apart from this, in patients with coronary heart disease also shortenings of ICT and PEP and an increase of the quotient LVET/S1S2 were made evident. During the cold tolerance test in healthy test persons, besides the prolongation of LVETI, no other changes were stated. On the other hand, in the patients a decrease of the quotient PEP/LVET and a shortening of PEP were existing. The diagnostic value of the analysis of the left-ventricular time intervals was insignificantly higher during the ergonovine test than at rest. However, during the cold pressure tests no differences were stated. The application of the analysis of the left-ventricular time intervals does not essentially enlarge the sensitiveness of the two tests in comparison to the analysis of the changes of the ST segment in the ECG. PMID:3188594

  6. Low cadence interval training at moderate intensity does not improve cycling performance in highly trained veteran cyclists

    PubMed Central

    Kristoffersen, Morten; Gundersen, Hilde; Leirdal, Stig; Iversen, Vegard V.

    2014-01-01

    Purpose: The aim of the present study was to investigate effects of low cadence training at moderate intensity on aerobic capacity, cycling performance, gross efficiency, freely chosen cadence, and leg strength in veteran cyclists. Method: Twenty-two well trained veteran cyclists [age: 47 ± 6 years, maximal oxygen consumption (VO2max): 57.9 ± 3.7 ml · kg−1 · min−1] were randomized into two groups, a low cadence training group and a freely chose cadence training group. Respiratory variables, power output, cadence and leg strength were tested before and after a 12 weeks training intervention period. The low cadence training group performed 12 weeks of moderate [73–82% of maximal heart rate (HRmax)] interval training (5 × 6 min) with a cadence of 40 revolutions per min (rpm) two times a week, in addition to their usual training. The freely chosen cadence group added 90 min of training at freely chosen cadence at moderate intensity. Results: No significant effects of the low cadence training on aerobic capacity, cycling performance, power output, cadence, gross efficiency, or leg strength was found. The freely chosen cadence group significantly improved both VO2max (58.9 ± 2.4 vs. 62.2 ± 3.2 ml · kg−1 · min−1), VO2 consumption at lactate threshold (49.4 ± 3.8 vs. 51.8 ± 3.5 ml · kg−1 · min−1) and during the 30 min performance test (52.8 ± 3.0 vs. 54.7 ± 3.5 ml · kg−1 · min−1), and power output at lactate threshold (284 ± 47 vs. 294 ± 48 W) and during the 30 min performance test (284 ± 42 vs. 297 ± 50 W). Moreover, a significant difference was seen when comparing the change in freely chosen cadence from pre- to post between the groups during the 30 min performance test (2.4 ± 5.0 vs. −2.7 ± 6.2). Conclusion: Twelve weeks of low cadence (40 rpm) interval training at moderate intensity (73–82% of HRmax) twice a week does not improve aerobic capacity, cycling performance or leg strength in highly trained veteran cyclists

  7. High Resolution ECG for Evaluation of QT Interval Variability during Exposure to Acute Hypoxia

    NASA Technical Reports Server (NTRS)

    Zupet, P.; Finderle, Z.; Schlegel, Todd T.; Starc, V.

    2010-01-01

    Ventricular repolarization instability as quantified by the index of QT interval variability (QTVI) is one of the best predictors for risk of malignant ventricular arrhythmias and sudden cardiac death. Because it is difficult to appropriately monitor early signs of organ dysfunction at high altitude, we investigated whether high resolution advanced ECG (HR-ECG) analysis might be helpful as a non-invasive and easy-to-use tool for evaluating the risk of cardiac arrhythmias during exposure to acute hypoxia. 19 non-acclimatized healthy trained alpinists (age 37, 8 plus or minus 4,7 years) participated in the study. Five-minute high-resolution 12-lead electrocardiograms (ECGs) were recorded (Cardiosoft) in each subject at rest in the supine position breathing room air and then after breathing 12.5% oxygen for 30 min. For beat-to-beat RR and QT variability, the program of Starc was utilized to derive standard time domain measures such as root mean square of the successive interval difference (rMSSD) of RRV and QTV, the corrected QT interval (QTc) and the QTVI in lead II. Changes were evaluated with paired-samples t-test with p-values less than 0.05 considered statistically significant. As expected, the RR interval and its variability both decreased with increasing altitude, with p = 0.000 and p = 0.005, respectively. Significant increases were found in both the rMSSDQT and the QTVI in lead II, with p = 0.002 and p = 0.003, respectively. There was no change in QTc interval length (p = non significant). QT variability parameters may be useful for evaluating changes in ventricular repolarization caused by hypoxia. These changes might be driven by increases in sympathetic nervous system activity at ventricular level.

  8. Seismic recurrence intervals and timing of aseismic subduction inferred from emerged corals and reefs of the Central Vanuatu (New Hebrides) Frontal Arc

    NASA Astrophysics Data System (ADS)

    Taylor, Frederick W.; Edwards, R. Lawrence; Wasserburg, G. J.; Frohlich, Cliff

    1990-01-01

    The recognition and dating of corals that have been killed by tectonic uplift allow us to date paleoseismic uplifts in the Vanuatu island arc. We recognize corals that record paleouplifts by their similarity to those known to have died during contemporary sudden uplifts and date them (1) by counting annual coral growth bands (only if part of the coral is alive at the time of collection) or (2) by newly developed techniques for obtaining 230Th ages by mass spectrometry. The mass spectrometric method produces isotopic ages with precisions of ±3 to ±9 years (2σ) in the 0-1000 years B.P. time range. The 230Th ages in this time range appear to be accurate. Samples whose ages are known by counting coral growth bands give 230Th ages that are indistinguishable from their growth band ages. By dividing the average increment of uplift for the latest Holocene uplifts by the mean Holocene uplift rate, we can estimate average seismic uplift recurrence intervals for the past 6000 years. The results for each of four central Vanuatu arc segments are (1) North Santo emerged 1.2 m in 1866 A.D. and 0.6 m 107 years later in 1973 A.D. The average coseismic uplift of 0.9 m and mean Holocene uplift rate of 4.3 mm yr-1 suggest a longer recurrence interval of 212 years. (2) South Santo emerged 0.29 m in 1946 and 0.26 m 19 years later in 1965, including the related 1971 event. Here the mean Holocene uplift rate is 5.5 mm yr-1. The uplift data suggest a longer average recurrence interval of about 51 years. (3) North Malekula emerged 1.23 m near 1729 A. D. and 1.05 m 236 years later in 1965. The mean Holocene uplift rate of 2.7 mm yr-1 and mean coseismic uplift of 1.14 m for dated events suggest a longer recurrence interval of 422 years. (4) Part of southernmost Malekula has uplifted continuously or episodically by about 0.35 m from about 1957 until at least mid-1983 A.D. The maximum uplift of 2.7 mm yr-1 occurs near a nest of small earthquakes. Both the earthquakes and rapid uplift suggest

  9. Evaluation of Geochemical Proxies Preserved in the Sapropel Record from the Eastern Mediterranean Within the Pliocene-Holocene Time Interval

    NASA Astrophysics Data System (ADS)

    Gallego-Torres, D.; Martinez-Ruiz, F.; Paytan, A.; Kastner, M.

    2004-12-01

    Considerable research has been devoted during the last decade to productivity and oxygenation proxies of sapropel deposition in the Mediterranean. Pliocene-Holocene sapropel layers from Mediterranean basins are considered to be an important key to assess the role of productivity vs. anoxia in organic matter (OM) accumulation. Evaluation of proxy preservation within these sediments is therefore crucial to further investigate forcing mechanism for OM deposition. With this aim, diverse layers from Pliocene, Pleistocene and Holocene sediments recovered at ODP Site 964 in the eastern Mediterranean have been analyzed. Ba excess is recognized as a reliable proxy for enhanced productivity because it derives from barite crystals originated in the water column. Additionally, their S isotope composition revealed that barite is an authigenic phase (Paytan et al., 2004). This proxy also revealed of exceptional importance in Mediterranean basins because some sapropels have been partially or totally oxidized. Assessment of productivity variations cannot be based therefore on the OM record which is strongly subjected to diagenetic preservation. Certain redox-sensitive elements as Mn were also subjected to remobilization during oxidation precipitating upon encountering the oxidation front. However some well preserved trace-element ratios, used as oxygenation proxies, are still recognized. These consistently point to a relatively oxic environment during the deposition of Quaternary sapropels while Pliocene sapropels tend to be characterized by lower oxygen conditions. Ba excess also indicates that barite accumulation rates within sapropels decreased through time, being considerable higher during the Pliocene. Thus, elevated primary export production could have enhanced oxygen consumption leading to lower oxygen levels at this time. Paytan, A., F. Martinez-Ruiz, M. Eagle, A. Ivy, and S.D. Wankel (2004) Using sulfur isotopes in barite to elucidate the origin of high organic matter

  10. Ventriculo-atrial time interval measured on M mode echocardiography: a determining element in diagnosis, treatment, and prognosis of fetal supraventricular tachycardia

    PubMed Central

    Jaeggi, E; Fouron, J; Fournier, A; van Doesburg, N; Drblik, S; Proulx, F

    1998-01-01

    Objective—To determine whether M mode echocardiography can differentiate fetal supraventricular tachycardia according to the ventriculo-atrial (VA) time interval, and if the resulting division into short and long VA intervals holds any relation with clinical presentation, management, and fetal outcome.
Design—Retrospective case series.
Subjects—23 fetuses with supraventricular tachycardia.
Main outcome measures—A systematic review of the M mode echocardiograms (for VA and atrioventricular (AV) interval measurements), clinical profile, and final outcome.
Results—19 fetuses (82.6%) had supraventricular tachycardia of the short VA type (mean (SD) VA/AV ratio 0.34 (0.16); heart rate 231 (29) beats/min). Tachycardia was sustained in six and intermittent in 13. Hydrops was present in three (15.7%). Digoxin, the first drug given in 14, failed to control tachycardia in five. Three of these then received sotalol and converted to sinus rhythm. All fetuses of this group survived. Postnatally, supraventricular tachycardia recurred in three, two having Wolff-Parkinson-White syndrome. Four fetuses (17.4%) had long VA tachycardia (VA/AV ratio 3.89 (0.82); heart rate 226 (10) beats/min). Initial treatment with digoxin was ineffective in all, but sotalol was effective in two. Heart failure caused fetal death in one and premature delivery in one. All three surviving fetuses had recurrences of supraventricular tachycardia after birth: two had the permanent form of junctional reciprocating tachycardia and one had atrial ectopic tachycardia.
Conclusions—Careful measurement of ventriculo-atrial intervals on fetal M mode echocardiography can be used to distinguish short from long VA supraventricular tachycardia and may be helpful in optimising management. Digoxin, when indicated, may remain the drug of choice in the short VA type but appears ineffective in the long VA type.

 Keywords: fetus;  supraventricular tachycardia;  ventriculo-atrial interval

  11. A comparative analysis of spectral exponent estimation techniques for 1/fβ processes with applications to the analysis of stride interval time series

    PubMed Central

    Schaefer, Alexander; Brach, Jennifer S.; Perera, Subashan; Sejdić, Ervin

    2013-01-01

    Background The time evolution and complex interactions of many nonlinear systems, such as in the human body, result in fractal types of parameter outcomes that exhibit self similarity over long time scales by a power law in the frequency spectrum S(f) = 1/fβ. The scaling exponent β is thus often interpreted as a “biomarker” of relative health and decline. New Method This paper presents a thorough comparative numerical analysis of fractal characterization techniques with specific consideration given to experimentally measured gait stride interval time series. The ideal fractal signals generated in the numerical analysis are constrained under varying lengths and biases indicative of a range of physiologically conceivable fractal signals. This analysis is to complement previous investigations of fractal characteristics in healthy and pathological gait stride interval time series, with which this study is compared. Results The results of our analysis showed that the averaged wavelet coefficient method consistently yielded the most accurate results. Comparison with Existing Methods: Class dependent methods proved to be unsuitable for physiological time series. Detrended fluctuation analysis as most prevailing method in the literature exhibited large estimation variances. Conclusions The comparative numerical analysis and experimental applications provide a thorough basis for determining an appropriate and robust method for measuring and comparing a physiologically meaningful biomarker, the spectral index β. In consideration of the constraints of application, we note the significant drawbacks of detrended fluctuation analysis and conclude that the averaged wavelet coefficient method can provide reasonable consistency and accuracy for characterizing these fractal time series. PMID:24200509

  12. Systolic time intervals derived from electrocardiographic gated intra-renal artery Doppler waveform associated with left ventricular systolic function

    PubMed Central

    Lee, Wen-Hsien; Hsu, Po-Chao; Chu, Chun-Yuan; Chen, Szu-Chia; Lee, Hung-Hao; Lee, Meng-Kuang; Lee, Chee-Siong; Yen, Hsueh-Wei; Lin, Tsung-Hsien; Voon, Wen-Chol; Lai, Wen-Ter; Sheu, Sheng-Hsiung; Su, Ho-Ming

    2016-01-01

    The aims of this study were to investigate the correlation between renal and cardiac STIs, including pre-ejection period (PEP), ejection time (ET), and PEP/ET, and to assess the diagnostic values of renal STIs in predicting left ventricular ejection fraction (LVEF) <50%. The cross sectional observation study enrolled 230 participants. The renal STIs, including renal PEP (rPEP), renal ET (rET), and rPEP/rET, were measured from electrocardiographic gated renal Doppler ultrasound and cardiac PEP, ET, and PEP/ET were measured from echocardiography. Renal STIs were correlated with cardiac STIs (all P < 0.001). Multivariate analyses showed that rPEP/rET was independently associated with LVEF (unstandardized coefficient β = −0.116, P = 0.046) and LVEF <50% (odds ratio = 2.145, per 0.11 increase; P = 0.017). The areas under the curve for rPEP, 1/rET, and rPEP/rET in predicting LVEF <50% were 0.773, 0.764, and 0.821, respectively. The sensitivity and specificity of rPEP/rET > 0.46 in prediction of LVEF <50% were 76.7% and 78.1%, respectively. Our study demonstrated that the novel parameters of renal STIs were significantly associated with cardiac STIs. However, the clinical application of renal STIs needs to be investigated in future studies. PMID:27553182

  13. Protective effects of quercetin on cadmium fluoride induced oxidative stress at different intervals of time in mouse liver.

    PubMed

    Zargar, Seema; Siddiqi, Nikhat Jamal; Al Daihan, Sooad Khalaf; Wani, Tanveer A

    2015-01-01

    Quercetin, a member of the flavonoid family is a major antioxidant acquired in humans by food consumption, while Cadmium fluoride (CdF2) is one of the naturally occurring chemicals having adverse effects. The protective effect of quercetin on time dependent oxidative damage induced in mice liver by CdF2 was studied in the following groups of mice consisting of six mice each: (i) control group; (ii) mice treated with single i.p injection of 2 mg/kg bw CdF2 for 24 h; (iii) mice treated with single i.p injection of 2 mg/kg bw CdF2 for 48 h; (iv) mice treated with single i.p injection of quercetin (100 mg/kg bw); (v) mice treated with i.p injection of 100 mg/kg bw of quercetin followed by i.p injection of CdF2 (2 mg/kg bw) for 24 h; and (vi) mice treated with i.p injection of 100mg/kg bw of quercetin followed by CdF2 (2 mg/kg bw) for 48 h. Administration of quercetin two hours before CdF2 significantly reduced the biochemical alterations in reduced glutathione, ascorbic acid, lipid peroxidation, super oxide dismutase, catalase and total protein (p<0.05). Histopathology also showed the protective effect of quercetin. The livers treated with CdF2 were atrophic, markedly nodular, inflamed and necrotic. However, this effect was reduced to a minimum in the mice pre-treated for two hours with quercetin. PMID:25856559

  14. Effect of addition of lycopene to calcium hydroxide and chlorhexidine as intracanal medicament on fracture resistance of radicular dentin at two different time intervals: An in vitro study

    PubMed Central

    Madhusudhana, Koppolu; Archanagupta, Kasamsetty; Suneelkumar, Chinni; Lavanya, Anumula; Deepthi, Mandava

    2015-01-01

    Background: Long-term use of intracanal medicaments such as calcium hydroxide (CH) reduces the fracture resistance of dentin. The present study was undertaken to evaluate the fracture resistance of radicular dentin on long-term use of CH, chlorhexidine (CHX) with lycopene (LP). Aim: To compare the fracture resistance of radicular dentin when intracanal medicaments such as CH, CHX with LP were used for 1-week and 1-month time interval. Settings and Design: Sixty single-rooted extracted human permanent premolars were collected, and complete instrumentation was done. Samples were divided into three groups based on intracanal medicament used. Materials and Methods: Group 1 - no medicament was placed (CON), group 2 - mixture of 1.5 g of CH and 1 ml of 2% CHX (CHCHX), group 3 - mixture of 1.5 g of CH, 1 ml of CHX and 1 ml of 5% LP solution (CHCHXLP). After storage period of each group for 1-week and 1-month, middle 8 mm root cylinder was sectioned and tested for fracture resistance. Statistical Analysis: Results were analyzed using paired t-test. Results: At 1-month time interval, there was a statistically significant difference in fracture resistance between CHCHX and CHCHXLP groups. Conclusion: Addition of LP has not decreased the fracture resistance of radicular dentin after 1-month. PMID:26069405

  15. The Efficacy and Safety of Insulin Degludec Given in Variable Once-Daily Dosing Intervals Compared With Insulin Glargine and Insulin Degludec Dosed at the Same Time Daily

    PubMed Central

    Meneghini, Luigi; Atkin, Stephen L.; Gough, Stephen C.L.; Raz, Itamar; Blonde, Lawrence; Shestakova, Marina; Bain, Stephen; Johansen, Thue; Begtrup, Kamilla; Birkeland, Kåre I.

    2013-01-01

    OBJECTIVE The requirement to inject current basal insulin analogs at a fixed time each day may complicate adherence and compromise glycemic control. This trial evaluated the efficacy and safety of varying the daily injection time of insulin degludec (IDeg), an ultra-long-acting basal insulin. RESEARCH DESIGN AND METHODS This 26-week, open-label, treat-to-target trial enrolled adults (≥18 years) with type 2 diabetes who were either insulin naïve and receiving oral antidiabetic drugs (OADs) (HbA1c = 7–11%) or previously on basal insulin ± OAD(s) (HbA1c = 7–10%). Participants were randomized to 1) once-daily (OD) IDeg in a prespecified dosing schedule, creating 8–40-h intervals between injections (IDeg OD Flex; n = 229); 2) once-daily IDeg at the main evening meal (IDeg OD; n = 228); or 3) once-daily insulin glargine at the same time each day (IGlar OD; n = 230). The primary outcome was noninferiority of IDeg OD Flex to IGlar OD in HbA1c reduction after 26 weeks. RESULTS After 26 weeks, IDeg OD Flex, IDeg OD, and IGlar OD improved HbA1c by 1.28, 1.07, and 1.26% points, respectively (estimated treatment difference [IDeg OD Flex − IGlar OD]: 0.04% points [–0.12 to 0.20], confirming noninferiority). No statistically significant differences in overall or nocturnal hypoglycemia were found between IDeg OD Flex and IGlar OD. Comparable glycemic control and rates of hypoglycemia were seen with IDeg OD Flex and IDeg OD. Adverse event profiles were similar across groups. CONCLUSIONS The use of extreme dosing intervals of 8–40 h demonstrates that the daily injection time of IDeg can be varied without compromising glycemic control or safety. PMID:23340894

  16. Histopathologic evaluation of postmortem autolytic changes in bluegill (Lepomis macrohirus) and crappie (Pomoxis anularis) at varied time intervals and storage temperatures.

    PubMed

    George, Jami; Van Wettere, Arnaud J; Michaels, Blayk B; Crain, Debbi; Lewbart, Gregory A

    2016-01-01

    Information is lacking on preserving fish carcasses to minimize postmortem autolysis artifacts when a necropsy cannot be performed immediately. The purpose of this study was to qualitatively identify and score histologic postmortem changes in two species of freshwater fish (bluegill-Lepomis macrochirus; crappie-Pomoxis annularis), at varied time intervals and storage temperatures, to assess the histologic quality of collected samples. A pooled sample of 36 mix sex individuals of healthy bluegill and crappie were euthanized, stored either at room temperature, refrigerated at 4 °C, or frozen at -20 °C, and then necropsied at 0, 4, 24, and 48 h intervals. Histologic specimens were evaluated by light microscopy. Data showed that immediate harvesting of fresh samples provides the best quality and refrigeration would be the preferred method of storage if sample collection had to be delayed for up to 24 h. When sample collection must be delayed more than 24 h, the preferred method of storage to minimize autolysis artifacts is freezing if evaluation of the gastrointestinal tract is most important, or refrigeration if gill histology is most important. The gill arch, intestinal tract, followed by the liver and kidney were the most sensitive organs to autolysis. PMID:27114885

  17. Histopathologic evaluation of postmortem autolytic changes in bluegill (Lepomis macrohirus) and crappie (Pomoxis anularis) at varied time intervals and storage temperatures

    PubMed Central

    George, Jami; Van Wettere, Arnaud J.; Michaels, Blayk B.; Crain, Debbi

    2016-01-01

    Information is lacking on preserving fish carcasses to minimize postmortem autolysis artifacts when a necropsy cannot be performed immediately. The purpose of this study was to qualitatively identify and score histologic postmortem changes in two species of freshwater fish (bluegill—Lepomis macrochirus; crappie—Pomoxis annularis), at varied time intervals and storage temperatures, to assess the histologic quality of collected samples. A pooled sample of 36 mix sex individuals of healthy bluegill and crappie were euthanized, stored either at room temperature, refrigerated at 4 °C, or frozen at −20 °C, and then necropsied at 0, 4, 24, and 48 h intervals. Histologic specimens were evaluated by light microscopy. Data showed that immediate harvesting of fresh samples provides the best quality and refrigeration would be the preferred method of storage if sample collection had to be delayed for up to 24 h. When sample collection must be delayed more than 24 h, the preferred method of storage to minimize autolysis artifacts is freezing if evaluation of the gastrointestinal tract is most important, or refrigeration if gill histology is most important. The gill arch, intestinal tract, followed by the liver and kidney were the most sensitive organs to autolysis. PMID:27114885

  18. Further improved stability criteria for uncertain T-S fuzzy systems with interval time-varying delay by delay-partitioning approach.

    PubMed

    Yang, Jun; Luo, Wenpin; Cheng, Jun; Wang, Yonghu

    2015-09-01

    This paper focuses on further improved stability criteria for uncertain T-S fuzzy systems with interval time-varying delay by a delay-partitioning approach. A modified augmented Lyapunov-Krasovskii functional (LKF) is established by partitioning the delay in all integral terms. Then some tighter bounding inequalities, i.e., Peng-Park׳s integral inequality (reciprocally convex approach) and the Free-Matrix-Based integral inequality (which yields less conservative stability criteria than the use of Wirtinger-based inequality does) are introduced to reduce the enlargement in bounding the derivative of LKF as much as possible, therefore, less conservative results can be expected in terms of es and LMIs. Finally, a numerical example is included to show that the proposed methods are less conservative than existing ones. PMID:26073644

  19. Effect of Different Obturation Materials on Residual Antimicrobial Activity of 2% Chlorhexidine in Dentin at Different Time Intervals: An Ex Vivo Study

    PubMed Central

    Bolhari, Behnam; Dehghan, Somayyeh; Sharifian, Mohammad Reza; Bahador, Abbas

    2015-01-01

    Objectives: The aim of this study was to evaluate the effect of gutta percha/AH26 and Resilon/RealSeal SE on residual antimicrobial activity of chlorhexidine (CHX) in human root dentin and suggest the best filling material when CHX is used as final irrigant. Materials and Methods: One-hundred and forty-four single-rooted human teeth were selected for this study. Canals were instrumented to the apical size #35. Smear layer was removed using 5.25% NaOCl and 17% EDTA and then 108 teeth were irrigated with 2% CHX and randomly divided into three groups of gutta percha/AH26, Resilon/RealSeal SE and positive controls. Each group was divided into three subgroups for different time intervals (one, three and six weeks). Thirty-six teeth, as negative controls, were irrigated with saline and obturated with gutta percha/AH26 and Resilon/RealSeal SE. Dentin powder was prepared at the afore-mentioned intervals. After exposure to Enterococcus faecalis for 24 hours, colony forming units (CFUs) were counted and residual antimicrobial activity was calculated. The data were analyzed using the Kruskal Wallis test and one-way ANOVA. The significance level was set at P<0.05. Results: The antimicrobial activity of CHX gradually decreased in a time-dependent manner but it maintained over 95% of its antimicrobial activity after six weeks. Moreover, Resilon/RealSeal SE significantly decreased the antimicrobial activity of CHX in comparison with gutta-percha/AH26 (P<0.05). Conclusion: After a final irrigation with CHX, gutta-percha/AH26 is a better choice for root canal obturation. PMID:27252755

  20. Comparing Fat Oxidation in an Exercise Test with Moderate-Intensity Interval Training

    PubMed Central

    Alkahtani, Shaea

    2014-01-01

    This study compared fat oxidation rate from a graded exercise test (GXT) with a moderate-intensity interval training session (MIIT) in obese men. Twelve sedentary obese males (age 29 ± 4.1 years; BMI 29.1 ± 2.4 kg·m-2; fat mass 31.7 ± 4.4 %body mass) completed two exercise sessions: GXT to determine maximal fat oxidation (MFO) and maximal aerobic power (VO2max), and an interval cycling session during which respiratory gases were measured. The 30-min MIIT involved 5-min repetitions of workloads 20% below and 20% above the MFO intensity. VO2max was 31.8 ± 5.5 ml·kg-1·min-1 and all participants achieved ≥ 3 of the designated VO2max test criteria. The MFO identified during the GXT was not significantly different compared with the average fat oxidation rate in the MIIT session. During the MIIT session, fat oxidation rate increased with time; the highest rate (0.18 ± 0.11 g·min- 1) in minute 25 was significantly higher than the rate at minute 5 and 15 (p ≤ 0.01 and 0.05 respectively). In this cohort with low aerobic fitness, fat oxidation during the MIIT session was comparable with the MFO determined during a GXT. Future research may consider if the varying workload in moderate-intensity interval training helps adherence to exercise without compromising fat oxidation. Key Points Fat oxidation during interval exercise is not com-promised by the undulating exercise intensity Physiological measures corresponding with the MFO measured during the GXT correlated well to the MIIT The validity of exercise intensity markers derived from a GXT to reflect the physiological responses during MIIT. PMID:24570605

  1. The importance of independent chronology in integrating records of past climate change for the 60-8 ka INTIMATE time interval

    NASA Astrophysics Data System (ADS)

    Brauer, Achim; Hajdas, Irka; Blockley, Simon P. E.; Bronk Ramsey, Christopher; Christl, Marcus; Ivy-Ochs, Susan; Moseley, Gina E.; Nowaczyk, Norbert N.; Rasmussen, Sune O.; Roberts, Helen M.; Spötl, Christoph; Staff, Richard A.; Svensson, Anders

    2014-12-01

    This paper provides a brief overview of the most common dating techniques applied in palaeoclimate and palaeoenvironmental studies including four radiometric and isotopic dating methods (radiocarbon, 230Th disequilibrium, luminescence, cosmogenic nuclides) and two incremental methods based on layer counting (ice layer, varves). For each method, concise background information about the fundamental principles and methodological approaches is provided. We concentrate on the time interval of focus for the INTIMATE (Integrating Ice core, MArine and TErrestrial records) community (60-8 ka). This dating guide addresses palaeoclimatologists who aim at interpretation of their often regional and local proxy time series in a wider spatial context and, therefore, have to rely on correlation with proxy records obtained from different archives from various regions. For this reason, we especially emphasise scientific approaches for harmonising chronologies for sophisticated and robust proxy data integration. In this respect, up-to-date age modelling techniques are presented as well as tools for linking records by age equivalence including tephrochronology, cosmogenic 10Be and palaeomagnetic variations. Finally, to avoid inadequate documentation of chronologies and assure reliable correlation of proxy time series, this paper provides recommendations for minimum standards of uncertainty and age datum reporting.

  2. High-intensity interval training improves VO(2peak), maximal lactate accumulation, time trial and competition performance in 9-11-year-old swimmers.

    PubMed

    Sperlich, Billy; Zinner, Christoph; Heilemann, Ilka; Kjendlie, Per-Ludvik; Holmberg, Hans-Christer; Mester, Joachim

    2010-11-01

    Training volume in swimming is usually very high when compared to the relatively short competition time. High-intensity interval training (HIIT) has been demonstrated to improve performance in a relatively short training period. The main purpose of the present study was to examine the effects of a 5-week HIIT versus high-volume training (HVT) in 9-11-year-old swimmers on competition performance, 100 and 2,000 m time (T(100 m) and T(2,000 m)), VO(2peak) and rate of maximal lactate accumulation (Lac(max)). In a 5-week crossover study, 26 competitive swimmers with a mean (SD) age of 11.5 ± 1.4 years performed a training period of HIIT and HVT. Competition (P < 0.01; effect size = 0.48) and T(2,000 m) (P = 0.04; effect size = 0.21) performance increased following HIIT. No changes were found in T(100 m) (P = 0.20). Lac(max) increased following HIIT (P < 0.01; effect size = 0.43) and decreased after HVT (P < 0.01; effect size = 0.51). VO(2peak) increased following both interventions (P < 0.05; effect sizes = 0.46-0.57). The increases in competition performance, T(2,000 m), Lac(max) and VO(2peak) following HIIT were achieved in significantly less training time (~2 h/week). PMID:20683609

  3. A Clinical Trial of Optimal Time Interval Between Ablation and Diagnostic Activity When a Pretherapy RAI Scanning Is Performed on Patients With Differentiated Thyroid Carcinoma

    PubMed Central

    Yin, Yafu; Mao, Qiufen; Chen, Song; Li, Na; Li, Xuena; Li, Yaming

    2015-01-01

    Abstract This article investigates the association of the time interval between the diagnostic dose and ablation with the stunning effect, when a 74 MBq 131I pretherapy scanning was performed on patients with differentiated thyroid carcinoma (DTC); the patients who were diagnosed as DTC and would be performed radioiodine (RAI) ablation of thyroid remnants or metastases were recruited during January 2011 and May 2012 in our hospital. Thirty-seven patients with DTC who had the RAI ablation of thyroid remnants or metastases for the first time were recruited. All the patients received a dose of 1850 to 7400 MBq of 131I for ablation and a diagnostic scan was performed 24 hours after the administration of 74 MBq 131I before ablation. A posttherapy scan was performed 2 to 7 days after the ablation. The patients were broken down into 3 groups (G1, G2, and G3) according to the interval time between the diagnostic dose and therapy (1–3, 4–7, and >7 days). The fractional concentrations of 131I in remnants or functional metastases were quantified and expressed as therapeutic/diagnostic (Rx/Dx). The level of significance was set at 0.05. Sixty-seven foci were found both on pretherapy and posttherapy scans, the mean ratio of Rx/Dx was 0.43 ± 0.29, and the ratio of 49 foci (73.13%) was <0.6. The ratios in G1, G2, and G3 were 0.46 ± 0.29, 0.29 ± 0.18, and 0.55 ± 0.33, respectively. The differences between G1 and G2, and G2 and G3 were statistically significant (t = 2.40, P = 0.021 and t = 3.28, P = 0.002), whereas the difference between G1 and G3 was not significant (t = 1.01, P = 0.319). By a diagnostic scan of 74 MBq 131I, stunning prominently occurs with a time of 4 to 7 days between the diagnostic dose and ablation. We recommend that for less stunning effect, RAI ablation should be performed within 3 days or postponed until 1 week after the diagnostic dose administrated. PMID:26252311

  4. Manipulating Carbohydrate Availability Between Twice-Daily Sessions of High-Intensity Interval Training Over 2 Weeks Improves Time-Trial Performance.

    PubMed

    Cochran, Andrew J; Myslik, Frank; MacInnis, Martin J; Percival, Michael E; Bishop, David; Tarnopolsky, Mark A; Gibala, Martin J

    2015-10-01

    Commencing some training sessions with reduced carbohydrate (CHO) availability has been shown to enhance skeletal muscle adaptations, but the effect on exercise performance is less clear. We examined whether restricting CHO intake between twice daily sessions of high-intensity interval training (HIIT) augments improvements in exercise performance and mitochondrial content. Eighteen active but not highly trained subjects (peak oxygen uptake [VO2peak] = 44 ± 9 ml/kg/min), matched for age, sex, and fitness, were randomly allocated to two groups. On each of 6 days over 2 weeks, subjects completed two training sessions, each consisting of 5 × 4-min cycling intervals (60% of peak power), interspersed by 2 min of recovery. Subjects ingested either 195 g of CHO (HI-HI group: ~2.3 g/kg) or 17 g of CHO (HI-LO group: ~0.3 g/kg) during the 3-hr period between sessions. The training-induced improvement in 250-kJ time trial performance was greater (p = .02) in the HI-LO group (211 ± 66 W to 244 ± 75 W) compared with the HI-HI group (203 ± 53 W to 219 ± 60 W); however, the increases in mitochondrial content was similar between groups, as reflected by similar increases in citrate synthase maximal activity, citrate synthase protein content and cytochrome c oxidase subunit IV protein content (p > .05 for interaction terms). This is the first study to show that a short-term "train low, compete high" intervention can improve whole-body exercise capacity. Further research is needed to determine whether this type of manipulation can also enhance performance in highly-trained subjects. PMID:25811132

  5. Twelve Weeks of Sprint Interval Training Improves Indices of Cardiometabolic Health Similar to Traditional Endurance Training despite a Five-Fold Lower Exercise Volume and Time Commitment

    PubMed Central

    Martin, Brian J.; MacInnis, Martin J.; Skelly, Lauren E.; Tarnopolsky, Mark A.; Gibala, Martin J.

