Cueing listeners to attend to a target talker progressively improves word report as the duration of the cue-target interval lengthens to 2,000 ms.

PubMed

Holmes, Emma; Kitterick, Padraig T; Summerfield, A Quentin

2018-04-25

Endogenous attention is typically studied by presenting instructive cues in advance of a target stimulus array. For endogenous visual attention, task performance improves as the duration of the cue-target interval increases up to 800 ms. Less is known about how endogenous auditory attention unfolds over time or the mechanisms by which an instructive cue presented in advance of an auditory array improves performance. The current experiment used five cue-target intervals (0, 250, 500, 1,000, and 2,000 ms) to compare four hypotheses for how preparatory attention develops over time in a multi-talker listening task. Young adults were cued to attend to a target talker who spoke in a mixture of three talkers. Visual cues indicated the target talker's spatial location or their gender. Participants directed attention to location and gender simultaneously ("objects") at all cue-target intervals. Participants were consistently faster and more accurate at reporting words spoken by the target talker when the cue-target interval was 2,000 ms than 0 ms. In addition, the latency of correct responses progressively shortened as the duration of the cue-target interval increased from 0 to 2,000 ms. These findings suggest that the mechanisms involved in preparatory auditory attention develop gradually over time, taking at least 2,000 ms to reach optimal configuration, yet providing cumulative improvements in speech intelligibility as the duration of the cue-target interval increases from 0 to 2,000 ms. These results demonstrate an improvement in performance for cue-target intervals longer than those that have been reported previously in the visual or auditory modalities.

[Estimation of the atrioventricular time interval by pulse Doppler in the normal fetal heart].

PubMed

Hamela-Olkowska, Anita; Dangel, Joanna

2009-08-01

To assess normative values of the fetal atrioventricular (AV) time interval by pulse-wave Doppler methods on 5-chamber view. Fetal echocardiography exams were performed using Acuson Sequoia 512 in 140 singleton fetuses at 18 to 40 weeks of gestation with sinus rhythm and normal cardiac and extracardiac anatomy. Pulsed Doppler derived AV intervals were measured from left ventricular inflow/outflow view using transabdominal convex 3.5-6 MHz probe. The values of AV time interval ranged from 100 to 150 ms (mean 123 +/- 11.2). The AV interval was negatively correlated with the heart rhythm (p<0.001). Fetal heart rate decreased as gestation progressed (p<0.001). Thus, the AV intervals increased with the age of gestation (p=0.007). However, in the same subgroup of the fetal heart rate there was no relation between AV intervals and gestational age. Therefore, the AV intervals showed only the heart rate dependence. The 95th percentiles of AV intervals according to FHR ranged from 135 to 148 ms. 1. The AV interval duration was negatively correlated with the heart rhythm. 2. Measurement of AV time interval is easy to perform and has a good reproducibility. It may be used for the fetal heart block screening in anti-Ro and anti-La positive pregnancies. 3. Normative values established in the study may help obstetricians in assessing fetal abnormalities of the AV conduction.

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

PubMed Central

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. PMID:24135569

Aortic stiffness and the balance between cardiac oxygen supply and demand: the Rotterdam Study.

PubMed

Guelen, Ilja; Mattace-Raso, Francesco Us; van Popele, Nicole M; Westerhof, Berend E; Hofman, Albert; Witteman, Jacqueline Cm; Bos, Willem Jan W

2008-06-01

Aortic stiffness is an independent predictor of cardiovascular morbidity and mortality. We investigated whether aortic stiffness, estimated as aortic pulse wave velocity, is associated with decreased perfusion pressure estimated as the cardiac oxygen supply potential. Aortic stiffness and aortic pressure waves, reconstructed from finger blood pressure waves, were obtained in 2490 older adults within the framework of the Rotterdam Study, a large population-based study. Cardiac oxygen supply and demand were estimated using pulse wave analysis techniques, and related to aortic stiffness by linear regression analyses after adjustment for age, sex, mean arterial pressure and heart rate. Cardiac oxygen demand, estimated as the Systolic Pressure Time Index and the Rate Pressure Product, increased with increasing aortic stiffness [0.27 mmHg s (95% confidence interval: 0.21; 0.34)] and [42.2 mmHg/min (95% confidence interval: 34.1; 50.3)], respectively. Cardiac oxygen supply potential estimated as the Diastolic Pressure Time Index decreased [-0.70 mmHg s (95% confidence interval: -0.86; -0.54)] with aortic stiffening. Accordingly, the supply/demand ratio Diastolic Pressure Time Index/Systolic Pressure Time Index -1.11 (95% confidence interval: -0.14; -0.009) decreased with increasing aortic stiffness. Aortic stiffness is associated with estimates of increased cardiac oxygen demand and a decreased cardiac oxygen supply potential. These results may offer additional explanation for the relation between aortic stiffness and cardiovascular morbidity and mortality.

Time estimation by patients with frontal lesions and by Korsakoff amnesics.

PubMed

Mimura, M; Kinsbourne, M; O'Connor, M

2000-07-01

We studied time estimation in patients with frontal damage (F) and alcoholic Korsakoff (K) patients in order to differentiate between the contributions of working memory and episodic memory to temporal cognition. In Experiment 1, F and K patients estimated time intervals between 10 and 120 s less accurately than matched normal and alcoholic control subjects. F patients were less accurate than K patients at short (< 1 min) time intervals whereas K patients increasingly underestimated durations as intervals grew longer. F patients overestimated short intervals in inverse proportion to their performance on the Wisconsin Card Sorting Test. As intervals grew longer, overestimation yielded to underestimation for F patients. Experiment 2 involved time estimation while counting at a subjective 1/s rate. F patients' subjective tempo, though relatively rapid, did not fully explain their overestimation of short intervals. In Experiment 3, participants produced predetermined time intervals by depressing a mouse key. K patients underproduced longer intervals. F patients produced comparably to normal participants, but were extremely variable. Findings suggest that both working memory and episodic memory play an individual role in temporal cognition. Turnover within a short-term working memory buffer provides a metric for temporal decisions. The depleted working memory that typically attends frontal dysfunction may result in quicker turnover, and this may inflate subjective duration. On the other hand, temporal estimation beyond 30 s requires episodic remembering, and this puts K patients at a disadvantage.

Association between the physical activity and heart rate corrected-QT interval in older adults.

PubMed

Michishita, Ryoma; Fukae, Chika; Mihara, Rikako; Ikenaga, Masahiro; Morimura, Kazuhiro; Takeda, Noriko; Yamada, Yosuke; Higaki, Yasuki; Tanaka, Hiroaki; Kiyonaga, Akira

2015-07-01

Increased physical activity can reduce the incidence of cardiovascular disease and the mortality rate. In contrast, a prolonged heart rate corrected-QT (QTc) interval is associated with an increased risk of arrhythmias, sudden cardiac death and coronary artery disease. The present cross-sectional study was designed to clarify the association between the physical activity level and the QTc interval in older adults. The participants included 586 older adults (267 men and 319 women, age 71.2 ± 4.7 years) without a history of cardiovascular disease, who were taking cardioactive drugs. Electrocardiography was recorded with a standard resting 12-lead electrocardiograph, while the QTc interval was calculated according to Hodges' formula. The physical activity level was assessed using a triaxial accelerometer. The participants were divided into four categories, which were defined equally quartile distributions of the QTc interval. After adjusting for age, body mass index, waist circumference and the number of steps, the time spent in inactivity was higher and the time spent in light physical activity was significantly lower in the longest QTc interval group than in the shortest QTc interval group in both sexes (P < 0.05, respectively). However, there were no significant differences in the time spent in moderate and vigorous physical activities among the four groups in either sex. These results suggest that a decreased physical activity level, especially inactivity and light intensity physical activity, were associated with QTc interval in older adults. © 2014 Japan Geriatrics Society.

Swimming performance in juvenile shortnose sturgeon (Acipenser brevirostrum): the influence of time interval and velocity increments on critical swimming tests

PubMed Central

Kieffer, James D.

2017-01-01

Abstract The most utilized method to measure swimming performance of fishes has been the critical swimming speed (UCrit) test. In this test, the fish is forced to swim against an incrementally increasing flow of water until fatigue. Before the water velocity is increased, the fish swims at the water velocity for a specific, pre-arranged time interval. The magnitude of the velocity increments and the time interval for each swimming period can vary across studies making the comparison between and within species difficult. This issue has been acknowledged in the literature, however, little empirical evidence exists that tests the importance of velocity and time increments on swimming performance in fish. A practical application for fish performance is through the design of fishways that enable fish to bypass anthropogenic structures (e.g. dams) that block migration routes, which is one of the causes of world-wide decline in sturgeon populations. While fishways will improve sturgeon conservation, they need to be specifically designed to accommodate the swimming capabilities specific for sturgeons, and it is possible that current swimming methodologies have under-estimated the swimming performance of sturgeons. The present study assessed the UCrit of shortnose sturgeon using modified UCrit to determine the importance of velocity increment (5 and 10 cm s−1) and time (5, 15 and 30 min) intervals on swimming performance. UCrit was found to be influenced by both time interval and water velocity. UCrit was generally lower in sturgeon when they were swum using 5cm s−1 compared with 10 cm s−1 increments. Velocity increment influences the UCrit more than time interval. Overall, researchers must consider the impacts of using particular swimming criteria when designing their experiments. PMID:28835841

Observer Error when Measuring Safety-Related Behavior: Momentary Time Sampling versus Whole-Interval Recording

ERIC Educational Resources Information Center

Taylor, Matthew A.; Skourides, Andreas; Alvero, Alicia M.

2012-01-01

Interval recording procedures are used by persons who collect data through observation to estimate the cumulative occurrence and nonoccurrence of behavior/events. Although interval recording procedures can increase the efficiency of observational data collection, they can also induce error from the observer. In the present study, 50 observers were…

Time to diagnosis and treatment for cancer patients in the Netherlands: Room for improvement?

PubMed

Helsper, Charles C W; van Erp, Nicole N F; Peeters, Petra P H M; de Wit, Niek N J

2017-12-01

Reducing the duration of the diagnostic cancer care pathway is intensively pursued. The aim of this study was to chart the diagnostic pathway for the five most common cancers in the Netherlands. A retrospective cohort study using cancer patients' anonymised primary care data (free text and coded) linked to the Netherlands Cancer Registry. We determined the median duration of the following: 1. Primary care intervals (IPCs): the first cancer-related general practitioner consultation to referral, 2. Referral intervals (IRs): referral to diagnosis, 3. Treatment intervals (ITs): diagnosis to treatment and the overarching intervals, 4. Diagnostic intervals (IDs): IPC and IR combined and 5. Health care intervals (IHCs): IPC, IR and IT combined. For 465, 309, 197, 237 and 149 patients diagnosed with breast-, colorectal-, lung-, prostate cancer and melanoma, respectively; median IPC, IR and ID durations were shortest for breast cancer and melanoma (ID duration 7 and 21 days, respectively), intermediate for lung- and colon cancer (ID duration 49 and 54 days) and the longest for prostate cancer (ID duration 137 days). For all cancers, the duration of intervals increased steeply for the 10-25% with longest durations. For colorectal cancer, increasing ID durations showed increasing proportions of time attributable to primary care (IPC). Approximately 10-25% of cancer patients show substantially long duration of diagnostic intervals. Reducing primary care delay seems particularly relevant for colorectal cancer. Copyright © 2017 Elsevier Ltd. All rights reserved.

Human sinus arrhythmia as an index of vagal cardiac outflow

NASA Technical Reports Server (NTRS)

Eckberg, D. L.

1983-01-01

The human central vagal mechanisms were investigated by measuring the intervals between heartbeats during controlled breathing (at breathing intervals of 2.5-10 s and nominal tidal volumes of 1000 and 1500 ml) in six young men and women. It was found that as the breathing interval increased, the longest heart periods became longer, the shortest heart periods became shorter, and the peak-valley P-P intervals increased asymptotically. Peak-valley intervals also increased in proportion to tidal volume, although this influence was small. The phase angles between heart period changes and respiration were found to vary as linear functions of breathing interval. Heart period shortening began in inspiration at short breathing intervals and in expiration at long breathing intervals, while heart period lengthening began in early expiration at all breathing intervals studied. It is concluded that a close relationship exists between variations of respiratory depth and interval and the quantity, periodicity, and timing of vagal cardiac outflow in conscious humans. The results indicate that at usual breathing rates, phasic respiration-related changes of vagal motoneuron activity begin in expiration, progress slowly, and are incompletely expressed at fast breathing ratges.