    2016-01-01

    Aims We investigated whether sprint interval training (SIT) was a time-efficient exercise strategy to improve insulin sensitivity and other indices of cardiometabolic health to the same extent as traditional moderate-intensity continuous training (MICT). SIT involved 1 minute of intense exercise within a 10-minute time commitment, whereas MICT involved 50 minutes of continuous exercise per session. Methods Sedentary men (27±8y; BMI = 26±6kg/m2) performed three weekly sessions of SIT (n = 9) or MICT (n = 10) for 12 weeks or served as non-training controls (n = 6). SIT involved 3x20-second ‘all-out’ cycle sprints (~500W) interspersed with 2 minutes of cycling at 50W, whereas MICT involved 45 minutes of continuous cycling at ~70% maximal heart rate (~110W). Both protocols involved a 2-minute warm-up and 3-minute cool-down at 50W. Results Peak oxygen uptake increased after training by 19% in both groups (SIT: 32±7 to 38±8; MICT: 34±6 to 40±8ml/kg/min; p<0.001 for both). Insulin sensitivity index (CSI), determined by intravenous glucose tolerance tests performed before and 72 hours after training, increased similarly after SIT (4.9±2.5 to 7.5±4.7, p = 0.002) and MICT (5.0±3.3 to 6.7±5.0 x 10−4 min-1 [μU/mL]-1, p = 0.013) (p<0.05). Skeletal muscle mitochondrial content also increased similarly after SIT and MICT, as primarily reflected by the maximal activity of citrate synthase (CS; P<0.001). The corresponding changes in the control group were small for VO2peak (p = 0.99), CSI (p = 0.63) and CS (p = 0.97). Conclusions Twelve weeks of brief intense interval exercise improved indices of cardiometabolic health to the same extent as traditional endurance training in sedentary men, despite a five-fold lower exercise volume and time commitment. PMID:27115137

  6. Distribution of transition times in a stochastic model of excitable cell: Insights into the cell-intrinsic mechanisms of randomness in neuronal interspike intervals

    NASA Astrophysics Data System (ADS)

    Requena-Carrión, Jesús; Requena-Carrión, Víctor J.

    2016-04-01

    In this paper, we develop an analytical approach to studying random patterns of activity in excitable cells. Our analytical approach uses a two-state stochastic model of excitable system based on the electrophysiological properties of refractoriness and restitution, which characterize cell recovery after excitation. By applying the notion of probability density flux, we derive the distributions of transition times between states and the distribution of interspike interval (ISI) durations for a constant applied stimulus. The derived ISI distribution is unimodal and, provided that the time spent in the excited state is constant, can be approximated by a Rayleigh peak followed by an exponential tail. We then explore the role of the model parameters in determining the shape of the derived distributions and the ISI coefficient of variation. Finally, we use our analytical results to study simulation results from the stochastic Morris-Lecar neuron and from a three-state extension of the proposed stochastic model, which is capable of reproducing multimodal ISI histograms.

  7. A Shorter Time Interval Between First and Second Dengue Infections Is Associated With Protection From Clinical Illness in a School-based Cohort in Thailand

    PubMed Central

    Anderson, Kathryn B.; Gibbons, Robert V.; Cummings, Derek A.T.; Nisalak, Ananda; Green, Sharone; Libraty, Daniel H.; Jarman, Richard G.; Srikiatkhachorn, Anon; Mammen, Mammen P.; Darunee, Buddhari; Yoon, In-Kyu; Endy, Timothy P.

    2014-01-01

    Background. Despite the strong association between secondary dengue virus (DENV) infections and dengue hemorrhagic fever (DHF), the majority of secondary infections are subclinical or mild. The determinants of clinical severity remain unclear, though studies indicate a titer-dependent and time-dependent role of cross-protective anti-DENV antibodies. Methods. Data from 2 sequential prospective cohort studies were analyzed for subclinical and symptomatic DENV infections in schoolchildren in Kamphaeng Phet, Thailand (1998–2002 and 2004–2007). Children experiencing ≥1 DENV infection were selected as the population for analysis (contributing 2169 person-years of follow-up). Results. In total, 1696 children had ≥1 DENV infection detected during their enrollment; 268 experienced 2 or more infections. A shorter time interval between infections was associated with subclinical infection in children seronegative for DENV at enrollment, for whom a second-detected DENV infection is more likely to reflect a true second infection (average of 2.6 years between infections for DHF, 1.9 for DF, and 1.6 for subclinical infections). Conclusions. These findings support a pathogenesis model where cross-reactive antibodies wane from higher-titer, protective levels to lower-titer, detrimental levels. This is one of the first studies of human subjects to suggest a window of cross-protection following DENV infection since Sabin's challenge studies in the 1940s. PMID:23964110

  8. Time-Induced Super-Latent Inhibition Is Dependent on the Distinctiveness of the Retention-Interval Context from the Other Experimental Contexts

    ERIC Educational Resources Information Center

    Lubow, R.E.; De la Casa, L.G.

    2005-01-01

    A conditioned taste aversion experiment examined the role of the retention-interval context (between conditioning and test stages) on the modulation of long-delay latent inhibition (LI). A super-LI effect was obtained only when the animals spent the retention interval in a context that was different from that of preexposure, conditioning, and…

  9. Time Interval from Symptom Onset to Hospital Care in Patients with Acute Heart Failure: A Report from the Tokyo Cardiac Care Unit Network Emergency Medical Service Database

    PubMed Central

    Shiraishi, Yasuyuki; Kohsaka, Shun; Harada, Kazumasa; Sakai, Tetsuro; Takagi, Atsutoshi; Miyamoto, Takamichi; Iida, Kiyoshi; Tanimoto, Shuzou; Fukuda, Keiichi; Nagao, Ken; Sato, Naoki; Takayama, Morimasa

    2015-01-01

    Aims There seems to be two distinct patterns in the presentation of acute heart failure (AHF) patients; early- vs. gradual-onset. However, whether time-dependent relationship exists in outcomes of patients with AHF remains unclear. Methods The Tokyo Cardiac Care Unit Network Database prospectively collects information of emergency admissions via EMS service to acute cardiac care facilities from 67 participating hospitals in the Tokyo metropolitan area. Between 2009 and 2011, a total of 3811 AHF patients were registered. The documentation of symptom onset time was mandated by the on-site ambulance team. We divided the patients into two groups according to the median onset-to-hospitalization (OH) time for those patients (2h); early- (presenting ≤2h after symptom onset) vs. gradual-onset (late) group (>2h). The primary outcome was in-hospital mortality. Results The early OH group had more urgent presentation, as demonstrated by a higher systolic blood pressure (SBP), respiratory rate, and higher incidence of pulmonary congestion (48.6% vs. 41.6%; P<0.001); whereas medical comorbidities such as stroke (10.8% vs. 7.9%; P<0.001) and atrial fibrillation (30.0% vs. 26.0%; P<0.001) were more frequently seen in the late OH group. Overall, 242 (6.5%) patients died during hospitalization. Notably, a shorter OH time was associated with a better in-hospital mortality rate (odds ratio, 0.71; 95% confidence interval, 0.51−0.99; P = 0.043). Conclusions Early-onset patients had rather typical AHF presentations (e.g., higher SBP or pulmonary congestion) but had a better in-hospital outcome compared to gradual-onset patients. PMID:26562780

  10. Comparative evaluation of demineralization of radicular dentin with 17% ethylenediaminetetraacetic acid, 10% citric acid, and MTAD at different time intervals: An in vitro study

    PubMed Central

    Kumar, Yogender; Lohar, Jitendra; Bhat, Sureka; Bhati, Manisha; Gandhi, Aanesh; Mehta, Abhishek

    2016-01-01

    Background: The smear layer has the capability to protect the bacteria within the dentinal tubules from intracanal medicament. After removal of the smear layer from infected root canals, it allows disinfection of the entire root canal. The smear layer compromising the seal between the root canal sealer and root canal wall also decreases the penetration of irrigants into dentinal tubules. Aims: This study compares the amount of phosphorous liberated and demineralization of the radicular dentin with 17% ethylenediaminetetraacetic acid, 10% citric acid and mixture of doxycycline, citric acid, and a detergent at different time intervals. Materials and Methods: Extracted maxillary single-rooted teeth were prepared by using a combination of passive step-back and rotary 0.04 taper nickel-titanium files. Sodium hypochlorite 5.25% and sterile distilled water were used as an intracanal irrigant. The canals were then treated with 5 mL of one of the following solutions such as final rinse sterile distilled water, 5.25% sodium hypochlorite, 17% ethylenediaminetetraacetic acid (EDTA) or mixture of doxycycline, citric acid, and a detergent. The presence or absence of smear layer and the amount of erosion on the surface of the root canal walls at the coronal, middle, and apical portions of each canal were examined under a scanning electron microscope. Statistical Analysis: Data were analyzed by one-way analysis of variance (ANOVA) to determine whether there were significant differences between the groups. Results: The results show that mixture of doxycycline, citric acid, and a detergent is an effective solution for the removal of the smear layer and does not significantly change the structure of the dentinal tubules. Conclusions: In this study, 10% citric acid shows the maximum amount of dimeneralization of radicular dentine followed by mixture of doxycycline, citric acid, and a detergent, and 17% ethylenediaminetetraacetic acid. When all the subgroups were compared, it was seen

  11. A Dominant X-Linked QTL Regulating Pubertal Timing in Mice Found by Whole Genome Scanning and Modified Interval-Specific Congenic Strain Analysis

    PubMed Central

    Zhang, Chao; Guo, Zhengxia; Zhao, Ying; Zhou, Yuxun; Li, Kai; Xing, Zhenghong; Chen, Guoqiang; Liang, Yinming; Jin, Li; Xiao, Junhua

    2008-01-01

    Background Pubertal timing in mammals is triggered by reactivation of the hypothalamic-pituitary-gonadal (HPG) axis and modulated by both genetic and environmental factors. Strain-dependent differences in vaginal opening among inbred mouse strains suggest that genetic background contribute significantly to the puberty timing, although the exact mechanism remains unknown. Methodology/Principal Findings We performed a genome-wide scanning for linkage in reciprocal crosses between two strains, C3H/HeJ (C3H) and C57BL6/J (B6), which differed significantly in the pubertal timing. Vaginal opening (VO) was used to characterize pubertal timing in female mice, and the age at VO of all female mice (two parental strains, F1 and F2 progeny) was recorded. A genome-wide search was performed in 260 phenotypically extreme F2 mice out of 464 female progeny of the F1 intercrosses to identify quantitative trait loci (QTLs) controlling this trait. A QTL significantly associated was mapped to the DXMit166 marker (15.5 cM, LOD = 3.86, p<0.01) in the reciprocal cross population (C3HB6F2). This QTL contributed 2.1 days to the timing of VO, which accounted for 32.31% of the difference between the original strains. Further study showed that the QTL was B6-dominant and explained 10.5% of variation to this trait with a power of 99.4% at an alpha level of 0.05.The location of the significant ChrX QTL found by genome scanning was then fine-mapped to a region of ∼2.5 cM between marker DXMit68 and rs29053133 by generating and phenotyping a panel of 10 modified interval-specific congenic strains (mISCSs). Conclusions/Significance Such findings in our study lay a foundation for positional cloning of genes regulating the timing of puberty, and also reveal the fact that chromosome X (the sex chromosome) does carry gene(s) which take part in the regulative pathway of the pubertal timing in mice. PMID:18725948

  12. Mood and selective attention in the cold: the effect of interval versus continuous exercise.

    PubMed

    Muller, Matthew D; Muller, Sarah M; Kim, Chul-Ho; Ryan, Edward J; Gunstad, John; Glickman, Ellen L

    2011-07-01

    Both mood and cognitive function are altered in cold environments. Body warming through exercise may improve Stroop interference score and lessen total negative mood. The purpose of this study was to determine the effect of equal caloric bouts of interval (INT) and continuous (CONT) exercise on mood and selective attention in the cold. Eleven young men underwent two experimental trials in 5°C air. Both trials consisted of 90 min acute cold exposure (ACE), 30 min exercise (INT vs. CONT), and 60 min recovery (REC). The Profile of Mood States (POMS) and Stroop Color Word Test (SCWT) were administered at four time points. Mean body temperature decreased during ACE, increased during exercise, and decreased during REC. Repeated measures analysis of variance revealed a main effect for time for several of the POMS sub scores. In particular, negative mood was significantly decreased after exercise relative to ACE and then significantly increased during REC. Further, CONT appears to be more effective than INT at decreasing negative mood. Components of the SCWT supported both the arousal and distraction theories for simple perception, but no significant effects were shown for the interference score. In the cold, exercise decreases negative mood but does not appear to affect selective attention. Further mechanistic studies could determine the best mode and intensity of exercise for improving cognitive function in the cold. PMID:21152931

  13. Effect of night time-intervals, height of traps and lunar phases on sand fly collection in a highly endemic area for canine leishmaniasis.

    PubMed

    Gaglio, Gabriella; Brianti, Emanuele; Napoli, Ettore; Falsone, Luigi; Dantas-Torres, Filipe; Tarallo, Viviana D; Otranto, Domenico; Giannetto, Salvatore

    2014-05-01

    The activity of phlebotomine sand flies was monitored in a sub-urban area of Sicily in order to acquire data on seasonality and to elucidate the effect of the night time-intervals, height of traps from ground and lunar phases on the abundance of the capture. The study was conducted in the farm of the University of Messina (Italy). Light traps were placed as in the following: biweekly, from dusk to dawn, and from May to November; for three consecutive nights from 18:00 to 6:00, with the net bag being changed every 2h; for 30 days, at different heights from 18:00 to 6:00. A total of five species (i.e., Phlebotomus perniciosus, Phlebotomus neglectus, Phlebotomus sergenti, Phlebotomus perfiliewi, and Sergentomyia minuta), three of which are proven vectors of Leishmania infantum, were captured. The most abundant species was P. perniciosus (73.3%) followed by S. minuta (23.3%). The highest number of phlebotomine sand flies was collected in August and September with a peak of collection recorded in the evening (i.e., from 20:01 to 22.00). The number of phlebotomine sand flies collected at 50cm above the ground was significantly higher (P=0.041) than that captured at 150cm. Results of this study shed light on the ecology of main phlebotomine species in the Mediterranean area, and on the influence of some factors, such as time and height of traps, on the light trap capture efficiency. PMID:24561074

  14. Recurring patterns in stationary intervals of abdominal uterine electromyograms during gestation.

    PubMed

    Di Marco, Luigi Yuri; Di Maria, Costanzo; Tong, Wing-Chiu; Taggart, Michael J; Robson, Stephen C; Langley, Philip

    2014-08-01

    Abdominal uterine electromyograms (uEMG) studies have focused on uterine contractions to describe the evolution of uterine activity and preterm birth (PTB) prediction. Stationary, non-contracting uEMG has not been studied. The aim of the study was to investigate the recurring patterns in stationary uEMG, their relationship with gestation age and PTB, and PTB predictivity. A public database of 300 (38 PTB) three-channel (S1-S3) uEMG recordings of 30 min, collected between 22 and 35 weeks' gestation, was used. Motion and labour contraction-free intervals in uEMG were identified as 5-min weak-sense stationarity intervals in 268 (34 PTB) recordings. Sample entropy (SampEn), percentage recurrence (PR), percentage determinism (PD), entropy (ER), and maximum length (L MAX) of recurrence were calculated and analysed according to the time to delivery and PTB. Random time series were generated by random shuffle (RS) of actual data. Recurrence was present in actual data (p<0.001) but not RS. In S3, PR (p<0.005), PD (p<0.01), ER (p<0.005), and L MAX (p<0.05) were higher, and SampEn lower (p<0.005) in PTB. Recurrence indices increased (all p<0.001) and SampEn decreased (p<0.01) with decreasing time to delivery, suggesting increasingly regular and recurring patterns with gestation progression. All indices predicted PTB with AUC≥0.62 (p<0.05). Recurring patterns in stationary non-contracting uEMG were associated with time to delivery but were relatively poor predictors of PTB. PMID:25008004

  15. Effect of background region of interest and time-interval selection on glomerular filtration ratio estimation by percentage dose uptake of (99m)Tc-DTPA in comparison with (51)Cr-EDTA clearance in healthy cats.

    PubMed

    Debruyn, Katrien; Vandermeulen, Eva; Saunders, Jimmy H; Dobbeleir, André A; Ham, Hamphrey R; Peremans, Kathelijne

    2013-08-01

    Evaluation of glomerular function is a useful part of the diagnostic approach in animals suspected of having renal disease. Time-interval and background region of interest (bg ROI) selection are determining factors when calculating the glomerular filtration ratio (GFR) based on percentage uptake of (99m)technetium-labelled diethylene triamine penta-acetic acid ((99m)Tc-DTPA). Therefore, three different time intervals (60-120 s, 120-180 s, 60-180 s) and three different bg ROIs (C-shape, caudolateral, cranial + caudal) were investigated. In addition, global GFRs based on percentage dose uptake of (99m)Tc-DTPA for the different time-intervals and bg ROIs were compared with the global GFR based on (51)chromium-ethylene diaminic tetra-acetic acid ((51)Cr-EDTA) plasma clearance in nine healthy European domestic shorthair cats. Paired Student's t-tests and linear regression analysis were used to analyse the data. Different time intervals seemed to cause significant variation (P <0.01) in absolute GFR values, regardless of the choice of bg ROI. Significant differences (P <0.01) between bg ROIs were only observed in the 120-180s time interval between the C-shape and cranial + caudal bg ROI, and between the caudolateral and cranial + caudal bg ROI. The caudolateral bg ROI in the 60-180 s time interval showed the highest correlation coefficient (r = 0.882) between (99m)Tc-DTPA and (51)Cr-EDTA, although a significant difference (P <0.05) was present between both techniques. PMID:23349527

  16. Reproductive performance, blood urea nitrogen, and blood glucose concentration in beef heifers grazing annual ryegrass in the spring and supplemented at different intervals prior to timed AI.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In successive years, 76 Gelbvieh x Angus heifers [n = 36 (year 1) and n = 40 (year 2)] at 12 to 14 months of age were stratified by weight and randomly allocated to one of three treatments to determine the impact of rumen degradable carbohydrates at different intervals prior to breeding on conceptio...

  17. Sleep Deprivation and Time-on-Task Performance Decrement in the Rat Psychomotor Vigilance Task

    PubMed Central

    Oonk, Marcella; Davis, Christopher J.; Krueger, James M.; Wisor, Jonathan P.; Van Dongen, Hans P.A.

    2015-01-01

    Study Objectives: The rat psychomotor vigilance task (rPVT) was developed as a rodent analog of the human psychomotor vigilance task (hPVT). We examined whether rPVT performance displays time-on-task effects similar to those observed on the hPVT. Design: The rPVT requires rats to respond to a randomly presented light stimulus to obtain a water reward. Rats were water deprived for 22 h prior to each 30-min rPVT session to motivate performance. We analyzed rPVT performance over time on task and as a function of the response-stimulus interval, at baseline and after sleep deprivation. Setting: The study was conducted in an academic research vivarium. Participants: Male Long-Evans rats were trained to respond to a 0.5 sec stimulus light within 3 sec of stimulus onset. Complete data were available for n = 20 rats. Interventions: Rats performed the rPVT for 30 min at baseline and after 24 h total sleep deprivation by gentle handling. Measurements and Results: Compared to baseline, sleep deprived rats displayed increased performance lapses and premature responses, similar to hPVT lapses of attention and false starts. However, in contrast to hPVT performance, the time-on-task performance decrement was not significantly enhanced by sleep deprivation. Moreover, following sleep deprivation, rPVT response times were not consistently increased after short response-stimulus intervals. Conclusions: The rat psychomotor vigilance task manifests similarities to the human psychomotor vigilance task in global performance outcomes, but not in post-sleep deprivation effects of time on task and response-stimulus interval. Citation: Oonk M, Davis CJ, Krueger JM, Wisor JP, Van Dongen HPA. Sleep deprivation and time-on-task performance decrement in the rat psychomotor vigilance task. SLEEP 2015;38(3):445–451. PMID:25515099

  18. Evaluation of timings and outcomes in category-one caesarean sections: A retrospective cohort study

    PubMed Central

    Dunn, Clare Newton; Zhang, Qianpian; Sia, Josh Tjunrong; Assam, Pryseley Nkouibert; Tagore, Shephali; Sng, Ban Leong

    2016-01-01

    Background and Aims: A decision-to-delivery interval (DDI) of 30 min for category-one caesarean section (CS) deliveries is the standard of practice recommended by clinical guidelines. Our institution established a protocol for category-one (‘crash’) CS to expedite deliveries. The aim of this study is to evaluate DDI, factors that affect DDI and the mode of anaesthesia for category-one CS. Methods: This retrospective cohort study evaluated 390 women who underwent category-one CS in a tertiary obstetric centre. We analysed the factors associated with DDI, mode of anaesthesia and perinatal outcomes. Summary statistics were performed for the outcomes. The association factors were considered significant at P < 0.05. Results: The mean (standard deviation) DDI was 9.4 (3.2) min with all deliveries achieved within 30 min. The longest factor in the DDI was time taken to transfer patients. A shorter DDI was not significantly associated with improved perinatal outcomes. The majority (88.9%) of women had general anaesthesia (GA) for category-one CS. Of those who had an epidural catheter already in situ (34.4%), 25.6% had successful epidural extension. GA was associated with shorter DDI, but worse perinatal outcomes than regional anaesthesia (RA). Conclusions: Our ‘crash’ CS protocol achieved 100% of deliveries within 30 min. The majority (88.9%) of the patients had GA for category-one CS. GA was found to be associated with shorter anaesthesia and operation times, but poorer perinatal outcomes compared to RA. PMID:27601736

  19. Effects of time of suckling during the solar day on duration of the postpartum anovulatory interval in Brahman x Hereford (F1) cows.

    PubMed

    Gazal, O S; Guzman-Vega, G A; Williams, G L

    1999-05-01

    Previously published reports have indicated that postpartum anovulatory intervals can be markedly reduced and rebreeding performance enhanced in Bos taurus cows by eliminating nighttime suckling. We sought to confirm this hypothesis by examining the effects of day, nighttime, and ad libitum suckling on suckling behavior of calves, duration of the postpartum anovulatory interval, and pregnancy rates in 45 fall-calving Brahman x Hereford (F1) cows. Beginning on d 9 to 12 postpartum, calves were removed from lactating cows from 0700 to 1900 (Night-Suckled, n = 15) or from 1900 to 0700 (Day-Suckled, n = 15), or remained with their dams continuously (Ad Libitum-Suckled, n = 15). Cows in each group were maintained with fertile Angus bulls from d 10 postpartum until the first normal luteal phase or 100 d postpartum, whichever occurred first. Cows were observed for estrous behavior twice daily, and jugular blood samples were collected twice weekly for the determination of serum progesterone concentration. Mean number of suckling episodes per 24 h was greater (P < .0001) for the Ad Libitum-Suckled group than either Night- or Day-Suckled groups (5.9+/-.42 vs 3.8+/-.14, and 3.9+/-.32, respectively). Hourly analysis of suckling episodes in the Ad Libitum group indicated that they were not skewed toward a particular period, with suckling occurring at a periodicity of 4 to 6 h. Intervals to the first rise in progesterone > or = 1 ng/mL (32+/-2.5, 32+/-4.5, and 31+/-1.7 d, respectively), first normal luteal phase (38+/-3.1, 38+/-3.8, and 37+/-2.5 d, respectively), and first estrus (43+/-3.5, 40+/-3.9, and 36+/-1.1 d, respectively) did not differ (P > .05) among the three groups. Similarly, cumulative pregnancy rates within 100 d after calving did not differ (P > .05). These results in Bos indicus x Bos taurus (F1) cattle do not support the previous conclusions in Bos taurus that eliminating nighttime suckling reduces the postpartum anovulatory interval. PMID:10340568

  20. Radiographic anatomy and barium sulfate contrast transit time of the gastrointestinal tract of bearded dragons (Pogona vitticeps).

    PubMed

    Grosset, Claire; Daniaux, Lise; Guzman, David Sanchez-Migallon; Weber, Ernest Scott; Zwingenberger, Allison; Paul-Murphy, Joanne

    2014-01-01

    The positive contrast gastrointestinal study is a common non-invasive diagnostic technique that does not require anesthesia and enables good visualization of the digestive tract. Radiographic anatomy and reference intervals for gastrointestinal contrast transit time in inland bearded dragons (Pogona vitticeps) were established using seven animals administered 15 ml/kg of a 35% w/v suspension of barium by esophageal gavage. Dorso-ventral and lateral radiographic views were performed at 0, 15, 30 min, 1, 2, 4, 6, 8, 12 h, and then every 12 h up to 96 h after barium administration. Gastric emptying was complete at a median time of 10 h (range 4-24 h). Median jejunum and small intestinal emptying times were 1 h (range 30 min-2 h) and 29 h (range 24-48 h), respectively. Median transit time for cecum was 10 h (range 8-12 h). Median time for contrast to reach the colon was 31 h (range 12-72 h) after administration. Results were compared to those obtained in other reptilian species. This technique appeared safe in fasted bearded dragons and would be clinically applicable in other lizard species. PMID:24945023

  1. Programming with Intervals

    NASA Astrophysics Data System (ADS)

    Matsakis, Nicholas D.; Gross, Thomas R.

    Intervals are a new, higher-level primitive for parallel programming with which programmers directly construct the program schedule. Programs using intervals can be statically analyzed to ensure that they do not deadlock or contain data races. In this paper, we demonstrate the flexibility of intervals by showing how to use them to emulate common parallel control-flow constructs like barriers and signals, as well as higher-level patterns such as bounded-buffer producer-consumer. We have implemented intervals as a publicly available library for Java and Scala.

  2. EVALUATION OF SPRING OPERATED RELIEF VALVE MAINTENANCE INTERVALS AND EXTENSION OF MAINTENANCE TIMES USING A WEIBULL ANALYSIS WITH MODIFIED BAYESIAN UPDATING

    SciTech Connect

    Harris, S.; Gross, R.; Mitchell, E.

    2011-01-18

    The Savannah River Site (SRS) spring operated pressure relief valve (SORV) maintenance intervals were evaluated using an approach provided by the American Petroleum Institute (API RP 581) for risk-based inspection technology (RBI). In addition, the impact of extending the inspection schedule was evaluated using Monte Carlo Simulation (MCS). The API RP 581 approach is characterized as a Weibull analysis with modified Bayesian updating provided by SRS SORV proof testing experience. Initial Weibull parameter estimates were updated as per SRS's historical proof test records contained in the Center for Chemical Process Safety (CCPS) Process Equipment Reliability Database (PERD). The API RP 581 methodology was used to estimate the SORV's probability of failing on demand (PFD), and the annual expected risk. The API RP 581 methodology indicates that the current SRS maintenance plan is conservative. Cost savings may be attained in certain mild service applications that present low PFD and overall risk. Current practices are reviewed and recommendations are made for extending inspection intervals. The paper gives an illustration of the inspection costs versus the associated risks by using API RP 581 Risk Based Inspection (RBI) Technology. A cost effective maintenance frequency balancing both financial risk and inspection cost is demonstrated.

  3. Delivery times for caesarean section at Queen Elizabeth Central Hospital, Blantyre, Malawi: is a 30-minute 'informed to start of operative delivery time' achievable?

    PubMed

    O'Regan, M

    2003-08-01

    A timesheet questionnaire was used to assess the time it took from informing the anaesthetist about a case to the start of operative delivery in 78 consecutive patients undergoing caesarean section. Median (IQR [range]) times for grade-1 cases (immediate threat to the life of the mother or fetus) and grade-2 cases (fetal or maternal compromise without immediate threat to life) were 20 (17-35 [6-75]) min and 41 (27-60 [17-136]) min, respectively. Delays occurred in all the component time intervals examined. The primary avoidable delay was the patient's late arrival in theatre. Many significant delays were apparently not perceived by the anaesthetist. In nine (69%) grade-1 cases, the 30-min target decreed by the Association of Anaesthetists of Great Britain & Ireland and the Obstetric Anaesthetists' Association was achieved. PMID:12859467

  4. The effect of the time interval used to calculate mean wind velocity on the calculated drift potential, relative drift potential, and resultant drift direction for sands from three deserts in northern China

    NASA Astrophysics Data System (ADS)

    Zhang, Zhengcai; Dong, Zhibao; Zhao, Aiguo

    2016-01-01

    Wind is the power behind many erosion processes and is responsible for many of the characteristics of arid zone geomorphology. Wind velocity is a key factor in determining the potential sand transport, but the nature of the wind velocity data can strongly affect assessments of the risk of blowing sand. In this study, we obtained real-time wind velocity data in a region of the Tengger Desert with shifting sands, in the Badain Jaran Desert, and in the Madoi desertification land, with the data obtained at 1-min intervals, and used the data to determine the influence of how the wind velocity was calculated (mean versus mid-point values and the averaging time used to calculate these values) on sand drift potential. In the three regions, for both the mean and the mid-point wind velocities, the estimated drift potential decreased with increasing averaging time. The relationships between velocities calculated using the different averaging time intervals and the value calculated using a 1-min interval could be expressed as linear functions. The drift potential calculated using the mid-point wind velocity was larger than that calculated using the mean wind velocity.

  5. Interval polynomial positivity

    NASA Technical Reports Server (NTRS)

    Bose, N. K.; Kim, K. D.

    1989-01-01

    It is shown that a univariate interval polynomial is globally positive if and only if two extreme polynomials are globally positive. It is shown that the global positivity property of a bivariate interval polynomial is completely determined by four extreme bivariate polynomials. The cardinality of the determining set for k-variate interval polynomials is 2k. One of many possible generalizations, where vertex implication for global positivity holds, is made by considering the parameter space to be the set dual of a boxed domain.

  6. Updating representations of temporal intervals.

    PubMed

    Danckert, James; Anderson, Britt

    2015-12-01

    Effectively engaging with the world depends on accurate representations of the regularities that make up that world-what we call mental models. The success of any mental model depends on the ability to adapt to changes-to 'update' the model. In prior work, we have shown that damage to the right hemisphere of the brain impairs the ability to update mental models across a range of tasks. Given the disparate nature of the tasks we have employed in this prior work (i.e. statistical learning, language acquisition, position priming, perceptual ambiguity, strategic game play), we propose that a cognitive module important for updating mental representations should be generic, in the sense that it is invoked across multiple cognitive and perceptual domains. To date, the majority of our tasks have been visual in nature. Given the ubiquity and import of temporal information in sensory experience, we examined the ability to build and update mental models of time. We had healthy individuals complete a temporal prediction task in which intervals were initially drawn from one temporal range before an unannounced switch to a different range of intervals. Separate groups had the second range of intervals switch to one that contained either longer or shorter intervals than the first range. Both groups showed significant positive correlations between perceptual and prediction accuracy. While each group updated mental models of temporal intervals, those exposed to shorter intervals did so more efficiently. Our results support the notion of generic capacity to update regularities in the environment-in this instance based on temporal information. The task developed here is well suited to investigations in neurological patients and in neuroimaging settings. PMID:26303026

  7. Effect of Androctonus bicolor scorpion venom on serum electrolytes in rats: A 24-h time-course study.

    PubMed

    Al-Asmari, A; Khan, H A; Manthiri, R A

    2016-03-01

    Black fat-tailed scorpion (Androctonus bicolor) belongs to the family Buthidae and is one of the most venomous scorpions in the world. The effects of A. bicolor venom on serum electrolytes were not known and therefore investigated in this study. Adult male Wistar rats were randomly divided into seven groups with five animals in each group. One of the groups served as control and received vehicle only. The animals in the remaining groups received a single subcutaneous injection of crude A. bicolor venom (200 μg/kg bodyweight) and were killed at different time intervals including 30 min, 1 h, 2 h, 4 h, 8 h, and 24 h after venom injection. The results showed that scorpion venom caused significant increase in serum sodium levels within 30 min after injection which slightly subsided after 1 h and then persisted over 24 h. Serum potassium levels continued to significantly increase until 4 h and then slightly subsided. There were significant decreases in serum magnesium (Mg(+)) levels following scorpion venom injection, at all the time points during the course of study. Serum calcium levels were significantly increased during the entire course of study, whereas serum chloride was significantly decreased. In conclusion, A. bicolor envenomation in rats caused severe and persistent hypomagnesemia with accompanied hypernatremia, hyperkalemia, and hypercalcemia. It is important to measure serum Mg(+) levels in victims of scorpion envenomation, and patients with severe Mg(+) deficiency should be treated accordingly. PMID:25964378

  8. Effects of food form and timing of ingestion on appetite and energy intake in lean and obese young adults

    PubMed Central

    RD, Mattes; WW, Campbell

    2009-01-01

    Objective Overweight and obesity have been attributed to increased eating frequency and the size of eating events. This study explored the influence of the timing of eating events and food form on appetite and daily energy intake. Design Cross-over, clinical intervention where participants consumed 300 kcal loads of a solid (apple), semi-solid (apple sauce) and beverage (apple juice) at a meal or 2 hours later (snack). Subjects Twenty normal weight (body mass index - BMI=22.6±1.8kg/m2) and 20 obese (BMI=32.3±1.5kg/m2) adults. There were 10 males and 10 females within each BMI group. Measurements On 6 occasions, participants reported to the laboratory at their customary midday meal time. Appetite questionnaires and motor skills tests were completed upon arrival and at 30min intervals for the 2 hours participants were in the laboratory and at 30min intervals for 4 hours after leaving the laboratory. Diet recalls were collected the next day. Data were collected between January of 2006 and June of 2007. Results Whether consumed with a meal or alone as a snack, the beverage elicited the weakest appetitive response, the solid food form elicited the strongest appetitive response and the semi-solid response was intermediate. The appetite shift was greatest for the solid food when consumed as a snack. The interval between test food consumption and the first spontaneous eating event >100 kcal was shortest for the beverage. No significant treatment effects were observed for test day energy intake or between lean and obese individuals. Conclusion Based on the appetitive findings, consumption of an energy-yielding beverage either with a meal or as a snack poses a greater risk for promoting positive energy than macronutrient-matched semi-solid or solid foods consumed at these times. PMID:19248858

  9. Interval neural networks

    SciTech Connect

    Patil, R.B.

    1995-05-01

    Traditional neural networks like multi-layered perceptrons (MLP) use example patterns, i.e., pairs of real-valued observation vectors, ({rvec x},{rvec y}), to approximate function {cflx f}({rvec x}) = {rvec y}. To determine the parameters of the approximation, a special version of the gradient descent method called back-propagation is widely used. In many situations, observations of the input and output variables are not precise; instead, we usually have intervals of possible values. The imprecision could be due to the limited accuracy of the measuring instrument or could reflect genuine uncertainty in the observed variables. In such situation input and output data consist of mixed data types; intervals and precise numbers. Function approximation in interval domains is considered in this paper. We discuss a modification of the classical backpropagation learning algorithm to interval domains. Results are presented with simple examples demonstrating few properties of nonlinear interval mapping as noise resistance and finding set of solutions to the function approximation problem.

  10. Intervals in evolutionary algorithms for global optimization

    SciTech Connect

    Patil, R.B.

    1995-05-01

    Optimization is of central concern to a number of disciplines. Interval Arithmetic methods for global optimization provide us with (guaranteed) verified results. These methods are mainly restricted to the classes of objective functions that are twice differentiable and use a simple strategy of eliminating a splitting larger regions of search space in the global optimization process. An efficient approach that combines the efficient strategy from Interval Global Optimization Methods and robustness of the Evolutionary Algorithms is proposed. In the proposed approach, search begins with randomly created interval vectors with interval widths equal to the whole domain. Before the beginning of the evolutionary process, fitness of these interval parameter vectors is defined by evaluating the objective function at the center of the initial interval vectors. In the subsequent evolutionary process the local optimization process returns an estimate of the bounds of the objective function over the interval vectors. Though these bounds may not be correct at the beginning due to large interval widths and complicated function properties, the process of reducing interval widths over time and a selection approach similar to simulated annealing helps in estimating reasonably correct bounds as the population evolves. The interval parameter vectors at these estimated bounds (local optima) are then subjected to crossover and mutation operators. This evolutionary process continues for predetermined number of generations in the search of the global optimum.

  11. Comparative evaluation of the calcium release from mineral trioxide aggregate and its mixture with glass ionomer cement in different proportions and time intervals – An in vitro study

    PubMed Central

    Sawhney, Surbhi; Vivekananda Pai, A.R.

    2015-01-01

    Background Addition of glass ionomer cement (GIC) has been suggested to improve the setting time and handling characteristics of mineral trioxide aggregate (MTA). This study evaluated the effect of adding GIC to MTA in terms of calcium release, an issue that has not been previously studied. Materials and methods The study comprised four groups with five samples each: a control group of MTA alone and experimental groups I (1MTA:1GIC), II (2MTA:1GIC), and III (1MTA:2GIC) based on the mixture of MTA and GIC powders in the respective proportions by volume. Calcium release from the samples was measured by atomic absorption spectrophotometry at 15 min, 6 h, 24 h, and 1 week after setting. The level of statistical significance was set at p < 0.05. Results Groups I (1MTA:1GIC) and III (1MTA:2GIC) released significantly less calcium than the control group at all time periods, except at 15 min for group I. Group II (2MTA:1GIC) showed no significant difference in calcium release compared to the control at any time period. Group II exhibited greater calcium release than group I or III at all time periods, with significant differences between groups I and II at 1 week and between groups I and III at 24 h and 1 week. There were no statistical differences in calcium release between groups I and III. Conclusions Adding GIC to improve the setting time and handling properties of the MTA powder can be detrimental to the calcium-releasing ability of the resultant mixture, depending on the proportion of GIC added. Adding MTA and GIC at a proportion of 2:1 by volume did not impact calcium release from the mixture. These findings should be verified through further clinical studies. PMID:26644757

  12. Interval velocity analysis using wave field continuation

    SciTech Connect

    Zhusheng, Z. )

    1992-01-01

    In this paper, the author proposes a new interval velocity inversion method which, based on wave field continuation theory and fuzzy decision theory, uses CMP seismic gathers to automatically estimate interval velocity and two-way travel time in layered medium. The interval velocity calculated directly from wave field continuation is not well consistent with that derived from VSP data, the former is usually higher than the latter. Three major factors which influence the accuracy of interval velocity from wave field continuation are corrected, so that the two kinds of interval velocity are well consistent. This method brings better interval velocity, adapts weak reflection waves and resists noise well. It is a feasible method.

  13. Optimal Approximation of Quadratic Interval Functions

    NASA Technical Reports Server (NTRS)

    Koshelev, Misha; Taillibert, Patrick

    1997-01-01

    Measurements are never absolutely accurate, as a result, after each measurement, we do not get the exact value of the measured quantity; at best, we get an interval of its possible values, For dynamically changing quantities x, the additional problem is that we cannot measure them continuously; we can only measure them at certain discrete moments of time t(sub 1), t(sub 2), ... If we know that the value x(t(sub j)) at a moment t(sub j) of the last measurement was in the interval [x-(t(sub j)), x + (t(sub j))], and if we know the upper bound D on the rate with which x changes, then, for any given moment of time t, we can conclude that x(t) belongs to the interval [x-(t(sub j)) - D (t - t(sub j)), x + (t(sub j)) + D (t - t(sub j))]. This interval changes linearly with time, an is, therefore, called a linear interval function. When we process these intervals, we get an expression that is quadratic and higher order w.r.t. time t, Such "quadratic" intervals are difficult to process and therefore, it is necessary to approximate them by linear ones. In this paper, we describe an algorithm that gives the optimal approximation of quadratic interval functions by linear ones.

  14. Timing of HPV vaccine intervals among United States teens with consideration to the current ACIP schedule and the WHO 2-dose schedule.

    PubMed

    Cloessner, Emily A; Stokley, Shannon; Yankey, David; Markowitz, Lauri E

    2016-06-01

    The current recommendation for human papillomavirus (HPV) vaccination in the United States is for 3 doses to be administered over a 6 month period. In April 2014, the World Health Organization (WHO) recommended adoption of a 2-dose schedule, with doses spaced a minimum of 6 months apart, for teens who begin the series before age 15. We analyzed data from the 2013 National Immunization Survey-Teen to examine the timing of second and third dose receipt among US adolescents. All analyses were restricted to adolescents age 13-17 y who had adequate provider data. The Wilcoxon-Mann-Whitney test measured differences in time to receive vaccine doses among demographic and socioeconomic groups. Logistic regression identified socioeconomic characteristics associated with receiving the second dose of HPV vaccine at least 6 months after the first dose. The median time for teens to receive the second dose of HPV vaccine was 2.6 months after the first dose, and the median time to receive the third dose was 4.9 months after the second dose. Minority teens and teens living below the poverty level took significantly longer to receive doses. Among teens that initiated the HPV vaccine series before age 15 y, 28.6% received the second dose at least 6 months after the first dose. If these teens, who met the WHO criteria for up-to-date HPV vaccination, were classified as having completed the vaccination series, overall coverage in the US would increase 3.9 percentage points, with African American and Hispanic teens having the greatest increases in coverage. PMID:26587886

  15. Exact statistics of the gap and time interval between the first two maxima of random walks and Lévy flights.

    PubMed

    Majumdar, Satya N; Mounaix, Philippe; Schehr, Grégory

    2013-08-16

    We investigate the statistics of the gap G(n) between the two rightmost positions of a Markovian one-dimensional random walker (RW) after n time steps and of the duration L(n) which separates the occurrence of these two extremal positions. The distribution of the jumps η(i)'s of the RW, f(η), is symmetric and its Fourier transform has the small k behavior 1-f[over ^](k)~|k|(μ), with 0<μ≤2. For μ=2, the RW converges, for large n, to Brownian motion, while for 0<μ<2 it corresponds to a Lévy flight of index μ. We compute the joint probability density function (PDF) P(n)(g,l) of G(n) and L(n) and show that, when n→∞, it approaches a limiting PDF p(g,l). The corresponding marginal PDFs of the gap, p(gap)(g), and of L(n), p(time)(l), are found to behave like p(gap)(g)~g(-1-μ) for g>1 and 0<μ<2, and p(time)(l)~l(-γ(μ)) for l>1 with γ(1<μ≤2)=1+1/μ and γ(0<μ<1)=2. For l, g>1 with fixed lg(-μ), p(g,l) takes the scaling form p(g,l)~g(-1-2μ)p[over ˜](μ)(lg(-μ)), where p[over ˜](μ)(y) is a (μ-dependent) scaling function. We also present numerical simulations which verify our analytic results. PMID:23992054

  16. Impact of preload changes on positive and negative left ventricular dP/dt and systolic time intervals: preload changes on left ventricular function

    PubMed Central

    Jamshidi, Peiman; Kobza, Richard; Toggweiler, Stefan; Arand, Patti; Zuber, Michel; Erne, Paul

    2012-01-01

    Aim/objectives Previous work has shown that the electromechanical activation time (EMAT) is prolonged in patients with abnormally low left ventricular (LV) dP/dt. In the present study, we investigated whether EMAT was responsive to rapid changes in LV systolic function induced by abrupt increases in LV preload. Methods and results A total of 116 patients were assessed before and after LV angiography with a bolus injection of 40 mL of non-ionic contrast dye. Left ventricular end-diastolic pressure (LVEDP) increased from 18 ± 7 mmHg to 20 ± 8 mmHg (P < 0.01). In patients with a baseline dP/dt < 1500 mmHg/sec, dP/dt increased from 1098 ± 213 mmHg/sec to 1146 ±306 mmHg/sec (P=0.02) and EMAT decreased from 106 ± 29 ms to 103 ±18 ms (P=0.02). In patients with a baseline dP/dt > 1500 mmHg/sec, dP/dt decreased from 1894 ± 368 mmHg/sec to 1762 ± 403 mmHg/sec (P=0.01) and EMAT increased from 88 ± 13 ms to 93 ± 16 ms (P=0.02). Changes in negative dP/dt were similar to changes in dP/dt. Conclusion Electromechanical activation time is a non-invasively measured parameter that allows accurate and rapid detection of changes in LV contractility. PMID:22664818

  17. Continuous cardiac output and left atrial pressure monitoring by long time interval analysis of the pulmonary artery pressure waveform: proof of concept in dogs.

    PubMed

    Xu, Da; Olivier, N Bari; Mukkamala, Ramakrishna

    2009-02-01

    We developed a technique to continuously (i.e., automatically) monitor cardiac output (CO) and left atrial pressure (LAP) by mathematical analysis of the pulmonary artery pressure (PAP) waveform. The technique is unique to the few previous related techniques in that it jointly estimates the two hemodynamic variables and analyzes the PAP waveform over time scales greater than a cardiac cycle wherein wave reflections and inertial effects cease to be major factors. First, a 6-min PAP waveform segment is analyzed so as to determine the pure exponential decay and equilibrium pressure that would eventually result if cardiac activity suddenly ceased (i.e., after the confounding wave reflections and inertial effects vanish). Then, the time constant of this exponential decay is computed and assumed to be proportional to the average pulmonary arterial resistance according to a Windkessel model, while the equilibrium pressure is regarded as average LAP. Finally, average proportional CO is determined similar to invoking Ohm's law and readily calibrated with one thermodilution measurement. To evaluate the technique, we performed experiments in five dogs in which the PAP waveform and accurate, but highly invasive, aortic flow probe CO and LAP catheter measurements were simultaneously recorded during common hemodynamic interventions. Our results showed overall calibrated CO and absolute LAP root-mean-squared errors of 15.2% and 1.7 mmHg, respectively. For comparison, the root-mean-squared error of classic end-diastolic PAP estimates of LAP was 4.7 mmHg. On future successful human testing, the technique may potentially be employed for continuous hemodynamic monitoring in critically ill patients with pulmonary artery catheters. PMID:19057003

  18. Acquisition of “Start” and “Stop” response thresholds in peak-interval timing is differentially sensitive to protein synthesis inhibition in the dorsal and ventral striatum

    PubMed Central

    MacDonald, Christopher J.; Cheng, Ruey-Kuang; Meck, Warren H.

    2011-01-01

    Time-based decision-making in peak-interval timing procedures involves the setting of response thresholds for the initiation (“Start”) and termination (“Stop”) of a response sequence that is centered on a target duration. Using intracerebral infusions of the protein synthesis inhibitor anisomycin, we report that the acquisition of the “Start” response depends on normal functioning (including protein synthesis) in the dorsal striatum (DS), but not the ventral striatum (VS). Conversely, disruption of the VS, but not the DS, impairs the acquisition of the “Stop” response. We hypothesize that the dorsal and ventral regions of the striatum function as a competitive neural network that encodes the temporal boundaries marking the beginning and end of a timed response sequence. PMID:22435054

  19. Exact Statistics of the Gap and Time Interval between the First Two Maxima of Random Walks and Lévy Flights

    NASA Astrophysics Data System (ADS)

    Majumdar, Satya N.; Mounaix, Philippe; Schehr, Grégory

    2013-08-01

    We investigate the statistics of the gap Gn between the two rightmost positions of a Markovian one-dimensional random walker (RW) after n time steps and of the duration Ln which separates the occurrence of these two extremal positions. The distribution of the jumps ηi’s of the RW, f(η), is symmetric and its Fourier transform has the small k behavior 1-f^(k)˜|k|μ, with 0<μ≤2. For μ=2, the RW converges, for large n, to Brownian motion, while for 0<μ<2 it corresponds to a Lévy flight of index μ. We compute the joint probability density function (PDF) Pn(g,l) of Gn and Ln and show that, when n→∞, it approaches a limiting PDF p(g,l). The corresponding marginal PDFs of the gap, pgap(g), and of Ln, ptime(l), are found to behave like pgap(g)˜g-1-μ for g≫1 and 0<μ<2, and ptime(l)˜l-γ(μ) for l≫1 with γ(1<μ≤2)=1+1/μ and γ(0<μ<1)=2. For l, g≫1 with fixed lg-μ, p(g,l) takes the scaling form p(g,l)˜g-1-2μp˜μ(lg-μ), where p˜μ(y) is a (μ-dependent) scaling function. We also present numerical simulations which verify our analytic results.

  20. Easy identification of generalized common and conserved nested intervals.

    PubMed

    de Montgolfier, Fabien; Raffinot, Mathieu; Rusu, Irena

    2014-07-01

    In this article we explain how to easily compute gene clusters, formalized by classical or generalized nested common or conserved intervals, between a set of K genomes represented as K permutations. A b-nested common (resp. conserved) interval I of size |I| is either an interval of size 1 or a common (resp. conserved) interval that contains another b-nested common (resp. conserved) interval of size at least |I|-b. When b=1, this corresponds to the classical notion of nested interval. We exhibit two simple algorithms to output all b-nested common or conserved intervals between K permutations in O(Kn+nocc) time, where nocc is the total number of such intervals. We also explain how to count all b-nested intervals in O(Kn) time. New properties of the family of conserved intervals are proposed to do so. PMID:24650221

  1. Real-time fluorescence microscopy monitoring of porphyrin biodistribution

    NASA Astrophysics Data System (ADS)

    Kimel, Sol; Gottfried, Varda; Kunzi-Rapp, Karin; Akguen, Nermin; Schneckenburger, Herbert

    1996-01-01

    In vivo uptake of the natural porphyrins, uroporphyrin III (UP), coproporphyrin III (CP) and protoporphyrin IX (PP), was monitored by fluorescence microscopy. Experiments were performed using the chick chorioallantoic membrane (CAM) model, which allowed video documentation of fluorescence both in real time and after integration over a chosen time interval (usually 2 s). Sensitizers at a concentration of 50 (mu) M (100 (mu) L) were injected into a medium-sized vein (diameter approximately 40 micrometer) using an ultra-fine 10 micrometer diameter needle. Fluorescence images were quantitated by subtracting the fluorescence intensity of surrounding CAM tissue (Fmatrix) from the intravascular fluorescence intensity (Fintravascular), after transformation of the video frames into digital form. The differential fluorescence intensity, Fintravascular - Fmatrix, is a measure of the biodistribution. Real time measurements clearly showed that CP and UP fluorescence is associated with moving erythrocytes and not with endothelial cells of the vessel wall. Fluorescence intensity was monitored, up to 60 minutes after injection, by averaging the fluorescence over time intervals of 2 s and recording the integrated images. The fluorescence intensity reached its maximum in about 20 - 30 min after injection, presumably after monomerization inside erythrocyte membranes. The results are interpreted in terms of physical-chemical characteristics (e.g. hydrophilicity) and correlated with the photodynamically induced hemostasis in CAM blood vessels.

  2. Interval arithmetic operations for uncertainty analysis with correlated interval variables

    NASA Astrophysics Data System (ADS)

    Jiang, Chao; Fu, Chun-Ming; Ni, Bing-Yu; Han, Xu

    2016-08-01

    A new interval arithmetic method is proposed to solve interval functions with correlated intervals through which the overestimation problem existing in interval analysis could be significantly alleviated. The correlation between interval parameters is defined by the multidimensional parallelepiped model which is convenient to describe the correlative and independent interval variables in a unified framework. The original interval variables with correlation are transformed into the standard space without correlation, and then the relationship between the original variables and the standard interval variables is obtained. The expressions of four basic interval arithmetic operations, namely addition, subtraction, multiplication, and division, are given in the standard space. Finally, several numerical examples and a two-step bar are used to demonstrate the effectiveness of the proposed method.

  3. Comparison of Polar® RS800G3™ heart rate monitor with Polar® S810i™ and electrocardiogram to obtain the series of RR intervals and analysis of heart rate variability at rest.

    PubMed

    Barbosa, Marianne Penachini da Costa de Rezende; da Silva, Natália Turri; de Azevedo, Fábio Mícolis; Pastre, Carlos Marcelo; Vanderlei, Luiz Carlos Marques

    2016-03-01

    The Polar® RS800G3™ rate monitor was released in the market to replace the Polar® S810i™, and few studies have assessed that the RR series obtained by this equipment is reliable for analysis of heart rate variability (HRV). We compared HRV indexes among the devices Polar® RS800G3™, Polar® S810i™ and eletrocardiogram (ECG) to know whether the series of Polar® RS800G3™ are as reliable as those devices already validated. We analysed data from 30 healthy young adults, male, with an average age of 20·66 ± 1·40 years, which had captured the heart rate beat to beat in the three devices simultaneously with spontaneously breathing, first in the supine position and subsequently sit both for 30 min. The obtained series of RR intervals was used to calculate the indexes of HRV in the time domain (SDNN and RMSSD) and in the frequency domain (LF, HF and LF/HF). There were no significant differences in HRV indexes calculated from series obtained by the three devices, regardless of the position analysed, and a high correlation coefficient was observed. The results suggest that the Polar® RS800G3™ is able to capture series of RR intervals for analysis of HRV indexes as reliable as those obtained by ECG and Polar® S810i™. PMID:25348547

  4. Analysis of regression confidence intervals and Bayesian credible intervals for uncertainty quantification

    NASA Astrophysics Data System (ADS)

    Lu, Dan; Ye, Ming; Hill, Mary C.

    2012-09-01

    environmental problems with lengthy execution times that make credible intervals inconvenient or prohibitive, confidence intervals can provide important insight. During model development when frequent calculation of uncertainty intervals is important to understanding the consequences of various model construction alternatives and data collection strategies, strategic use of both confidence and credible intervals can be critical.

  5. Interval-valued random functions and the kriging of intervals

    SciTech Connect

    Diamond, P.

    1988-04-01

    Estimation procedures using data that include some values known to lie within certain intervals are usually regarded as problems of constrained optimization. A different approach is used here. Intervals are treated as elements of a positive cone, obeying the arithmetic of interval analysis, and positive interval-valued random functions are discussed. A kriging formalism for interval-valued data is developed. It provides estimates that are themselves intervals. In this context, the condition that kriging weights be positive is seen to arise in a natural way. A numerical example is given, and the extension to universal kriging is sketched.

  6. Effect of pre-slaughter management regarding transportation and time in lairage on certain stress parameters, carcass and meat quality characteristics in Kivircik lambs.

    PubMed

    Ekiz, Bulent; Ekiz, Elif Ergul; Kocak, Omur; Yalcintan, Hulya; Yilmaz, Alper

    2012-04-01

    Thirty Kivircik lambs were used to investigate effect of pre-slaughter treatment on certain haematological and biochemical parameters, carcass and meat quality characteristics. Lambs were divided into three treatments: 75 min transport and lairage for 18 h (TS-L18 h); 75 min transport and lairage for 30 min (TS-L30 min) and no pre-slaughter transport and lairage for 30 min (NTS). Treatment, as a main effect, did not influence haematological and biochemical parameters, but sampling time significantly affected these parameters, except total protein. Plasma cortisol concentration at exsanguination in TS-18 h, TS-30 min and NTS treatments were 117.34, 119.23 and 72.51 ng/ml, respectively. pH of longissimus dorsi muscle was higher in TS-L30 min than other treatments. TS-L30 min lambs had the highest shear force value, the lowest WHC and cooking loss. TS-L30 min treatment yielded the darkest meat immediately after cutting and 1 h later. Meat redness, yellowness and chroma values were similar in treatments. PMID:22197098

  7. Experimenting with musical intervals

    NASA Astrophysics Data System (ADS)

    Lo Presto, Michael C.

    2003-07-01

    When two tuning forks of different frequency are sounded simultaneously the result is a complex wave with a repetition frequency that is the fundamental of the harmonic series to which both frequencies belong. The ear perceives this 'musical interval' as a single musical pitch with a sound quality produced by the harmonic spectrum responsible for the waveform. This waveform can be captured and displayed with data collection hardware and software. The fundamental frequency can then be calculated and compared with what would be expected from the frequencies of the tuning forks. Also, graphing software can be used to determine equations for the waveforms and predict their shapes. This experiment could be used in an introductory physics or musical acoustics course as a practical lesson in superposition of waves, basic Fourier series and the relationship between some of the ear's subjective perceptions of sound and the physical properties of the waves that cause them.

  8. IDENTIFICATION OF SOURCES AND ESTIMATION OF EMISSION PROFILES FROM HIGHLY TIME-RESOLVED POLLUTANT MEASUREMENTS IN TAMPA, FL

    EPA Science Inventory

    Aerosol slurry samples were collected at 30-min intervals for sequential 1-month periods at each of two sites (Sydney and "Dairy") in the Tampa Bay area during the 2002 Bay Regional Atmospheric Chemistry Experiment using the University of Maryland Semicontinuous Elements in Aeros...

  9. An interval model updating strategy using interval response surface models

    NASA Astrophysics Data System (ADS)

    Fang, Sheng-En; Zhang, Qiu-Hu; Ren, Wei-Xin

    2015-08-01

    Stochastic model updating provides an effective way of handling uncertainties existing in real-world structures. In general, probabilistic theories, fuzzy mathematics or interval analyses are involved in the solution of inverse problems. However in practice, probability distributions or membership functions of structural parameters are often unavailable due to insufficient information of a structure. At this moment an interval model updating procedure shows its superiority in the aspect of problem simplification since only the upper and lower bounds of parameters and responses are sought. To this end, this study develops a new concept of interval response surface models for the purpose of efficiently implementing the interval model updating procedure. The frequent interval overestimation due to the use of interval arithmetic can be maximally avoided leading to accurate estimation of parameter intervals. Meanwhile, the establishment of an interval inverse problem is highly simplified, accompanied by a saving of computational costs. By this means a relatively simple and cost-efficient interval updating process can be achieved. Lastly, the feasibility and reliability of the developed method have been verified against a numerical mass-spring system and also against a set of experimentally tested steel plates.

  10. Effect Sizes, Confidence Intervals, and Confidence Intervals for Effect Sizes

    ERIC Educational Resources Information Center

    Thompson, Bruce

    2007-01-01

    The present article provides a primer on (a) effect sizes, (b) confidence intervals, and (c) confidence intervals for effect sizes. Additionally, various admonitions for reformed statistical practice are presented. For example, a very important implication of the realization that there are dozens of effect size statistics is that "authors must…

  11. Improved outcomes for emergency department patients whose ambulance off-stretcher time is not delayed

    PubMed Central

    Crilly, Julia; Keijzers, Gerben; Tippett, Vivienne; O’Dwyer, John; Lind, James; Bost, Nerolie; O’Dwyer, Marilla; Shiels, Sue; Wallis, Marianne

    2015-01-01

    Objective To describe and compare characteristics and outcomes of patients who arrive by ambulance to the ED. We aimed to (i) compare patients with a delayed ambulance offload time (AOT) >30 min with those who were not delayed; and (ii) identify predictors of an ED length of stay (LOS) of >4 h for ambulance-arriving patients. Methods A retrospective, multi-site cohort study was undertaken in Australia using 12 months of linked health data (September 2007–2008). Outcomes of AOT delayed and non-delayed presentations were compared. Logistic regression analysis was undertaken to identify predictors of an ED LOS of >4 h. Results Of the 40 783 linked, analysable ambulance presentations, AOT delay of >30 min was experienced by 15%, and 63% had an ED LOS of >4 h. Patients with an AOT <30 min had better outcomes for: time to triage; ambulance time at hospital; time to see healthcare professional; proportion seen within recommended triage time frame; and ED LOS for both admitted and non-admitted patients. In-hospital mortality did not differ. Strong predictors of an ED LOS >4 h included: hospital admission, older age, triage category, and offload delay >30 min. Conclusion Patients arriving to the ED via ambulance and offloaded within 30 min experience better outcomes than those delayed. Given that offload delay is a modifiable predictor of an ED LOS of >4 h, targeted improvements in the ED arrival process for ambulance patients might be useful. PMID:25940975

  12. [Birth interval differentials in Rwanda].

    PubMed

    Ilinigumugabo, A

    1992-01-01

    Data from the 1983 Rwanda Fertility Survey are the basis for this study of variations in birth intervals. An analysis of the quality of the Rwandan birth data showed it to be relatively good. The life table technique utilized in this study is explained in a section on methodology, which also describes the Rwanda Fertility Survey questionnaires. A comparison of birth intervals in which live born children died before their first birthday or survived the first birthday shows that infant mortality shortens birth intervals by an average of 5 months. The first birth interval was almost 28 months when the oldest child survived, but declined to 23 months when the oldest child died before age 1. The effect of mortality on birth intervals increased with parity, from 5 months for the first birth interval to 5.5 months for the second and third and 6.4 months for subsequent intervals. The differences amounted to 9 or 10 months for women separating at parities under 4 and over 14 months for women separating at parities of 4 or over. Birth intervals generally increased with parity, maternal age, and the duration of the union. But women entering into unions at higher ages had shorter birth intervals. In the absence of infant mortality and dissolution of the union, women attending school beyong the primary level had first birth intervals 6 months shorter on average than other women. Controlling for infant mortality and marital dissolution, women working for wages had average birth intervals of under 2 years for the first 5 births. Father's occupation had a less marked influence on birth intervals. Urban residence was associated with a shortening of the average birth interval by 6 months between the first and second birth and 5 months between the second and third births. In the first 5 births, Tutsi women had birth intervals 1.5 months longer on average than Hutu women. Women in polygamous unions did not have significantly different birth intervals except perhaps among older women

  13. Extended Time on Academic Assignments: Does Increased Time Lead to Improved Performance for Children with Attention-Deficit/Hyperactivity Disorder?

    ERIC Educational Resources Information Center

    Pariseau, Meaghan E.; Fabiano, Gregory A.; Massetti, Greta M.; Hart, Katie C.; Pelham, William E., Jr.

    2010-01-01

    Researchers examined the impact of an extended time accommodation on appropriate classroom behavior and rate of work completion for 33 children with attention-deficit/hyperactivity disorder (ADHD). Participants received standard (30 min) or extended (45 min) time to complete seatwork in a within-subject, crossover design study. Appropriate…

  14. Precise Interval Timer for Software Defined Radio

    NASA Technical Reports Server (NTRS)

    Pozhidaev, Aleksey (Inventor)

    2014-01-01

    A precise digital fractional interval timer for software defined radios which vary their waveform on a packet-by-packet basis. The timer allows for variable length in the preamble of the RF packet and allows to adjust boundaries of the TDMA (Time Division Multiple Access) Slots of the receiver of an SDR based on the reception of the RF packet of interest.

  15. Teaching Confidence Intervals Using Simulation

    ERIC Educational Resources Information Center

    Hagtvedt, Reidar; Jones, Gregory Todd; Jones, Kari

    2008-01-01

    Confidence intervals are difficult to teach, in part because most students appear to believe they understand how to interpret them intuitively. They rarely do. To help them abandon their misconception and achieve understanding, we have developed a simulation tool that encourages experimentation with multiple confidence intervals derived from the…

  16. Automatic Error Analysis Using Intervals

    ERIC Educational Resources Information Center

    Rothwell, E. J.; Cloud, M. J.

    2012-01-01

    A technique for automatic error analysis using interval mathematics is introduced. A comparison to standard error propagation methods shows that in cases involving complicated formulas, the interval approach gives comparable error estimates with much less effort. Several examples are considered, and numerical errors are computed using the INTLAB…

  17. Explorations in Statistics: Confidence Intervals

    ERIC Educational Resources Information Center

    Curran-Everett, Douglas

    2009-01-01

    Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This third installment of "Explorations in Statistics" investigates confidence intervals. A confidence interval is a range that we expect, with some level of confidence, to include the true value of a population parameter…

  18. A Review of Confidence Intervals.

    ERIC Educational Resources Information Center

    Mauk, Anne-Marie Kimbell

    This paper summarizes information leading to the recommendation that statistical significance testing be replaced, or at least accompanied by, the reporting of effect sizes and confidence intervals. It discusses the use of confidence intervals, noting that the recent report of the American Psychological Association Task Force on Statistical…

  19. Children's Discrimination of Melodic Intervals.

    ERIC Educational Resources Information Center

    Schellenberg, E. Glenn; Trehub, Sandra E.

    1996-01-01

    Adults and children listened to tone sequences and were required to detect changes either from intervals with simple frequency ratios to intervals with complex ratios or vice versa. Adults performed better on changes from simple to complex ratios than on the reverse changes. Similar performance was observed for 6-year olds who had never taken…

  20. Influence of high ovarian hormones on QT interval duration in young African women

    PubMed Central

    Balayssac‐Siransy, Edwige; Ouattara, Soualiho; Adoubi, Anicet; Kouamé, Chantal; Hauhouot‐Attoungbré, Marie‐Laure; Dah, Cyrille; Bogui, Pascal

    2014-01-01

    Abstract The longer QT interval duration observed in women compared to men is usually attributed to sexual hormones. The aim of our study was to investigate, among black African women, the influence of hormonal variations during the menstrual cycle on the duration of the QT interval. Fourteen young black African women, healthy, sedentary, aged 24 ± 1.7 years, with a regular menstrual cycle (28 ± 1 days) were selected from 59 volunteers. At each phase of their menstrual cycle, menstrual 2.9 ± 0.6 days, follicular 13 ± 1.5 days, and luteal 23.1 ± 1.4 days, an electrocardiogram was performed in supine position after a resting period of 30 min, to measure QT interval duration. QT interval was corrected by Bazett's (QTcb) and Fridericia's (QTcf) formulae. Then, blood samples were obtained to measure estradiol, progesterone, and serum electrolytes (K+, Ca2+, Mg2+). There was no significant difference in uncorrected QT intervals between the three phases of the menstrual cycle. It was the same for QTcb and QTcf. Moreover, during the menstrual cycle, we did not observe any correlation between each QT, QTcb, QTcf, and estradiol levels which raised during the follicular phase (356.61 ± 160.77 pg/mL) and progesterone levels which raised during the luteal phase (16.38 ± 5.88 ng/mL). Finally, the method of Bland and Altman demonstrated that the corrections of QT by Bazett and Fridericia formulae were not interchangeable. The results of this study showed that high levels of estradiol and progesterone in young black African women did not influence the QT, QTcb and QTcf intervals duration during the menstrual cycle. PMID:24760517

  1. Birth records from Swiss married couples analyzed over the past 35 years reveal an aging of first-time mothers by 5.1 years while the interpregnancy interval has shortened.

    PubMed

    Kalberer, Urs; Baud, David; Fontanet, Arnaud; Hohlfeld, Patrick; de Ziegler, Dominique

    2009-12-01

    Although the general trend for delaying childbearing is generally viewed as causing infertility, its consequences on the interpregnancy interval have been unknown. A study of birth records for Swiss married women from 1969 to 2006 revealed that the woman's age at first birth has increased from 25.0 to 30.1 years, whereas calculated theoretical interpregnancy intervals after the first and second child decreased from 23.2 to 13 and from 22.4 to 7.9 months, respectively. PMID:19608170

  2. Image magnification using interval information.

    PubMed

    Jurio, Aranzazu; Pagola, Miguel; Mesiar, Radko; Beliakov, Gleb; Bustince, Humberto

    2011-11-01

    In this paper, a simple and effective image-magnification algorithm based on intervals is proposed. A low-resolution image is magnified to form a high-resolution image using a block-expanding method. Our proposed method associates each pixel with an interval obtained by a weighted aggregation of the pixels in its neighborhood. From the interval and with a linear K(α) operator, we obtain the magnified image. Experimental results show that our algorithm provides a magnified image with better quality (peak signal-to-noise ratio) than several existing methods. PMID:21632304

  3. Interval estimates and their precision

    NASA Astrophysics Data System (ADS)

    Marek, Luboš; Vrabec, Michal

    2015-06-01

    A task very often met in in practice is computation of confidence interval bounds for the relative frequency within sampling without replacement. A typical situation includes preelection estimates and similar tasks. In other words, we build the confidence interval for the parameter value M in the parent population of size N on the basis of a random sample of size n. There are many ways to build this interval. We can use a normal or binomial approximation. More accurate values can be looked up in tables. We consider one more method, based on MS Excel calculations. In our paper we compare these different methods for specific values of M and we discuss when the considered methods are suitable. The aim of the article is not a publication of new theoretical methods. This article aims to show that there is a very simple way how to compute the confidence interval bounds without approximations, without tables and without other software costs.