Bayesian lead time estimation for the Johns Hopkins Lung Project data.

PubMed

Jang, Hyejeong; Kim, Seongho; Wu, Dongfeng

2013-09-01

Lung cancer screening using X-rays has been controversial for many years. A major concern is whether lung cancer screening really brings any survival benefits, which depends on effective treatment after early detection. The problem was analyzed from a different point of view and estimates were presented of the projected lead time for participants in a lung cancer screening program using the Johns Hopkins Lung Project (JHLP) data. The newly developed method of lead time estimation was applied where the lifetime T was treated as a random variable rather than a fixed value, resulting in the number of future screenings for a given individual is a random variable. Using the actuarial life table available from the United States Social Security Administration, the lifetime distribution was first obtained, then the lead time distribution was projected using the JHLP data. The data analysis with the JHLP data shows that, for a male heavy smoker with initial screening ages at 50, 60, and 70, the probability of no-early-detection with semiannual screens will be 32.16%, 32.45%, and 33.17%, respectively; while the mean lead time is 1.36, 1.33 and 1.23 years. The probability of no-early-detection increases monotonically when the screening interval increases, and it increases slightly as the initial age increases for the same screening interval. The mean lead time and its standard error decrease when the screening interval increases for all age groups, and both decrease when initial age increases with the same screening interval. The overall mean lead time estimated with a random lifetime T is slightly less than that with a fixed value of T. This result is hoped to be of benefit to improve current screening programs. Copyright © 2013 Ministry of Health, Saudi Arabia. Published by Elsevier Ltd. All rights reserved.

Temporal structure in the light response of relay cells in the dorsal lateral geniculate nucleus of the cat.

PubMed Central

Funke, K; Wörgötter, F

1995-01-01

1. The spike interval pattern during the light responses of 155 on- and 81 off-centre cells of the dorsal lateral geniculate nucleus (LGN) was studied in anaesthetized and paralysed cats by the use of a novel analysis. Temporally localized interval distributions were computed from a 100 ms time window, which was shifted along the time axis in 10 ms steps, resulting in a 90% overlap between two adjacent windows. For each step the interval distribution was computed inside the time window with 1 ms resolution, and plotted as a greyscale-coded pixel line orthogonal to the time axis. For visual stimulation, light or dark spots of different size and contrast were presented with different background illumination levels. 2. Two characteristic interval patterns were observed during the sustained response component of the cells. Mainly on-cells (77%) responded with multimodal interval distributions, resulting in elongated 'bands' in the 2-dimensional time window plots. In similar situations, the interval distributions for most (71%) off-cells were rather wide and featureless. In those cases where interval bands (i.e. multimodal interval distributions) were observed for off-cells (14%), they were always much wider than for the on-cells. This difference between the on- and off-cell population was independent of the background illumination and the contrast of the stimulus. Y on-cells also tended to produce wider interval bands than X on-cells. 3. For most stimulation situations the first interval band was centred around 6-9 ms, which has been called the fundamental interval; higher order bands are multiples thereof. The fundamental interval shifted towards larger sizes with decreasing stimulus contrast. Increasing stimulus size, on the other hand, resulted in a redistribution of the intervals into higher order bands, while at the same time the location of the fundamental interval remained largely unaffected. This was interpreted as an effect of the increasing surround inhibition at the geniculate level, by which individual retinal EPSPs were cancelled. A changing level of adaptation can result in a mixed shift/redistribution effect because of the changing stimulus contrast and changing level of tonic inhibition. 4. The occurrence of interval bands is not directly related to the shape of the autocorrelation function, which can be flat, weakly oscillatory or strongly oscillatory, regardless of the interval band pattern. 5. A simple computer model was devised to account for the observed cell behaviour. The model is highly robust against parameter variations.(ABSTRACT TRUNCATED AT 400 WORDS) Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 15 PMID:7562612

On cell resistance and immune response time lag in a model for the HIV infection

NASA Astrophysics Data System (ADS)

Solovey, Guillermo; Peruani, Fernando; Ponce Dawson, Silvina; Maria Zorzenon dos Santos, Rita

2004-11-01

Recently, a cellular automata model has been introduced (Phys. Rev. Lett. 87 (2001) 168102) to describe the spread of the HIV infection among target cells in lymphoid tissues. The model reproduces qualitatively the entire course of the infection displaying, in particular, the two time scales that characterize its dynamics. In this work, we investigate the robustness of the model against changes in three of its parameters. Two of them are related to the resistance of the cells to get infected. The other one describes the time interval necessary to mount specific immune responses. We have observed that an increase of the cell resistance, at any stage of the infection, leads to a reduction of the latency period, i.e., of the time interval between the primary infection and the onset of AIDS. However, during the early stages of the infection, when the cell resistance increase is combined with an increase in the initial concentration of infected cells, the original behavior is recovered. Therefore we find a long and a short latency regime (eight and one year long, respectively) depending on the value of the cell resistance. We have obtained, on the other hand, that changes on the parameter that describes the immune system time lag affects the time interval during which the primary infection occurs. Using different extended versions of the model, we also discuss how the two-time scale dynamics is affected when we include inhomogeneities on the cells properties, as for instance, on the cell resistance or on the time interval to mount specific immune responses.

Hospital factors impact variation in emergency department length of stay more than physician factors.

PubMed

Krall, Scott P; Cornelius, Angela P; Addison, J Bruce

2014-03-01

To analyze the correlation between the many different emergency department (ED) treatment metric intervals and determine if the metrics directly impacted by the physician correlate to the "door to room" interval in an ED (interval determined by ED bed availability). Our null hypothesis was that the cause of the variation in delay to receiving a room was multifactorial and does not correlate to any one metric interval. We collected daily interval averages from the ED information system, Meditech©. Patient flow metrics were collected on a 24-hour basis. We analyzed the relationship between the time intervals that make up an ED visit and the "arrival to room" interval using simple correlation (Pearson Correlation coefficients). Summary statistics of industry standard metrics were also done by dividing the intervals into 2 groups, based on the average ED length of stay (LOS) from the National Hospital Ambulatory Medical Care Survey: 2008 Emergency Department Summary. Simple correlation analysis showed that the doctor-to-discharge time interval had no correlation to the interval of "door to room (waiting room time)", correlation coefficient (CC) (CC=0.000, p=0.96). "Room to doctor" had a low correlation to "door to room" CC=0.143, while "decision to admitted patients departing the ED time" had a moderate correlation of 0.29 (p <0.001). "New arrivals" (daily patient census) had a strong correlation to longer "door to room" times, 0.657, p<0.001. The "door to discharge" times had a very strong correlation CC=0.804 (p<0.001), to the extended "door to room" time. Physician-dependent intervals had minimal correlation to the variation in arrival to room time. The "door to room" interval was a significant component to the variation in "door to discharge" i.e. LOS. The hospital-influenced "admit decision to hospital bed" i.e. hospital inpatient capacity, interval had a correlation to delayed "door to room" time. The other major factor affecting department bed availability was the "total patients per day." The correlation to the increasing "door to room" time also reflects the effect of availability of ED resources (beds) on the patient evaluation time. The time that it took for a patient to receive a room appeared more dependent on the system resources, for example, beds in the ED, as well as in the hospital, than on the physician.

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 Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). The CLIPS expert system shell has been used as the main rule engine for implementing the algorithm rules. Python programming language and the module "PyCLIPS" are used for building the necessary code for algorithm implementation. More than 1.7 million intervals constitute the Concise List of Frames (CLF) from 20 different seismic stations have been used for evaluating the proposed algorithm and evaluating stations behaviour and performance. The initial results showed that proposed algorithm can help in better understanding of the operation and performance of those stations. Different important information, such as alerts and some station performance parameters, can be derived from the proposed algorithm. For IMS interval-based data and at any period of time it is possible to analyze station behavior, determine the missing data, generate necessary alerts, and to measure some of station performance attributes. The details of the proposed algorithm, methodology, implementation, experimental results, advantages, and limitations of this research are presented. Finally, future directions and recommendations are discussed.

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

PubMed Central

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

2012-01-01

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

Assessing and minimizing contamination in time of flight based validation data

NASA Astrophysics Data System (ADS)

Lennox, Kristin P.; Rosenfield, Paul; Blair, Brenton; Kaplan, Alan; Ruz, Jaime; Glenn, Andrew; Wurtz, Ronald

2017-10-01

Time of flight experiments are the gold standard method for generating labeled training and testing data for the neutron/gamma pulse shape discrimination problem. As the popularity of supervised classification methods increases in this field, there will also be increasing reliance on time of flight data for algorithm development and evaluation. However, time of flight experiments are subject to various sources of contamination that lead to neutron and gamma pulses being mislabeled. Such labeling errors have a detrimental effect on classification algorithm training and testing, and should therefore be minimized. This paper presents a method for identifying minimally contaminated data sets from time of flight experiments and estimating the residual contamination rate. This method leverages statistical models describing neutron and gamma travel time distributions and is easily implemented using existing statistical software. The method produces a set of optimal intervals that balance the trade-off between interval size and nuisance particle contamination, and its use is demonstrated on a time of flight data set for Cf-252. The particular properties of the optimal intervals for the demonstration data are explored in detail.

Long-term cardiovascular risk of nonsteroidal anti-inflammatory drug use according to time passed after first-time myocardial infarction: a nationwide cohort study.

PubMed

Olsen, Anne-Marie Schjerning; Fosbøl, Emil L; Lindhardsen, Jesper; Folke, Fredrik; Charlot, Mette; Selmer, Christian; Bjerring Olesen, Jonas; Lamberts, Morten; Ruwald, Martin H; Køber, Lars; Hansen, Peter R; Torp-Pedersen, Christian; Gislason, Gunnar H

2012-10-16

The cardiovascular risk after the first myocardial infarction (MI) declines rapidly during the first year. We analyzed whether the cardiovascular risk associated with using nonsteroidal anti-inflammatory drugs (NSAIDs) was associated with the time elapsed following first-time MI. We identified patients aged 30 years or older admitted with first-time MI in 1997 to 2009 and subsequent NSAID use by individual-level linkage of nationwide registries of hospitalization and drug dispensing from pharmacies in Denmark. We calculated the incidence rates of death and a composite end point of coronary death or nonfatal recurrent MIs associated with NSAID use in 1-year time intervals up to 5 years after inclusion and analyzed risk by using multivariable adjusted time-dependent Cox proportional hazards models. Of the 99 187 patients included, 43 608 (44%) were prescribed NSAIDs after the index MI. There were 36 747 deaths and 28 693 coronary deaths or nonfatal recurrent MIs during the 5 years of follow-up. Relative to noncurrent treatment with NSAIDs, the use of any NSAID in the years following MI was persistently associated with an increased risk of death (hazard ratio 1.59 [95% confidence interval, 1.49-1.69]) after 1 year and hazard ratio 1.63 [95% confidence interval, 1.52-1.74] after 5 years) and coronary death or nonfatal recurrent MI (hazard ratio, 1.30 [95% confidence interval,l 1.22-1.39] and hazard ratio, 1.41 [95% confidence interval, 1.28-1.55]). The use of NSAIDs is associated with persistently increased coronary risk regardless of time elapsed after first-time MI. We advise long-term caution in the use of NSAIDs for patients after MI.

Potential confounding in the association between short birth intervals and increased neonatal, infant, and child mortality

PubMed Central

Perin, Jamie; Walker, Neff

2015-01-01

Background Recent steep declines in child mortality have been attributed in part to increased use of contraceptives and the resulting change in fertility behaviour, including an increase in the time between births. Previous observational studies have documented strong associations between short birth spacing and an increase in the risk of neonatal, infant, and under-five mortality, compared to births with longer preceding birth intervals. In this analysis, we compare two methods to estimate the association between short birth intervals and mortality risk to better inform modelling efforts linking family planning and mortality in children. Objectives Our goal was to estimate the mortality risk for neonates, infants, and young children by preceding birth space using household survey data, controlling for mother-level factors and to compare the results to those from previous analyses with survey data. Design We assessed the potential for confounding when estimating the relative mortality risk by preceding birth interval and estimated mortality risk by birth interval in four categories: less than 18 months, 18–23 months, 24–35 months, and 36 months or longer. We estimated the relative risks among women who were 35 and older at the time of the survey with two methods: in a Cox proportional hazards regression adjusting for potential confounders and also by stratifying Cox regression by mother, to control for all factors that remain constant over a woman's childbearing years. We estimated the overall effects for birth spacing in a meta-analysis with random survey effects. Results We identified several factors known for their associations with neonatal, infant, and child mortality that are also associated with preceding birth interval. When estimating the effect of birth spacing on mortality, we found that regression adjustment for these factors does not substantially change the risk ratio for short birth intervals compared to an unadjusted mortality ratio. For birth intervals less than 18 months, standard regression adjustment for confounding factors estimated a risk ratio for neonatal mortality of 2.28 (95% confidence interval: 2.18–2.37). This same effect estimated within mother is 1.57 (95% confidence interval: 1.52–1.63), a decline of almost one-third in the effect on neonatal mortality. Conclusions Neonatal, infant, and child mortality are strongly and significantly related to preceding birth interval, where births within a short interval of time after the previous birth have increased mortality. Previous analyses have demonstrated this relationship on average across all births; however, women who have short spaces between births are different from women with long spaces. Among women 35 years and older where a comparison of birth spaces within mother is possible, we find a much reduced although still significant effect of short birth spaces on child mortality. PMID:26562139

Potential confounding in the association between short birth intervals and increased neonatal, infant, and child mortality.