  4. Simple Interval Timers for Microcomputers.

    ERIC Educational Resources Information Center

    McInerney, M.; Burgess, G.

    1985-01-01

    Discusses simple interval timers for microcomputers, including (1) the Jiffy clock; (2) CPU count timers; (3) screen count timers; (4) light pen timers; and (5) chip timers. Also examines some of the general characteristics of all types of timers. (JN)

  5. Duration perception in crossmodally-defined intervals.

    PubMed

    Mayer, Katja M; Di Luca, Massimiliano; Ernst, Marc O

    2014-03-01

    How humans perform duration judgments with multisensory stimuli is an ongoing debate. Here, we investigated how sub-second duration judgments are achieved by asking participants to compare the duration of a continuous sound to the duration of an empty interval in which onset and offset were marked by signals of different modalities using all combinations of visual, auditory and tactile stimuli. The pattern of perceived durations across five stimulus durations (ranging from 100 ms to 900 ms) follows the Vierordt Law. Furthermore, intervals with a sound as onset (audio-visual, audio-tactile) are perceived longer than intervals with a sound as offset. No modality ordering effect is found for visualtactile intervals. To infer whether a single modality-independent or multiple modality-dependent time-keeping mechanisms exist we tested whether perceived duration follows a summative or a multiplicative distortion pattern by fitting a model to all modality combinations and durations. The results confirm that perceived duration depends on sensory latency (summative distortion). Instead, we did not find evidence for multiplicative distortions. The results of the model and the behavioural data support the concept of a single time-keeping mechanism that allows for judgments of durations marked by multisensory stimuli. PMID:23953664

  6. Intra-hole fluid convection: High-resolution temperature time monitoring

    NASA Astrophysics Data System (ADS)

    Cermak, Vladimir; Safanda, Jan; Kresl, Milan

    2008-01-01

    SummaryIntra-hole convection was monitored in detail by a string of five high resolution temperature probes arranged in an 8-m long unit lowered step-by-step into a slim experimental borehole. The experiment was performed in the test hole Sporilov (Prague). A 50-m long depth interval (between 80 and 130 m) was covered in five successive steps. The hole itself is 150 m deep and 112 mm in diameter. The experiment occurred in the internal plastic tube 5 cm in diameter which is sealed from the influx of ground water in the surrounding strata. In the studied interval the temperature gradient varies in the range of 0.020-0.0215 K/m. The borehole was drilled in 1993 and has been in equilibrium since then. Temperature as a function of time was sampled in 15 s intervals and the individual measuring steps took from 1.5 to 2.5 days, each temperature time series thus contained 9000 up to 16,000 data points. The obtained results revealed: (1) temperature-time series present a complex apparently random oscillation pattern with the amplitude of up to 0.045 K; (2) the statistical analysis confirmed a quasi-periodic skeleton of a two-frequency oscillation structure. Shorter periods of 10 up to 30 min are superposed on longer variations with period of several hours. (3) The quasi-periodicity may be hidden under a considerable amount of noise. (4) Within the studied interval the quasi-periodic convection may alternate with a relatively "quiet" regime when temperature oscillations decreased to only 0.004-0.01 K range. (5) Regardless of certain deterministic rules present in the dynamics, the bulk of temperature variations are chaotic.

  7. QT interval in anorexia nervosa.

    PubMed Central

    Cooke, R A; Chambers, J B; Singh, R; Todd, G J; Smeeton, N C; Treasure, J; Treasure, T

    1994-01-01

    OBJECTIVES--To determine the incidence of a long QT interval as a marker for sudden death in patients with anorexia nervosa and to assess the effect of refeeding. To define a long QT interval by linear regression analysis and estimation of the upper limit of the confidence interval (95% CI) and to compare this with the commonly used Bazett rate correction formula. DESIGN--Prospective case control study. SETTING--Tertiary referral unit for eating disorders. SUBJECTS--41 consecutive patients with anorexia nervosa admitted over an 18 month period. 28 age and sex matched normal controls. MAIN OUTCOME MEASURES--maximum QT interval measured on 12 lead electrocardiograms. RESULTS--43.6% of the variability in the QT interval was explained by heart rate alone (p < 0.00001) and group analysis contributed a further 5.9% (p = 0.004). In 6 (15%) patients the QT interval was above the upper limit of the 95% CI for the prediction based on the control equation (NS). Two patients died suddenly; both had a QT interval at or above the upper limit of the 95% CI. In patients who reached their target weights the QT interval was significantly shorter (median 9.8 ms; p = 0.04) relative to the upper limit of the 60% CI of the control regression line, which best discriminated between patients and controls. The median Bazett rate corrected QT interval (QTc) in patients and controls was 435 v 405 ms.s-1/2 (p = 0.0004), and before and after refeeding it was 435 v 432 ms.s1/2 (NS). In 14(34%) patients and three (11%) controls the QTc was > 440 ms.s-1/2 (p = 0.053). CONCLUSIONS--The QT interval was longer in patients with anorexia nervosa than in age and sex matched controls, and there was a significant tendency to reversion to normal after refeeding. The Bazett rate correction formula overestimated the number of patients with QT prolongation and also did not show an improvement with refeeding. PMID:8068473

  8. Is there a rationale for short cardioplegia re-dosing intervals?

    PubMed Central

    Durandy, Yves D

    2015-01-01

    While cardioplegia has been used on millions of patients during the last decades, the debate over the best technique is still going on. Cardioplegia is not only meant to provide a non-contracting heart and a field without blood, thus avoiding the risk of gas emboli, but also used for myocardial protection. Its electromechanical effect is easily confirmed through direct vision of the heart and continuous electrocardiogram monitoring, but there is no consensus on the best way to assess the quality of myocardial protection. The optimal approach is thus far from clear and the considerable amount of literature on the subject fails to provide a definite answer. Cardioplegia composition (crystalloid vs blood, with or without various substrate enhancement), temperature and site(s) of injection have been extensively researched. While less frequently studied, re-dosing interval is also an important factor. A common and intuitive idea is that shorter re-dosing intervals lead to improved myocardial protection. A vast majority of surgeons use re-dosing intervals of 20-30 min, or even less, during coronary artery bypass graft and multidose cardioplegia has been the “gold standard” for decades. However, one-shot cardioplegia is becoming more commonly used and is likely to be a valuable alternative. Some surgeons prefer the comfort of single-shot cardioplegia while others feel more confident with shorter re-dosing intervals. There is no guarantee that a single strategy can be safely applied to all patients, irrespective of their age, comorbidities or cardiopathy. The goal of this review is to discuss the rationale for short re-dosing intervals. PMID:26516420

  9. Is there a rationale for short cardioplegia re-dosing intervals?

    PubMed

    Durandy, Yves D

    2015-10-26

    While cardioplegia has been used on millions of patients during the last decades, the debate over the best technique is still going on. Cardioplegia is not only meant to provide a non-contracting heart and a field without blood, thus avoiding the risk of gas emboli, but also used for myocardial protection. Its electromechanical effect is easily confirmed through direct vision of the heart and continuous electrocardiogram monitoring, but there is no consensus on the best way to assess the quality of myocardial protection. The optimal approach is thus far from clear and the considerable amount of literature on the subject fails to provide a definite answer. Cardioplegia composition (crystalloid vs blood, with or without various substrate enhancement), temperature and site(s) of injection have been extensively researched. While less frequently studied, re-dosing interval is also an important factor. A common and intuitive idea is that shorter re-dosing intervals lead to improved myocardial protection. A vast majority of surgeons use re-dosing intervals of 20-30 min, or even less, during coronary artery bypass graft and multidose cardioplegia has been the "gold standard" for decades. However, one-shot cardioplegia is becoming more commonly used and is likely to be a valuable alternative. Some surgeons prefer the comfort of single-shot cardioplegia while others feel more confident with shorter re-dosing intervals. There is no guarantee that a single strategy can be safely applied to all patients, irrespective of their age, comorbidities or cardiopathy. The goal of this review is to discuss the rationale for short re-dosing intervals. PMID:26516420

  10. Sensory superstition on multiple interval schedules.

    PubMed

    Starr, B C; Staddon, J E

    1982-03-01

    Pigeons were exposed to multiple schedules in which an irregular repeating sequence of five stimulus components was correlated with the same reinforcement schedule throughout. Stable, idiosyncratic, response-rate differences developed across components. Components were rank-ordered by response rate; an approximately linear relation was found between rank order and the deviation of mean response rate from the overall mean rate. Nonzero slopes of this line were found for multiple fixed-interval and variable-time schedules and for multiple variable-interval schedules both when number of reinforcements was the same in all components and when it varied. The steepest function slopes were found in the variable schedules with relatively long interfood intervals and relatively short component durations. When just one stimulus was correlated with all components of a multiple variable-interval schedule, the slope of the line was close to zero. The results suggest that food-rate differences may be induced initially by different reactions to the stimuli and subsequently maintained by food. PMID:7069361

  11. Sensory superstition on multiple interval schedules.

    PubMed Central

    Starr, B C; Staddon, J E

    1982-01-01

    Pigeons were exposed to multiple schedules in which an irregular repeating sequence of five stimulus components was correlated with the same reinforcement schedule throughout. Stable, idiosyncratic, response-rate differences developed across components. Components were rank-ordered by response rate; an approximately linear relation was found between rank order and the deviation of mean response rate from the overall mean rate. Nonzero slopes of this line were found for multiple fixed-interval and variable-time schedules and for multiple variable-interval schedules both when number of reinforcements was the same in all components and when it varied. The steepest function slopes were found in the variable schedules with relatively long interfood intervals and relatively short component durations. When just one stimulus was correlated with all components of a multiple variable-interval schedule, the slope of the line was close to zero. The results suggest that food-rate differences may be induced initially by different reactions to the stimuli and subsequently maintained by food. PMID:7069361

  12. Generalized Confidence Intervals and Fiducial Intervals for Some Epidemiological Measures.

    PubMed

    Bebu, Ionut; Luta, George; Mathew, Thomas; Agan, Brian K

    2016-01-01

    For binary outcome data from epidemiological studies, this article investigates the interval estimation of several measures of interest in the absence or presence of categorical covariates. When covariates are present, the logistic regression model as well as the log-binomial model are investigated. The measures considered include the common odds ratio (OR) from several studies, the number needed to treat (NNT), and the prevalence ratio. For each parameter, confidence intervals are constructed using the concepts of generalized pivotal quantities and fiducial quantities. Numerical results show that the confidence intervals so obtained exhibit satisfactory performance in terms of maintaining the coverage probabilities even when the sample sizes are not large. An appealing feature of the proposed solutions is that they are not based on maximization of the likelihood, and hence are free from convergence issues associated with the numerical calculation of the maximum likelihood estimators, especially in the context of the log-binomial model. The results are illustrated with a number of examples. The overall conclusion is that the proposed methodologies based on generalized pivotal quantities and fiducial quantities provide an accurate and unified approach for the interval estimation of the various epidemiological measures in the context of binary outcome data with or without covariates. PMID:27322305

  13. Generalized Confidence Intervals and Fiducial Intervals for Some Epidemiological Measures

    PubMed Central

    Bebu, Ionut; Luta, George; Mathew, Thomas; Agan, Brian K.

    2016-01-01

    For binary outcome data from epidemiological studies, this article investigates the interval estimation of several measures of interest in the absence or presence of categorical covariates. When covariates are present, the logistic regression model as well as the log-binomial model are investigated. The measures considered include the common odds ratio (OR) from several studies, the number needed to treat (NNT), and the prevalence ratio. For each parameter, confidence intervals are constructed using the concepts of generalized pivotal quantities and fiducial quantities. Numerical results show that the confidence intervals so obtained exhibit satisfactory performance in terms of maintaining the coverage probabilities even when the sample sizes are not large. An appealing feature of the proposed solutions is that they are not based on maximization of the likelihood, and hence are free from convergence issues associated with the numerical calculation of the maximum likelihood estimators, especially in the context of the log-binomial model. The results are illustrated with a number of examples. The overall conclusion is that the proposed methodologies based on generalized pivotal quantities and fiducial quantities provide an accurate and unified approach for the interval estimation of the various epidemiological measures in the context of binary outcome data with or without covariates. PMID:27322305

  14. Greater impact of acute high-intensity interval exercise on post-exercise executive function compared to moderate-intensity continuous exercise.

    PubMed

    Tsukamoto, Hayato; Suga, Tadashi; Takenaka, Saki; Tanaka, Daichi; Takeuchi, Tatsuya; Hamaoka, Takafumi; Isaka, Tadao; Hashimoto, Takeshi

    2016-03-01

    Aerobic moderate-intensity continuous exercise (MCE) can improve executive function (EF) acutely, potentially through the activation of both physiological and psychological factors. Recently, high-intensity interval exercise (HIIE) has been reported to be more beneficial for physical adaptation than MCE. Factors for EF improvement can potentially be more enhanced by HIIE than by MCE; but the effects of HIIE on EF remain unknown. Therefore, we aimed to examine to what extent HIIE impacts post-exercise EF immediately after exercise and during post-exercise recovery, compared with traditional MCE. Twelve healthy male subjects performed cycle ergometer exercise based on either HIIE or MCE protocols in a randomized and counterbalanced order. The HIIE protocol consisted of four 4-min bouts at 90% of peak VO2 with 3-min active recovery at 60% of peak VO2. A volume-matched MCE protocol was applied at 60% of peak VO2. To evaluate EF, a color-words Stroop task was performed pre- and post-exercise. Improvement in EF immediately after exercise was the same for the HIIE and MCE protocols. However, the improvement of EF by HIIE was sustained during 30 min of post-exercise recovery, during which MCE returned to the pre-exercise level. The EF response in the post-exercise recovery was associated with changes in physiological and psychological responses. The present findings showed that HIIE and MCE were capable of improving EF. Moreover, HIIE could prolong improvement in EF during post-exercise recovery. For the first time, we suggest that HIIE may be more effective strategy than MCE for improving EF. PMID:26723268

  15. Tuning for temporal interval in human apparent motion detection.

    PubMed

    Bours, Roger J E; Stuur, Sanne; Lankheet, Martin J M

    2007-01-01

    Detection of apparent motion in random dot patterns requires correlation across time and space. It has been difficult to study the temporal requirements for the correlation step because motion detection also depends on temporal filtering preceding correlation and on integration at the next levels. To specifically study tuning for temporal interval in the correlation step, we performed an experiment in which prefiltering and postintegration were held constant and in which we used a motion stimulus containing coherent motion for a single interval value only. The stimulus consisted of a sparse random dot pattern in which each dot was presented in two frames only, separated by a specified interval. On each frame, half of the dots were refreshed and the other half was a displaced reincarnation of the pattern generated one or several frames earlier. Motion energy statistics in such a stimulus do not vary from frame to frame, and the directional bias in spatiotemporal correlations is similar for different interval settings. We measured coherence thresholds for left-right direction discrimination by varying motion coherence levels in a Quest staircase procedure, as a function of both step size and interval. Results show that highest sensitivity was found for an interval of 17-42 ms, irrespective of viewing distance. The falloff at longer intervals was much sharper than previously described. Tuning for temporal interval was largely, but not completely, independent of step size. The optimal temporal interval slightly decreased with increasing step size. Similarly, the optimal step size decreased with increasing temporal interval. PMID:17461670

  16. The influence of anti-VEGF therapy on present day management of macular edema due to BRVO and CRVO: a longitudinal analysis on visual function, injection time interval and complications.

    PubMed

    Papadia, Marina; Misteli, Marie; Jeannin, Bruno; Herbort, Carl P

    2014-12-01

    at presentation was 0.24 ± 0.2 and improved to 0.81 ± 0.38 (p < 0.01) at 48 months. MP improved from 184.9 ± 92 to 362.5 ± 56.2 (p < 0.01) at 42 months follow-up. The number of injections varied from 1 to 25 (mean 5.5 ± 5.43). 31/44 eyes received 1-4 injections (group 1) of which all were recurrence free, with a follow-up of at least 1 years in all. 13/44 eyes received more than 5 injections (group 2) with functional and morphological parameters maintained in 9/13 but only 1/13 patients showed resolution. Rhythm of injection varied from one patient to another but 8/13 patients needing continuous injections had a constant time interval between injections. In 8/44 patients, laser photocoagulation had to be performed due to ischemic complications. The visual outcome using bevacizumab intravitreal injection was exceptionally good and functional parameters such as BCVA, MP, and VFT improved significantly. In about two-thirds of patients, resolution was obtained after 1-4 injections. In one-third of patients, continuous injections were necessary but a constant rhythm for re-injection for each patient could be established allowing to reduce to a minimum follow-up visits. The absence of significant side effects allowed to re-treat apparently without limitation achieving maintained visual function. FA monitoring for the detection of ischemic complications should not be neglected especially in cases where bevacizumab could be discontinued. PMID:25245600

  17. Cohort Study of the Impact of Time to Antibiotic Administration on Mortality in Patients with Febrile Neutropenia

    PubMed Central

    Rosa, Regis G.

    2014-01-01

    The time to antibiotic administration (TTA) has been proposed as a quality-of-care measure in febrile neutropenia (FN); however, few data regarding the impact of the TTA on the mortality of adult cancer patients with FN are available. The objective of this study was to determine whether the TTA is a predictor of mortality in adult cancer patients with FN. A prospective cohort study of all consecutive cases of FN, evaluated from October 2009 to August 2011, at a single tertiary referral hospital in southern Brazil was performed. The TTA was assessed as a predictive factor for mortality within 28 days of FN onset using the Cox proportional hazards model. Kaplan-Meier curves were used for an assessment of the mortality rates according to different TTAs; the log-rank test was used for between-group comparisons. In total, 307 cases of FN (169 subjects) were evaluated. During the study period, there were 29 deaths. In a Cox regression analysis, the TTA was independently associated with mortality within 28 days (hazard ratio [HR], 1.18; 95% confidence interval [CI], 1.10 to 1.26); each increase of 1 h in the TTA raised the risk of mortality within 28 days by 18%. Patients with FN episodes with a TTA of ≤30 min had lower 28-day mortality rates than those with a TTA of between 31 min and 60 min (3.0% versus 18.1%; log-rank P = 0.0002). Early antibiotic administration was associated with higher survival rates in the context of FN. Efforts should be made to ensure that FN patients receive effective antibiotic therapy as soon as possible. A target of 30 min to the TTA should be adopted for cancer patients with FN. PMID:24752269

  18. Overconfidence in Interval Estimates: What Does Expertise Buy You?

    ERIC Educational Resources Information Center

    McKenzie, Craig R. M.; Liersch, Michael J.; Yaniv, Ilan

    2008-01-01

    People's 90% subjective confidence intervals typically contain the true value about 50% of the time, indicating extreme overconfidence. Previous results have been mixed regarding whether experts are as overconfident as novices. Experiment 1 examined interval estimates from information technology (IT) professionals and UC San Diego (UCSD) students…

  19. Pigeons' Memory for Number of Events: Effects of Intertrial Interval and Delay Interval Illumination

    ERIC Educational Resources Information Center

    Hope, Chris; Santi, Angelo

    2004-01-01

    In Experiment 1, pigeons were trained at a 0-s baseline delay to discriminate sequences of light flashes (illumination of the feeder) that varied in number but not time (2f/4s and 8f/4s). During training, the intertrial interval was illuminated by the houselight for Group Light, but it was dark for Group Dark. Testing conducted with dark delay…

  20. Uniform Continuity on Unbounded Intervals

    ERIC Educational Resources Information Center

    Pouso, Rodrigo Lopez

    2008-01-01

    We present a teaching approach to uniform continuity on unbounded intervals which, hopefully, may help to meet the following pedagogical objectives: (i) To provide students with efficient and simple criteria to decide whether a continuous function is also uniformly continuous; and (ii) To provide students with skill to recognize graphically…

  1. Influence of dose-death interval on colchicine and metabolite distribution in decomposed skeletal tissues.

    PubMed

    Imfeld, Anic B; Watterson, James H

    2016-03-01

    The semi-quantitative analysis of decomposed bone of rats exposed to colchicine and euthanized following different time intervals postexposure (i.e., dose-death interval, DDI) is described. Rats received colchicine (50 mg/kg, i.p.) and were euthanized 30 min (DDI1; n = 4), 60 min (DDI2; n = 4), or 180 min (DDI3; n = 4) postdose. Drug-free animals (n = 3) served as negative controls. Perimortem heart plasma was collected. Remains were decomposed to skeleton outdoors and then collected and sorted (skull, vertebrae, rib, pelvis, femur, tibia). Bones were dried, pulverized, and prepared by microwave-assisted extraction and microplate solid-phase extraction (MAE-MPSPE), followed by analysis for colchicine, 3-demethylcolchicine (3DMC), and 2-demethylcolchicine (2DMC) by ultra-high-performance liquid chromatography with photodiode array detection (UHPLC-PDA) at 350 nm. Bone type was a main effect (Kruskall-Wallis, p < 0.05) with respect to drug level (expressed as mass-normalized response ratio, RR/m) for each analyte, at each DDI. For all samples, DDI was a main effect (Kruskall-Wallis, p < 0.05) with respect to analyte level, and the ratio of analyte levels (RR3DMC/RRCOLCH, RR2DMC/RRCOLCH, and RR2DMC/RR3DMC). Bone COLCH levels varied by 19-fold, 12-fold, and 60-fold across all bone types in the DDI1, DDI2, and DDI3 groups, respectively. Bone 3DMC levels varied by 12-fold, 11-fold and 17-fold across all bone types in the DDI1, DDI2, and DDI3 groups, respectively. Bone 2DMC levels varied by 20-fold, 14-fold, and 14-fold across all bone types in the DDI1, DDI2, and DDI3 groups, respectively. Values of RR3DMC/RRCOLCH varied by 16-fold, 5-fold, and 5-fold across all bone types in the DDI1, DDI2, and DDI3 groups, respectively. Values of RR2DMC/RRCOLCH varied by 10-fold, 6-fold, and 12-fold across all bone types in the DDI1, DDI2, and DDI3 groups, respectively. Values of RR2DMC/RR3DMC varied by 3-fold, 5-fold, and 2-fold across all bone types in the DDI1, DDI2, and DDI3 groups

  2. Fluctuations of healthy and unhealthy heartbeat intervals

    NASA Astrophysics Data System (ADS)

    Lan, Boon Leong; Toda, Mikito

    2013-04-01

    We show that the RR-interval fluctuations, defined as the difference between successive natural-logarithm of the RR interval, for healthy, congestive-heart-failure (CHF) and atrial-fibrillation (AF) subjects are well modeled by non-Gaussian stable distributions. Our results suggest that healthy or unhealthy RR-interval fluctuation can generally be modeled as a sum of a large number of independent physiological effects which are identically distributed with infinite variance. Furthermore, we show for the first time that one indicator —the scale parameter of the stable distribution— is sufficient to robustly distinguish the three groups of subjects. The scale parameters for healthy subjects are smaller than those for AF subjects but larger than those for CHF subjects —this ordering suggests that the scale parameter could be used to objectively quantify the severity of CHF and AF over time and also serve as an early warning signal for a healthy person when it approaches either boundary of the healthy range.

  3. New Madrid seismic zone recurrence intervals

    SciTech Connect

    Schweig, E.S. Center for Earthquake Research and Information, Memphis, TN ); Ellis, M.A. )

    1993-03-01

    Frequency-magnitude relations in the New Madrid seismic zone suggest that great earthquakes should occur every 700--1,200 yrs, implying relatively high strain rates. These estimates are supported by some geological and GPS results. Recurrence intervals of this order should have produced about 50 km of strike-slip offset since Miocene time. No subsurface evidence for such large displacements is known within the seismic zone. Moreover, the irregular fault pattern forming a compressive step that one sees today is not compatible with large displacements. There are at least three possible interpretations of the observations of short recurrence intervals and high strain rates, but apparently youthful fault geometry and lack of major post-Miocene deformation. One is that the seismological and geodetic evidence are misleading. A second possibility is that activity in the region is cyclic. That is, the geological and geodetic observations that suggest relatively short recurrence intervals reflect a time of high, but geologically temporary, pore-fluid pressure. Zoback and Zoback have suggested such a model for intraplate seismicity in general. Alternatively, the New Madrid seismic zone is geologically young feature that has been active for only the last few tens of thousands of years. In support of this, observe an irregular fault geometry associated with a unstable compressive step, a series of en echelon and discontinuous lineaments that may define the position of a youthful linking fault, and the general absence of significant post-Eocene faulting or topography.

  4. Constraint-based Attribute and Interval Planning

    NASA Technical Reports Server (NTRS)

    Jonsson, Ari; Frank, Jeremy

    2013-01-01

    In this paper we describe Constraint-based Attribute and Interval Planning (CAIP), a paradigm for representing and reasoning about plans. The paradigm enables the description of planning domains with time, resources, concurrent activities, mutual exclusions among sets of activities, disjunctive preconditions and conditional effects. We provide a theoretical foundation for the paradigm, based on temporal intervals and attributes. We then show how the plans are naturally expressed by networks of constraints, and show that the process of planning maps directly to dynamic constraint reasoning. In addition, we de ne compatibilities, a compact mechanism for describing planning domains. We describe how this framework can incorporate the use of constraint reasoning technology to improve planning. Finally, we describe EUROPA, an implementation of the CAIP framework.

  5. Fourier Analysis of Musical Intervals

    NASA Astrophysics Data System (ADS)

    LoPresto, Michael C.

    2008-11-01

    Use of a microphone attached to a computer to capture musical sounds and software to display their waveforms and harmonic spectra has become somewhat commonplace. A recent article in The Physics Teacher aptly demonstrated the use of MacScope2 in just such a manner as a way to teach Fourier analysis.3 A logical continuation of this project is to use MacScope not just to analyze the Fourier composition of musical tones but also musical intervals.

  6. High Intensity Interval Training Improves Glycaemic Control and Pancreatic β Cell Function of Type 2 Diabetes Patients

    PubMed Central

    Madsen, Søren Møller; Thorup, Anne Cathrine; Overgaard, Kristian; Jeppesen, Per Bendix

    2015-01-01

    Physical activity improves the regulation of glucose homeostasis in both type 2 diabetes (T2D) patients and healthy individuals, but the effect on pancreatic β cell function is unknown. We investigated glycaemic control, pancreatic function and total fat mass before and after 8 weeks of low volume high intensity interval training (HIIT) on cycle ergometer in T2D patients and matched healthy control individuals. Study design/method: Elderly (56 yrs±2), non-active T2D patients (n = 10) and matched (52 yrs±2) healthy controls (CON) (n = 13) exercised 3 times (10×60 sec. HIIT) a week over an 8 week period on a cycle ergometer. Participants underwent a 2-hour oral glucose tolerance test (OGTT). On a separate day, resting blood pressure measurement was conducted followed by an incremental maximal oxygen uptake (V˙O2max) cycle ergometer test. Finally, a whole body dual X-ray absorptiometry (DXA) was performed. After 8 weeks of training, the same measurements were performed. Results: in the T2D-group, glycaemic control as determined by average fasting venous glucose concentration (p = 0.01), end point 2-hour OGTT (p = 0.04) and glycosylated haemoglobin (p = 0.04) were significantly reduced. Pancreatic homeostasis as determined by homeostatic model assessment of insulin resistance (HOMA-IR) and HOMA β cell function (HOMA-%β) were both significantly ameliorated (p = 0.03 and p = 0.03, respectively). Whole body insulin sensitivity as determined by the disposition index (DI) was significantly increased (p = 0.03). During OGTT, the glucose continuum was significantly reduced at -15 (p = 0.03), 30 (p = 0.03) and 120 min (p = 0.03) and at -10 (p = 0.003) and 0 min (p = 0.003) with an additional improvement (p = 0.03) of its 1st phase (30 min) area under curve (AUC). Significant abdominal fat mass losses were seen in both groups (T2D: p = 0.004 and CON: p = 0.02) corresponding to a percentage change of -17.84%±5.02 and -9.66%±3.07, respectively. Conclusion: these results

  7. An Event Restriction Interval Theory of Tense

    ERIC Educational Resources Information Center

    Beamer, Brandon Robert

    2012-01-01

    This dissertation presents a novel theory of tense and tense-like constructions. It is named after a key theoretical component of the theory, the event restriction interval. In Event Restriction Interval (ERI) Theory, sentences are semantically evaluated relative to an index which contains two key intervals, the evaluation interval and the event…

  8. Night-time consumption of protein or carbohydrate results in increased morning resting energy expenditure in active college-aged men.

    PubMed

    Madzima, Takudzwa A; Panton, Lynn B; Fretti, Sarah K; Kinsey, Amber W; Ormsbee, Michael J

    2014-01-14

    The purpose of the present study was to investigate whether whey protein (WP), casein protein (CP), carbohydrate (CHO) or a non-energy-containing placebo (PLA) consumed before sleep alters morning appetite and resting energy expenditure (REE) in active men. A total of eleven men (age: 23·6 (sem 1·0) years; body fat: 16·3 (sem 2·5) %) participated in this randomised, double-blind, cross-over study. A single dose of WP (30 g), CP (30 g), CHO (33 g) or PLA was consumed 30 min before sleep, and each trial was separated by 48-72 h. The next morning (05.00-08.00 hours), measurements of satiety, hunger and desire to eat and REE were taken. After a 30 min equilibration period, REE in the supine position was measured for 60 min. An analysis of 10 min mean intervals over the final 50 min of the measurement period was conducted. Statistical analyses were conducted using repeated-measures ANOVA for metabolic variables, and a one-way ANOVA was used for measuring changes in appetite markers. Group differences were examined by Tukey's post hoc analysis. There were no significant differences in appetite measures among the groups. There was a main group effect for REE. The predicted REE was significantly greater after consumption of the WP (8151 (sem 67) kJ/d), CP (8126 (sem 67) kJ/d) and CHO (7988 (sem 67) kJ/d) than after that of the PLA (7716 (sem 67) kJ/d, P <0·0001). There were no significant differences between the WP and CP groups in any metabolic measurements. Night-time consumption of WP, CP or CHO, in the hours close to sleep, elicits favourable effects on the next-morning metabolism when compared with that of a PLA in active young men. PMID:23768612

  9. Renal blood flow transit time in the study of renal transplants

    SciTech Connect

    Sfakianakis, G.; Ihmeidan, I.; Kyriakides, G.; Martinez, B.; Hourani, M.; Miller, J.; Serafini, A.

    1985-05-01

    Radio-hippurate scintigraphy has been used to study renal transplant function because of its unique advantages over other noninvasive methods. Despite a great sensitivity in diagnosing the existence of a functional problem the test lacks in specificity. In an effort to differentiate between acute tubular necrosis (ATN) and graft rejection (RJ) the authors preceded hippurate scintigraphy by measurements of renal flow transit time (TT). After an intravenous injection of 8 mCi of Tc-99m-sulfur-colloid flow curves from the kidney and the abdominal aorta in 1 sec intervals for 1 min were obtained. Renal transit time was mathematically calculated and corrected for bolus and circulatory differences by dividing it with the corresponding Aortic TT (corrected Renal TT(cRTT). Radiohippuran (O-I-131-Hippurate), 150 ..mu..Ci was injected subsequently and of the different computer generated parameters the 30 min net cortical residual (% of the peak) activity (Hippuran Residual Activity, HRA) was found more sensitive and reproducible for comparisons. Results of documented cases showed a statistically significant difference. Uncomplicated cases (usually on antirejection therapy) showed a tendency to increasing the cRTTs with time (not significantly) but their HRAs were significantly lower than in ATN and RJ (p< 0.001).

  10. Physical exertion in simple reaction time and continuous attention of sport participants.

    PubMed

    Tsorbatzoudis, H; Barkoukis, V; Danis, A; Grouios, G

    1998-04-01

    To investigate the effect of physical exertion on simple reaction time and continuous attention of sport participants, an experiment was conducted with 46 male university students and 12 male cyclists. The subjects were assigned to three experimental and two control groups. The subjects of the experimental groups were asked to perform, following a 5-min, period of warming up, a high intensity exercise protocol for 5 min., on a mechanically braked cycle ergometer (Group A) or a moderate intensity exercise protocol for 30 min, on the same cycle ergometer (Groups B and C). Shortly before and immediately after the physical exercise subjects of all groups were asked to perform a test of simple reaction time and continuous attention. The subjects of the control groups were asked to perform at rest both tests of the simple reaction time and the continuous attention twice, with a 10-min. and a 35-min. interval between the first and second attempts, respectively. The results did not support the notion that exercise of moderate or high intensity influences significantly the cognitive performance of aerobically trained or untrained subjects. The results are discussed in the light of the current research findings concerning exertion and human psychomotor performance. PMID:9638756

  11. Time required to achieve homogeneity in swine feed mixtures.

    PubMed

    Ikeda, G J; Miller, E; King, M T; Perfetti, G A; Warner, C R; Adamo, N C; Sporn, E M

    1982-03-01

    FD&C Red No. 3 was mixed with 20 kg pig feed to give a concentration of 0.1%. A mixing time of 30 min was sufficient to achieve homogeneity for this mixture. For larger amounts or more flocculent types of additives, a longer time may be required. Ammoniated glycyrrhizin was mixed with 8 separate batches of pig feed at a concentration of 1%; 1 h was sufficient mixing time. PMID:7200977

  12. Time to First Cigarette Predicts Cessation Outcomes in Adolescent Smokers

    PubMed Central

    Branstetter, Steven A.; Muscat, Joshua E.; Horn, Kimberly A.

    2013-01-01

    Introduction: This study examined the relationship between the time to the first cigarette (TTFC) of the morning with quit status among adolescent smokers at the completion of a school-based smoking cessation program. Among those who did not quit, the relationship of TTFC with changes in cigarettes/day (CPD) was also examined. Methods: A total of 1,167 adolescent smokers (1,024 nonquitters and 143 quitters) from 4 states participating in efficacy and effectiveness studies of the Not-On-Tobacco (N-O-T) cessation program were assessed prior to entry into the program and again 3 months later at the end of treatment. Linear and logistic regression analyses determined the influence of treatment condition, age, gender, motivation to quit, confidence in quitting ability, baseline CPD, and TTFC on quit status and end-of-treatment CPD. Results: Adolescents with a TTFC of >30min of waking were twice as likely to quit at end of treatment. Additionally, among those who did not quit at end of treatment (n = 700 for TTFC ≤30min and n = 324 for TTFC for >30min), those with a TTFC within 30min of waking smoked a greater number of CPD. The relationships of TTFC with both of these outcomes remained when controlling for all other predictor variables. Conclusions: Identifying adolescent smokers who smoke their first cigarette of the day within the first 30min of waking prior to a quit attempt may help to classify those individuals as having a greater risk for cessation failure. Thus, TTFC may be a behavioral indicator of nicotine dependence in adolescents. PMID:23811009

  13. [Effect of local moderate hyperthermia in combination with chemotherapy by N-nitroso-1,3-bis-(2-chloroethyl)urea (BCNU) on the descending colon of the rat with transplanted Yoshida sarcoma. 2. Monochemotherapy in combination with subsequent hyperthermia at various time intervals].

    PubMed

    Lorenz, M; Biwer, E; Habs, M; Schmähl, D

    1984-01-01

    There are numerous reports on in vitro and in vivo investigations of hyperthermia for cytostasis of malignant tumors. Combination of chemotherapy and hyperthermia is to potentiate the therapeutic effect. The time interval between the two types of therapy was the main subject of the present investigation. Local hyperthermia (43 degrees C, 60 min) following BCNU chemotherapy at intervals of 0, 3, 6, 9, 12, and 24 h, respectively, was studied in a colonic Yoshida sarcoma model in Sprague-Dawley rats. No significant increase in the curing rate resulted from hyperthermic treatment. The results suggest that the highly anticipated hyperthermic peritoneal lavages should be investigated in controlled animal experiments prior to clinical use. PMID:6503501

  14. Orders on Intervals Over Partially Ordered Sets: Extending Allen's Algebra and Interval Graph Results

    SciTech Connect

    Zapata, Francisco; Kreinovich, Vladik; Joslyn, Cliff A.; Hogan, Emilie A.

    2013-08-01

    To make a decision, we need to compare the values of quantities. In many practical situations, we know the values with interval uncertainty. In such situations, we need to compare intervals. Allen’s algebra describes all possible relations between intervals on the real line, and ordering relations between such intervals are well studied. In this paper, we extend this description to intervals in an arbitrary partially ordered set (poset). In particular, we explicitly describe ordering relations between intervals that generalize relation between points. As auxiliary results, we provide a logical interpretation of the relation between intervals, and extend the results about interval graphs to intervals over posets.

  15. Pigeons' Choices between Fixed-Interval and Random-Interval Schedules: Utility of Variability?

    ERIC Educational Resources Information Center

    Andrzejewski, Matthew E.; Cardinal, Claudia D.; Field, Douglas P.; Flannery, Barbara A.; Johnson, Michael; Bailey, Kathleen; Hineline, Philip N.

    2005-01-01

    Pigeons' choosing between fixed-interval and random-interval schedules of reinforcement was investigated in three experiments using a discrete-trial procedure. In all three experiments, the random-interval schedule was generated by sampling a probability distribution at an interval (and in multiples of the interval) equal to that of the…

  16. Receptor modeling for multiple time resolved species: The Baltimore supersite

    NASA Astrophysics Data System (ADS)

    Ogulei, David; Hopke, Philip K.; Zhou, Liming; Paatero, Pentti; Park, Seung Shik; Ondov, John M.

    A number of advances have been made toward solving receptor modeling problems using advanced factor analysis methods. Most recently, a factor analysis method has been developed for source apportionment utilizing aerosol compositional data with varying temporal resolution. The data used in that study had time resolutions ranged from 10 min to 1 h. In this work, this expanded model is tested using a data set from the Ponca Street site of the Baltimore supersite with time resolutions ranging from 30 min to 24 h. The nature of this data set implies that traditional eigenvalue-based methods cannot adequately resolve source factors for the atmospheric situation under consideration. Also, valuable temporal information is lost if one averaged or interpolated data in an attempt to produce a data set of the identical time resolution. Each data point has been used in its original time schedule and the source contributions were averaged to correspond to the specific sampling time interval. A weighting coefficient, w24, was incorporated in the modeling equations in order to improve data fitting for the 24-h data in the model. A total of nine sources were resolved: oil-fired power plant (2%), diesel emissions (1%), secondary sulfate (23%), coal-fired power plant (3%), incinerator (9%), steel plant (12%), aged sea salt (1%), secondary nitrate (23%), and spark-ignition emissions (26%). The results showed the very strong influence of the adjacent interstate highways I-95 and I-895 as well as the tunnel toll booths located to the south of the sampling site. Most of the sulfate observed was found to be associated with distant coal-fired power plants situated in the heavily industrialized midwestern parts of the United States. The contribution of the steel plant (<10 miles, 141°SE) to the observed PM concentrations (12%) was also significant.

  17. Military Applicability of Interval Training for Health and Performance.

    PubMed

    Gibala, Martin J; Gagnon, Patrick J; Nindl, Bradley C

    2015-11-01

    Militaries from around the globe have predominantly used endurance training as their primary mode of aerobic physical conditioning, with historical emphasis placed on the long distance run. In contrast to this traditional exercise approach to training, interval training is characterized by brief, intermittent bouts of intense exercise, separated by periods of lower intensity exercise or rest for recovery. Although hardly a novel concept, research over the past decade has shed new light on the potency of interval training to elicit physiological adaptations in a time-efficient manner. This work has largely focused on the benefits of low-volume interval training, which involves a relatively small total amount of exercise, as compared with the traditional high-volume approach to training historically favored by militaries. Studies that have directly compared interval and moderate-intensity continuous training have shown similar improvements in cardiorespiratory fitness and the capacity for aerobic energy metabolism, despite large differences in total exercise and training time commitment. Interval training can also be applied in a calisthenics manner to improve cardiorespiratory fitness and strength, and this approach could easily be incorporated into a military conditioning environment. Although interval training can elicit physiological changes in men and women, the potential for sex-specific adaptations in the adaptive response to interval training warrants further investigation. Additional work is needed to clarify adaptations occurring over the longer term; however, interval training deserves consideration from a military applicability standpoint as a time-efficient training strategy to enhance soldier health and performance. There is value for military leaders in identifying strategies that reduce the time required for exercise, but nonetheless provide an effective training stimulus. PMID:26506197

  18. Effects of inter-food interval on the variety effect in an instrumental food-seeking task. Clarifying the role of habituation☆

    PubMed Central

    Thrailkill, Eric A.; Epstein, Leonard H.; Bouton, Mark E.

    2014-01-01

    Food variety increases consumption and the rate of instrumental behavior that is reinforced by food in humans and animals. The present experiment investigated the relationship between the variety effect and habituation to food by testing the role of the interval between successive food presentations on responding in an operant food-seeking task. Habituation to food was expected at short, but not long, interfood intervals. The effects of variety on food’s long-term reinforcing value were also tested. Four groups of rats were trained to lever-press on different random-interval (RI) schedules of reinforcement to earn 45-mg food pellets. Half the rats in each group received an unpredictable mix of grain and sucrose pellets, while the other half consistently received sucrose pellets. Response rate began at a high rate and then decreased within each 30-min session for groups that received short inter-pellet intervals (i.e., RI-3 s and RI-6 s reinforcement schedules) but not in groups that received longer inter-pellet intervals (i.e., RI-12 s and RI-24 s). A variety effect in the form of higher responding in the mix group than the sucrose-only group was also only evident at the shorter intervals. Habituation and variety effects were also most evident with the short intervals when we controlled for the number of reinforcers earned, suggesting that they were not merely due to rapid satiation. The variety effect also appeared quickly when groups trained with longer inter-pellet intervals (RI-12 s and RI-24 s) were transitioned to shorter intervals (RI-3 s and RI-6 s). There was no effect of variety on resistance to extinction or on resistance to the response-suppressing effects of pre-session feeding. The results more clearly link this version of the variety effect to the short-term effect of variety on food habituation. PMID:25261732

  19. Application of EPA unmix and nonparametric wind regression on high time resolution trace elements and speciated mercury in Tampa, Florida aerosol.

    PubMed

    Pancras, Joseph Patrick; Vedantham, Ram; Landis, Matthew S; Norris, Gary A; Ondov, John M

    2011-04-15

    Intensive ambient air sampling was conducted in Tampa, FL, during October and November of 2002. Fine particulate matter (PM(2.5)) was collected at 30 min resolution using the Semicontinuous Elements in Aerosol Sampler II (SEAS-II) and analyzed off-line for up to 45 trace elements by high-resolution ICPMS (HR-ICPMS). Divalent reactive gaseous mercury and particulate bound mercury were also measured semicontinuously (2 h). Application of the United States Environmental Protection Agency's (EPA) Unmix receptor model on the 30 min resolution trace metals data set identified eight possible sources: residual oil combustion, lead recycling, coal combustion, a Cd-rich source, biomass burning, marine aerosol, general industrial, and coarse dust contamination. The source contribution estimates from EPA Unmix were then run in a nonparametric wind regression (NWR) model, which convincingly identified plausible source origins. When the 30 min ambient concentrations of trace elements were time integrated (2 h) and combined with speciated mercury concentrations, the model identified only four sources, some of which appeared to be merged source profiles that were identified as separate sources by using the 30 min resolution data. This work demonstrates that source signatures that can be captured at 30 min resolution may be lost when sampling for longer durations. PMID:21401082

  20. Timing During Interruptions in Timing

    ERIC Educational Resources Information Center

    Fortin, Claudette; Bedard, Marie-Claude; Champagne, Julie

    2005-01-01

    Duration and location of breaks in time interval production were manipulated in various conditions of stimulus presentation (Experiments 1-4). Produced intervals shortened and then stabilized as break duration lengthened, suggesting that participants used the break as a preparatory period to restart timing as quickly as possible at the end of the…

  1. Min and Max Extreme Interval Values

    ERIC Educational Resources Information Center

    Jance, Marsha L.; Thomopoulos, Nick T.

    2011-01-01

    The paper shows how to find the min and max extreme interval values for the exponential and triangular distributions from the min and max uniform extreme interval values. Tables are provided to show the min and max extreme interval values for the uniform, exponential, and triangular distributions for different probabilities and observation sizes.

  2. Familiarity-Frequency Ratings of Melodic Intervals

    ERIC Educational Resources Information Center

    Jeffries, Thomas B.

    1972-01-01

    Objective of this study was to determine subjects' reliability in rating randomly played ascending and descending melodic intervals within the octave on the basis of their familiarity with each type of interval and the frequency of their having experienced each type of interval in music. (Author/CB)

  3. Interval process model and non-random vibration analysis

    NASA Astrophysics Data System (ADS)

    Jiang, C.; Ni, B. Y.; Liu, N. Y.; Han, X.; Liu, J.

    2016-07-01

    This paper develops an interval process model for time-varying or dynamic uncertainty analysis when information of the uncertain parameter is inadequate. By using the interval process model to describe a time-varying uncertain parameter, only its upper and lower bounds are required at each time point rather than its precise probability distribution, which is quite different from the traditional stochastic process model. A correlation function is defined for quantification of correlation between the uncertain-but-bounded variables at different times, and a matrix-decomposition-based method is presented to transform the original dependent interval process into an independent one for convenience of subsequent uncertainty analysis. More importantly, based on the interval process model, a non-random vibration analysis method is proposed for response computation of structures subjected to time-varying uncertain external excitations or loads. The structural dynamic responses thus can be derived in the form of upper and lower bounds, providing an important guidance for practical safety analysis and reliability design of structures. Finally, two numerical examples and one engineering application are investigated to demonstrate the feasibility of the interval process model and corresponding non-random vibration analysis method.

  4. Stress-induced hyperthermia depends on both time of day and light condition.

    PubMed

    Peloso, Elizabeth; Wachulec, Maciej; Satinoff, Evelyn

    2002-04-01

    Rats placed in an environment other than their home cage increase their body temperature (Tb) by more than 1 degree C. This stress-induced hyperthermia is considered to be a fever, in the sense that the Tb rise seems to reflect an upward shift in the level of regulated Tb (set point). The circadian rhythm of Tb also reflects changes in set point. One might therefore expect to see differences in response to such stress during various phases of the light-dark (LD) cycle as Tb fluctuates between L and D. To test this, 3- to 6-month-old male Long-Evans rats were taken from their home cages (12:12 LD) and placed individually in a Plexiglas container for 30 min. Tb and activity were measured via telemetry. In the first experiment, rats were placed in the container during day (from 1 to 3 h after lights on) and night (from 1 to 3 h after lights off), with light on or off during the test. There was a significant Tb rise in response to placement in the container at all times except when the rats were tested during the night with light on in the container; in that condition there was no Tb rise. In the second experiment, the authors determined that 30 min of light in the home cage before the test did not affect Tb: If the light was on in the test situation, hyperthermia was inhibited, and if it was off, hyperthermia was as high as control levels. In the third experiment, to determine whether this effect was time dependent, the test was performed at 4-h intervals, with light on or off during the test. The strongest inhibiting effect of light was in early night. In the fourth experiment, the authors turned the lights on during early night while the rats were in their home cages. This reduced their Tb significantly by less than 0.3 degrees C. The authors conclude that both clock time and light condition during testing are factors affecting the Tb rise in response to stress. PMID:12002163

  5. The Effects of Interval Duration on Temporal Tracking and Alternation Learning

    ERIC Educational Resources Information Center

    Ludvig, Elliot A.; Staddon, John E. R.

    2005-01-01

    On cyclic-interval reinforcement schedules, animals typically show a postreinforcement pause that is a function of the immediately preceding time interval ("temporal tracking"). Animals, however, do not track single-alternation schedules--when two different intervals are presented in strict alternation on successive trials. In this experiment,…

  6. Response Priming Patterns Differ with Interstimulus Interval Duration

    ERIC Educational Resources Information Center

    Spencer, Kristie A.; Wiley, Erin

    2008-01-01

    Priming paradigms make it possible to study the nature of response preparation before the onset of movement. One way to examine this process is through manipulation of the interstimulus interval (ISI). The timing of the prime and target presentation has been shown to have distinct effects on reaction time patterns, in both healthy and…

  7. Time?

    NASA Astrophysics Data System (ADS)

    Amoroso, Richard L.

    2013-09-01

    The concept of time in the `clockwork' Newtonian world was irrelevant; and has generally been ignored until recently by several generations of physicists since the implementation of quantum mechanics. We will set aside the utility of time as a property relating to physical calculations of events relating to a metrics line element or as an aspect of the transformation of a particles motion/interaction in a coordinate system or in relation to thermodynamics etc., i.e. we will discard all the usual uses of time as a concept used to circularly define physical parameters in terms of other physical parameters; concentrating instead on time as an aspect of the fundamental cosmic topology of our virtual reality especially as it inseparably relates to the nature and role of the observer in natural science.

  8. Confidence Intervals in Qtl Mapping by Bootstrapping

    PubMed Central

    Visscher, P. M.; Thompson, R.; Haley, C. S.

    1996-01-01

    The determination of empirical confidence intervals for the location of quantitative trait loci (QTLs) was investigated using simulation. Empirical confidence intervals were calculated using a bootstrap resampling method for a backcross population derived from inbred lines. Sample sizes were either 200 or 500 individuals, and the QTL explained 1, 5, or 10% of the phenotypic variance. The method worked well in that the proportion of empirical confidence intervals that contained the simulated QTL was close to expectation. In general, the confidence intervals were slightly conservatively biased. Correlations between the test statistic and the width of the confidence interval were strongly negative, so that the stronger the evidence for a QTL segregating, the smaller the empirical confidence interval for its location. The size of the average confidence interval depended heavily on the population size and the effect of the QTL. Marker spacing had only a small effect on the average empirical confidence interval. The LOD drop-off method to calculate empirical support intervals gave confidence intervals that generally were too small, in particular if confidence intervals were calculated only for samples above a certain significance threshold. The bootstrap method is easy to implement and is useful in the analysis of experimental data. PMID:8725246

  9. Establishment of reference intervals and transfusion criterion for Sonoclot analysis.

    PubMed

    Zhang, Zhen-Lu; Chen, You-Ping; Tao, Cui-Hua; Liu, Xiao-Hui; Li, Meng-Ya; Zhou, Xin

    2016-08-01

    Sonoclot analyzer has been widely used in many countries. But the reference intervals provided by the manufacturer were derived from only 45 participants, and there was no cut-off value for transfusion for Sonoclot analysis. This study aimed to establish reference intervals and transfusion criterion for Sonoclot analysis. Volunteers were recruited from healthy Chinese adults and patients undergoing cardiac surgery. Blood samples were withdrawn from forearm vein and measured for activated clotting time (ACT), clot rate (CR), platelet function (PF), activated partial thromboplastin time (APTT), fibrinogen concentration (FIB), and platelet count (PLT). The reference intervals were determined by the nonparametric method. Cut-off values were determined by the receiver operating characteristics curve. A total of 135 healthy volunteers and 281 patients were enrolled. The 95% reference intervals were 96-195 s, 22-51 signal U/min, >1.6 for ACT, CR, PF respectively. In the 281 patients, the results of APTT, FIB, PLT, ACT, CR, and PF ranged from 20.5-300.0 s, 0.28-4.11 g/L, (19.0-387.3)×109/L, 80-514 s, 2.9-74 signal U/min, and 0.1-5.1 respectively. The cut-off values for transfusion were >208, ≤14, and ≤1.3 for ACT, CR, PF respectively. The cut-off values of Sonoclot analysis were within the manufacturer's reference intervals, while they were outside the reference intervals established in this study. The results suggested that the manufacturer's reference intervals were not suitable for Chinese. The reference intervals and cut-off values established in this study will be helpful to Chinese patients. PMID:27465342

  10. High-intensity interval training: Modulating interval duration in overweight/obese men

    PubMed Central

    Smith-Ryan, Abbie E.; Melvin, Malia N.; Wingfield, Hailee L.

    2015-01-01

    Introduction High-intensity interval training (HIIT) is a time-efficient strategy shown to induce various cardiovascular and metabolic adaptations. Little is known about the optimal tolerable combination of intensity and volume necessary for adaptations, especially in clinical populations. Objectives In a randomized controlled pilot design, we evaluated the effects of two types of interval training protocols, varying in intensity and interval duration, on clinical outcomes in overweight/obese men. Methods Twenty-five men [body mass index (BMI) > 25 kg·m2] completed baseline body composition measures: fat mass (FM), lean mass (LM) and percent body fat (%BF) and fasting blood glucose, lipids and insulin (IN). A graded exercise cycling test was completed for peak oxygen consumption (VO2peak) and power output (PO). Participants were randomly assigned to high-intensity short interval (1MIN-HIIT), high-intensity interval (2MIN-HIIT) or control groups. 1MIN-HIIT and 2MIN-HIIT completed 3 weeks of cycling interval training, 3 days/week, consisting of either 10 × 1 min bouts at 90% PO with 1 min rests (1MIN-HIIT) or 5 × 2 min bouts with 1 min rests at undulating intensities (80%–100%) (2MIN-HIIT). Results There were no significant training effects on FM (Δ1.06 ± 1.25 kg) or %BF (Δ1.13% ± 1.88%), compared to CON. Increases in LM were not significant but increased by 1.7 kg and 2.1 kg for 1MIN and 2MIN-HIIT groups, respectively. Increases in VO2peak were also not significant for 1MIN (3.4 ml·kg−1·min−1) or 2MIN groups (2.7 ml·kg−1·min−1). IN sensitivity (HOMA-IR) improved for both training groups (Δ −2.78 ± 3.48 units; p < 0.05) compared to CON. Conclusion HIIT may be an effective short-term strategy to improve cardiorespiratory fitness and IN sensitivity in overweight males. PMID:25913937

  11. Short-interval estimations of trigonometric parallaxes

    NASA Technical Reports Server (NTRS)

    Gatewood, G.; Stein, J.; Difatta, C.; Kiewiet De Jonge, J.; Prosser, J.; Reiland, T.

    1985-01-01

    A technique for estimating trigonometric parallaxes in a matter of days or weeks is presented. The technique relies on the discrepancy between the instantaneous proper motion and the proper motion of a star. The main sources of error in the method are the standard error of the individual observations (0.004 arcsec) and the arbitrary limit placed on the observation interval. The parallactic motion of an MO dwarf of known parallax and a blue magnitude of 11.2 is determined. The slope inferred is within 10 percent of the value (0.555 arcsec) derived from a 1.5-year study of Barnard's star. It is concluded that the technique, if used on the same time scale as conventional techniques, would yield results of much higher accuracy.

  12. Light-intensity and high-intensity interval training improve cardiometabolic health in rats.

    PubMed

    Batacan, Romeo B; Duncan, Mitch J; Dalbo, Vincent J; Connolly, Kylie J; Fenning, Andrew S

    2016-09-01

    Physical activity has the potential to reduce cardiometabolic risk factors but evaluation of different intensities of physical activity and the mechanisms behind their health effects still need to be fully established. This study examined the effects of sedentary behaviour, light-intensity training, and high-intensity interval training on biometric indices, glucose and lipid metabolism, inflammatory and oxidative stress markers, and vascular and cardiac function in adult rats. Rats (12 weeks old) were randomly assigned to 1 of 4 groups: control (CTL; no exercise), sedentary (SED; no exercise and housed in small cages to reduce activity), light-intensity trained (LIT; four 30-min exercise bouts/day at 8 m/min separated by 2-h rest period, 5 days/week), and high-intensity interval trained (HIIT, four 2.5-min work bouts/day at 50 m/min separated by 3-min rest periods, 5 days/week). After 12 weeks of intervention, SED had greater visceral fat accumulation (p < 0.01) and slower cardiac conduction (p = 0.04) compared with the CTL group. LIT and HIIT demonstrated beneficial changes in body weight, visceral and epididymal fat weight, glucose regulation, low-density lipoprotein cholesterol, total cholesterol, and mesenteric vessel contractile response compared with the CTL group (p < 0.05). LIT had significant improvements in insulin sensitivity and cardiac conduction compared with the CTL and SED groups whilst HIIT had significant improvements in systolic blood pressure and endothelium-independent vasodilation to aorta and mesenteric artery compared with the CTL group (p < 0.05). LIT and HIIT induce health benefits by improving traditional cardiometabolic risk factors. LIT improves cardiac health while HIIT promotes improvements in vascular health. PMID:27523646

  13. Source Identification of PM2.5 in Steubenville, Ohio Using a Hybrid Method for Highly Time-resolved Data

    EPA Science Inventory

    A new source-type identification method, Reduction and Species Clustering Using Episodes (ReSCUE), was developed to exploit the temporal synchronicity between species to form clusters of species that vary together. High time-resolution (30 min) PM2.5 sampling was condu...

  14. Effects of high-intensity interval training and moderate-intensity continuous training on endothelial function and cardiometabolic risk markers in obese adults.

    PubMed

    Sawyer, Brandon J; Tucker, Wesley J; Bhammar, Dharini M; Ryder, Justin R; Sweazea, Karen L; Gaesser, Glenn A

    2016-07-01

    We hypothesized that high-intensity interval training (HIIT) would be more effective than moderate-intensity continuous training (MICT) at improving endothelial function and maximum oxygen uptake (V̇o2 max) in obese adults. Eighteen participants [35.1 ± 8.1 (SD) yr; body mass index = 36.0 ± 5.0 kg/m(2)] were randomized to 8 wk (3 sessions/wk) of either HIIT [10 × 1 min, 90-95% maximum heart rate (HRmax), 1-min active recovery] or MICT (30 min, 70-75% HRmax). Brachial artery flow-mediated dilation (FMD) increased after HIIT (5.13 ± 2.80% vs. 8.98 ± 2.86%, P = 0.02) but not after MICT (5.23 ± 2.82% vs. 3.05 ± 2.76%, P = 0.16). Resting artery diameter increased after MICT (3.68 ± 0.58 mm vs. 3.86 ± 0.58 mm, P = 0.02) but not after HIIT (4.04 ± 0.70 mm vs. 4.09 ± 0.70 mm; P = 0.63). There was a significant (P = 0.02) group × time interaction in low flow-mediated constriction (L-FMC) between MICT (0.63 ± 2.00% vs. -2.79 ± 3.20%; P = 0.03) and HIIT (-1.04 ± 4.09% vs. 1.74 ± 3.46%; P = 0.29). V̇o2 max increased (P < 0.01) similarly after HIIT (2.19 ± 0.65 l/min vs. 2.64 ± 0.88 l/min) and MICT (2.24 ± 0.48 l/min vs. 2.55 ± 0.61 l/min). Biomarkers of cardiovascular risk and endothelial function were unchanged. HIIT and MICT produced different vascular adaptations in obese adults, with HIIT improving FMD and MICT increasing resting artery diameter and enhancing L-FMC. HIIT required 27.5% less total exercise time and ∼25% less energy expenditure than MICT. PMID:27255523

  15. Statistical regularities in the return intervals of volatility

    NASA Astrophysics Data System (ADS)

    Wang, F.; Weber, P.; Yamasaki, K.; Havlin, S.; Stanley, H. E.

    2007-01-01

    We discuss recent results concerning statistical regularities in the return intervals of volatility in financial markets. In particular, we show how the analysis of volatility return intervals, defined as the time between two volatilities larger than a given threshold, can help to get a better understanding of the behavior of financial time series. We find scaling in the distribution of return intervals for thresholds ranging over a factor of 25, from 0.6 to 15 standard deviations, and also for various time windows from one minute up to 390 min (an entire trading day). Moreover, these results are universal for different stocks, commodities, interest rates as well as currencies. We also analyze the memory in the return intervals which relates to the memory in the volatility and find two scaling regimes, ℓ<ℓ* with α1=0.64±0.02 and ℓ> ℓ* with α2=0.92±0.04; these exponent values are similar to results of Liu et al. for the volatility. As an application, we use the scaling and memory properties of the return intervals to suggest a possibly useful method for estimating risk.

  16. Procrastination by pigeons with fixed-interval response requirements.

    PubMed

    Mazur, J E

    1998-03-01

    Two experiments studied the phenomenon of procrastination, in which pigeons chose a larger, more delayed response requirement over a smaller, more immediate response requirement. The response requirements were fixed-interval schedules that did not lead to an immediate food reinforcer, but that interrupted a 55-s period in which food was delivered at random times. The experiments used an adjusting-delay procedure in which the delay to the start of one fixed-interval requirement was varied over trials to estimate an indifference point--a delay at which the two alternatives were chosen about equally often. Experiment 1 found that as the delay to a shorter fixed-interval requirement was increased, the adjusting delay to a longer fixed-interval requirement also increased, and the rate of increase depended on the duration of the longer fixed-interval requirement. Experiment 2 found a strong preference for a fixed delay of 10 s to the start of a fixed-interval requirement compared to a mixed delay of either 0 or 20 s. The results help to distinguish among different equations that might describe the decreasing effectiveness of a response requirement with increasing delay, and they suggest that delayed reinforcers and delayed response requirements have symmetrical but opposite effects on choice. PMID:9540230

  17. Procrastination by pigeons with fixed-interval response requirements.

    PubMed Central

    Mazur, J E

    1998-01-01

    Two experiments studied the phenomenon of procrastination, in which pigeons chose a larger, more delayed response requirement over a smaller, more immediate response requirement. The response requirements were fixed-interval schedules that did not lead to an immediate food reinforcer, but that interrupted a 55-s period in which food was delivered at random times. The experiments used an adjusting-delay procedure in which the delay to the start of one fixed-interval requirement was varied over trials to estimate an indifference point--a delay at which the two alternatives were chosen about equally often. Experiment 1 found that as the delay to a shorter fixed-interval requirement was increased, the adjusting delay to a longer fixed-interval requirement also increased, and the rate of increase depended on the duration of the longer fixed-interval requirement. Experiment 2 found a strong preference for a fixed delay of 10 s to the start of a fixed-interval requirement compared to a mixed delay of either 0 or 20 s. The results help to distinguish among different equations that might describe the decreasing effectiveness of a response requirement with increasing delay, and they suggest that delayed reinforcers and delayed response requirements have symmetrical but opposite effects on choice. PMID:9540230

  18. Antipsychotic Polypharmacy and Corrected QT Interval: A Systematic Review

    PubMed Central

    Takeuchi, Hiroyoshi; Suzuki, Takefumi; Remington, Gary; Uchida, Hiroyuki

    2015-01-01

    Objective: It remains unclear whether antipsychotic polypharmacy, a common clinical practice, is related to an increased risk of corrected time between start of Q wave and end of T wave (QTc) interval prolongation. We conducted a systematic review of the literature to address this important issue. Method: A systematic literature search was conducted in October 2014, using MEDLINE, Embase, and PsycINFO. Studies and case reports were included if they reported QTc intervals or QTc interval changes before and after antipsychotic polypharmacy or QTc intervals in both antipsychotic polypharmacy and monotherapy groups. Results: A total of 21 articles (10 clinical trials, 4 observational studies, and 7 case reports) met inclusion criteria. The clinical trials have shown that a combination treatment with risperidone or pimozide is not obviously related to an increase in QTc interval, whereas ziprasidone or sertindole combined with clozapine may prolong QTc interval. Among the 4 observational studies, antipsychotic polypharmacy was not clearly associated with QTc prolongation in 3 studies, each cross-sectional. In contrast, one prospective study showed a significant increase in QTc interval following antipsychotic coadministration. The case reports indicated an increased risk of QTc prolongation in at least some patients receiving antipsychotic polypharmacy. Conclusions: Currently available evidence fails to confirm that antipsychotic polypharmacy worsens QTc prolongation in general, although the evidence is scarce and inconsistent. Clinicians are advised to remain conservative in resorting to antipsychotic polypharmacy, as a combination of some QTc-prolongation liable antipsychotics may further prolong QTc interval, and efficacy supporting the clinical benefits of antipsychotic polypharmacy is equivocal, at best. PMID:26174525

  19. Measurement and interpretation of electrocardiographic QT intervals in murine hearts.

    PubMed

    Zhang, Yanmin; Wu, JingJing; King, James H; Huang, Christopher L-H; Fraser, James A

    2014-06-01

    Alterations in ECG QT intervals correlate with the risk of potentially fatal arrhythmias, for which transgenic murine hearts are becoming increasingly useful experimental models. However, QT intervals are poorly defined in murine ECGs. As a consequence, several different techniques have been used to measure murine QT intervals. The present work develops a consistent measure of the murine QT interval that correlates with changes in the duration of ventricular myocyte action potentials (APs). Volume-conducted ECGs were compared with simultaneously recorded APs, obtained using floating intracellular microelectrodes in Langendorff-perfused mouse hearts. QT intervals were measured from the onset of the QRS complex. The interval, Q-APR90, measured to the time at 90% AP recovery, was compared with two measures of the QT interval. QT1 was measured to the recovery of the ECG trace to the isoelectric baseline for entirely positive T-waves or to the trough of any negative T-wave undershoot. QT2-used extensively in previous studies-was measured to the return of any ECG trough to the isoelectric baseline. QT1, but not QT2, closely correlated with changes in Q-APR90. These findings were confirmed over a range of pacing rates, in low K(+) concentration solutions, and in Scn5a+/ΔKPQ hearts used to model human long QT syndrome. Application of this method in whole anesthetized mice similarly demonstrated a prolonged corrected QT (QTc) in Scn5a+/ΔKPQ hearts. We therefore describe a robust method for the determination of QT and QTc intervals that correlate with the duration of ventricular myocyte APs in murine hearts. PMID:24705556

  20. Capacitated max -Batching with Interval Graph Compatibilities

    NASA Astrophysics Data System (ADS)

    Nonner, Tim

    We consider the problem of partitioning interval graphs into cliques of bounded size. Each interval has a weight, and the weight of a clique is the maximum weight of any interval in the clique. This natural graph problem can be interpreted as a batch scheduling problem. Solving a long-standing open problem, we show NP-hardness, even if the bound on the clique sizes is constant. Moreover, we give a PTAS based on a novel dynamic programming technique for this case.

  1. A note on the path interval distance.

    PubMed

    Coons, Jane Ivy; Rusinko, Joseph

    2016-06-01

    The path interval distance accounts for global congruence between locally incongruent trees. We show that the path interval distance provides a lower bound for the nearest neighbor interchange distance. In contrast to the Robinson-Foulds distance, random pairs of trees are unlikely to be maximally distant from one another under the path interval distance. These features indicate that the path interval distance should play a role in phylogenomics where the comparison of trees on a fixed set of taxa is becoming increasingly important. PMID:27040521

  2. Walking Changes the Dynamics of Cognitive Estimates of Time Intervals

    ERIC Educational Resources Information Center

    Kiefer, Adam W.; Riley, Michael A.; Shockley, Kevin; Villard, Sebastien; Van Orden, Guy C.