PubMed

Perin, Jamie; Walker, Neff

2015-01-01

Recent steep declines in child mortality have been attributed in part to increased use of contraceptives and the resulting change in fertility behaviour, including an increase in the time between births. Previous observational studies have documented strong associations between short birth spacing and an increase in the risk of neonatal, infant, and under-five mortality, compared to births with longer preceding birth intervals. In this analysis, we compare two methods to estimate the association between short birth intervals and mortality risk to better inform modelling efforts linking family planning and mortality in children. Our goal was to estimate the mortality risk for neonates, infants, and young children by preceding birth space using household survey data, controlling for mother-level factors and to compare the results to those from previous analyses with survey data. We assessed the potential for confounding when estimating the relative mortality risk by preceding birth interval and estimated mortality risk by birth interval in four categories: less than 18 months, 18-23 months, 24-35 months, and 36 months or longer. We estimated the relative risks among women who were 35 and older at the time of the survey with two methods: in a Cox proportional hazards regression adjusting for potential confounders and also by stratifying Cox regression by mother, to control for all factors that remain constant over a woman's childbearing years. We estimated the overall effects for birth spacing in a meta-analysis with random survey effects. We identified several factors known for their associations with neonatal, infant, and child mortality that are also associated with preceding birth interval. When estimating the effect of birth spacing on mortality, we found that regression adjustment for these factors does not substantially change the risk ratio for short birth intervals compared to an unadjusted mortality ratio. For birth intervals less than 18 months, standard regression adjustment for confounding factors estimated a risk ratio for neonatal mortality of 2.28 (95% confidence interval: 2.18-2.37). This same effect estimated within mother is 1.57 (95% confidence interval: 1.52-1.63), a decline of almost one-third in the effect on neonatal mortality. Neonatal, infant, and child mortality are strongly and significantly related to preceding birth interval, where births within a short interval of time after the previous birth have increased mortality. Previous analyses have demonstrated this relationship on average across all births; however, women who have short spaces between births are different from women with long spaces. Among women 35 years and older where a comparison of birth spaces within mother is possible, we find a much reduced although still significant effect of short birth spaces on child mortality.

Digestive tract evacuation in northern squawfish (Ptychocheilus oregonensis)

USGS Publications Warehouse

Beyer, J.M.; Lucchetti, G.; Gray, G.

1988-01-01

Digestive tract evacuation in northern squawfish (Ptychocheilus oregonensis) (170–1900 g) was studied in fish allowed to feed voluntarily on salmon (4–70 g) at three water temperatures (10, 15, and 20 °C). Squawfish were sacrificed at 1- or 2-h intervals until evacuation approximated 90%. Amount of food evacuated for a given time interval increased approximately three times as the temperature was increased and as the prey weight was increased and two times as the predator weight was increased. The 90% emptying time (ET90) decreased by about two thirds as the temperature doubled and by about one half as the predator weight increased 10 times, but approximately doubled when the prey weight increased 4 times. Two-fish meals (17–20 g each, 35–39 g total) were evacuated more slowly than meals of one fish weighing 17–20 g, but at the same rate as meals of one fish weighing 35–40 g. Equations derived are easily applied to a wide range of water temperatures, prey weights, and predator weights.

The effect of hospital care on early survival after penetrating trauma.

PubMed

Clark, David E; Doolittle, Peter C; Winchell, Robert J; Betensky, Rebecca A

2014-12-01

The effectiveness of emergency medical interventions can be best evaluated using time-to-event statistical methods with time-varying covariates (TVC), but this approach is complicated by uncertainty about the actual times of death. We therefore sought to evaluate the effect of hospital intervention on mortality after penetrating trauma using a method that allowed for interval censoring of the precise times of death. Data on persons with penetrating trauma due to interpersonal assault were combined from the 2008 to 2010 National Trauma Data Bank (NTDB) and the 2004 to 2010 National Violent Death Reporting System (NVDRS). Cox and Weibull proportional hazards models for survival time (t SURV ) were estimated, with TVC assumed to have constant effects for specified time intervals following hospital arrival. The Weibull model was repeated with t SURV interval-censored to reflect uncertainty about the precise times of death, using an imputation method to accommodate interval censoring along with TVC. All models showed that mortality was increased by older age, female sex, firearm mechanism, and injuries involving the head/neck or trunk. Uncensored models showed a paradoxical increase in mortality associated with the first hour in a hospital. The interval-censored model showed that mortality was markedly reduced after admission to a hospital, with a hazard ratio (HR) of 0.68 (95% CI 0.63, 0.73) during the first 30 min declining to a HR of 0.01 after 120 min. Admission to a verified level I trauma center (compared to other hospitals in the NTDB) was associated with a further reduction in mortality, with a HR of 0.93 (95% CI 0.82, 0.97). Time-to-event models with TVC and interval censoring can be used to estimate the effect of hospital care on early mortality after penetrating trauma or other acute medical conditions and could potentially be used for interhospital comparisons.

Estimating short-run and long-run interaction mechanisms in interictal state.

PubMed

Ozkaya, Ata; Korürek, Mehmet

2010-04-01

We address the issue of analyzing electroencephalogram (EEG) from seizure patients in order to test, model and determine the statistical properties that distinguish between EEG states (interictal, pre-ictal, ictal) by introducing a new class of time series analysis methods. In the present study: firstly, we employ statistical methods to determine the non-stationary behavior of focal interictal epileptiform series within very short time intervals; secondly, for such intervals that are deemed non-stationary we suggest the concept of Autoregressive Integrated Moving Average (ARIMA) process modelling, well known in time series analysis. We finally address the queries of causal relationships between epileptic states and between brain areas during epileptiform activity. We estimate the interaction between different EEG series (channels) in short time intervals by performing Granger-causality analysis and also estimate such interaction in long time intervals by employing Cointegration analysis, both analysis methods are well-known in econometrics. Here we find: first, that the causal relationship between neuronal assemblies can be identified according to the duration and the direction of their possible mutual influences; second, that although the estimated bidirectional causality in short time intervals yields that the neuronal ensembles positively affect each other, in long time intervals neither of them is affected (increasing amplitudes) from this relationship. Moreover, Cointegration analysis of the EEG series enables us to identify whether there is a causal link from the interictal state to ictal state.

Effect of gender and sports on the risk of full-thickness articular cartilage lesions in anterior cruciate ligament-injured knees: a nationwide cohort study from Sweden and Norway of 15 783 patients.

PubMed

Røtterud, Jan Harald; Sivertsen, Einar A; Forssblad, Magnus; Engebretsen, Lars; Årøen, Asbjørn

2011-07-01

The presence of an articular cartilage lesion in anterior cruciate ligament-injured knees is considered a predictor of osteoarthritis. This study was undertaken to evaluate risk factors for full-thickness articular cartilage lesions in anterior cruciate ligament-injured knees, in particular the role of gender and the sport causing the initial injury. Cohort study (prognosis); Level of evidence, 2. Primary unilateral anterior cruciate ligament reconstructions prospectively registered in the Swedish and the Norwegian National Knee Ligament Registry during 2005 through 2008 were included (N = 15 783). Logistic regression analyses were used to evaluate risk factors for cartilage lesions. A total of 1012 patients (6.4%) had full-thickness cartilage lesions. The median time from injury to surgery was 9 months (range, 0 days-521 months). Male patients had an increased odds of full-thickness cartilage lesions compared with females (odds ratio = 1.22; 95% confidence interval, 1.04-1.42). In males, team handball had an increase in the odds of full-thickness cartilage lesions compared with soccer (odds ratio = 2.36; 95% confidence interval, 1.33-4.19). Among female patients, no sport investigated showed a significant decrease or increase in the odds of full-thickness cartilage lesions. The odds of a full-thickness cartilage lesion increased by 1.006 (95% confidence interval, 1.005-1.008) for each month elapsed from time of injury until anterior cruciate ligament reconstruction when all patients were considered, while time from injury to surgery did not affect the odds significantly in those patients reconstructed within 1 year of injury (odds ratio = 0.98; 95% confidence interval, 0.95-1.02). Previous surgery increased the odds of having a full-thickness cartilage lesion (odds ratio = 1.40; 95% confidence interval, 1.21-1.63). One year of increasing patient age also increased the odds (odds ratio = 1.05; 95% confidence interval, 1.05-1.06). Male gender is associated with an increased risk of full-thickness articular cartilage lesions in anterior cruciate ligament-injured knees. Male team handball players had an increased risk of full-thickness lesions. No other sports investigated were found to have significant effect on the risk in either gender. Furthermore, age, previous surgery, and time from injury to surgery exceeding 12 months are risk factors for full-thickness cartilage lesions.

Experiment Description and Results for Arrival Operations Using Interval Management with Spacing to Parallel Dependent Runways (IMSPiDR)

NASA Technical Reports Server (NTRS)

Baxley, Brian T.; Murdoch, Jennifer L.; Swieringa, Kurt A.; Barmore, Bryan E.; Capron, William R.; Hubbs, Clay E.; Shay, Richard F.; Abbott, Terence S.

2013-01-01

The predicted increase in the number of commercial aircraft operations creates a need for improved operational efficiency. Two areas believed to offer increases in aircraft efficiency are optimized profile descents and dependent parallel runway operations. Using Flight deck Interval Management (FIM) software and procedures during these operations, flight crews can achieve by the runway threshold an interval assigned by air traffic control (ATC) behind the preceding aircraft that maximizes runway throughput while minimizing additional fuel consumption and pilot workload. This document describes an experiment where 24 pilots flew arrivals into the Dallas Fort-Worth terminal environment using one of three simulators at NASA?s Langley Research Center. Results indicate that pilots delivered their aircraft to the runway threshold within +/- 3.5 seconds of their assigned time interval, and reported low workload levels. In general, pilots found the FIM concept, procedures, speeds, and interface acceptable. Analysis of the time error and FIM speed changes as a function of arrival stream position suggest the spacing algorithm generates stable behavior while in the presence of continuous (wind) or impulse (offset) error. Concerns reported included multiple speed changes within a short time period, and an airspeed increase followed shortly by an airspeed decrease.

Effect of time of day and duration into shift on hazardous exposures to biological fluids.

PubMed

Macias, D J; Hafner, J; Brillman, J C; Tandberg, D

1996-06-01

To determine whether hospital employee biological hazardous exposure rates varied with time of day or increased with time interval into shift. This was a retrospective occurrence report review conducted at a university hospital with an emergency medicine residency program. Health care worker biological hazardous exposure data over a 30-month period were reviewed. Professional status, date, time, and type of exposure (needlestick, laceration, splash), time interval into shift of exposure, and hospital location of exposure were recorded. Hourly employee counts and risky procedure counts were matched by location with each reported exposure, to determine hourly rates of biological hazardous exposures. Analysis of 411 recorded exposures demonstrated that more people were exposed between 9:00 AM and 11:00 AM (p < 0.05), yet the exposure risk did not vary significantly when expressed as the number of exposures per worker or per procedure. Of the 393 exposures with data describing time interval into shift when the exposure occurred, significant numbers of exposures occurred during the first hour and at shift's end [when corrected for exposures per worker (p < 0.05) or exposures per procedure (p < 0.05)]. While the number of exposures are increased in the AM hours, the exposure rate (as a function of workers or procedures) does not vary with time of the day. However, the exposure rate is increased during the first hour and last 2 hours of a shift. Efforts to increase worker precautions at the beginning and end of shifts are warranted.