    2009-01-01

    Cognitive performance exhibits patterns of trial-to-trial variation that can be described as 1/f or pink noise, as do repeated measures of locomotor performance. Although cognitive and locomotor performances are known to interact when performed concurrently, it is not known whether concurrent performance affects the tasks' pink noise dynamical…

  3. Statistical Properties of Extreme Solar Activity Intervals

    NASA Astrophysics Data System (ADS)

    Lioznova, A. V.; Blinov, A. V.

    2014-01-01

    A study of long-term solar variability reflected in indirect indices of past solar activity leads to stimulating results. We compare the statistics of intervals of very low and very high solar activity derived from two cosmogenic radionuclide records and look for consistency in their timing and physical interpretation. According to the applied criteria, the numbers of minima and of maxima are 61 and 68, respectively, from the 10Be record, and 42 and 46 from the 14C record. The difference between the enhanced and depressed states of solar activity becomes apparent in the difference in their statistical distributions. We find no correlation between the level or type (minimum or maximum) of an extremum and the level or type of the predecessor. The hypothesis of solar activity as a periodic process on the millennial time scale is not supported by the existing proxies. A new homogeneous series of 10Be measurements in polar ice covering the Holocene would be of great value for eliminating the existing discrepancy in the available solar activity reconstructions.

  4. High-Intensity Interval Training for Improving Postprandial Hyperglycemia

    ERIC Educational Resources Information Center

    Little, Jonathan P.; Francois, Monique E.

    2014-01-01

    High-intensity interval training (HIIT) has garnered attention in recent years as a time-efficient exercise option for improving cardiovascular and metabolic health. New research demonstrates that HIIT may be particularly effective for improving postprandial hyperglycemia in individuals with, or at risk for, type 2 diabetes (T2D). These findings…

  5. Interval and Contour Processing in Autism

    ERIC Educational Resources Information Center

    Heaton, Pamela

    2005-01-01

    High functioning children with autism and age and intelligence matched controls participated in experiments testing perception of pitch intervals and musical contours. The finding from the interval study showed superior detection of pitch direction over small pitch distances in the autism group. On the test of contour discrimination no group…

  6. SINGLE-INTERVAL GAS PERMEABILITY ESTIMATION

    EPA Science Inventory

    Single-interval, steady-steady-state gas permeability testing requires estimation of pressure at a screened interval which in turn requires measurement of friction factors as a function of mass flow rate. Friction factors can be obtained by injecting air through a length of pipe...

  7. Interval colorectal carcinoma: An unsolved debate.

    PubMed

    Benedict, Mark; Galvao Neto, Antonio; Zhang, Xuchen

    2015-12-01

    Colorectal carcinoma (CRC), as the third most common new cancer diagnosis, poses a significant health risk to the population. Interval CRCs are those that appear after a negative screening test or examination. The development of interval CRCs has been shown to be multifactorial: location of exam-academic institution versus community hospital, experience of the endoscopist, quality of the procedure, age of the patient, flat versus polypoid neoplasia, genetics, hereditary gastrointestinal neoplasia, and most significantly missed or incompletely excised lesions. The rate of interval CRCs has decreased in the last decade, which has been ascribed to an increased understanding of interval disease and technological advances in the screening of high risk individuals. In this article, we aim to review the literature with regard to the multifactorial nature of interval CRCs and provide the most recent developments regarding this important gastrointestinal entity. PMID:26668498

  8. Constructing Confidence Intervals for Qtl Location

    PubMed Central

    Mangin, B.; Goffinet, B.; Rebai, A.

    1994-01-01

    We describe a method for constructing the confidence interval of the QTL location parameter. This method is developed in the local asymptotic framework, leading to a linear model at each position of the putative QTL. The idea is to construct a likelihood ratio test, using statistics whose asymptotic distribution does not depend on the nuisance parameters and in particular on the effect of the QTL. We show theoretical properties of the confidence interval built with this test, and compare it with the classical confidence interval using simulations. We show in particular, that our confidence interval has the correct probability of containing the true map location of the QTL, for almost all QTLs, whereas the classical confidence interval can be very biased for QTLs having small effect. PMID:7896108

  9. Interval colorectal carcinoma: An unsolved debate

    PubMed Central

    Benedict, Mark; Neto, Antonio Galvao; Zhang, Xuchen

    2015-01-01

    Colorectal carcinoma (CRC), as the third most common new cancer diagnosis, poses a significant health risk to the population. Interval CRCs are those that appear after a negative screening test or examination. The development of interval CRCs has been shown to be multifactorial: location of exam-academic institution versus community hospital, experience of the endoscopist, quality of the procedure, age of the patient, flat versus polypoid neoplasia, genetics, hereditary gastrointestinal neoplasia, and most significantly missed or incompletely excised lesions. The rate of interval CRCs has decreased in the last decade, which has been ascribed to an increased understanding of interval disease and technological advances in the screening of high risk individuals. In this article, we aim to review the literature with regard to the multifactorial nature of interval CRCs and provide the most recent developments regarding this important gastrointestinal entity. PMID:26668498

  10. Interval Management Display Design Study

    NASA Technical Reports Server (NTRS)

    Baxley, Brian T.; Beyer, Timothy M.; Cooke, Stuart D.; Grant, Karlus A.

    2014-01-01

    In 2012, the Federal Aviation Administration (FAA) estimated that U.S. commercial air carriers moved 736.7 million passengers over 822.3 billion revenue-passenger miles. The FAA also forecasts, in that same report, an average annual increase in passenger traffic of 2.2 percent per year for the next 20 years, which approximates to one-and-a-half times the number of today's aircraft operations and passengers by the year 2033. If airspace capacity and throughput remain unchanged, then flight delays will increase, particularly at those airports already operating near or at capacity. Therefore it is critical to create new and improved technologies, communications, and procedures to be used by air traffic controllers and pilots. National Aeronautics and Space Administration (NASA), the FAA, and the aviation industry are working together to improve the efficiency of the National Airspace System and the cost to operate in it in several ways, one of which is through the creation of the Next Generation Air Transportation System (NextGen). NextGen is intended to provide airspace users with more precise information about traffic, routing, and weather, as well as improve the control mechanisms within the air traffic system. NASA's Air Traffic Management Technology Demonstration-1 (ATD-1) Project is designed to contribute to the goals of NextGen, and accomplishes this by integrating three NASA technologies to enable fuel-efficient arrival operations into high-density airports. The three NASA technologies and procedures combined in the ATD-1 concept are advanced arrival scheduling, controller decision support tools, and aircraft avionics to enable multiple time deconflicted and fuel efficient arrival streams in high-density terminal airspace.

  11. Fibrinolytic Therapy in CCU Instead of Emergency Ward: How It Affects Door to Needle Time?

    PubMed Central

    Zeraati, Fatemeh; Homayounfar, Shahram; Esna-Ashari, Farzaneh; Khalili, Marzieh

    2014-01-01

    Background: The door-to-needle-time (DNT) is considered a standard time for scheduling thrombolysis for acute ST-segment elevation of myocardial infarction and this time can be reduced by minimizing the delay in starting thrombolytic treatment once the patient has reached to the hospital. This study was carried out on a sample of Iranian patients with acute myocardial infarction to determine the DNT in those after changing schedule of thrombolysis during 8 years from emergency to coronary care unit (CCU). Methods: A descriptive cross-sectional study was carried out on all consecutive patients with a confirmed diagnosis of acute myocardial infarction admitted to the emergency ward of Ekbatan Hospital in Hamadan, Iran, within 2011 and had an indication of fibrinolytic therapy, which 47 patients were finally indicated to receive streptokinase in the part of CCU. Results: The mean time interval between arrival at the hospital and electrocardiogram (ECG) assessment was 6.30 min, taking ECG and patient's admission was 21.6 min and transferring the patient from admission to CCU ward was 31.9. The time between transferring the patients to CCU ward and fibrinolytic administration order and the time between its ordering and infusion was 31.2 min and 14.0 min respectively. In sum, the DNT was estimated 84.48 ± 53.00 min ranged 30-325 min that was significantly more than standard DNT (P <0.01). Furthermore, DNT mean in this study is significantly more than a study conducted 8 years ago in the same hospital (P <0.01). Conclusions: The DNT is higher than the standard level and higher than the estimated level in the past. This shows that DNT was longer after transferring to CCU. PMID:24829715

  12. Real-Time Very High-Resolution Regional 4D Assimilation in Supporting CRYSTAL-FACE Experiment

    NASA Technical Reports Server (NTRS)

    Wang, Donghai; Minnis, Patrick

    2004-01-01

    To better understand tropical cirrus cloud physical properties and formation processes with a view toward the successful modeling of the Earth's climate, the CRYSTAL-FACE (Cirrus Regional Study of Tropical Anvils and Cirrus Layers - Florida Area Cirrus Experiment) field experiment took place over southern Florida from 1 July to 29 July 2002. During the entire field campaign, a very high-resolution numerical weather prediction (NWP) and assimilation system was performed in support of the mission with supercomputing resources provided by NASA Center for Computational Sciences (NCCS). By using NOAA NCEP Eta forecast for boundary conditions and as a first guess for initial conditions assimilated with all available observations, two nested 15/3 km grids are employed over the CRYSTAL-FACE experiment area. The 15-km grid covers the southeast US domain, and is run two times daily for a 36-hour forecast starting at 0000 UTC and 1200 UTC. The nested 3-km grid covering only southern Florida is used for 9-hour and 18-hour forecasts starting at 1500 and 0600 UTC, respectively. The forecasting system provided more accurate and higher spatial and temporal resolution forecasts of 4-D atmospheric fields over the experiment area than available from standard weather forecast models. These forecasts were essential for flight planning during both the afternoon prior to a flight day and the morning of a flight day. The forecasts were used to help decide takeoff times and the most optimal flight areas for accomplishing the mission objectives. See more detailed products on the web site http://asd-www.larc.nasa.gov/mode/crystal. The model/assimilation output gridded data are archived on the NASA Center for Computational Sciences (NCCS) UniTree system in the HDF format at 30-min intervals for real-time forecasts or 5-min intervals for the post-mission case studies. Particularly, the data set includes the 3-D cloud fields (cloud liquid water, rain water, cloud ice, snow and graupe/hail).

  13. CONFIDENCE INTERVALS AND STANDARD ERROR INTERVALS: WHAT DO THEY MEAN IN TERMS OF STATISTICAL SIGNIFICANCE?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We investigate the use of confidence intervals and standard error intervals to draw conclusions regarding tests of hypotheses about normal population means. Mathematical expressions and algebraic manipulations are given, and computer simulations are performed to assess the usefulness of confidence ...

  14. Oscillatory dynamics of vasoconstriction and vasodilation identified by time-localized phase coherence

    NASA Astrophysics Data System (ADS)

    Sheppard, L. W.; Vuksanović, V.; McClintock, P. V. E.; Stefanovska, A.

    2011-06-01

    We apply wavelet-based time-localized phase coherence to investigate the relationship between blood flow and skin temperature, and between blood flow and instantaneous heart rate (IHR), during vasoconstriction and vasodilation provoked by local cooling or heating of the skin. A temperature-controlled metal plate (≈10 cm2) placed on the volar side of the left arm was used to provide the heating and cooling. Beneath the plate, the blood flow was measured by laser Doppler flowmetry and the adjacent skin temperature by a thermistor. Two 1 h datasets were collected from each of the ten subjects. In each case a 30 min basal recording was followed by a step change in plate temperature, to either 24 °C or 42 °C. The IHR was derived from simultaneously recorded ECG. We confirm the changes in the energy and frequency of blood flow oscillations during cooling and heating reported earlier. That is, during cooling, there was a significant decrease in the average frequency of myogenic blood flow oscillations (p < 0.05) and the myogenic spectral peak became more prominent. During heating, there was a significant (p < 0.05) general increase in spectral energy, associated with vasodilation, except in the myogenic interval. Weak phase coherence between temperature and blood flow was observed for unperturbed skin, but it increased in all frequency intervals as a result of heating. It was not significantly affected by cooling. We also show that significant (p < 0.05) phase coherence exists between blood flow and IHR in the respiratory and myogenic frequency intervals. Cooling did not affect this phase coherence in any of the frequency intervals, whereas heating enhanced the phase coherence in the respiratory and myogenic intervals. This can be explained by the reduction in vascular resistance produced by heating, a process where myogenic mechanisms play a key role. We conclude that the mechanisms of vasodilation and vasoconstriction, in response to temperature change, are

  15. Oscillatory dynamics of vasoconstriction and vasodilation identified by time-localized phase coherence.

    PubMed

    Sheppard, L W; Vuksanović, V; McClintock, P V E; Stefanovska, A

    2011-06-21

    We apply wavelet-based time-localized phase coherence to investigate the relationship between blood flow and skin temperature, and between blood flow and instantaneous heart rate (IHR), during vasoconstriction and vasodilation provoked by local cooling or heating of the skin. A temperature-controlled metal plate (approximately 10 cm2) placed on the volar side of the left arm was used to provide the heating and cooling. Beneath the plate, the blood flow was measured by laser Doppler flowmetry and the adjacent skin temperature by a thermistor. Two 1 h datasets were collected from each of the ten subjects. In each case a 30 min basal recording was followed by a step change in plate temperature, to either 24 °C or 42 °C. The IHR was derived from simultaneously recorded ECG. We confirm the changes in the energy and frequency of blood flow oscillations during cooling and heating reported earlier. That is, during cooling, there was a significant decrease in the average frequency of myogenic blood flow oscillations (p < 0.05) and the myogenic spectral peak became more prominent. During heating, there was a significant (p < 0.05) general increase in spectral energy, associated with vasodilation, except in the myogenic interval. Weak phase coherence between temperature and blood flow was observed for unperturbed skin, but it increased in all frequency intervals as a result of heating. It was not significantly affected by cooling. We also show that significant (p < 0.05) phase coherence exists between blood flow and IHR in the respiratory and myogenic frequency intervals. Cooling did not affect this phase coherence in any of the frequency intervals, whereas heating enhanced the phase coherence in the respiratory and myogenic intervals. This can be explained by the reduction in vascular resistance produced by heating, a process where myogenic mechanisms play a key role. We conclude that the mechanisms of vasodilation and vasoconstriction, in response to temperature change

  16. Reliability of Time to Exhaustion Treadmill Running as a Measure of Human Endurance Capacity.

    PubMed

    Alghannam, A F; Jedrzejewski, D; Tweddle, M; Gribble, H; Bilzon, J L J; Betts, J A

    2016-03-01

    Little if any research has examined the variability in time to exhaustion (TTE) during submaximal treadmill running. This study investigated the test-retest reliability of submaximal treadmill TTE as a measure of endurance capacity. 16 endurance-trained males (n=14) and females (n=2) completed a run to exhaustion at 70% V̇O2max (T1) and repeated the same run 3 weeks later (T2). At 30-min intervals during each run, expired gas, heart rate (HR) and ratings of perceived exertion (RPE) were collected. Mean ± SD TTE was 96 ± 20 min in T1 vs. 101 ± 29 min in T2 (P=0.3). The mean ± 95% confidence intervals (CI) of the coefficient of variance (CV) was 5.4% (1.4-9.6). The average intraclass correlation coefficient (± 95% CI) was 0.88 (0.67-0.96) between trials. The respiratory-exchange ratio was not different between trials, T1: 0.87 ± 0.1 and T2: 0.89 ± 0.1 (P>0.05) and neither was total whole-body carbohydrate oxidation (2.1 ± 0.4 g·min(-1) and 2.3 ± 0.6 g·min(-1)), fat oxidation (0.6 ± 0.2 g·min(-1)), HR (178 ± 8 and 175 ± 7 beats·min(-1)) or RPE (17 ± 3 and 16 ± 3). These results suggest that use of prolonged treadmill-based TTE can be a reliable research tool to assess human endurance capacity in aerobically-trained men and women. PMID:26669250

  17. Ongoing behavior predicts perceptual report of interval duration

    PubMed Central

    Gouvêa, Thiago S.; Monteiro, Tiago; Soares, Sofia; Atallah, Bassam V.; Paton, Joseph J.

    2014-01-01

    The ability to estimate the passage of time is essential for adaptive behavior in complex environments. Yet, it is not known how the brain encodes time over the durations necessary to explain animal behavior. Under temporally structured reinforcement schedules, animals tend to develop temporally structured behavior, and interval timing has been suggested to be accomplished by learning sequences of behavioral states. If this is true, trial to trial fluctuations in behavioral sequences should be predictive of fluctuations in time estimation. We trained rodents in an duration categorization task while continuously monitoring their behavior with a high speed camera. Animals developed highly reproducible behavioral sequences during the interval being timed. Moreover, those sequences were often predictive of perceptual report from early in the trial, providing support to the idea that animals may use learned behavioral patterns to estimate the duration of time intervals. To better resolve the issue, we propose that continuous and simultaneous behavioral and neural monitoring will enable identification of neural activity related to time perception that is not explained by ongoing behavior. PMID:24672473

  18. Physiology and its Importance for Reference Intervals

    PubMed Central

    Sikaris, Kenneth A

    2014-01-01

    Reference intervals are ideally defined on apparently healthy individuals and should be distinguished from clinical decision limits that are derived from known diseased patients. Knowledge of physiological changes is a prerequisite for understanding and developing reference intervals. Reference intervals may differ for various subpopulations because of differences in their physiology, most obviously between men and women, but also in childhood, pregnancy and the elderly. Changes in laboratory measurements may be due to various physiological factors starting at birth including weaning, the active toddler, immunological learning, puberty, pregnancy, menopause and ageing. The need to partition reference intervals is required when there are significant physiological changes that need to be recognised. It is important that laboratorians are aware of these changes otherwise reference intervals that attempt to cover a widened inter-individual variability may lose their usefulness. It is virtually impossible for any laboratory to directly develop reference intervals for each of the physiological changes that are currently known, however indirect techniques can be used to develop or validate reference intervals in some difficult situations such as those for children. Physiology describes our life’s journey, and it is only when we are familiar with that journey that we can appreciate a pathological departure. PMID:24659833

  19. Interval Estimates of Multivariate Effect Sizes: Coverage and Interval Width Estimates under Variance Heterogeneity and Nonnormality

    ERIC Educational Resources Information Center

    Hess, Melinda R.; Hogarty, Kristine Y.; Ferron, John M.; Kromrey, Jeffrey D.

    2007-01-01

    Monte Carlo methods were used to examine techniques for constructing confidence intervals around multivariate effect sizes. Using interval inversion and bootstrapping methods, confidence intervals were constructed around the standard estimate of Mahalanobis distance (D[superscript 2]), two bias-adjusted estimates of D[superscript 2], and Huberty's…

  20. Post-KR Delay Intervals and Mental Practice: A Test of Adams' Closed Loop Theory

    ERIC Educational Resources Information Center

    Bole, Ronald

    1976-01-01

    The present study suggests that post-KR delay interval time or activity in the interval has little to do with learning on a self-paced positioning task, not ruling out that on ballistic tasks or more complex nonballistic tasks that a learner could make use of additional time or strategy. (MB)

  1. Importance of QT interval in clinical practice.

    PubMed

    Ambhore, Anand; Teo, Swee-Guan; Bin Omar, Abdul Razakjr; Poh, Kian-Keong

    2014-12-01

    Long QT interval is an important finding that is often missed by electrocardiogram interpreters. Long QT syndrome (inherited and acquired) is a potentially lethal cardiac channelopathy that is frequently mistaken for epilepsy. We present a case of long QT syndrome with multiple cardiac arrests presenting as syncope and seizures. The long QTc interval was aggravated by hypomagnesaemia and drugs, including clarithromycin and levofloxacin. Multiple drugs can cause prolongation of the QT interval, and all physicians should bear this in mind when prescribing these drugs. PMID:25630313

  2. Short Interval Leaf Movements of Cotton 12

    PubMed Central

    Miller, Charles S.

    1975-01-01

    Gossypium hirsutum L. cv. Lankart plants exhibited three different types of independent short interval leaf movements which were superimposed on the circadian movements. The different types were termed SIRV (short interval rhythmical vertical), SIHM (short interval horizontal movements), and SHAKE (short stroked SIRV). The 36-minute period SIRV movements occurred at higher moisture levels. The 176-minute period SIHM occurred at lower moisture levels and ceased as the stress increased. The SHAKE movements were initiated with further stresses. The SLEEP (circadian, diurnal) movements ceased with further stress. The last to cease just prior to permanent wilting were the SHAKE movements. PMID:16659123

  3. 18F-FDG PET/CT oncologic imaging at extended injection-to-scan acquisition time intervals derived from a single-institution 18F-FDG-directed surgery experience: feasibility and quantification of 18F-FDG accumulation within 18F-FDG-avid lesions and background tissues

    PubMed Central

    2014-01-01

    Background 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) is a well-established imaging modality for a wide variety of solid malignancies. Currently, only limited data exists regarding the utility of PET/CT imaging at very extended injection-to-scan acquisition times. The current retrospective data analysis assessed the feasibility and quantification of diagnostic 18F-FDG PET/CT oncologic imaging at extended injection-to-scan acquisition time intervals. Methods 18F-FDG-avid lesions (not surgically manipulated or altered during 18F-FDG-directed surgery, and visualized both on preoperative and postoperative 18F-FDG PET/CT imaging) and corresponding background tissues were assessed for 18F-FDG accumulation on same-day preoperative and postoperative 18F-FDG PET/CT imaging. Multiple patient variables and 18F-FDG-avid lesion variables were examined. Results For the 32 18F-FDG-avid lesions making up the final 18F-FDG-avid lesion data set (from among 7 patients), the mean injection-to-scan times of the preoperative and postoperative 18F-FDG PET/CT scans were 73 (±3, 70-78) and 530 (±79, 413-739) minutes, respectively (P < 0.001). The preoperative and postoperative mean 18F-FDG-avid lesion SUVmax values were 7.7 (±4.0, 3.6-19.5) and 11.3 (±6.0, 4.1-29.2), respectively (P < 0.001). The preoperative and postoperative mean background SUVmax values were 2.3 (±0.6, 1.0-3.2) and 2.1 (±0.6, 1.0-3.3), respectively (P = 0.017). The preoperative and postoperative mean lesion-to-background SUVmax ratios were 3.7 (±2.3, 1.5-9.8) and 5.8 (±3.6, 1.6-16.2), respectively, (P < 0.001). Conclusions 18F-FDG PET/CT oncologic imaging can be successfully performed at extended injection-to-scan acquisition time intervals of up to approximately 5 half-lives for 18F-FDG while maintaining good/adequate diagnostic image quality. The resultant increase in the 18F-FDG-avid lesion SUVmax values, decreased background SUVmax values, and

  4. Calibration intervals at Bendix Kansas City

    SciTech Connect

    James, R.T.

    1980-01-01

    The calibration interval evaluation methods and control in each calibrating department of the Bendix Corp., Kansas City Division is described, and a more detailed description of those employed in metrology is provided.

  5. Combination of structural reliability and interval analysis

    NASA Astrophysics Data System (ADS)

    Qiu, Zhiping; Yang, Di; Elishakoff, Isaac

    2008-02-01

    In engineering applications, probabilistic reliability theory appears to be presently the most important method, however, in many cases precise probabilistic reliability theory cannot be considered as adequate and credible model of the real state of actual affairs. In this paper, we developed a hybrid of probabilistic and non-probabilistic reliability theory, which describes the structural uncertain parameters as interval variables when statistical data are found insufficient. By using the interval analysis, a new method for calculating the interval of the structural reliability as well as the reliability index is introduced in this paper, and the traditional probabilistic theory is incorporated with the interval analysis. Moreover, the new method preserves the useful part of the traditional probabilistic reliability theory, but removes the restriction of its strict requirement on data acquisition. Example is presented to demonstrate the feasibility and validity of the proposed theory.

  6. Almost primes in almost all short intervals

    NASA Astrophysics Data System (ADS)

    TERÄVÄINEN, JONI

    2016-09-01

    Let $E_k$ be the set of positive integers having exactly $k$ prime factors. We show that almost all intervals $[x,x+\\log^{1+\\varepsilon} x]$ contain $E_3$ numbers, and almost all intervals $[x,x+\\log^{3.51} x]$ contain $E_2$ numbers. By this we mean that there are only $o(X)$ integers $1\\leq x\\leq X$ for which the mentioned intervals do not contain such numbers. The result for $E_3$ numbers is optimal up to the $\\varepsilon$ in the exponent. The theorem on $E_2$ numbers improves a result of Harman, which had the exponent $7+\\varepsilon$ in place of $3.51$. We will also consider general $E_k$ numbers, and find them on intervals whose lengths approach $\\log x$ as $k\\to \\infty$.

  7. Optimising sprint interval exercise to maximise energy expenditure and enjoyment in overweight boys.

    PubMed

    Crisp, Nicole A; Fournier, Paul A; Licari, Melissa K; Braham, Rebecca; Guelfi, Kym J

    2012-12-01

    The aim of this study was to identify the sprint frequency that when supplemented to continuous exercise at the intensity that maximises fat oxidation (Fat(max)), optimises energy expenditure, acute postexercise energy intake and enjoyment. Eleven overweight boys completed 30 min of either continuous cycling at Fat(max) (MOD), or sprint interval exercise that consisted of continuous cycling at Fat(max) interspersed with 4-s maximal sprints every 2 min (SI(120)), every 1 min (SI(60)), or every 30 s (SI(30)). Energy expenditure was assessed during exercise, after which participants completed a modified Physical Activity Enjoyment Scale (PACES) followed by a buffet-type breakfast to measure acute postexercise energy intake. Energy expenditure increased with increasing sprint frequency (p < 0.001), but the difference between SI(60) and SI(30) did not reach significance (p = 0.076), likely as a result of decreased sprint quality as indicated by a significant decline in peak power output from SI(60) to SI(30) (p = 0.034). Postexercise energy intake was similar for MOD, SI(120), and SI(30) (p > 0.05), but was significantly less for SI(60) compared with MOD (p = 0.025). PACES was similar for MOD, SI(120), and SI(60) (p > 0.05), but was less for SI(30) compared with MOD (p = 0.038), SI(120) (p = 0.009), and SI(60) (p = 0.052). In conclusion, SI(60) appears optimal for overweight boys given that it maximises energy expenditure (i.e., there was no additional increase in expenditure with a further increase in sprint frequency) without prompting increased energy intake. This, coupled with the fact that enjoyment was not compromised, may have important implications for increased adherence and long-term energy balance. PMID:23176528

  8. Patterns of interval correlations in neural oscillators with adaptation

    PubMed Central

    Schwalger, Tilo; Lindner, Benjamin

    2013-01-01

    Neural firing is often subject to negative feedback by adaptation currents. These currents can induce strong correlations among the time intervals between spikes. Here we study analytically the interval correlations of a broad class of noisy neural oscillators with spike-triggered adaptation of arbitrary strength and time scale. Our weak-noise theory provides a general relation between the correlations and the phase-response curve (PRC) of the oscillator, proves anti-correlations between neighboring intervals for adapting neurons with type I PRC and identifies a single order parameter that determines the qualitative pattern of correlations. Monotonically decaying or oscillating correlation structures can be related to qualitatively different voltage traces after spiking, which can be explained by the phase plane geometry. At high firing rates, the long-term variability of the spike train associated with the cumulative interval correlations becomes small, independent of model details. Our results are verified by comparison with stochastic simulations of the exponential, leaky, and generalized integrate-and-fire models with adaptation. PMID:24348372

  9. Reference intervals for serum creatine kinase in athletes

    PubMed Central

    Mougios, Vassilis

    2007-01-01

    Background The serum concentration of creatine kinase (CK) is used widely as an index of skeletal muscle fibre damage in sport and exercise. Since athletes have higher CK values than non‐athletes, comparing the values of athletes to the normal values established in non‐athletes is pointless. The purpose of this study was to introduce reference intervals for CK in athletes. Method CK was assayed in serum samples from 483 male athletes and 245 female athletes, aged 7–44. Samples had been obtained throughout the training and competition period. For comparison, CK was also assayed in a smaller number of non‐athletes. Reference intervals (2.5th to 97.5th percentile) were calculated by the non‐parametric method. Results The reference intervals were 82–1083 U/L (37°C) in male and 47–513 U/L in female athletes. The upper reference limits were twice the limits reported for moderately active non‐athletes in the literature or calculated in the non‐athletes in this study. The upper limits were up to six times higher than the limits reported for inactive individuals in the literature. When reference intervals were calculated specifically in male football (soccer) players and swimmers, a threefold difference in the upper reference limit was found (1492 vs 523 U/L, respectively), probably resulting from the different training and competition demands of the two sports. Conclusion Sport training and competition have profound effects on the reference intervals for serum CK. Introducing sport‐specific reference intervals may help to avoid misinterpretation of high values and to optimise training. PMID:17526622

  10. Probability Distribution for Flowing Interval Spacing

    SciTech Connect

    S. Kuzio

    2004-09-22

    Fracture spacing is a key hydrologic parameter in analyses of matrix diffusion. Although the individual fractures that transmit flow in the saturated zone (SZ) cannot be identified directly, it is possible to determine the fractured zones that transmit flow from flow meter survey observations. The fractured zones that transmit flow as identified through borehole flow meter surveys have been defined in this report as flowing intervals. The flowing interval spacing is measured between the midpoints of each flowing interval. The determination of flowing interval spacing is important because the flowing interval spacing parameter is a key hydrologic parameter in SZ transport modeling, which impacts the extent of matrix diffusion in the SZ volcanic matrix. The output of this report is input to the ''Saturated Zone Flow and Transport Model Abstraction'' (BSC 2004 [DIRS 170042]). Specifically, the analysis of data and development of a data distribution reported herein is used to develop the uncertainty distribution for the flowing interval spacing parameter for the SZ transport abstraction model. Figure 1-1 shows the relationship of this report to other model reports that also pertain to flow and transport in the SZ. Figure 1-1 also shows the flow of key information among the SZ reports. It should be noted that Figure 1-1 does not contain a complete representation of the data and parameter inputs and outputs of all SZ reports, nor does it show inputs external to this suite of SZ reports. Use of the developed flowing interval spacing probability distribution is subject to the limitations of the assumptions discussed in Sections 5 and 6 of this analysis report. The number of fractures in a flowing interval is not known. Therefore, the flowing intervals are assumed to be composed of one flowing zone in the transport simulations. This analysis may overestimate the flowing interval spacing because the number of fractures that contribute to a flowing interval cannot be

  11. The lucid interval associated with epidural bleeding: evolving understanding.

    PubMed

    Ganz, Jeremy C

    2013-04-01

    The aim of this paper was to elucidate the evolution of our understanding of the term "lucid interval." A number of texts were reviewed to assess their suitability for analysis. The primary requirement was that the text contain detailed descriptions of a series of patients. Details of the clinical course, the findings and timing of surgery, and, when relevant, the time of death and postmortem findings were required. Books written by Henri-François Le Dran, Percival Pott, and James Hill fulfilled these criteria. Surgical findings included the presence and type of fractures, changes in the bone, separation of periosteum, malodorous or purulent material, tense brain, and hematoma. Postmortem findings supplemented and/or complemented the surgical findings. The courses of the patients were then tabulated, and the correlation between different clinical and operative findings was thereby determined. Our understanding of a lucid interval began in the early 18th century with the work of Henri-François Le Dran and Percival Pott in London. They did not, however, demonstrate an interval without symptoms between trauma and deterioration in patients with epidural hematomas (EDHs). The interval they described was longer than usually expected with EDHs and occurred exclusively in patients who had a posttraumatic infection. In 1751, James Hill, from Dumfries, Scotland, described the first hematoma-related lucid interval in a patient with a subdural hematoma. The first case of a lucid interval associated with an EDH was described by John Abernethy. In the 19th century, Jonathan Hutchinson and Walter Jacobson described the interval as it is known today, in cases of EDH. The most recent work on the topic came from studies in Cincinnati and Oslo, where it was demonstrated that bleeding can separate dura mater and that hemorrhage into the epidural space can be shunted out via the veins. This shunting could delay the accumulation of a hematoma and thus the rise in intracranial pressure

  12. Variations in rupture process with recurrence interval in a repeated small earthquake

    USGS Publications Warehouse

    Vidale, J.E.; Ellsworth, W.L.; Cole, A.; Marone, C.

    1994-01-01

    In theory and in laboratory experiments, friction on sliding surfaces such as rock, glass and metal increases with time since the previous episode of slip. This time dependence is a central pillar of the friction laws widely used to model earthquake phenomena. On natural faults, other properties, such as rupture velocity, porosity and fluid pressure, may also vary with the recurrence interval. Eighteen repetitions of the same small earthquake, separated by intervals ranging from a few days to several years, allow us to test these laboratory predictions in situ. The events with the longest time since the previous earthquake tend to have about 15% larger seismic moment than those with the shortest intervals, although this trend is weak. In addition, the rupture durations of the events with the longest recurrence intervals are more than a factor of two shorter than for the events with the shortest intervals. Both decreased duration and increased friction are consistent with progressive fault healing during the time of stationary contact.In theory and in laboratory experiments, friction on sliding surfaces such as rock, glass and metal increases with time since the previous episode of slip. This time dependence is a central pillar of the friction laws widely used to model earthquake phenomena. On natural faults, other properties, such as rupture velocity, porosity and fluid pressure, may also vary with the recurrence interval. Eighteen repetitions of the same small earthquake, separated by intervals ranging from a few days to several years, allow us to test these laboratory predictions in situ. The events with the longest time since the previous earthquake tend to have about 15% larger seismic moment than those with the shortest intervals, although this trend is weak. In addition, the rupture durations of the events with the longest recurrence intervals are more than a factor of two shorter than for the events with the shortest intervals. Both decreased duration and

  13. Regularization and control of irregular vehicular motion through a series of signals at disordered intervals

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi

    2011-06-01

    We study the control and regularization of irregular motion of a vehicle moving through the series of traffic signals positioned at disordered intervals. All signals are controlled by both cycle time and phase shift. The nonlinear dynamic model of the vehicular motion controlled by signals is described in terms of the stochastic nonlinear map. The vehicle exhibits a very complex behavior with varying both cycle time and strength of disordered intervals. The delay or advance of tour time is compensated by synchronizing the phase shift with disordered intervals. The irregular motion induced by the disordered configuration of signals is regularized for various values of cycle time.

  14. Natural frequencies of structures with interval parameters

    NASA Astrophysics Data System (ADS)

    Sofi, A.; Muscolino, G.; Elishakoff, I.

    2015-07-01

    This paper deals with the evaluation of the lower and upper bounds of the natural frequencies of structures with uncertain-but-bounded parameters. The solution of the generalized interval eigenvalue problem is pursued by taking into account the actual variability and dependencies of uncertain structural parameters affecting the mass and stiffness matrices. To this aim, interval uncertainties are handled by applying the improved interval analysis via extra unitary interval (EUI), recently introduced by the first two authors. By associating an EUI to each uncertain-but-bounded parameter, the cases of mass and stiffness matrices affected by fully disjoint, completely or partially coincident uncertainties are considered. Then, based on sensitivity analysis, it is shown that the bounds of the interval eigenvalues can be evaluated as solution of two appropriate deterministic eigenvalue problems without requiring any combinatorial procedure. If the eigenvalues are monotonic functions of the uncertain parameters, then the exact bounds are obtained. The accuracy of the proposed method is demonstrated by numerical results concerning truss and beam structures with material and/or geometrical uncertainties.

  15. Realtime Multichannel System for Beat to Beat QT Interval Variability

    NASA Technical Reports Server (NTRS)

    Starc, Vito; Schlegel, Todd T.

    2006-01-01

    The measurement of beat-to-beat QT interval variability (QTV) shows clinical promise for identifying several types of cardiac pathology. However, until now, there has been no device capable of displaying, in real time on a beattobeat basis, changes in QTV in all 12 conventional leads in a continuously monitored patient. While several software programs have been designed to analyze QTV, heretofore, such programs have all involved only a few channels (at most) and/or have required laborious user interaction or offline calculations and postprocessing, limiting their clinical utility. This paper describes a PC-based ECG software program that in real time, acquires, analyzes and displays QTV and also PQ interval variability (PQV) in each of the eight independent channels that constitute the 12lead conventional ECG. The system also processes certain related signals that are derived from singular value decomposition and that help to reduce the overall effects of noise on the realtime QTV and PQV results.

  16. Pigeons' choices between fixed-interval and random-interval schedules: utility of variability?

    PubMed

    Andrzejewski, Matthew E; Cardinal, Claudia D; Field, Douglas P; Flannery, Barbara A; Johnson, Michael; Bailey, Kathleen; Hineline, Philip N

    2005-03-01

    Pigeons' choosing between fixed-interval and random-interval schedules of reinforcement was investigated in three experiments using a discrete-trial procedure. In all three experiments, the random-interval schedule was generated by sampling a probability distribution at an interval (and in multiples of the interval) equal to that of the fixed-interval schedule. Thus the programmed delays to reinforcement on the random alternative were never shorter and were often longer than the fixed interval. Despite this feature, the fixed schedule was not strongly preferred. Increases in the probability used to generate the random interval resulted in decreased preferences for the fixed schedule. In addition, the number of consecutive choices on the preferred alternative varied directly with preference, whereas the consecutive number of choices on the nonpreferred alternative was fairly constant. The probability of choosing the random alternative was unaffected by the immediately prior interval encountered on that schedule, even when it was very long relative to the average value. The results loosely support conceptions of a "preference for variability" from foraging theory and the "utility of behavioral variability" from human decision-making literatures. PMID:15828591

  17. Stability Problem of Canard-Cycles on a Finite Interval

    NASA Astrophysics Data System (ADS)

    Chumakov, Gennadii A.; Chumakova, Nataliya A.; Lashina, Elena A.

    2010-09-01

    A detailed study of two-variable mathematical model of a heterogeneous catalytic reaction is presented with special attention to the stability problem of canard-cycles on a finite interval. Our analysis of the global error behavior in a long-time numerical integration shows that a high sensitive dependence on the initial conditions appears due to the existence of a shower-type bundle of trajectories which is formed by stable and unstable canard solutions.

  18. Perceptual interference decays over short unfilled intervals.

    PubMed

    Schulkind, M D

    2000-09-01

    The perceptual interference effect refers to the fact that object identification is directly related to the amount of information available at initial exposure. The present article investigated whether perceptual interference would dissipate when a short, unfilled interval was introduced between exposures to a degraded object. Across three experiments using both musical and pictorial stimuli, identification performance increased directly with the length of the unfilled interval. Consequently, significant perceptual interference was obtained only when the interval between exposures was relatively short (< 500 msec for melodies; < 300 msec for pictures). These results are consistent with explanations that attribute perceptual interference to increased perceptual noise created by exposures to highly degraded objects. The data also suggest that perceptual interference is mediated by systems that are not consciously controlled by the subject and that perceptual interference in the visual domain decays more rapidly than perceptual interference in the auditory domain. PMID:11105520

  19. Comparison of time-dependent effects of (+)-methamphetamine or forced swim on monoamines, corticosterone, glucose, creatine, and creatinine in rats

    PubMed Central

    Herring, Nicole R; Schaefer, Tori L; Tang, Peter H; Skelton, Matthew R; Lucot, James P; Gudelsky, Gary A; Vorhees, Charles V; Williams, Michael T

    2008-01-01

    Background Methamphetamine (MA) use is a worldwide problem. Abusers can have cognitive deficits, monoamine reductions, and altered magnetic resonance spectroscopy findings. Animal models have been used to investigate some of these effects, however many of these experiments have not examined the impact of MA on the stress response. For example, numerous studies have demonstrated (+)-MA-induced neurotoxicity and monoamine reductions, however the effects of MA on other markers that may play a role in neurotoxicity or cell energetics such as glucose, corticosterone, and/or creatine have received less attention. In this experiment, the effects of a neurotoxic regimen of (+)-MA (4 doses at 2 h intervals) on brain monoamines, neostriatal GFAP, plasma corticosterone, creatinine, and glucose, and brain and muscle creatine were evaluated 1, 7, 24, and 72 h after the first dose. In order to compare MA's effects with stress, animals were subjected to a forced swim test in a temporal pattern similar to MA administration [i.e., (30 min/session) 4 times at 2 h intervals]. Results MA increased corticosterone from 1–72 h with a peak 1 h after the first treatment, whereas glucose was only increased 1 h post-treatment. Neostriatal and hippocampal monoamines were decreased at 7, 24, and 72 h, with a concurrent increase in GFAP at 72 h. There was no effect of MA on regional brain creatine, however plasma creatinine was increased during the first 24 h and decreased by 72 h. As with MA treatment, forced swim increased corticosterone more than MA initially. Unlike MA, forced swim reduced creatine in the cerebellum with no change in other brain regions while plasma creatinine was decreased at 1 and 7 h. Glucose in plasma was decreased at 7 h. Conclusion Both MA and forced swim increase demand on energy substrates but in different ways, and MA has persistent effects on corticosterone that are not attributable to stress alone. PMID:18513404

  20. Intervality and coherence in complex networks.

    PubMed

    Domínguez-García, Virginia; Johnson, Samuel; Muñoz, Miguel A

    2016-06-01

    Food webs-networks of predators and prey-have long been known to exhibit "intervality": species can generally be ordered along a single axis in such a way that the prey of any given predator tend to lie on unbroken compact intervals. Although the meaning of this axis-usually identified with a "niche" dimension-has remained a mystery, it is assumed to lie at the basis of the highly non-trivial structure of food webs. With this in mind, most trophic network modelling has for decades been based on assigning species a niche value by hand. However, we argue here that intervality should not be considered the cause but rather a consequence of food-web structure. First, analysing a set of 46 empirical food webs, we find that they also exhibit predator intervality: the predators of any given species are as likely to be contiguous as the prey are, but in a different ordering. Furthermore, this property is not exclusive of trophic networks: several networks of genes, neurons, metabolites, cellular machines, airports, and words are found to be approximately as interval as food webs. We go on to show that a simple model of food-web assembly which does not make use of a niche axis can nevertheless generate significant intervality. Therefore, the niche dimension (in the sense used for food-web modelling) could in fact be the consequence of other, more fundamental structural traits. We conclude that a new approach to food-web modelling is required for a deeper understanding of ecosystem assembly, structure, and function, and propose that certain topological features thought to be specific of food webs are in fact common to many complex networks. PMID:27368797

  1. Intervality and coherence in complex networks

    NASA Astrophysics Data System (ADS)

    Domínguez-García, Virginia; Johnson, Samuel; Muñoz, Miguel A.

    2016-06-01

    Food webs—networks of predators and prey—have long been known to exhibit "intervality": species can generally be ordered along a single axis in such a way that the prey of any given predator tend to lie on unbroken compact intervals. Although the meaning of this axis—usually identified with a "niche" dimension—has remained a mystery, it is assumed to lie at the basis of the highly non-trivial structure of food webs. With this in mind, most trophic network modelling has for decades been based on assigning species a niche value by hand. However, we argue here that intervality should not be considered the cause but rather a consequence of food-web structure. First, analysing a set of 46 empirical food webs, we find that they also exhibit predator intervality: the predators of any given species are as likely to be contiguous as the prey are, but in a different ordering. Furthermore, this property is not exclusive of trophic networks: several networks of genes, neurons, metabolites, cellular machines, airports, and words are found to be approximately as interval as food webs. We go on to show that a simple model of food-web assembly which does not make use of a niche axis can nevertheless generate significant intervality. Therefore, the niche dimension (in the sense used for food-web modelling) could in fact be the consequence of other, more fundamental structural traits. We conclude that a new approach to food-web modelling is required for a deeper understanding of ecosystem assembly, structure, and function, and propose that certain topological features thought to be specific of food webs are in fact common to many complex networks.

  2. Children's artistic responses to musical intervals.

    PubMed

    Smith, L D; Williams, R N

    1999-01-01

    In one experiment, White South African boys drew pictures in response to four musical intervals. In the second, the subjects were of both sexes and drawn from White, urban Black, and rural Black populations. Six intervals were used. Drawing content was similar cross-culturally. Consonances were perceived as generally positive; dissonances, generally negative. There was also an activity dimension. Children in a lower grade drew more concrete pictures than did those in a higher grade, regardless of age. Even young listeners were fairly consistent in their responses. This suggests that perception of musical meaning is a universal rather than culturally based phenomenon. PMID:10696271

  3. Optimal Colonoscopy Surveillance Interval after Polypectomy

    PubMed Central

    Kim, Tae Oh

    2016-01-01

    The detection and removal of adenomatous polyps and postpolypectomy surveillance are considered important for the control of colorectal cancer (CRC). Surveillance using colonoscopy is an effective tool for preventing CRC after colorectal polypectomy, especially if compliance is good. In current practice, the intervals between colonoscopies after polypectomy are variable. Different recommendations for recognizing at risk groups and defining surveillance intervals after an initial finding of colorectal adenomas have been published. However, high-grade dysplasia and the number and size of adenomas are known major cancer predictors. Based on this, a subgroup of patients that may benefit from intensive surveillance colonoscopy can be identified. PMID:27484812

  4. Statistical analysis on multifractal detrended cross-correlation coefficient for return interval by oriented percolation

    NASA Astrophysics Data System (ADS)

    Deng, Wei; Wang, Jun

    2015-06-01

    We investigate and quantify the multifractal detrended cross-correlation of return interval series for Chinese stock markets and a proposed price model, the price model is established by oriented percolation. The return interval describes the waiting time between two successive price volatilities which are above some threshold, the present work is an attempt to quantify the level of multifractal detrended cross-correlation for the return intervals. Further, the concept of MF-DCCA coefficient of return intervals is introduced, and the corresponding empirical research is performed. The empirical results show that the return intervals of SSE and SZSE are weakly positive multifractal power-law cross-correlated, and exhibit the fluctuation patterns of MF-DCCA coefficients. The similar behaviors of return intervals for the price model is also demonstrated.

  5. Sex Differences in the Generalization of Fear as a Function of Retention Intervals

    ERIC Educational Resources Information Center

    Lynch, Joseph, III; Cullen, Patrick K.; Jasnow, Aaron M.; Riccio, David C.

    2013-01-01

    In previous studies using male rodents, context change disrupted a fear response at a short, but not a long, retention interval. Here, we examined the effects of context changes on fear responses as a function of time in male and female rats. Males displayed context discrimination at all intervals, whereas females exhibited generalization by 5 d.…

  6. A Comparison of Two Reading Fluency Methods: Repeated Readings to a Fluency Criterion and Interval Sprinting

    ERIC Educational Resources Information Center

    Kostewicz, Douglas E.; Kubina, Richard M., Jr.

    2010-01-01

    Teachers have used the method of repeated readings to build oral reading fluency in students with and without special needs. A new fluency building intervention called interval sprinting uses shorter timing intervals (i.e., sprints) across a passage. This study used an alternating treatment design to compare repeated readings and interval…

  7. An Evaluation of Progressively Increasing Intertrial Intervals on the Acquisition and Generalization of Three Social Skills

    ERIC Educational Resources Information Center

    Francisco, Monica T.; Hanley, Gregory P.

    2012-01-01

    We evaluated the effects of different intertrial intervals (ITIs; time between programmed learning opportunities) on the acquisition and generalization of 2 preschoolers' social skills. Independent and generalized skills were observed only when the daily ITI was gradually increased from short to progressively longer intervals. (Contains 1 figure…

  8. An Empirical Method for Establishing Positional Confidence Intervals Tailored for Composite Interval Mapping of QTL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improved genetic resolution and availability of sequenced genomes have made positional cloning of moderate-effect QTL (quantitative trait loci) realistic in several systems, emphasizing the need for precise and accurate derivation of positional confidence intervals (CIs). Support interval (SI) meth...

  9. Coefficient Omega Bootstrap Confidence Intervals: Nonnormal Distributions

    ERIC Educational Resources Information Center

    Padilla, Miguel A.; Divers, Jasmin

    2013-01-01

    The performance of the normal theory bootstrap (NTB), the percentile bootstrap (PB), and the bias-corrected and accelerated (BCa) bootstrap confidence intervals (CIs) for coefficient omega was assessed through a Monte Carlo simulation under conditions not previously investigated. Of particular interests were nonnormal Likert-type and binary items.…

  10. Interval scanning photomicrography of microbial cell populations.

    NASA Technical Reports Server (NTRS)

    Casida, L. E., Jr.

    1972-01-01

    A single reproducible area of the preparation in a fixed focal plane is photographically scanned at intervals during incubation. The procedure can be used for evaluating the aerobic or anaerobic growth of many microbial cells simultaneously within a population. In addition, the microscope is not restricted to the viewing of any one microculture preparation, since the slide cultures are incubated separately from the microscope.

  11. MEETING DATA QUALITY OBJECTIVES WITH INTERVAL INFORMATION

    EPA Science Inventory

    Immunoassay test kits are promising technologies for measuring analytes under field conditions. Frequently, these field-test kits report the analyte concentrations as falling in an interval between minimum and maximum values. Many project managers use field-test kits only for scr...

  12. Gauss-Laguerre interval quadrature rule

    NASA Astrophysics Data System (ADS)

    Milovanovic, Gradimir V.; Cvetkovic, Aleksandar S.

    2005-10-01

    In this paper we prove the existence and uniqueness of the Gaussian interval quadrature formula with respect to the generalized Laguerre weight function. An algorithm for numerical construction has also investigated and some suitable solutions are proposed. A few numerical examples are included.

  13. Happiness Scale Interval Study. Methodological Considerations

    ERIC Educational Resources Information Center

    Kalmijn, W. M.; Arends, L. R.; Veenhoven, R.

    2011-01-01

    The Happiness Scale Interval Study deals with survey questions on happiness, using verbal response options, such as "very happy" and "pretty happy". The aim is to estimate what degrees of happiness are denoted by such terms in different questions and languages. These degrees are expressed in numerical values on a continuous [0,10] scale, which are…

  14. Coefficient Alpha Bootstrap Confidence Interval under Nonnormality

    ERIC Educational Resources Information Center

    Padilla, Miguel A.; Divers, Jasmin; Newton, Matthew

    2012-01-01

    Three different bootstrap methods for estimating confidence intervals (CIs) for coefficient alpha were investigated. In addition, the bootstrap methods were compared with the most promising coefficient alpha CI estimation methods reported in the literature. The CI methods were assessed through a Monte Carlo simulation utilizing conditions…

  15. Emotion and Implicit Timing

    PubMed Central

    Droit-Volet, Sylvie

    2016-01-01

    This study examined the effects of emotion on implicit timing. In the implicit timing task used, the participants did not receive any temporal instructions. Instead they were simply asked and trained to press a key as quickly as possible after a stimulus (response stimulus) that was separated from a preceding stimulus by a given temporal interval (reference interval duration). However, in the testing phase, the interval duration was the reference interval duration or a shorter or longer interval duration. In addition, the participants attended two sessions: a first baseline session in which no stimulus was presented during the inter-stimulus intervals, and a second emotional session in which emotional facial expressions (angry, neutral and sad facial expressions) were presented during these intervals. Results showed faster RTs for interval durations close to the reference duration in both the baseline and the emotional conditions and yielded a U-shaped curve. This suggests that implicit processing of time persists in emotional contexts. In addition, the RT was faster for the facial expressions of anger than for those of neutrality and sadness. However, the U-shaped RT curve did not peak clearly at a shorter interval duration for the angry than for the other facial expressions. This lack of time distortion in an implicit timing task in response to arousing emotional stimuli questions the idea of an automatic speeding-up of the interval clock system involved in the representation of time. PMID:27380409

  16. Neonatal anoxia leads to time dependent progression of mitochondrial linked apoptosis in rat cortex and associated long term sensorimotor deficits.

    PubMed

    Samaiya, Puneet K; Narayan, Gopeshwar; Kumar, Ashok; Krishnamurthy, Sairam

    2016-08-01

    Neonatal anoxia arises due to oxygen deprivation at the time of birth and results in life long neurodevelopmental deficits and sometimes may lead to death. The present study investigated the time dependent cortical mitochondrial dysfunction linked apoptosis and related sensorimotor deficits in neonates. Neonates after 30h to birth (P2) were subjected to anoxia of two episodes (10min in each) at a time interval of 24h by passing 100% N2 into an enclosed chamber as confirmed by pulse oximetry. Sensorimotor activities like reflex latency and hanging latency were carried out 24h after last anoxic episode i.e. from P4 (day-1) and continued up to P10 (day-7). Mitochondrial dysfunction after anoxia was evident by the decrease in respiration states, respiratory control ratio (RCR), antioxidant enzyme activity but an increase in oxidative stress and lipid peroxidation and alteration in mitochondrial membrane potential (MMP) at different time points (30min, 24h and day-7). A change in expression of Bcl-2 family proteins and opening of mitochondrial transition pore (mPTP) in terms of mitochondrial swelling was observed resulting in release of cytochrome-C which further activated intrinsic (mitochondrial) pathway of apoptosis through increased expression of caspase-9/3 as confirmed by flow cytometry. In conclusion, anoxia injury leads to progressive activation of mitochondrial events leading to increase in apoptotic cell death following secondary pathological insult. Therefore, strategies in limiting mitochondrial-linked apoptosis during the secondary insult input process may be useful in treatment of long term sensorimotor deficits following anoxia. PMID:27184438

  17. Estimating Neuronal Information: Logarithmic Binning of Neuronal Inter-Spike Intervals.

    PubMed

    Dorval, Alan D

    2011-02-01

    Neurons communicate via the relative timing of all-or-none biophysical signals called spikes. For statistical analysis, the time between spikes can be accumulated into inter-spike interval histograms. Information theoretic measures have been estimated from these histograms to assess how information varies across organisms, neural systems, and disease conditions. Because neurons are computational units that, to the extent they process time, work not by discrete clock ticks but by the exponential decays of numerous intrinsic variables, we propose that neuronal information measures scale more naturally with the logarithm of time. For the types of inter-spike interval distributions that best describe neuronal activity, the logarithm of time enables fewer bins to capture the salient features of the distributions. Thus, discretizing the logarithm of inter-spike intervals, as compared to the inter-spike intervals themselves, yields histograms that enable more accurate entropy and information estimates for fewer bins and less data. Additionally, as distribution parameters vary, the entropy and information calculated from the logarithm of the inter-spike intervals are substantially better behaved, e.g., entropy is independent of mean rate, and information is equally affected by rate gains and divisions. Thus, when compiling neuronal data for subsequent information analysis, the logarithm of the inter-spike intervals is preferred, over the untransformed inter-spike intervals, because it yields better information estimates and is likely more similar to the construction used by nature herself. PMID:24839390

  18. Microsatellite Instability Status of Interval Colorectal Cancers in a Korean Population

    PubMed Central

    Lee, Kil Woo; Park, Soo-Kyung; Yang, Hyo-Joon; Jung, Yoon Suk; Choi, Kyu Yong; Kim, Kyung Eun; Jung, Kyung Uk; Kim, Hyung Ook; Kim, Hungdai; Chun, Ho-Kyung; Park, Dong Il

    2016-01-01

    Background/Aims A subset of patients may develop colorectal cancer after a colonoscopy that is negative for malignancy. These missed or de novo lesions are referred to as interval cancers. The aim of this study was to determine whether interval colon cancers are more likely to result from the loss of function of mismatch repair genes than sporadic cancers and to demonstrate microsatellite instability (MSI). Methods Interval cancer was defined as a cancer that was diagnosed within 5 years of a negative colonoscopy. Among the patients who underwent an operation for colorectal cancer from January 2013 to December 2014, archived cancer specimens were evaluated for MSI by sequencing microsatellite loci. Results Of the 286 colon cancers diagnosed during the study period, 25 (8.7%) represented interval cancer. MSI was found in eight of the 25 patients (32%) that presented interval cancers compared with 22 of the 261 patients (8.4%) that presented sporadic cancers (p=0.002). In the multivariable logistic regression model, MSI was associated with interval cancer (OR, 3.91; 95% confidence interval, 1.38 to 11.05). Conclusions Interval cancers were approximately four times more likely to show high MSI than sporadic cancers. Our findings indicate that certain interval cancers may occur because of distinct biological features. PMID:27114419

  19. Musical training generalises across modalities and reveals efficient and adaptive mechanisms for reproducing temporal intervals.

    PubMed

    Aagten-Murphy, David; Cappagli, Giulia; Burr, David

    2014-03-01

    Expert musicians are able to time their actions accurately and consistently during a musical performance. We investigated how musical expertise influences the ability to reproduce auditory intervals and how this generalises across different techniques and sensory modalities. We first compared various reproduction strategies and interval length, to examine the effects in general and to optimise experimental conditions for testing the effect of music, and found that the effects were robust and consistent across different paradigms. Focussing on a 'ready-set-go' paradigm subjects reproduced time intervals drawn from distributions varying in total length (176, 352 or 704 ms) or in the number of discrete intervals within the total length (3, 5, 11 or 21 discrete intervals). Overall, Musicians performed more veridical than Non-Musicians, and all subjects reproduced auditory-defined intervals more accurately than visually-defined intervals. However, Non-Musicians, particularly with visual stimuli, consistently exhibited a substantial and systematic regression towards the mean interval. When subjects judged intervals from distributions of longer total length they tended to regress more towards the mean, while the ability to discriminate between discrete intervals within the distribution had little influence on subject error. These results are consistent with a Bayesian model that minimizes reproduction errors by incorporating a central tendency prior weighted by the subject's own temporal precision relative to the current distribution of intervals. Finally a strong correlation was observed between all durations of formal musical training and total reproduction errors in both modalities (accounting for 30% of the variance). Taken together these results demonstrate that formal musical training improves temporal reproduction, and that this improvement transfers from audition to vision. They further demonstrate the flexibility of sensorimotor mechanisms in adapting to

  20. The Rotator Interval of the Shoulder

    PubMed Central

    Frank, Rachel M.; Taylor, Dean; Verma, Nikhil N.; Romeo, Anthony A.; Mologne, Timothy S.; Provencher, Matthew T.

    2015-01-01

    Biomechanical studies have shown that repair or plication of rotator interval (RI) ligamentous and capsular structures decreases glenohumeral joint laxity in various directions. Clinical outcomes studies have reported successful outcomes after repair or plication of these structures in patients undergoing shoulder stabilization procedures. Recent studies describing arthroscopic techniques to address these structures have intensified the debate over the potential benefit of these procedures as well as highlighted the differences between open and arthroscopic RI procedures. The purposes of this study were to review the structures of the RI and their contribution to shoulder instability, to discuss the biomechanical and clinical effects of repair or plication of rotator interval structures, and to describe the various surgical techniques used for these procedures and outcomes. PMID:26779554

  1. Efficient computation of parameter confidence intervals

    NASA Technical Reports Server (NTRS)

    Murphy, Patrick C.

    1987-01-01

    An important step in system identification of aircraft is the estimation of stability and control derivatives from flight data along with an assessment of parameter accuracy. When the maximum likelihood estimation technique is used, parameter accuracy is commonly assessed by the Cramer-Rao lower bound. It is known, however, that in some cases the lower bound can be substantially different from the parameter variance. Under these circumstances the Cramer-Rao bounds may be misleading as an accuracy measure. This paper discusses the confidence interval estimation problem based on likelihood ratios, which offers a more general estimate of the error bounds. Four approaches are considered for computing confidence intervals of maximum likelihood parameter estimates. Each approach is applied to real flight data and compared.

  2. Partitioned-Interval Quantum Optical Communications Receiver

    NASA Technical Reports Server (NTRS)

    Vilnrotter, Victor A.

    2013-01-01

    The proposed quantum receiver in this innovation partitions each binary signal interval into two unequal segments: a short "pre-measurement" segment in the beginning of the symbol interval used to make an initial guess with better probability than 50/50 guessing, and a much longer segment used to make the high-sensitivity signal detection via field-cancellation and photon-counting detection. It was found that by assigning as little as 10% of the total signal energy to the pre-measurement segment, the initial 50/50 guess can be improved to about 70/30, using the best available measurements such as classical coherent or "optimized Kennedy" detection.

  3. Drug discrimination under two concurrent fixed-interval fixed-interval schedules.

    PubMed Central

    McMillan, D E; Li, M

    2000-01-01

    Pigeons were trained to discriminate 5.0 mg/kg pentobarbital from saline under a two-key concurrent fixed-interval (FI) 100-s FI 200-s schedule of food presentation, and later tinder a concurrent FI 40-s FI 80-s schedule, in which the FI component with the shorter time requirement reinforced responding on one key after drug administration (pentobarbital-biased key) and on the other key after saline administration (saline-biased key). After responding stabilized under the concurrent FI 100-s FI 200-s schedule, pigeons earned an average of 66% (after pentobarbital) to 68% (after saline) of their reinforcers for responding under the FI 100-s component of the concurrent schedule. These birds made an average of 70% of their responses on both the pentobarbital-biased key after the training dose of pentobarbital and the saline-biased key after saline. After responding stabilized under the concurrent FI 40-s FI 80-s schedule, pigeons earned an average of 67% of their reinforcers for responding under the FI 40 component after both saline and the training dose of pentobarbital. These birds made an average of 75% of their responses on the pentobarbital-biased key after the training dose of pentobarbital, but only 55% of their responses on the saline-biased key after saline. In test sessions preceded by doses of pentobarbital, chlordiazepoxide, ethanol, phencyclidine, or methamphetamine, the dose-response curves were similar under these two concurrent schedules. Pentobarbital, chlordiazepoxide, and ethanol produced dose-dependent increases in responding on the pentobarbital-biased key as the doses increased. For some birds, at the highest doses of these drugs, the dose-response curve turned over. Increasing doses of phencyclidine produced increased responding on the pentobarbital-biased key in some, but not all, birds. After methamphetamine, responding was largely confined to the saline-biased key. These data show that pigeons can perform drug discriminations under concurrent

  4. Drug discrimination under two concurrent fixed-interval fixed-interval schedules.

    PubMed

    McMillan, D E; Li, M

    2000-07-01

    Pigeons were trained to discriminate 5.0 mg/kg pentobarbital from saline under a two-key concurrent fixed-interval (FI) 100-s FI 200-s schedule of food presentation, and later tinder a concurrent FI 40-s FI 80-s schedule, in which the FI component with the shorter time requirement reinforced responding on one key after drug administration (pentobarbital-biased key) and on the other key after saline administration (saline-biased key). After responding stabilized under the concurrent FI 100-s FI 200-s schedule, pigeons earned an average of 66% (after pentobarbital) to 68% (after saline) of their reinforcers for responding under the FI 100-s component of the concurrent schedule. These birds made an average of 70% of their responses on both the pentobarbital-biased key after the training dose of pentobarbital and the saline-biased key after saline. After responding stabilized under the concurrent FI 40-s FI 80-s schedule, pigeons earned an average of 67% of their reinforcers for responding under the FI 40 component after both saline and the training dose of pentobarbital. These birds made an average of 75% of their responses on the pentobarbital-biased key after the training dose of pentobarbital, but only 55% of their responses on the saline-biased key after saline. In test sessions preceded by doses of pentobarbital, chlordiazepoxide, ethanol, phencyclidine, or methamphetamine, the dose-response curves were similar under these two concurrent schedules. Pentobarbital, chlordiazepoxide, and ethanol produced dose-dependent increases in responding on the pentobarbital-biased key as the doses increased. For some birds, at the highest doses of these drugs, the dose-response curve turned over. Increasing doses of phencyclidine produced increased responding on the pentobarbital-biased key in some, but not all, birds. After methamphetamine, responding was largely confined to the saline-biased key. These data show that pigeons can perform drug discriminations under concurrent

  5. One-way ANOVA based on interval information

    NASA Astrophysics Data System (ADS)

    Hesamian, Gholamreza

    2016-08-01

    This paper deals with extending the one-way analysis of variance (ANOVA) to the case where the observed data are represented by closed intervals rather than real numbers. In this approach, first a notion of interval random variable is introduced. Especially, a normal distribution with interval parameters is introduced to investigate hypotheses about the equality of interval means or test the homogeneity of interval variances assumption. Moreover, the least significant difference (LSD method) for investigating multiple comparison of interval means is developed when the null hypothesis about the equality of means is rejected. Then, at a given interval significance level, an index is applied to compare the interval test statistic and the related interval critical value as a criterion to accept or reject the null interval hypothesis of interest. Finally, the method of decision-making leads to some degrees to accept or reject the interval hypotheses. An applied example will be used to show the performance of this method.

  6. Quantifying chaotic dynamics from interspike intervals

    NASA Astrophysics Data System (ADS)

    Pavlov, A. N.; Pavlova, O. N.; Mohammad, Y. K.; Shihalov, G. M.

    2015-03-01

    We address the problem of characterization of chaotic dynamics at the input of a threshold device described by an integrate-and-fire (IF) or a threshold crossing (TC) model from the output sequences of interspike intervals (ISIs). We consider the conditions under which quite short sequences of spiking events provide correct identification of the dynamical regime characterized by the single positive Lyapunov exponent (LE). We discuss features of detecting the second LE for both types of the considered models of events generation.

  7. Targeted Estimation of Binary Variable Importance Measures with Interval-Censored Outcomes

    PubMed Central

    van der Laan, Mark J.; Page, Kimberly

    2015-01-01

    In most experimental and observational studies, participants are not followed in continuous time. Instead, data is collected about participants only at certain monitoring times. These monitoring times are random and often participant specific. As a result, outcomes are only known up to random time intervals, resulting in interval-censored data. In contrast, when estimating variable importance measures on interval-censored outcomes, practitioners often ignore the presence of interval censoring, and instead treat the data as continuous or right-censored, applying ad hoc approaches to mask the true interval censoring. In this article, we describe targeted minimum loss–based estimation (TMLE) methods tailored for estimation of binary variable importance measures with interval-censored outcomes. We demonstrate the performance of the interval-censored TMLE procedure through simulation studies and apply the method to analyze the effects of a variety of variables on spontaneous hepatitis C virus clearance among injecton drug users, using data from the “International Collaboration of Incident HIV and HCV in Injecting Cohorts” project. PMID:24637001

  8. Robust inter-beat interval estimation in cardiac vibration signals.

    PubMed

    Brüser, C; Winter, S; Leonhardt, S

    2013-02-01

    Reliable and accurate estimation of instantaneous frequencies of physiological rhythms, such as heart rate, is critical for many healthcare applications. Robust estimation is especially challenging when novel unobtrusive sensors are used for continuous health monitoring in uncontrolled environments, because these sensors can create significant amounts of potentially unreliable data. We propose a new flexible algorithm for the robust estimation of local (beat-to-beat) intervals from cardiac vibration signals, specifically ballistocardiograms (BCGs), recorded by an unobtrusive bed-mounted sensor. This sensor allows the measurement of motions of the body which are caused by cardiac activity. Our method requires neither a training phase nor any prior knowledge about the morphology of the heart beats in the analyzed waveforms. Instead, three short-time estimators are combined using a Bayesian approach to continuously estimate the inter-beat intervals. We have validated our method on over-night BCG recordings from 33 subjects (8 normal, 25 insomniacs). On this dataset, containing approximately one million heart beats, our method achieved a mean beat-to-beat interval error of 0.78% with a coverage of 72.69%. PMID:23343518

  9. long interval microtremor array survey in sedimentary basin

    NASA Astrophysics Data System (ADS)

    Yoshimi, M.; Sugiyama, T.