Waning vaccine protection against influenza A (H3N2) illness in children and older adults during a single season.

PubMed

Belongia, Edward A; Sundaram, Maria E; McClure, David L; Meece, Jennifer K; Ferdinands, Jill; VanWormer, Jeffrey J

2015-01-01

Recent studies have suggested that vaccine-induced protection against influenza may decline within one season. We reanalyzed data from a study of influenza vaccine effectiveness to determine if time since vaccination was an independent predictor of influenza A (H3N2). Patients with acute respiratory illness were actively recruited during the 2007-2008 season. Respiratory swabs were tested for influenza, and vaccination dates were determined by a validated immunization registry. The association between influenza RT-PCR result and vaccination interval (days) was examined using multivariable logistic regression, adjusting for calendar time, age and other confounders. There were 629 vaccinated participants, including 177 influenza A (H3N2) cases and 452 test negative controls. The mean (SD) interval from vaccination to illness onset was 101.7 (25.9) days for influenza cases and 93.0 (29.9) days for controls. There was a significant association between vaccination interval and influenza result in the main effects model. The adjusted odds ratio (aOR) for influenza was 1.12 (CI 1.01, 1.26) for every 14 day increase in the vaccination interval. Age modified the association between vaccination interval and influenza (p=0.005 for interaction). Influenza was associated with increasing vaccination interval in young children and older adults, but not in adolescents or non-elderly adults. Similar results were found when calendar week of vaccine receipt was assessed as the primary exposure variable. Identification of influenza A (H3N2) was associated with increasing time since vaccination among young children and older adults during a single influenza season. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

The Time Course of the Probability of Transition Into and Out of REM Sleep

PubMed Central

Bassi, Alejandro; Vivaldi, Ennio A.; Ocampo-Garcés, Adrián

2009-01-01

Study Objectives: A model of rapid eye movement (REM) sleep expression is proposed that assumes underlying regulatory mechanisms operating as inhomogenous Poisson processes, the overt results of which are the transitions into and out of REM sleep. Design: Based on spontaneously occurring REM sleep episodes (“Episode”) and intervals without REM sleep (“Interval”), 3 variables are defined and evaluated over discrete 15-second epochs using a nonlinear logistic regression method: “Propensity” is the instantaneous rate of into-REM transition occurrence throughout an Interval, “Volatility” is the instantaneous rate of out-of-REM transition occurrence throughout an Episode, and “Opportunity” is the probability of being in non-REM (NREM) sleep at a given time throughout an Interval, a requisite for transition. Setting: 12:12 light:dark cycle, isolated boxes. Participants: Sixteen male Sprague-Dawley rats Interventions: None. Spontaneous sleep cycles. Measurements and Results: The highest levels of volatility and propensity occur, respectively, at the very beginning of Episodes and Intervals. The new condition stabilizes rapidly, and variables reach nadirs at minute 1.25 and 2.50, respectively. Afterward, volatility increases markedly, reaching values close to the initial level. Propensity increases moderately, the increment being stronger through NREM sleep bouts occurring at the end of long Intervals. Short-term homeostasis is evidenced by longer REM sleep episodes lowering propensity in the following Interval. Conclusions: The stabilization after transitions into Episodes or Intervals and the destabilization after remaining for some time in either condition may be described as resulting from continuous processes building up during Episodes and Intervals. These processes underlie the overt occurrence of transitions. Citation: Bassi A; Vivaldi EA; Ocampo-Garcées A. The time course of the probability of transition into and out of REM sleep. SLEEP 2009;32(5):655-669 PMID:19480233

Evaluating dedicated and intrinsic models of temporal encoding by varying context

PubMed Central

Spencer, Rebecca M.C.; Karmarkar, Uma; Ivry, Richard B.

2009-01-01

Two general classes of models have been proposed to account for how people process temporal information in the milliseconds range. Dedicated models entail a mechanism in which time is explicitly encoded; examples include clock–counter models and functional delay lines. Intrinsic models, such as state-dependent networks (SDN), represent time as an emergent property of the dynamics of neural processing. An important property of SDN is that the encoding of duration is context dependent since the representation of an interval will vary as a function of the initial state of the network. Consistent with this assumption, duration discrimination thresholds for auditory intervals spanning 100 ms are elevated when an irrelevant tone is presented at varying times prior to the onset of the test interval. We revisit this effect in two experiments, considering attentional issues that may also produce such context effects. The disruptive effect of a variable context was eliminated or attenuated when the intervals between the irrelevant tone and test interval were made dissimilar or the duration of the test interval was increased to 300 ms. These results indicate how attentional processes can influence the perception of brief intervals, as well as point to important constraints for SDN models. PMID:19487188

Voter model with non-Poissonian interevent intervals

NASA Astrophysics Data System (ADS)

Takaguchi, Taro; Masuda, Naoki

2011-09-01

Recent analysis of social communications among humans has revealed that the interval between interactions for a pair of individuals and for an individual often follows a long-tail distribution. We investigate the effect of such a non-Poissonian nature of human behavior on dynamics of opinion formation. We use a variant of the voter model and numerically compare the time to consensus of all the voters with different distributions of interevent intervals and different networks. Compared with the exponential distribution of interevent intervals (i.e., the standard voter model), the power-law distribution of interevent intervals slows down consensus on the ring. This is because of the memory effect; in the power-law case, the expected time until the next update event on a link is large if the link has not had an update event for a long time. On the complete graph, the consensus time in the power-law case is close to that in the exponential case. Regular graphs bridge these two results such that the slowing down of the consensus in the power-law case as compared to the exponential case is less pronounced as the degree increases.

Interval Management with Spacing to Parallel Dependent Runways (IMSPIDR) Experiment and Results

NASA Technical Reports Server (NTRS)

Baxley, Brian T.; Swieringa, Kurt A.; Capron, William R.

2012-01-01

An area in aviation operations that may offer an increase in efficiency is the use of continuous descent arrivals (CDA), especially during dependent parallel runway operations. However, variations in aircraft descent angle and speed can cause inaccuracies in estimated time of arrival calculations, requiring an increase in the size of the buffer between aircraft. This in turn reduces airport throughput and limits the use of CDAs during high-density operations, particularly to dependent parallel runways. The Interval Management with Spacing to Parallel Dependent Runways (IMSPiDR) concept uses a trajectory-based spacing tool onboard the aircraft to achieve by the runway an air traffic control assigned spacing interval behind the previous aircraft. This paper describes the first ever experiment and results of this concept at NASA Langley. Pilots flew CDAs to the Dallas Fort-Worth airport using airspeed calculations from the spacing tool to achieve either a Required Time of Arrival (RTA) or Interval Management (IM) spacing interval at the runway threshold. Results indicate flight crews were able to land aircraft on the runway with a mean of 2 seconds and less than 4 seconds standard deviation of the air traffic control assigned time, even in the presence of forecast wind error and large time delay. Statistically significant differences in delivery precision and number of speed changes as a function of stream position were observed, however, there was no trend to the difference and the error did not increase during the operation. Two areas the flight crew indicated as not acceptable included the additional number of speed changes required during the wind shear event, and issuing an IM clearance via data link while at low altitude. A number of refinements and future spacing algorithm capabilities were also identified.

Schedule-induced drinking as functions of interpellet interval and draught size in the Java macaque1

PubMed Central

Allen, Joseph D.; Kenshalo, Dan R.

1978-01-01

Three Java monkeys received food pellets that were assigned by both ascending and descending series of fixed-time schedules whose values varied between 8 and 256 seconds. The draught size dispensed by a concurrently available water-delivery tube was systematically varied between 1.0 and 0.3 milliliter per lick at various fixed-time values during the second and third series determinations. Session water intake was bitonically related to the interpellet interval and was determined by the interaction of (1) the probability of initiating a drinking bout, which fell off at the highest interpellet intervals and, (2) the size of the bout, which increased directly with increases in interpellet interval. Variations in draught size had little effect on total session intakes, but reduced bout size at draught sizes of 0.5 milliliter and below. Thus, a volume-regulation process of schedule-induced drinking operated generally at the session-intake level, but was limited to higher draught sizes at the bout level. PMID:16812093

Schedule-induced drinking as functions of interpellet interval and draught size in the Java macaque.

PubMed

Allen, J D; Kenshalo, D R

1978-09-01

Three Java monkeys received food pellets that were assigned by both ascending and descending series of fixed-time schedules whose values varied between 8 and 256 seconds. The draught size dispensed by a concurrently available water-delivery tube was systematically varied between 1.0 and 0.3 milliliter per lick at various fixed-time values during the second and third series determinations. Session water intake was bitonically related to the interpellet interval and was determined by the interaction of (1) the probability of initiating a drinking bout, which fell off at the highest interpellet intervals and, (2) the size of the bout, which increased directly with increases in interpellet interval. Variations in draught size had little effect on total session intakes, but reduced bout size at draught sizes of 0.5 milliliter and below. Thus, a volume-regulation process of schedule-induced drinking operated generally at the session-intake level, but was limited to higher draught sizes at the bout level.

Cleaning frequency and the microbial load in ice-cream.

PubMed

Holm, Sonya; Toma, Ramses B; Reiboldt, Wendy; Newcomer, Chris; Calicchia, Melissa

2002-07-01

This study investigates the efficacy of a 62 h cleaning frequency in the manufacturing of ice-cream. Various product and product contact surfaces were sampled progressively throughout the time period between cleaning cycles, and analyzed for microbial growth. The coliform and standard plate counts (SPC) of these samples did not vary significantly over time after 0, 24, 48, or 62 h from Cleaning in Place (CiP). Data for product contact surfaces were significant for the SPC representing sample locations. Some of the variables in cleaning practices had significant influence on microbial loads. An increase in the number of flavors manufactured caused a decrease in SPC within the 24 h interval, but by the 48 h interval the SPC increased. More washouts within the first 24 h interval were favorable, as indicated by decreased SPC. The more frequently the liquefier was sanitized within the 62 h interval, the lower the SPC. This study indicates that food safety was not compromised and safety practices were effectively implemented throughout the process.

Long-term reliability of ImPACT in professional ice hockey.

PubMed

Echemendia, Ruben J; Bruce, Jared M; Meeuwisse, Willem; Comper, Paul; Aubry, Mark; Hutchison, Michael

2016-02-01

This study sought to assess the test-retest reliability of Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) across 2-4 year time intervals and evaluate the utility of a newly proposed two-factor (Speed/Memory) model of ImPACT across multiple language versions. Test-retest data were collected from non-concussed National Hockey League (NHL) players across 2-, 3-, and 4-year time intervals. The two-factor model was examined using different language versions (English, French, Czech, Swedish) of the test using a one-year interval, and across 2-4 year intervals using the English version of the test. The two-factor Speed index improved reliability across multiple language versions of ImPACT. The Memory factor also improved but reliability remained below the traditional cutoff of .70 for use in clinical decision-making. ImPACT reliabilities remained low (below .70) regardless of whether the four-composite or the two-factor model was used across 2-, 3-, and 4-year time intervals. The two-factor approach increased ImPACT's one-year reliability over the traditional four-composite model among NHL players. The increased stability in test scores improves the test's ability to detect cognitive changes following injury, which increases the diagnostic utility of the test and allows for better return to play decision-making by reducing the risk of exposing an athlete to additional trauma while the brain may be at a heightened vulnerability to such trauma. Although the Speed Index increases the clinical utility of the test, the stability of the Memory index remains low. Irrespective of whether the two-factor or traditional four-composite approach is used, these data suggest that new baselines should occur on a yearly basis in order to maximize clinical utility.

LIGHT EXPOSURE AMONG ADOLESCENTS WITH DELAYED SLEEP PHASE DISORDER: A PROSPECTIVE COHORT STUDY

PubMed Central

Auger, R. Robert; Burgess, Helen J.; Dierkhising, Ross A.; Sharma, Ruchi G.; Slocumb, Nancy L.