    2011-12-01

    Microtremor array survey is one of the easiest passive inspection methods to estimate the subsurface velocity structure of sedimentary basin. Since the method utilizes ambient noise, of which stochastic features are not always stable both spatially and temporally, longer observation interval is necessary to obtain reliable results. We conducted microtremor array surveys each observation interval is more than ten days to test robustness of the microtoremors (frequency range: 0.1 to 1 Hz) and phase velocities estimation. Velocity seismometers with natural period more than 5 sec. are deployed connected with 24 bit A/D, GPS time-calibrated data loggers. Each observation comprises of twelve stations arranged as three regular triangle arrays with radii several hundred meters to several kilometers to enable wide-band phase velocity estimation (0.1 to 1 Hz at maximum) necessary for Vs estimation at each site (south Niigata, central Japan). Each continuous data are segmented to hourly data sets, and they are analyzed with SPAC method to obtain phase velocity estimations. Estimated phase velocities are fluctuated especially in the lower frequency range (say, below 0.3 Hz). Our observation shows importance of longer interval observation to obtain reliable phase velocity estimates with microtremor array survey.

  10. Age effects in discrimination of intervals within rhythmic tone sequences.

    PubMed

    Fitzgibbons, Peter J; Gordon-Salant, Sandra

    2015-01-01

    This study measured listener sensitivity to increments of a target inter-onset interval (IOI) embedded within tone sequences that featured different rhythmic patterns. The sequences consisted of six 50-ms 1000-Hz tone bursts separated by silent intervals that were adjusted to create different timing patterns. Control sequences were isochronous, with all tonal IOIs fixed at either 200 or 400 ms, while other patterns featured combinations of the two IOIs arranged to create different sequential tonal groupings. Duration difference limens in milliseconds for increments of a single sequence IOI were measured adaptively by adjusting the duration of an inter-tone silent interval. Specific target IOIs within sequences differed across discrimination conditions. Listeners included younger normal-hearing adults and groups of older adults with and without hearing loss. Discrimination performance measured for each of the older groups of listeners was observed to be equivalent, with each group exhibiting significantly poorer discrimination performance than the younger listeners in each sequence condition. Additionally, the specific influence of variable rhythmic grouping on temporal sensitivity was found to be greatest among older listeners. PMID:25618068

  11. Effect of time of dosing relative to a meal on the raft formation of an anti-reflux agent.

    PubMed

    Washington, N; Greaves, J L; Wilson, C G

    1990-01-01

    Gamma scintigraphy was used in twelve healthy volunteers to establish whether the time of dosing of Liquid Gaviscon relative to a meal influenced its therapeutic action. Indium-113m labelled Liquid Gaviscon was administered to fasted subjects, 30 min after a technetium-99m labelled meal or immediately before ingestion of the meal. The time for 50% of the Gaviscon to empty from the stomach was 0.36 +/- 0.13 h, 3.10 +/- 0.31 h and 0.68 +/- 0.04 h (s.e.m.), respectively. The preparation was found to empty rapidly from the fasted stomach and could not be floated on a meal consumed subsequently. For raft formation to occur, Liquid Gaviscon should be taken 30 min after a meal. PMID:1969950

  12. Differential Preparation Intervals Modulate Repetition Processes in Task Switching: An ERP Study

    PubMed Central

    Wang, Min; Yang, Ping; Zhao, Qian-Jing; Wang, Meng; Jin, Zhenlan; Li, Ling

    2016-01-01

    In task-switching paradigms, reaction times (RTs) switch cost (SC) and the neural correlates underlying the SC are affected by different preparation intervals. However, little is known about the effect of the preparation interval on the repetition processes in task-switching. To examine this effect we utilized a cued task-switching paradigm with long sequences of repeated trials. Response-stimulus intervals (RSI) and cue-stimulus intervals (CSI) were manipulated in short and long conditions. Electroencephalography (EEG) and behavioral data were recorded. We found that with increasing repetitions, RTs were faster in the short CSI conditions, while P3 amplitudes decreased in the LS (long RSI and short CSI) conditions. Positive correlations between RT benefit and P3 activation decrease (repeat 1 − repeat 5), and between the slope of the RT and P3 regression lines were observed only in the LS condition. Our findings suggest that differential preparation intervals modulate repetition processes in task switching. PMID:26924974

  13. Sampling-interval-dependent stability for linear sampled-data systems with non-uniform sampling

    NASA Astrophysics Data System (ADS)

    Shao, Hanyong; Lam, James; Feng, Zhiguang

    2016-09-01

    This paper is concerned with the sampling-interval-dependent stability of linear sampled-data systems with non-uniform sampling. A new Lyapunov-like functional is constructed to derive sampling-interval-dependent stability results. The Lyapunov-like functional has three features. First, it depends on time explicitly. Second, it may be discontinuous at the sampling instants. Third, it is not required to be positive definite between sampling instants. Moreover, the new Lyapunov-like functional can make use of the information fully of the sampled-data system, including that of both ends of the sampling interval. By making a new proposition for the Lyapunov-like functional, a sampling-interval-dependent stability criterion with reduced conservatism is derived. The new sampling-interval-dependent stability criterion is further extended to linear sampled-data systems with polytopic uncertainties. Finally, examples are given to illustrate the reduced conservatism of the stability criteria.

  14. Differential Preparation Intervals Modulate Repetition Processes in Task Switching: An ERP Study.

    PubMed

    Wang, Min; Yang, Ping; Zhao, Qian-Jing; Wang, Meng; Jin, Zhenlan; Li, Ling

    2016-01-01

    In task-switching paradigms, reaction times (RTs) switch cost (SC) and the neural correlates underlying the SC are affected by different preparation intervals. However, little is known about the effect of the preparation interval on the repetition processes in task-switching. To examine this effect we utilized a cued task-switching paradigm with long sequences of repeated trials. Response-stimulus intervals (RSI) and cue-stimulus intervals (CSI) were manipulated in short and long conditions. Electroencephalography (EEG) and behavioral data were recorded. We found that with increasing repetitions, RTs were faster in the short CSI conditions, while P3 amplitudes decreased in the LS (long RSI and short CSI) conditions. Positive correlations between RT benefit and P3 activation decrease (repeat 1 - repeat 5), and between the slope of the RT and P3 regression lines were observed only in the LS condition. Our findings suggest that differential preparation intervals modulate repetition processes in task switching. PMID:26924974

  15. Confidence intervals in Flow Forecasting by using artificial neural networks

    NASA Astrophysics Data System (ADS)

    Panagoulia, Dionysia; Tsekouras, George

    2014-05-01

    One of the major inadequacies in implementation of Artificial Neural Networks (ANNs) for flow forecasting is the development of confidence intervals, because the relevant estimation cannot be implemented directly, contrasted to the classical forecasting methods. The variation in the ANN output is a measure of uncertainty in the model predictions based on the training data set. Different methods for uncertainty analysis, such as bootstrap, Bayesian, Monte Carlo, have already proposed for hydrologic and geophysical models, while methods for confidence intervals, such as error output, re-sampling, multi-linear regression adapted to ANN have been used for power load forecasting [1-2]. The aim of this paper is to present the re-sampling method for ANN prediction models and to develop this for flow forecasting of the next day. The re-sampling method is based on the ascending sorting of the errors between real and predicted values for all input vectors. The cumulative sample distribution function of the prediction errors is calculated and the confidence intervals are estimated by keeping the intermediate value, rejecting the extreme values according to the desired confidence levels, and holding the intervals symmetrical in probability. For application of the confidence intervals issue, input vectors are used from the Mesochora catchment in western-central Greece. The ANN's training algorithm is the stochastic training back-propagation process with decreasing functions of learning rate and momentum term, for which an optimization process is conducted regarding the crucial parameters values, such as the number of neurons, the kind of activation functions, the initial values and time parameters of learning rate and momentum term etc. Input variables are historical data of previous days, such as flows, nonlinearly weather related temperatures and nonlinearly weather related rainfalls based on correlation analysis between the under prediction flow and each implicit input

  16. A Constraint-based Attribute and Interval Planning

    NASA Technical Reports Server (NTRS)

    Frank, Jeremy; Jonsson, Ari; Clancy, Daniel (Technical Monitor)

    2001-01-01

    In this paper we introduce Constraint-based Attribute and Interval Planning (CAIP), a new paradigm for representing and reasoning about plans. The paradigm enables the description of planning domains with time, resources, concurrent activities, mutual exclusions among sets of activities, disjunctive preconditions and conditional effects. We provide a theoretical foundation for the paradigm using a mapping to first order logic. We also show that CAIP plans are naturally expressed by networks of constraints, and that planning maps directly to dynamic constraint reasoning. In addition, we show how constraint templates are used to provide a compact mechanism for describing planning domains.

  17. Methodological issues for determining intervals of subsequent cancer screening

    PubMed Central

    Bae, Jong-Myon

    2014-01-01

    The gap between nationwide recommendations of cancer screening and the related evidences obtained from Korean adults should be filled. Estimation of the mean sojourn time (MST) in a specific cancer is important to determine the intervals of subsequent screening. This author arranged the methods for calculating MST into 5 categories based on the parameters used. Under the legal barrier for protection of individual privacy and confidentiality in a Korean academic situation, the methods involving the use of transition rates or prevalence/incidence ratio would be applicable among these methods. PMID:25078383

  18. The dose delivery effect of the different Beam ON interval in FFF SBRT: TrueBEAM

    NASA Astrophysics Data System (ADS)

    Tawonwong, T.; Suriyapee, S.; Oonsiri, S.; Sanghangthum, T.; Oonsiri, P.

    2016-03-01

    The purpose of this study is to determine the dose delivery effect of the different Beam ON interval in Flattening Filter Free Stereotactic Body Radiation Therapy (FFF-SBRT). The three 10MV-FFF SBRT plans (2 half rotating Rapid Arc, 9 to10 Gray/Fraction) were selected and irradiated in three different intervals (100%, 50% and 25%) using the RPM gating system. The plan verification was performed by the ArcCHECK for gamma analysis and the ionization chamber for point dose measurement. The dose delivery time of each interval were observed. For gamma analysis (2%&2mm criteria), the average percent pass of all plans for 100%, 50% and 25% intervals were 86.1±3.3%, 86.0±3.0% and 86.1±3.3%, respectively. For point dose measurement, the average ratios of each interval to the treatment planning were 1.012±0.015, 1.011±0.014 and 1.011±0.013 for 100%, 50% and 25% interval, respectively. The average dose delivery time was increasing from 74.3±5.0 second for 100% interval to 154.3±12.6 and 347.9±20.3 second for 50% and 25% interval, respectively. The same quality of the dose delivery from different Beam ON intervals in FFF-SBRT by TrueBEAM was illustrated. While the 100% interval represents the breath-hold treatment technique, the differences for the free-breathing using RPM gating system can be treated confidently.

  19. Automatic Abstraction for Intervals Using Boolean Formulae

    NASA Astrophysics Data System (ADS)

    Brauer, Jörg; King, Andy

    Traditionally, transfer functions have been manually designed for each operation in a program. Recently, however, there has been growing interest in computing transfer functions, motivated by the desire to reason about sequences of operations that constitute basic blocks. This paper focuses on deriving transfer functions for intervals - possibly the most widely used numeric domain - and shows how they can be computed from Boolean formulae which are derived through bit-blasting. This approach is entirely automatic, avoids complicated elimination algorithms, and provides a systematic way of handling wrap-arounds (integer overflows and underflows) which arise in machine arithmetic.

  20. Optimal ABC inventory classification using interval programming

    NASA Astrophysics Data System (ADS)

    Rezaei, Jafar; Salimi, Negin

    2015-08-01

    Inventory classification is one of the most important activities in inventory management, whereby inventories are classified into three or more classes. Several inventory classifications have been proposed in the literature, almost all of which have two main shortcomings in common. That is, the previous methods mainly rely on an expert opinion to derive the importance of the classification criteria which results in subjective classification, and they need precise item parameters before implementing the classification. While the problem has been predominantly considered as a multi-criteria, we examine the problem from a different perspective, proposing a novel optimisation model for ABC inventory classification in the form of an interval programming problem. The proposed interval programming model has two important features compared to the existing methods: it provides optimal results instead of an expert-based classification and it does not require precise values of item parameters, which are not almost always available before classification. Finally, by illustrating the proposed classification model in the form of numerical example, conclusion and suggestions for future works are presented.

  1. Physicochemical characterization of Capstone depleted uranium aerosols I: uranium concentration in aerosols as a function of time and particle size.

    PubMed

    Parkhurst, Mary Ann; Cheng, Yung Sung; Kenoyer, Judson L; Traub, Richard J

    2009-03-01

    During the Capstone Depleted Uranium (DU) Aerosol Study, aerosols containing DU were produced inside unventilated armored vehicles (i.e., Abrams tanks and Bradley Fighting Vehicles) by perforation with large-caliber DU penetrators. These aerosols were collected and characterized, and the data were subsequently used to assess human health risks to personnel exposed to DU aerosols. The DU content of each aerosol sample was first quantified by radioanalytical methods, and selected samples, primarily those from the cyclone separator grit chambers, were analyzed radiochemically. Deposition occurred inside the vehicles as particles settled on interior surfaces. Settling rates of uranium from the aerosols were evaluated using filter cassette samples that collected aerosol as total mass over eight sequential time intervals. A moving filter was used to collect aerosol samples over time, particularly within the first minute after a shot. The results demonstrate that the peak uranium concentration in the aerosol occurred in the first 10 s after perforation, and the concentration decreased in the Abrams tank shots to about 50% within 1 min and to less than 2% after 30 min. The initial and maximum uranium concentrations were lower in the Bradley vehicle than those observed in the Abrams tank, and the concentration levels decreased more slowly. Uranium mass concentrations in the aerosols as a function of particle size were evaluated using samples collected in a cyclone sampler, which collected aerosol continuously for 2 h after perforation. The percentages of uranium mass in the cyclone separator stages ranged from 38 to 72% for the Abrams tank with conventional armor. In most cases, it varied with particle size, typically with less uranium associated with the smaller particle sizes. Neither the Abrams tank with DU armor nor the Bradley vehicle results were specifically correlated with particle size and can best be represented by their average uranium mass concentrations of 65

  2. Physicochemical Characterization of Capstone Depleted Uranium Aerosols I: Uranium Concentration in Aerosols as a Function of Time and Particle Size

    SciTech Connect

    Parkhurst, MaryAnn; Cheng, Yung-Sung; Kenoyer, Judson L.; Traub, Richard J.

    2009-03-01

    During the Capstone Depleted Uranium (DU) Aerosol Study, aerosols containing depleted uranium were produced inside unventilated armored vehicles (i.e., Abrams tanks and Bradley Fighting Vehicles) by perforation with large-caliber DU penetrators. These aerosols were collected and characterized, and the data were subsequently used to assess human health risks to personnel exposed to DU aerosols. The DU content of each aerosol sample was first quantified by radioanalytical methods, and selected samples, primarily those from the cyclone separator grit chambers, were analyzed radiochemically. Deposition occurred inside the vehicles as particles settled on interior surfaces. Settling rates of uranium from the aerosols were evaluated using filter cassette samples that collected aerosol as total mass over eight sequential time intervals. A moving filter was used to collect aerosol samples over time particularly within the first minute after the shot. The results demonstrate that the peak uranium concentration in the aerosol occurred in the first 10 s, and the concentration decreased in the Abrams tank shots to about 50% within 1 min and to less than 2% 30 min after perforation. In the Bradley vehicle, the initial (and maximum) uranium concentration was lower than those observed in the Abrams tank and decreased more slowly. Uranium mass concentrations in the aerosols as a function of particle size were evaluated using samples collected in the cyclone samplers, which collected aerosol continuously for 2 h post perforation. The percentages of uranium mass in the cyclone separator stages from the Abrams tank tests ranged from 38% to 72% and, in most cases, varied with particle size, typically with less uranium associated with the smaller particle sizes. Results with the Bradley vehicle ranged from 18% to 29% and were not specifically correlated with particle size.

  3. Happiness Scale Interval Study. Methodological Considerations.

    PubMed

    Kalmijn, W M; Arends, L R; Veenhoven, R

    2011-07-01

    The Happiness Scale Interval Study deals with survey questions on happiness, using verbal response options, such as 'very happy' and 'pretty happy'. The aim is to estimate what degrees of happiness are denoted by such terms in different questions and languages. These degrees are expressed in numerical values on a continuous [0,10] scale, which are then used to compute 'transformed' means and standard deviations. Transforming scores on different questions to the same scale allows to broadening the World Database of Happiness considerably. The central purpose of the Happiness Scale Interval Study is to identify the happiness values at which respondents change their judgment from e.g. 'very happy' to 'pretty happy' or the reverse. This paper deals with the methodological/statistical aspects of this approach. The central question is always how to convert the frequencies at which the different possible responses to the same question given by a sample into information on the happiness distribution in the relevant population. The primary (cl)aim of this approach is to achieve this in a (more) valid way. To this end, a model is introduced that allows for dealing with happiness as a latent continuous random variable, in spite of the fact that it is measured as a discrete one. The [0,10] scale is partitioned in as many contiguous parts as the number of possible ratings in the primary scale sums up to. Any subject with a (self-perceived) happiness in the same subinterval is assumed to select the same response. For the probability density function of this happiness random variable, two options are discussed. The first one postulates a uniform distribution within each of the different subintervals of the [0,10] scale. On the basis of these results, the mean value and variance of the complete distribution can be estimated. The method is described, including the precision of the estimates obtained in this way. The second option assumes the happiness distribution to be described

  4. Dissociating Temporal Preparation Processes as a Function of the Inter-Trial Interval Duration

    ERIC Educational Resources Information Center

    Vallesi, Antonino; Lozano, Violeta N.; Correa, Angel

    2013-01-01

    Preparation over time is a ubiquitous capacity which implies decreasing uncertainty about when critical events will occur. This capacity is usually studied with the variable foreperiod paradigm, which consists in the random variation of the time interval (foreperiod) between a warning stimulus and a target. With this paradigm, response time (RT)…

  5. The patch microstructure in concrete: effect of mixing time

    SciTech Connect

    Diamond, Sidney . E-Mail: diamond@ecn.purdue.edu

    2005-05-01

    It has been previously shown by backscatter-mode scanning electron microscopy (SEM) that various laboratory- and field-mixed concretes exhibit dense areas or patches of hardened cement paste (hcp) alternating with highly porous areas or patches. The present work represents an effort to establish whether this distinctive microstructure was a result of inadequate mixing. A conventional laboratory concrete was prepared and subjected to prolonged mixing in an efficient pan mixer, with small samples being removed periodically, compacted, and cured for 28 days. Examination indicated that evidences of the patchy microstructure persisted despite prolonged mixing for up to 30 min, far beyond normal concrete mixing times.

  6. Multiresolution Wavelet Analysis of Heartbeat Intervals Discriminates Healthy Patients from Those with Cardiac Pathology

    NASA Astrophysics Data System (ADS)

    Thurner, Stefan; Feurstein, Markus C.; Teich, Malvin C.

    1998-02-01

    We applied multiresolution wavelet analysis to the sequence of times between human heartbeats ( R-R intervals) and have found a scale window, between 16 and 32 heartbeat intervals, over which the widths of the R-R wavelet coefficients fall into disjoint sets for normal and heart-failure patients. This has enabled us to correctly classify every patient in a standard data set as belonging either to the heart-failure or normal group with 100% accuracy, thereby providing a clinically significant measure of the presence of heart failure from the R-R intervals alone. Comparison is made with previous approaches, which have provided only statistically significant measures.

  7. Effect of temporal sampling and timing for soil moisture measurements at field scale

    NASA Astrophysics Data System (ADS)

    Snapir, B.; Hobbs, S.

    2012-04-01

    Estimating soil moisture at field scale is valuable for various applications such as irrigation scheduling in cultivated watersheds, flood and drought prediction, waterborne disease spread assessment, or even determination of mobility with lightweight vehicles. Synthetic aperture radar on satellites in low Earth orbit can provide fine resolution images with a repeat time of a few days. For an Earth observing satellite, the choice of the orbit is driven in particular by the frequency of measurements required to meet a certain accuracy in retrieving the parameters of interest. For a given target, having only one image every week may not enable to capture the full dynamic range of soil moisture - soil moisture can change significantly within a day when rainfall occurs. Hence this study focuses on the effect of temporal sampling and timing of measurements in terms of error on the retrieved signal. All the analyses are based on in situ measurements of soil moisture (acquired every 30 min) from the OzNet Hydrological Monitoring Network in Australia for different fields over several years. The first study concerns sampling frequency. Measurements at different frequencies were simulated by sub-sampling the original data. Linear interpolation was used to estimate the missing intermediate values, and then this time series was compared to the original. The difference between these two signals is computed for different levels of sub-sampling. Results show that the error increases linearly when the interval is less than 1 day. For intervals longer than a day, a sinusoidal component appears on top of the linear growth due to the diurnal variation of surface soil moisture. Thus, for example, the error with measurements every 4.5 days can be slightly less than the error with measurements every 2 days. Next, for a given sampling interval, this study evaluated the effect of the time during the day at which measurements are made. Of course when measurements are very frequent the time

  8. The effect of instrumental timbre on interval discrimination.

    PubMed

    Zarate, Jean Mary; Ritson, Caroline R; Poeppel, David

    2013-01-01

    We tested non-musicians and musicians in an auditory psychophysical experiment to assess the effects of timbre manipulation on pitch-interval discrimination. Both groups were asked to indicate the larger of two presented intervals, comprised of four sequentially presented pitches; the second or fourth stimulus within a trial was either a sinusoidal (or "pure"), flute, piano, or synthetic voice tone, while the remaining three stimuli were all pure tones. The interval-discrimination tasks were administered parametrically to assess performance across varying pitch distances between intervals ("interval-differences"). Irrespective of timbre, musicians displayed a steady improvement across interval-differences, while non-musicians only demonstrated enhanced interval discrimination at an interval-difference of 100 cents (one semitone in Western music). Surprisingly, the best discrimination performance across both groups was observed with pure-tone intervals, followed by intervals containing a piano tone. More specifically, we observed that: 1) timbre changes within a trial affect interval discrimination; and 2) the broad spectral characteristics of an instrumental timbre may influence perceived pitch or interval magnitude and make interval discrimination more difficult. PMID:24066179

  9. Proceedings of the 12th Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting

    NASA Technical Reports Server (NTRS)

    Wardrip, S. C. (Editor)

    1981-01-01

    The meeting gave PTTI managers, systems engineers, and program planners a transparent view of the state-of-the-art, an opportunity to express needs, a view of important future trends, and a review of relevant past accomplishments. The PTTI users were provided with new and useful applications, procedures, and techniques. Emphasis is placed on military applications and avionics.

  10. Information geometry of interspike intervals in spiking neurons.

    PubMed

    Ikeda, Kazushi

    2005-12-01

    An information geometrical method is developed for characterizing or classifying neurons in cortical areas, whose spike rates fluctuate in time. Under the assumption that the interspike intervals of a spike sequence of a neuron obey a gamma process with a time-variant spike rate and a fixed shape parameter, we formulate the problem of characterization as a semiparametric statistical estimation, where the spike rate is a nuisance parameter. We derive optimal criteria from the information geometrical viewpoint when certain assumptions are added to the formulation, and we show that some existing measures, such as the coefficient of variation and the local variation, are expressed as estimators of certain functions under the same assumptions. PMID:16212769

  11. Method of high precision interval measurement in pulse laser ranging system

    NASA Astrophysics Data System (ADS)

    Wang, Zhen; Lv, Xin-yuan; Mao, Jin-jin; Liu, Wei; Yang, Dong

    2013-09-01

    Laser ranging is suitable for laser system, for it has the advantage of high measuring precision, fast measuring speed,no cooperative targets and strong resistance to electromagnetic interference,the measuremen of laser ranging is the key paremeters affecting the performance of the whole system.The precision of the pulsed laser ranging system was decided by the precision of the time interval measurement, the principle structure of laser ranging system was introduced, and a method of high precision time interval measurement in pulse laser ranging system was established in this paper.Based on the analysis of the factors which affected the precision of range measure,the pulse rising edges discriminator was adopted to produce timing mark for the start-stop time discrimination,and the TDC-GP2 high precision interval measurement system based on TMS320F2812 DSP was designed to improve the measurement precision.Experimental results indicate that the time interval measurement method in this paper can obtain higher range accuracy. Compared with the traditional time interval measurement system,the method simplifies the system design and reduce the influence of bad weather conditions,furthermore,it satisfies the requirements of low costs and miniaturization.

  12. Confidence Intervals Make a Difference: Effects of Showing Confidence Intervals on Inferential Reasoning

    ERIC Educational Resources Information Center

    Hoekstra, Rink; Johnson, Addie; Kiers, Henk A. L.

    2012-01-01

    The use of confidence intervals (CIs) as an addition or as an alternative to null hypothesis significance testing (NHST) has been promoted as a means to make researchers more aware of the uncertainty that is inherent in statistical inference. Little is known, however, about whether presenting results via CIs affects how readers judge the…

  13. Extended score interval in the assessment of basic surgical skills

    PubMed Central

    Acosta, Stefan; Sevonius, Dan; Beckman, Anders

    2015-01-01

    Introduction The Basic Surgical Skills course uses an assessment score interval of 0–3. An extended score interval, 1–6, was proposed by the Swedish steering committee of the course. The aim of this study was to analyze the trainee scores in the current 0–3 scored version compared to a proposed 1–6 scored version. Methods Sixteen participants, seven females and nine males, were evaluated in the current and proposed assessment forms by instructors, observers, and learners themselves during the first and second day. In each assessment form, 17 tasks were assessed. The inter-rater reliability between the current and the proposed score sheets were evaluated with intraclass correlation (ICC) with 95% confidence intervals (CI). Results The distribution of scores for ‘knot tying’ at the last time point and ‘bowel anastomosis side to side’ given by the instructors in the current assessment form showed that the highest score was given in 31 and 62%, respectively. No ceiling effects were found in the proposed assessment form. The overall ICC between the current and proposed score sheets after assessment by the instructors increased from 0.38 (95% CI 0.77–0.78) on Day 1 to 0.83 (95% CI 0.51–0.94) on Day 2. Discussion A clear ceiling effect of scores was demonstrated in the current assessment form, questioning its validity. The proposed score sheet provides more accurate scores and seems to be a better feedback instrument for learning technical surgical skills in the Basic Surgical Skills course. PMID:25636607

  14. Comparison of Cardiorespiratory and Metabolic Responses in Kettlebell High-Intensity Interval Training Versus Sprint Interval Cycling.

    PubMed

    Williams, Brian M; Kraemer, Robert R

    2015-12-01

    The purpose of this study was to determine the effectiveness of a novel exercise protocol we developed for kettlebell high-intensity interval training (KB-HIIT) by comparing the cardiorespiratory and metabolic responses to a standard sprint interval cycling (SIC) exercise protocol. Eight men volunteered for the study and completed 2 preliminary sessions, followed by two 12-minute sessions of KB-HIIT and SIC in a counterbalanced fashion. In the KB-HITT session, 3 circuits of 4 exercises were performed using a Tabata regimen. In the SIC session, three 30-second sprints were performed, with 4 minutes of recovery in between the first 2 sprints and 2.5 minutes of recovery after the last sprint. A within-subjects' design over multiple time points was used to compare oxygen consumption (V[Combining Dot Above]O2), respiratory exchange ratio (RER), tidal volume (TV), breathing frequency (f), minute ventilation (VE), caloric expenditure rate (kcal·min), and heart rate (HR) between the exercise protocols. Additionally, total caloric expenditure was compared. A significant group effect, time effect, and group × time interaction were found for V[Combining Dot Above]O2, RER, and TV, with V[Combining Dot Above]O2 being higher and TV and RER being lower in the KB-HIIT compared with the SIC. Only a significant time effect and group × time interaction were found for f, VE, kcal·min, and HR. Additionally, total caloric expenditure was found to be significantly higher during the KB-HIIT. The results of this study suggest that KB-HIIT may be more attractive and sustainable than SIC and can be effective in stimulating cardiorespiratory and metabolic responses that could improve health and aerobic performance. PMID:26360962

  15. A centrifugal direct recombinase polymerase amplification (direct-RPA) microdevice for multiplex and real-time identification of food poisoning bacteria.

    PubMed

    Choi, Goro; Jung, Jae Hwan; Park, Byung Hyun; Oh, Seung Jun; Seo, Ji Hyun; Choi, Jong Seob; Kim, Do Hyun; Seo, Tae Seok

    2016-06-21

    In this study, we developed a centrifugal direct recombinase polymerase amplification (direct-RPA) microdevice for multiplex and real-time identification of food poisoning bacteria contaminated milk samples. The microdevice was designed to contain identical triplicate functional units and each unit has four reaction chambers, thereby making it possible to perform twelve direct-RPA reactions simultaneously. The integrated microdevice consisted of two layers: RPA reagents were injected in the top layer, while spiked milk samples with food poisoning bacteria were loaded into sample reservoirs in the bottom layer. For multiplex bacterial detection, the target gene-specific primers and probes were dried in each reaction chamber. The introduced samples and reagents could be equally aliquoted and dispensed into each reaction chamber by centrifugal force, and then the multiplex direct-RPA reaction was executed. The target genes of bacteria spiked in milk could be amplified at 39 °C without a DNA extraction step by using the direct-RPA cocktails, which were a combination of a direct PCR buffer and RPA enzymes. As the target gene amplification proceeded, the increased fluorescence signals coming from the reaction chambers were recorded in real-time at an interval of 2 min. The entire process, including the sample distribution, the direct-RPA reaction, and the real-time analysis, was accomplished with a custom-made portable genetic analyzer and a miniaturized optical detector. Monoplex, duplex, and triplex food poisoning bacteria (Salmonella enterica, Escherichia coli O157:H7, and Vibrio parahaemolyticus) detection was successfully performed with a detection sensitivity of 4 cells per 3.2 μL of milk samples within 30 min. By implementing the direct-PRA on the miniaturized centrifugal microsystem, the on-site food poisoning bacteria analysis would be feasible with high speed, sensitivity, and multiplicity. PMID:27216297

  16. Pitch strength of regular-interval click trains with different length “runs” of regular intervals

    PubMed Central

    Yost, William A.; Mapes-Riordan, Dan; Shofner, William; Dye, Raymond; Sheft, Stanley

    2009-01-01

    Click trains were generated with first- and second-order statistics following Kaernbach and Demany [J. Acoust. Soc. Am. 104, 2298–2306 (1998)]. First-order intervals are between successive clicks, while second-order intervals are those between every other click. Click trains were generated with a repeating alternation of fixed and random intervals which produce a pitch at the reciprocal of the duration of the fixed interval. The intervals were then randomly shuffled and compared to the unshuffled, alternating click trains in pitch-strength comparison experiments. In almost all comparisons for the first-order interval stimuli, the shuffled-interval click trains had a stronger pitch strength than the unshuffled-interval click trains. The shuffled-interval click trains only produced stronger pitches for second-order interval stimuli when the click trains were unfiltered. Several experimental conditions and an analysis of runs of regular and random intervals in these click trains suggest that the auditory system is sensitive to runs of regular intervals in a stimulus that contains a mix of regular and random intervals. These results indicate that fine-structure regularity plays a more important role in pitch perception than randomness, and that the long-term autocorrelation function or spectra of these click trains are not good predictors of pitch strength. PMID:15957774

  17. Maximum likelihood estimation for semiparametric transformation models with interval-censored data

    PubMed Central

    Zeng, Donglin; Mao, Lu; Lin, D. Y.

    2016-01-01

    Interval censoring arises frequently in clinical, epidemiological, financial and sociological studies, where the event or failure of interest is known only to occur within an interval induced by periodic monitoring. We formulate the effects of potentially time-dependent covariates on the interval-censored failure time through a broad class of semiparametric transformation models that encompasses proportional hazards and proportional odds models. We consider nonparametric maximum likelihood estimation for this class of models with an arbitrary number of monitoring times for each subject. We devise an EM-type algorithm that converges stably, even in the presence of time-dependent covariates, and show that the estimators for the regression parameters are consistent, asymptotically normal, and asymptotically efficient with an easily estimated covariance matrix. Finally, we demonstrate the performance of our procedures through simulation studies and application to an HIV/AIDS study conducted in Thailand. PMID:27279656

  18. About Hemispheric Differences in the Processing of Temporal Intervals

    ERIC Educational Resources Information Center

    Grondin, S.; Girard, C.

    2005-01-01

    The purpose of the present study was to identify differences between cerebral hemispheres for processing temporal intervals ranging from .9 to 1.4s. The intervals to be judged were marked by series of brief visual signals located in the left or the right visual field. Series of three (two standards and one comparison) or five intervals (four…

  19. 46 CFR 176.675 - Extension of examination intervals.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Extension of examination intervals. 176.675 Section 176... 100 GROSS TONS) INSPECTION AND CERTIFICATION Hull and Tailshaft Examinations § 176.675 Extension of examination intervals. The intervals between drydock examinations and internal structural...

  20. Application of Sequential Interval Estimation to Adaptive Mastery Testing

    ERIC Educational Resources Information Center

    Chang, Yuan-chin Ivan

    2005-01-01

    In this paper, we apply sequential one-sided confidence interval estimation procedures with beta-protection to adaptive mastery testing. The procedures of fixed-width and fixed proportional accuracy confidence interval estimation can be viewed as extensions of one-sided confidence interval procedures. It can be shown that the adaptive mastery…