2012-01-01

Our study objective was to compare light exposure and sleep parameters between adolescents with delayed sleep phase disorder (n=16, 15.3 ± 1.8 years) and unaffected controls (n=22, 13.7 ± 2.4 years) using a prospective cohort design. Participants wore wrist actigraphs with photosensors for 14 days. Mean hourly lux levels from 20:00-05:00 h and 05:00-14:00 h were examined, in addition to the 9-hour intervals prior to sleep onset and after sleep offset. Sleep parameters were compared separately, and were also included as covariates within models that analyzed associations with specified light intervals. Additional covariates included group and school night status. Adolescent subjects with delayed sleep phase disorder received more evening (p<0.02, 22:00-02:00 h) and less morning light (p<0.05, 08:00-09:00 h and 10:00-12:00 h) than controls, but had less pre-sleep exposure with adjustments for the time of sleep onset (p<0.03, fifth-seventh hours prior to onset hour). No differences were identified with respect to the sleep offset interval. Increased total sleep time and later sleep offset times were associated with decreased evening (p<0.001 and p=0.02, respectively) and morning (p=0.01 and p<0.001, respectively) exposure, and later sleep onset times were associated with increased evening exposure (p<0.001). Increased total sleep time also correlated with increased exposure during the 9 hours before sleep-onset (p=0.01), and a later sleep onset time corresponded with decreased exposure during the same interval (p<0.001). Outcomes persisted regardless of school night status. In conclusion, light exposure interpretation requires adjustments for sleep timing among adolescents with delayed sleep phase disorder. Pre- and post-sleep exposure do not appear to contribute directly to phase delays. Sensitivity to morning light may be reduced among adolescents with delayed sleep phase disorder. PMID:22080736

Why noise is useful in functional and neural mechanisms of interval timing?

PubMed Central

2013-01-01

Background The ability to estimate durations in the seconds-to-minutes range - interval timing - is essential for survival, adaptation and its impairment leads to severe cognitive and/or motor dysfunctions. The response rate near a memorized duration has a Gaussian shape centered on the to-be-timed interval (criterion time). The width of the Gaussian-like distribution of responses increases linearly with the criterion time, i.e., interval timing obeys the scalar property. Results We presented analytical and numerical results based on the striatal beat frequency (SBF) model showing that parameter variability (noise) mimics behavioral data. A key functional block of the SBF model is the set of oscillators that provide the time base for the entire timing network. The implementation of the oscillators block as simplified phase (cosine) oscillators has the additional advantage that is analytically tractable. We also checked numerically that the scalar property emerges in the presence of memory variability by using biophysically realistic Morris-Lecar oscillators. First, we predicted analytically and tested numerically that in a noise-free SBF model the output function could be approximated by a Gaussian. However, in a noise-free SBF model the width of the Gaussian envelope is independent of the criterion time, which violates the scalar property. We showed analytically and verified numerically that small fluctuations of the memorized criterion time leads to scalar property of interval timing. Conclusions Noise is ubiquitous in the form of small fluctuations of intrinsic frequencies of the neural oscillators, the errors in recording/retrieving stored information related to criterion time, fluctuation in neurotransmitters’ concentration, etc. Our model suggests that the biological noise plays an essential functional role in the SBF interval timing. PMID:23924391

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…

Waking and scrambling in holographic heating up

NASA Astrophysics Data System (ADS)

Ageev, D. S.; Aref'eva, I. Ya.

2017-10-01

Using holographic methods, we study the heating up process in quantum field theory. As a holographic dual of this process, we use absorption of a thin shell on a black brane. We find the explicit form of the time evolution of the quantum mutual information during heating up from the temperature Ti to the temperature T f in a system of two intervals in two-dimensional space-time. We determine the geometric characteristics of the system under which the time dependence of the mutual information has a bell shape: it is equal to zero at the initial instant, becomes positive at some subsequent instant, further attains its maximum, and again decreases to zero. Such a behavior of the mutual information occurs in the process of photosynthesis. We show that if the distance x between the intervals is less than log 2/2π T i, then the evolution of the holographic mutual information has a bell shape only for intervals whose lengths are bounded from above and below. For sufficiently large x, i.e., for x < log 2/2π T i, the bell-like shape of the time dependence of the quantum mutual information is present only for sufficiently large intervals. Moreover, the zone narrows as T i increases and widens as T f increases.

The impact of children's internalizing and externalizing problems on parenting: Transactional processes and reciprocal change over time.

PubMed

Serbin, Lisa A; Kingdon, Danielle; Ruttle, Paula L; Stack, Dale M

2015-11-01

Most theoretical models of developmental psychopathology involve a transactional, bidirectional relation between parenting and children's behavior problems. The present study utilized a cross-lagged panel, multiple interval design to model change in bidirectional relations between child and parent behavior across successive developmental periods. Two major categories of child behavior problems, internalizing and externalizing, and two aspects of parenting, positive (use of support and structure) and harsh discipline (use of physical punishment), were modeled across three time points spaced 3 years apart. Two successive developmental intervals, from approximately age 7.5 to 10.5 and from 10.5 to 13.5, were included. Mother-child dyads (N = 138; 65 boys) from a lower income longitudinal sample of families participated, with standardized measures of mothers rating their own parenting behavior and teachers reporting on child's behavior. Results revealed different types of reciprocal relations between specific aspects of child and parent behavior, with internalizing problems predicting an increase in positive parenting over time, which subsequently led to a reduction in internalizing problems across the successive 3-year interval. In contrast, externalizing predicted reduced levels of positive parenting in a reciprocal sequence that extended across two successive intervals and predicted increased levels of externalizing over time. Implications for prevention and early intervention are discussed.

Enhanced ionization of the Martian nightside ionosphere during solar energetic particle events

NASA Astrophysics Data System (ADS)

Nemec, F.; Morgan, D. D.; Dieval, C.; Gurnett, D. A.; Futaana, Y.

2013-12-01

The nightside ionosphere of Mars is highly variable and very irregular, controlled to a great extent by the configuration of the crustal magnetic fields. The ionospheric reflections observed by the MARSIS radar sounder on board the Mars Express spacecraft in this region are typically oblique (reflection by a distant feature), so that they cannot be used to determine the peak altitude precisely. Nevertheless, the peak electron density can be in principle readily determined. However, in more than 90% of measurements the peak electron densities are too low to be detected. We focus on the time intervals of solar energetic particle (SEP) events. One may expect high energy particle precipitation into the nightside ionosphere to increase the electron density there. Thus, comparison of characteristics between SEP/no-SEP time intervals is important to understand the formation mechanism of the nightside ionosphere. The time intervals of SEP events are determined using the increase in the background counts recorded by the ion sensor (IMA) of the ASPERA-3 particle instrument on board Mars Express. Then we use MARSIS measurements to determine how much the nightside ionosphere is enhanced during these time intervals. We show that the peak electron densities during these periods are large enough to be detected in more than 30% of measurements, while the reflections from the ground almost entirely disappear, indicating that the nightside electron densities are tremendously increased as compared to the normal nightside conditions. The influence of various parameters on the formation of the nightside ionosphere is thoroughly discussed.

Maternal Circadian Eating Time and Frequency Are Associated with Blood Glucose Concentrations during Pregnancy.

PubMed

Loy, See Ling; Chan, Jerry Kok Yen; Wee, Poh Hui; Colega, Marjorelee T; Cheung, Yin Bun; Godfrey, Keith M; Kwek, Kenneth; Saw, Seang Mei; Chong, Yap-Seng; Natarajan, Padmapriya; Müller-Riemenschneider, Falk; Lek, Ngee; Chong, Mary Foong-Fong; Yap, Fabian

2017-01-01

Synchronizing eating schedules to daily circadian rhythms may improve metabolic health, but its association with gestational glycemia is unknown. This study examined the association of maternal night-fasting intervals and eating episodes with blood glucose concentrations during pregnancy. This was a cross-sectional study within a prospective cohort in Singapore. Maternal 24-h dietary recalls, fasting glucose, and 2-h glucose concentrations were ascertained at 26-28 wk gestation for 1061 women (aged 30.7 ± 5.1 y). Night-fasting intervals were based on the longest fasting duration during the night (1900-0659). Eating episodes were defined as events that provided >50 kcal, with a time interval between eating episodes of ≥15 min. Multiple linear regressions with adjustment for confounders were conducted. Mean ± SD night-fasting intervals and eating episodes per day were 9.9 ± 1.6 h and 4.2 ± 1.3 times/d, respectively; fasting and 2-h glucose concentrations were 4.4 ± 0.5 and 6.6 ± 1.5 mmol/L, respectively. In adjusted models, each hourly increase in night-fasting intervals was associated with a 0.03 mmol/L decrease in fasting glucose (95% CI: -0.06, -0.01 mmol/L), whereas each additional daily eating episode was associated with a 0.15 mmol/L increase in 2-h glucose (95% CI: 0.03, 0.28 mmol/L). Conversely, night-fasting intervals and daily eating episodes were not associated with 2-h and fasting glucose, respectively. Increased maternal night-fasting intervals and reduced eating episodes per day were associated with decreased fasting glucose and 2-h glucose, respectively, in the late-second trimester of pregnancy. This points to potential alternative strategies to improve glycemic control in pregnant women. This study was registered at www.clinicaltrials.gov as NCT01174875. © 2017 American Society for Nutrition.

Maternal circadian eating time and frequency are associated with blood glucose levels during pregnancy

PubMed Central

Loy, See Ling; Chan, Jerry Kok Yen; Wee, Poh Hui; Colega, Marjorelee T.; Cheung, Yin Bun; Godfrey, Keith M.; Kwek, Kenneth; Saw, Seang Mei; Chong, Yap-Seng; Natarajan, Padmapriya; Müller-Riemenschneider, Falk; Lek, Ngee; Chong, Mary Foong-Fong; Yap, Fabian

2017-01-01

Background Synchronizing eating schedules with daily circadian rhythms may improve metabolic health, but its association with gestational glycemia is unknown. Objective This study examined the association of maternal night-fasting intervals and eating episodes with blood glucose levels during pregnancy. Methods This was a cross-sectional study within a prospective cohort in Singapore. Maternal 24-hour dietary recalls, fasting glucose and 2-hour glucose concentrations were ascertained at 26-28 weeks’ gestation for 1061 women (age 30.7 ± 5.1 years). Night-fasting intervals were based on the longest fasting duration during the night (1900-0659h). Eating episodes were defined as events which provided >50 kcal, with a time interval between eating episodes of at least 15 minutes. Multiple linear regressions with adjustment for confounders were conducted. Results Mean ± standard deviation night-fasting intervals and eating episodes per day were 9.9 ± 1.6 hours and 4.2 ± 1.3 times per day, respectively; fasting and 2-hour glucose concentrations were 4.4 ± 0.5 and 6.6 ± 1.5 mmol/L, respectively. In adjusted models, each hourly increase in night-fasting interval was associated with a 0.03 mmol/L decrease in fasting glucose (95% CI: -0.06, -0.01 mmol/L), while each additional daily eating episode was associated with a 0.15 mmol/L increase in 2-hour glucose (95% CI: 0.03, 0.28 mmol/L). Conversely, night-fasting intervals and daily eating episodes were not associated with 2-hour and fasting glucose, respectively. Conclusions Increased maternal night-fasting intervals and reduced eating episodes per day were associated with decreased fasting glucose and 2-hour glucose, respectively, in the late-second trimester of pregnancy. This points to potential alternative strategies to improve glycemic control in pregnant women. This study was registered at www.clinicaltrials.gov as NCT01174875. PMID:27798346

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.

Interval training attenuates the metabolic disturbances in type 1 diabetes rat model.

PubMed

Rocha, Ricelli Endrigo Ruppel; Coelho, Isabela; Pequito, Daniela Cristina T; Yamagushi, Adriana; Borghetti, Gina; Yamazaki, Ricardo Key; Brito, Gleisson Alisson Pereira de; Machado, Juliano; Kryczyk, Marcelo; Nunes, Everson Araújo; Venera, Graciela; Fernandes, Luiz Claudio

2013-11-01

This study investigated the effect of interval training on blood biochemistry and immune parameters in type 1 diabetic rats. Male Wistar rats were divided into four groups: sedentary (SE, n = 15), interval training (IT, n = 17), diabetic sedentary (DSE, n = 17), diabetic interval training (DIT, n = 17). Diabetes was induced by i.v. injection of streptozotocin (60 mg/kg). Swimming Interval Training consisted of 30-s exercise with 30-s rest, for 30 minutes, during 6 weeks, four times a week, with an overload of 15% of body mass. Plasma glucose, lactate, triacylglycerol and total cholesterol concentrations, phagocytic capacity, cationic vesicle content, and superoxide anion and hydrogen peroxide production by blood neutrophils and peritoneal macrophages were evaluated. Proliferation of mesenteric lymphocytes was also estimated. Interval training resulted in attenuation of the resting hyperglycemic state and decreased blood lipids in the DIT group. Diabetes increased the functionality of blood neutrophils and peritoneal macrophages in the DSE group. Interval training increased all functionality parameters of peritoneal macrophages in the IT group. Interval training also led to a twofold increase in the proliferation of mesenteric lymphocytes after 6 weeks of exercise in the DIT group. Low-volume high-intensity physical exercise attenuates hyperglycemia and dislipidemia induced by type 1 diabetes, and induces changes in the functionality of innate and acquired immunity.

THE QUESTION "RECOVERY SPEED OR RESISTANCE INCREASE" OF THE X-IRRADIATED SKIN OF FROGS (RANA ESCULENTA) IN SMALL FRACTIONATION (in German)

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

Amoroso, C.; Lorenz, W.

1959-01-01

Sixty-one frogs (Rana esculenta) were irradiated in urethan anesthesia. The right upper leg was irradiated with a surface dose of 12,000 r. The left upper legs of the same animals were irradiated subsequently with a surface dose of 2 times 6000 r, respectively 3 times 4000 r at intervals of 1, 3, 6, 24, or 72 hours. The single irradiation of 12,000 r caused changes of the pigentation and formation of ulcers after 3 weeks. After 8 weeks 35 out of 61 animals had formation of ulcers. The first tendency for healing was observed after 10 weeks. By the usemore » of divided doses of 3 times 4000 r or 2 tirees 6000 r, with intervals as short as one hour, the effect of the irradiation caused less damage, probably due to increased resistence, which may have developed during the intervals between irradiations. (auth)« less

An analysis of first-time blood donors return behaviour using regression models.

PubMed

Kheiri, S; Alibeigi, Z

2015-08-01

Blood products have a vital role in saving many patients' lives. The aim of this study was to analyse blood donor return behaviour. Using a cross-sectional follow-up design of 5-year duration, 864 first-time donors who had donated blood were selected using a systematic sampling. The behaviours of donors via three response variables, return to donation, frequency of return to donation and the time interval between donations, were analysed based on logistic regression, negative binomial regression and Cox's shared frailty model for recurrent events respectively. Successful return to donation rated at 49·1% and the deferral rate was 13·3%. There was a significant reverse relationship between the frequency of return to donation and the time interval between donations. Sex, body weight and job had an effect on return to donation; weight and frequency of donation during the first year had a direct effect on the total frequency of donations. Age, weight and job had a significant effect on the time intervals between donations. Aging decreases the chances of return to donation and increases the time interval between donations. Body weight affects the three response variables, i.e. the higher the weight, the more the chances of return to donation and the shorter the time interval between donations. There is a positive correlation between the frequency of donations in the first year and the total number of return to donations. Also, the shorter the time interval between donations is, the higher the frequency of donations. © 2015 British Blood Transfusion Society.

Changes in apparent duration follow shifts in perceptual timing

PubMed Central

Bruno, Aurelio; Ayhan, Inci; Johnston, Alan

2015-01-01

It is well established that the apparent duration of moving visual objects is greater at higher as compared to slower speeds. Here we report the effects of acceleration and deceleration on the perceived duration of a drifting grating with average speed kept constant (10°/s).For acceleration, increasing the speed range progressively reduced perceived duration. The magnitude of apparent duration compression was determined by speed rather than temporal frequency and was proportional to speed range (independent of standard duration) rather than acceleration. The perceived duration reduction was also proportional to the standard length. The effects of increases and decreases in speed were highly asymmetric. Reducing speed through the interval induced a moderate increase in perceived duration. These results could not be explained by changes in apparent onset or offset or differences in perceived average speed between intervals containing increasing speed and intervals containing decreasing speed. Paradoxically, for intervals combining increasing speed and decreasing speed, compression only occurred when increasing speed occurred in the second half of the interval. We show that this pattern of results in the duration domain was concomitant with changes in the reported direction of apparent motion of Gaussian blobs, embedded in intervals of increasing or decreasing speed, that could be predicted from adaptive changes in the temporal impulse response function. We detected similar changes after flicker adaptation, suggesting that the two effects might be linked through changes in the temporal tuning of visual filters. PMID:26024450

Cardiac conductive disturbance in patients with polycystic ovary syndrome.

PubMed

Huang, Jen-Hung; Tsai, Jen-Chen; Hsu, Ming-I; Chen, Yi-Jen

2010-12-01

Polycystic ovary syndrome (PCOS) is the most common endocrine abnormality of reproductive-aged women and increases the risk of cardiovascular disease. However, the effects of PCOS on electrocardiograms (ECGs) are not fully elucidated. The aim of this study was to evaluate the characteristics of ECGs in patients with PCOS. This study included 24 patients with PCOS and 12 patients without PCOS. The heart rate, PR interval, QRS duration, Sokolow-Lyon voltage (SV1 + RV5/6), Cornell voltage (RaVL + SV3), QT interval and QTc interval were measured in 12-lead ECGs. The QRS duration was wider in patients with PCOS than those without PCOS (91 ± 8 vs. 81 ± 10 ms, p < 0.05). The heart rate, PR interval, Sokolow-Lyon voltage, product of the QRS duration times Cornell voltage combination, QT interval, QTc interval, QT dispersion and QTc dispersion were similar between the two groups. PCOS is associated with a widening QRS duration, which may contribute to its increased cardiovascular risks.

Induced chromosomal aberrations in somatic cells of Nigella sativa L. by mitomycin C.

PubMed

Kumar, P; Nizam, J

1978-01-01

A cytological study was carried out on root tips of Nigella sativa L. by treatment with Mitomycin C at 0.001% for six time intervals (10, 15, 20, 30, 40, and 50 min). The chromosomal abnormalities were increasingly proportionate to the increase in time of treatment. The seedlings treated with a 0.001% concentration of Mitomycin C for 10 min. did not show any significant effect. At other time intervals, the effect was observed to be quite significant. Beyond 40 min. treatment almost all the cells would become sticky. Thirty minutes' treatment showed significant effect, inducing various types of chromosomal aberrations in the anaphase, such as bridges and fragments of 34.13% and 48.07%, respectively.

Study on system dynamics of evolutionary mix-game models

NASA Astrophysics Data System (ADS)

Gou, Chengling; Guo, Xiaoqian; Chen, Fang

2008-11-01

Mix-game model is ameliorated from an agent-based MG model, which is used to simulate the real financial market. Different from MG, there are two groups of agents in Mix-game: Group 1 plays a majority game and Group 2 plays a minority game. These two groups of agents have different bounded abilities to deal with historical information and to count their own performance. In this paper, we modify Mix-game model by assigning the evolution abilities to agents: if the winning rates of agents are smaller than a threshold, they will copy the best strategies the other agent has; and agents will repeat such evolution at certain time intervals. Through simulations this paper finds: (1) the average winning rates of agents in Group 1 and the mean volatilities increase with the increases of the thresholds of Group 1; (2) the average winning rates of both groups decrease but the mean volatilities of system increase with the increase of the thresholds of Group 2; (3) the thresholds of Group 2 have greater impact on system dynamics than the thresholds of Group 1; (4) the characteristics of system dynamics under different time intervals of strategy change are similar to each other qualitatively, but they are different quantitatively; (5) As the time interval of strategy change increases from 1 to 20, the system behaves more and more stable and the performances of agents in both groups become better also.

The time dependent association of adrenaline administration and survival from out-of-hospital cardiac arrest.

PubMed

Ewy, Gordon A; Bobrow, Bentley J; Chikani, Vatsal; Sanders, Arthur B; Otto, Charles W; Spaite, Daniel W; Kern, Karl B

2015-11-01

Recommended for decades, the therapeutic value of adrenaline (epinephrine) in the resuscitation of patients with out-of-hospital cardiac arrest (OHCA) is controversial. To investigate the possible time-dependent outcomes associated with adrenaline administration by Emergency Medical Services personnel (EMS). A retrospective analysis of prospectively collected data from a near statewide cardiac resuscitation database between 1 January 2005 and 30 November 2013. Multivariable logistic regression was used to analyze the effect of the time interval between EMS dispatch and the initial dose of adrenaline on survival. The primary endpoints were survival to hospital discharge and favourable neurologic outcome. Data from 3469 patients with witnessed OHCA were analyzed. Their mean age was 66.3 years and 69% were male. An initially shockable rhythm was present in 41.8% of patients. Based on a multivariable logistic regression model with initial adrenaline administration time interval (AATI) from EMS dispatch as the covariate, survival was greatest when adrenaline was administered very early but decreased rapidly with increasing (AATI); odds ratio 0.94 (95% Confidence Interval (CI) 0.92-0.97). The AATI had no significant effect on good neurological outcome (OR=0.96, 95% CI=0.90-1.02). In patients with OHCA, survival to hospital discharge was greater in those treated early with adrenaline by EMS especially in the subset of patients with a shockable rhythm. However survival rapidly decreased with increasing adrenaline administration time intervals (AATI). Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Sequential Processing and the Matching-Stimulus Interval Effect in ERP Components: An Exploration of the Mechanism Using Multiple Regression

PubMed Central

Steiner, Genevieve Z.; Barry, Robert J.; Gonsalvez, Craig J.

2016-01-01

In oddball tasks, increasing the time between stimuli within a particular condition (target-to-target interval, TTI; nontarget-to-nontarget interval, NNI) systematically enhances N1, P2, and P300 event-related potential (ERP) component amplitudes. This study examined the mechanism underpinning these effects in ERP components recorded from 28 adults who completed a conventional three-tone oddball task. Bivariate correlations, partial correlations and multiple regression explored component changes due to preceding ERP component amplitudes and intervals found within the stimulus series, rather than constraining the task with experimentally constructed intervals, which has been adequately explored in prior studies. Multiple regression showed that for targets, N1 and TTI predicted N2, TTI predicted P3a and P3b, and Processing Negativity (PN), P3b, and TTI predicted reaction time. For rare nontargets, P1 predicted N1, NNI predicted N2, and N1 predicted Slow Wave (SW). Findings show that the mechanism is operating on separate stages of stimulus-processing, suggestive of either increased activation within a number of stimulus-specific pathways, or very long component generator recovery cycles. These results demonstrate the extent to which matching-stimulus intervals influence ERP component amplitudes and behavior in a three-tone oddball task, and should be taken into account when designing similar studies. PMID:27445774

Sequential Processing and the Matching-Stimulus Interval Effect in ERP Components: An Exploration of the Mechanism Using Multiple Regression.

PubMed

Steiner, Genevieve Z; Barry, Robert J; Gonsalvez, Craig J

2016-01-01

In oddball tasks, increasing the time between stimuli within a particular condition (target-to-target interval, TTI; nontarget-to-nontarget interval, NNI) systematically enhances N1, P2, and P300 event-related potential (ERP) component amplitudes. This study examined the mechanism underpinning these effects in ERP components recorded from 28 adults who completed a conventional three-tone oddball task. Bivariate correlations, partial correlations and multiple regression explored component changes due to preceding ERP component amplitudes and intervals found within the stimulus series, rather than constraining the task with experimentally constructed intervals, which has been adequately explored in prior studies. Multiple regression showed that for targets, N1 and TTI predicted N2, TTI predicted P3a and P3b, and Processing Negativity (PN), P3b, and TTI predicted reaction time. For rare nontargets, P1 predicted N1, NNI predicted N2, and N1 predicted Slow Wave (SW). Findings show that the mechanism is operating on separate stages of stimulus-processing, suggestive of either increased activation within a number of stimulus-specific pathways, or very long component generator recovery cycles. These results demonstrate the extent to which matching-stimulus intervals influence ERP component amplitudes and behavior in a three-tone oddball task, and should be taken into account when designing similar studies.

Sampling effects on the identification of roadkill hotspots: Implications for survey design.

PubMed

Santos, Sara M; Marques, J Tiago; Lourenço, André; Medinas, Denis; Barbosa, A Márcia; Beja, Pedro; Mira, António

2015-10-01

Although locating wildlife roadkill hotspots is essential to mitigate road impacts, the influence of study design on hotspot identification remains uncertain. We evaluated how sampling frequency affects the accuracy of hotspot identification, using a dataset of vertebrate roadkills (n = 4427) recorded over a year of daily surveys along 37 km of roads. "True" hotspots were identified using this baseline dataset, as the 500-m segments where the number of road-killed vertebrates exceeded the upper 95% confidence limit of the mean, assuming a Poisson distribution of road-kills per segment. "Estimated" hotspots were identified likewise, using datasets representing progressively lower sampling frequencies, which were produced by extracting data from the baseline dataset at appropriate time intervals (1-30 days). Overall, 24.3% of segments were "true" hotspots, concentrating 40.4% of roadkills. For different groups, "true" hotspots accounted from 6.8% (bats) to 29.7% (small birds) of road segments, concentrating from <40% (frogs and toads, snakes) to >60% (lizards, lagomorphs, carnivores) of roadkills. Spatial congruence between "true" and "estimated" hotspots declined rapidly with increasing time interval between surveys, due primarily to increasing false negatives (i.e., missing "true" hotspots). There were also false positives (i.e., wrong "estimated" hotspots), particularly at low sampling frequencies. Spatial accuracy decay with increasing time interval between surveys was higher for smaller-bodied (amphibians, reptiles, small birds, small mammals) than for larger-bodied species (birds of prey, hedgehogs, lagomorphs, carnivores). Results suggest that widely used surveys at weekly or longer intervals may produce poor estimates of roadkill hotspots, particularly for small-bodied species. Surveying daily or at two-day intervals may be required to achieve high accuracy in hotspot identification for multiple species. Copyright © 2015 Elsevier Ltd. All rights reserved.

Iron Metabolism Genes, Low-Level Lead Exposure, and QT Interval

PubMed Central

Park, Sung Kyun; Hu, Howard; Wright, Robert O.; Schwartz, Joel; Cheng, Yawen; Sparrow, David; Vokonas, Pantel S.; Weisskopf, Marc G.

2009-01-01

Background Cumulative exposure to lead has been shown to be associated with depression of electrocardiographic conduction, such as QT interval (time from start of the Q wave to end of the T wave). Because iron can enhance the oxidative effects of lead, we examined whether polymorphisms in iron metabolism genes [hemochromatosis (HFE), transferrin (TF) C2, and heme oxygenase-1 (HMOX-1)] increase susceptibility to the effects of lead on QT interval in 613 community-dwelling older men. Methods We used standard 12-lead electrocardiograms, K-shell X-ray fluorescence, and graphite furnace atomic absorption spectrometry to measure QT interval, bone lead, and blood lead levels, respectively. Results A one-interquartile-range increase in tibia lead level (13 μg/g) was associated with a 11.35-msec [95% confidence interval (CI), 4.05–18.65 msec] and a 6.81-msec (95% CI, 1.67–11.95 msec) increase in the heart-rate–corrected QT interval among persons carrying long HMOX-1 alleles and at least one copy of an HFE variant, respectively, but had no effect in persons with short and middle HMOX-1 alleles and the wild-type HFE genotype. The lengthening of the heart-rate–corrected QT interval with higher tibia lead and blood lead became more pronounced as the total number (0 vs. 1 vs. ≥2) of gene variants increased (tibia, p-trend = 0.01; blood, p-trend = 0.04). This synergy seems to be driven by a joint effect between HFE variant and HMOX-1 L alleles. Conclusion We found evidence that gene variants related to iron metabolism increase the impacts of low-level lead exposure on the prolonged QT interval. This is the first such report, so these results should be interpreted cautiously and need to be independently verified. PMID:19165391

Effects of environmental support on overt and covert visuospatial rehearsal.

PubMed

Lilienthal, Lindsey; Myerson, Joel; Abrams, Richard A; Hale, Sandra

2018-09-01

People can rehearse to-be-remembered locations either overtly, using eye movements, or covertly, using only shifts of spatial attention. The present study examined whether the effectiveness of these two strategies depends on environmental support for rehearsal. In Experiment 1, when environmental support (i.e., the array of possible locations) was present and participants could engage in overt rehearsal during retention intervals, longer intervals resulted in larger spans, whereas in Experiment 2, when support was present but participants could only engage in covert rehearsal, longer intervals resulted in smaller spans. When environmental support was absent, however, longer retention intervals resulted in smaller memory spans regardless of which rehearsal strategies were available. In Experiment 3, analyses of participants' eye movements revealed that the presence of support increased participants' fixations of to-be-remembered target locations more than fixations of non-targets, and that this was associated with better memory performance. Further, although the total time fixating targets increased, individual target fixations were actually briefer. Taken together, the present findings suggest that in the presence of environmental support, overt rehearsal is more effective than covert rehearsal at maintaining to-be-remembered locations in working memory, and that having more time for overt rehearsal can actually increase visuospatial memory spans.

How preservation time changes the linear viscoelastic properties of porcine liver.

PubMed

Wex, C; Stoll, A; Fröhlich, M; Arndt, S; Lippert, H

2013-01-01

The preservation time of a liver graft is one of the crucial factors for the success of a liver transplantation. Grafts are kept in a preservation solution to delay cell destruction and cellular edema and to maximize organ function after transplantation. However, longer preservation times are not always avoidable. In this paper we focus on the mechanical changes of porcine liver with increasing preservation time, in order to establish an indicator for the quality of a liver graft dependent on preservation time. A time interval of 26 h was covered and the rheological properties of liver tissue studied using a stress-controlled rheometer. For samples of 1 h preservation time 0.8% strain was found as the limit of linear viscoelasticity. With increasing preservation time a decrease in the complex shear modulus as an indicator for stiffness was observed for the frequency range from 0.1 to 10 Hz. A simple fractional derivative representation of the Kelvin Voigt model was applied to gain further information about the changes of the mechanical properties of liver with increasing preservation time. Within the small shear rate interval of 0.0001-0.01 s⁻¹ the liver showed Newtonian-like flow behavior.

What effect do substorms have on the content of the radiation belts?

PubMed Central

Rae, I. J.; Murphy, K. R.; Freeman, M. P.; Huang, C.‐L.; Spence, H. E.; Boyd, A. J.; Coxon, J. C.; Jackman, C. M.; Kalmoni, N. M. E.; Watt, C. E. J.

2016-01-01

Abstract Substorms are fundamental and dynamic processes in the magnetosphere, converting captured solar wind magnetic energy into plasma energy. These substorms have been suggested to be a key driver of energetic electron enhancements in the outer radiation belts. Substorms inject a keV “seed” population into the inner magnetosphere which is subsequently energized through wave‐particle interactions up to relativistic energies; however, the extent to which substorms enhance the radiation belts, either directly or indirectly, has never before been quantified. In this study, we examine increases and decreases in the total radiation belt electron content (TRBEC) following substorms and geomagnetically quiet intervals. Our results show that the radiation belts are inherently lossy, shown by a negative median change in TRBEC at all intervals following substorms and quiet intervals. However, there are up to 3 times as many increases in TRBEC following substorm intervals. There is a lag of 1–3 days between the substorm or quiet intervals and their greatest effect on radiation belt content, shown in the difference between the occurrence of increases and losses in TRBEC following substorms and quiet intervals, the mean change in TRBEC following substorms or quiet intervals, and the cross correlation between SuperMAG AL (SML) and TRBEC. However, there is a statistically significant effect on the occurrence of increases and decreases in TRBEC up to a lag of 6 days. Increases in radiation belt content show a significant correlation with SML and SYM‐H, but decreases in the radiation belt show no apparent link with magnetospheric activity levels. PMID:27656336

Effect of low body temperature on associative interference in conditioned taste aversion.

PubMed

Christianson, John P; Anderson, Mathew J; Misanin, James R; Hinderliter, Charles F

2005-06-01

When two novel conditioned stimuli precede an unconditioned stimulus (US), the interval between the two conditioned stimuli (CS1 and CS2) influences the magnitude of the CS-US associability of each CS. As the interval between CS1 and CS2 increases, the associability of CS1 with the US decreases due to interference by CS2 and the associability of CS2 increases, given its temporal proximity to the US. Because hypothermia has been reported to increase the interval at which conditioned taste aversions can be formed, its influence was examined on the above relationship, i.e., how interference from CS2 affects the associability of CS1 with the US. Rats received a conditioned taste aversion procedure where CS1 and CS2 were presented either one after the other or separated by an 80-min. delay. For all subjects, the US or pseudo-US was presented immediately after CS2. When hypothermia was interpolated between the two flavor stimuli that were spaced 80 min. apart, CS2-interference with the CS1-US association was greatly attenuated. We propose that hypothermia modifies internal timing mechanisms such that the externally timed 80-min. CS1-CS2 interval was perceived as much shorter for rats made hypothermic. As a result of this perceived shortened inter-CS interval, CS2 produced less interference for the CS1-US association than would be expected for such a relatively long delay between CS1 and CS2.

Body Size of Male Youth Soccer Players: 1978-2015.

PubMed

Malina, Robert M; Figueiredo, António J; Coelho-E-Silva, Manuel J

2017-10-01

Studies of the body size and proportions of athletes have a long history. Comparisons of athletes within specific sports across time, though not extensive, indicate both positive and negative trends. To evaluate secular variation in heights and weights of male youth soccer players reported in studies between 1978 and 2015. Reported mean ages, heights, and weights of male soccer players 9-18 years of age were extracted from the literature and grouped into two intervals: 1978-99 and 2000-15. A third-order polynomial was fitted to the mean heights and weights across the age range for each interval, while the Preece-Baines model 1 was fitted to the grand means of mean heights and mean weights within each chronological year to estimate ages at peak height velocity and peak weight velocity for each time interval. Third-order polynomials applied to all data points and estimates based on the Preece-Baines model applied to grand means for each age group provided similar fits. Both indicated secular changes in body size between the two intervals. Secular increases in height and weight between 1978-99 and 2000-15 were especially apparent between 13 and 16 years of age, but estimated ages at peak height velocity (13.01 and 12.91 years) and peak weight velocity (13.86 and 13.77 years) did not differ between the time intervals. Although the body size of youth soccer players increased between 1978-99 and 2000-15, estimated ages at peak height velocity and peak weight velocity did not change. The increase in height and weight likely reflected improved health and nutritional conditions, in addition to the selectivity of soccer reflected in systematic selection and retention of players advanced in maturity status, and exclusion of late maturing players beginning at about 12-13 years of age. Enhanced training programs aimed at the development of strength and power are probably an additional factor contributing to secular increases in body weight.

The impact of labor-saving technology on first birth intervals in rural Ethiopia.

PubMed

Gibson, Mhairi; Mace, Ruth

2002-02-01

Across the developing world labor-saving technologies introduce considerable savings in the time and energy that women allocate to work. Hormonal studies on natural fertility populations indicate that such a reduction in energetic expenditure (rather than improved nutritional status alone) can lead to increased ovarian function. Other qualitative studies have highlighted a link between labor-saving technology and behavioral changes affecting subsequent age at marriage, which may affect fertility. This biodemographic study was designed to investigate whether these physiological and behavioral changes affect fertility at a population level by focusing on a recent water development scheme in Southern Ethiopia. The demographic consequences of a reduction in women's workload following the installation of water points, specifically the variation in length of first birth interval (time lapsed between marriage and first birth), are investigated. First birth interval length is closely associated with lifetime fertility in populations that do not practice contraception, longer intervals being associated with lower fertility. Using life tables and multivariate hazard modeling techniques a number of significant predictors of first birth interval length are identified. Covariates such as age at marriage, season of marriage, village ecology, and access to improved water supply have significant effects on variation in first birth intervals. When entered into models as a time-varying covariate, access to a water tap stand is associated with an immediate reduction in length of first birth intervals.

Effects of High Intensity Interval Training on Increasing Explosive Power, Speed, and Agility

NASA Astrophysics Data System (ADS)

Fajrin, F.; Kusnanik, N. W.; Wijono

2018-01-01

High Intensity Interval Training (HIIT) is a type of exercise that combines high-intensity exercise and low intensity exercise in a certain time interval. This type of training is very effective and efficient to improve the physical components. The process of improving athletes achievement related to how the process of improving the physical components, so the selection of a good practice method will be very helpful. This study aims to analyze how is the effects of HIIT on increasing explosive power, speed, and agility. This type of research is quantitative with quasi-experimental methods. The design of this study used the Matching-Only Design, with data analysis using the t-test (paired sample t-test). After being given the treatment for six weeks, the results showed there are significant increasing in explosive power, speed, and agility. HIIT in this study used a form of exercise plyometric as high-intensity exercise and jogging as mild or moderate intensity exercise. Increase was due to the improvement of neuromuscular characteristics that affect the increase in muscle strength and performance. From the data analysis, researchers concluded that, Exercises of High Intensity Interval Training significantly effect on the increase in Power Limbs, speed, and agility.

Use of Individual Flight Corridors to Avoid Vortex Wakes

NASA Technical Reports Server (NTRS)

Rossow, Vernon J.

2001-01-01

Vortex wakes of aircraft pose a hazard to following aircraft until the energetic parts of their flow fields have decayed to a harmless level. It is suggested here that in-trail spacings between aircraft can be significantly and safely reduced by designing an individual, vortex-free flight corridor for each aircraft. Because each aircraft will then have its own flight corridor, which is free of vortex wakes while in use by the assigned aircraft, the time intervals between aircraft operations can be safely reduced to the order of seconds. The productivity of airports can then be substantially increased. How large the offset distances between operational corridors need to be to have them vortex free, and how airports need to be changed to accommodate an individual flight-corridor process for landing and takeoff operations, are explored. Estimates are then made of the productivity of an individual flight-corridor system as a function of the in-trail time interval between operations for various values of wake decay time, runway width, and the velocity of a sidewind. The results confirm the need for short time intervals between aircraft operations if smaller offset distances and increased productivity are to be achieved.

HESS Opinions: The need for process-based evaluation of large-domain hyper-resolution models

NASA Astrophysics Data System (ADS)

Melsen, Lieke A.; Teuling, Adriaan J.; Torfs, Paul J. J. F.; Uijlenhoet, Remko; Mizukami, Naoki; Clark, Martyn P.

2016-03-01

A meta-analysis on 192 peer-reviewed articles reporting on applications of the variable infiltration capacity (VIC) model in a distributed way reveals that the spatial resolution at which the model is applied has increased over the years, while the calibration and validation time interval has remained unchanged. We argue that the calibration and validation time interval should keep pace with the increase in spatial resolution in order to resolve the processes that are relevant at the applied spatial resolution. We identified six time concepts in hydrological models, which all impact the model results and conclusions. Process-based model evaluation is particularly relevant when models are applied at hyper-resolution, where stakeholders expect credible results both at a high spatial and temporal resolution.

HESS Opinions: The need for process-based evaluation of large-domain hyper-resolution models

NASA Astrophysics Data System (ADS)

Melsen, L. A.; Teuling, A. J.; Torfs, P. J. J. F.; Uijlenhoet, R.; Mizukami, N.; Clark, M. P.

2015-12-01

A meta-analysis on 192 peer-reviewed articles reporting applications of the Variable Infiltration Capacity (VIC) model in a distributed way reveals that the spatial resolution at which the model is applied has increased over the years, while the calibration and validation time interval has remained unchanged. We argue that the calibration and validation time interval should keep pace with the increase in spatial resolution in order to resolve the processes that are relevant at the applied spatial resolution. We identified six time concepts in hydrological models, which all impact the model results and conclusions. Process-based model evaluation is particularly relevant when models are applied at hyper-resolution, where stakeholders expect credible results both at a high spatial and temporal resolution.

Relationship between menstruation status and work conditions in Japan.

PubMed

Nishikitani, Mariko; Nakao, Mutsuhiro; Tsurugano, Shinobu; Inoure, Mariko; Yano, Eiji

2017-01-01

Menstrual problems can significantly impact daily and work life. In reaction to a shrinking population, the Japanese government is encouraging more women to participate in the labor force. Actual success in achieving this aim, however, is limited. Specifically, participation in the workforce by women during their reproductive years is impacted by their health, which involves not only work conditions, but also traditional family circumstances. Therefore, it is important to further assess and gather more information about the health status of women who work during their reproductive years in Japan. Specifically, women's health can be represented by menstruation status, which is a pivotal indicator. In this study, we assessed the association between short rest periods in work intervals and menstruation and other health status indicators among female workers in Japan. Study participants were recruited from the alumnae of a university, which provided a uniform educational level. All 9864 female alumnae were asked to join the survey and 1630 (17%) accepted. The final sample of study participants ( n  = 505) were aged 23-43 years, had maintained the same job status for at least 1 year, and were not shift workers, had no maternal status, and did not lack any related information. The participants were divided into two groups according to interval time, with 11 h between end of work and resumption of daily work as a benchmark. This interval time was based on EU regulations and the goal set by the government of Japan. Health outcomes included: menstrual cycle, dysmenorrhoea symptoms, anxiety regarding health, and satisfaction in terms of health. Multiple logistic regression analyses were conducted to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for health indexes in association with interval time by adjusting for confounding variables that included both psychosocial and biological factors. We compared the health status of women in the workforce with and without a sufficient interval time of 11 h/day. Workers who had a short interval time had a significantly higher prevalence of anxiety about health and dissatisfaction with their health. For menstruation status, only abnormal menstruation cycles were observed more often among workers in the short interval group than those of the long interval group. However, this association disappeared when biological confounding factors were adjusted in a multivariable regression model. Dysmenorrhea symptoms did not show a statistically significant association with short interval time. This study found a significant association between a short interval time of less than 11 h/day and subjective health indicators and the menstrual health status of women in the workforce. Menstrual health was more affected by biological factors than social psychological factors. A long work time and short interval time could increase worker anxiety and dissatisfaction and may deteriorate the menstrual cycle.

Inconsistencies in Numerical Simulations of Dynamical Systems Using Interval Arithmetic

NASA Astrophysics Data System (ADS)

Nepomuceno, Erivelton G.; Peixoto, Márcia L. C.; Martins, Samir A. M.; Rodrigues, Heitor M.; Perc, Matjaž

Over the past few decades, interval arithmetic has been attracting widespread interest from the scientific community. With the expansion of computing power, scientific computing is encountering a noteworthy shift from floating-point arithmetic toward increased use of interval arithmetic. Notwithstanding the significant reliability of interval arithmetic, this paper presents a theoretical inconsistency in a simulation of dynamical systems using a well-known implementation of arithmetic interval. We have observed that two natural interval extensions present an empty intersection during a finite time range, which is contrary to the fundamental theorem of interval analysis. We have proposed a procedure to at least partially overcome this problem, based on the union of the two generated pseudo-orbits. This paper also shows a successful case of interval arithmetic application in the reduction of interval width size on the simulation of discrete map. The implications of our findings on the reliability of scientific computing using interval arithmetic have been properly addressed using two numerical examples.

Tailoring magnetic domains in Gd-Fe thin films

NASA Astrophysics Data System (ADS)

Talapatra, A.; Chelvane, J. Arout; Mohanty, J.

2018-05-01

This paper presents the global modification of magnetic domains and magnetic properties in amorphous Gd19Fe81 thin films with rapid thermal processing at two distinct temperatures (250oC and 450oC), and with different time intervals viz., 2, 5, 10 and 20 minutes. 100 nm thick as-prepared films display nano-scale meandering stripe domains with high magnetic phase contrast which is the signature of perpendicular magnetic anisotropy. The films processed at 250oC for various time intervals show successive reduction in magnetic phase contrast and domain size. The domain pattern completely disappeared, and topography dominated mixed magnetic phase has been obtained for the films processed at 450oC for time intervals greater than 2 minutes. The magnetization measurements indicate the reduction in perpendicular magnetic anisotropy with increase in saturation magnetization for all the rapid thermal processed films. The experimental outputs have been used to simulate the domain pattern. Reduction in uniaxial anisotropy along with the increase in saturation magnetization successfully explain the experimental trend of decrease in domain size and magnetic contrast.

Zinc Chloride Influence on The Resins Furan Polymerization to Foundry Moulds

NASA Astrophysics Data System (ADS)

de Miranda, Leila Figueiredo; Vale, Marcus; Júnior, Antonio Hortêncio Munhoz; Masson, Terezinha Jocelen; de Andrade e Silva, Leonardo Gondin

The resins used in foundry molds developed for the automotive market has led to major changes in the manufacturing method of foundry molds. The polymerization of these resins and a subsequent curing are used to connect to the foundry sand in a rigid structure capable of receiving and holding liquid metal. It is essential to know the process of polymerization of these resins and their impact on the final properties of the obtained molds, especially in the mechanical characteristics. In this work it was studied the influence of the addition of zinc chloride (in solution) in the sand-furan resin mixture, with the aim of reducing the relation between the extraction time intervals and time bench life. The results showed that addition of percentages of the order of 5.0wt% to 7.5wt% zinc chloride solution reduces this ratio between 10% and 17%; this means that the casting model may be extracted from the sand mass in a smaller time interval increasing the productivity of manufacturing molds. It was also observed that there was also an increase of 9% to 18% in bench life intervals.

Parturition in gilts: duration of farrowing, birth intervals and placenta expulsion in relation to maternal, piglet and placental traits.

PubMed

van Rens, Birgitte T T M; van der Lende, Tette

2004-07-01

Large White x Meishan F2 crossbred gilts (n = 57) were observed continuously during farrowing while the placentae of their offspring were labeled in order to examine the duration of farrowing and placenta expulsion in relation to maternal-, piglet- and placental traits and the duration of birth interval in relation to birth weight, birth order and placental traits. Independently from each other, litter size, gestation length and offspring directed aggression significantly (P 0.05) affected duration of farrowing. An increase in litter size was associated with an increase of duration of farrowing and an increase in gestation length was associated with a decrease of duration of farrowing. Aggressive gilts took longer to farrow, compared to non-aggressive ones. After taking into account litter size, gestation length and offspring directed aggression, placental thickness (i.e., placental weight corrected for placental surface area) was significantly (P < 0.05) related to duration of farrowing, i.e., litters with on average thicker placentae took longer to farrow. The latter effect is the result of the fact that individual placental thickness significantly (P < 0.01) affected individual birth interval, independent of birth weight. The piglet has to break its own membranes to be able to start its journey through the uterus towards the birth channel. Apparently, a thicker placenta offers more resistance and thus prolongs the process of birth. Independent of placental thickness, birth interval significantly (P < 0.01) decreased with an increase in birth order (first born to last born). The high variation of birth intervals for the last born piglets, caused a slight increase in average birth interval for the latter piglets. Litters with on average more areolae per placenta took significantly (P < 0.001) less time to be born than litters with on average less areolae per placenta (independent of total number of piglets born and other placental traits), while birth intervals within litters were not affected by this trait. Thus, these results are probably due to a gilt trait rather than a piglet trait. Since the number of areolae represent the number of uterine glands present, the gilt trait might be uterine development. Duration of placenta expulsion significantly (P < 0.01) increased with an increase of duration of farrowing. Furthermore, the first placenta was expelled significantly (P < 0.01) earlier relative to last piglet when duration of farrowing was protracted, while there was no relation of the time interval between first placenta and last piglet and the duration of placenta expulsion. In conclusion, the most important finding of this study is that placental thickness rather than birth weight appears to play an important role in the duration of birth intervals and as a result, of duration of parturition in gilts.

Are calving interval, abortions, incidence of stillbirths and pre-weaning losses in Nguni cows associated with linear type traits?

PubMed

Zindove, T J; Chimonyo, M

2015-09-01

The association of six linear type traits with calving interval, abortions, incidence of stillbirths and pre-weaning losses in Nguni cows in semi-arid and sub-humid communal areas was investigated. It was hypothesised that the odds of a cow having caving interval greater than 1 year, aborting, experiencing stillbirths or losing a calf from calving to weaning decreased with increase in body depth, rump height, flank circumference, chest circumference, navel height and body length. Navel height was measured as the distance from the ground to the lowest point of the cow's belly bottom (navel). Data were collected from a total of 200 Nguni cows from two sites experiencing sub-humid and semi-arid environments (100 each) between May and June 2013. Cows in sub-humid regions were 2.57 times more likely to have a calving interval of 1 year than cows in semi-arid areas. As body depth increased, the number of calves lost by a cow before weaning decreased linearly (p < 0.05) in all parities except parity 4. Cows in semi-arid regions were 2.13 times more likely to lose a calf from calving to weaning. For each unit increase in body depth, the odds of a cow aborting decreased by 1.12 and the odds of a cow having stillbirth decreased by 1.15. Rump height, flank circumference, chest circumference, navel height and body length were not associated with calving interval, abortions, incidence of stillbirths and pre-weaning losses. It was, therefore, concluded that body depth influences calving interval, incidence of stillbirths and abortions in Nguni cows. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of the time interval from harvesting to the pre-drying step on natural fumonisin contamination in freshly harvested corn from the State of Parana, Brazil.

PubMed

Da Silva, M; Garcia, G T; Vizoni, E; Kawamura, O; Hirooka, E Y; Ono, E Y S

2008-05-01

Natural mycoflora and fumonisins were analysed in 490 samples of freshly harvested corn (Zea mays L.) (2003 and 2004 crops) collected at three points in the producing chain from the Northern region of Parana State, Brazil, and correlated to the time interval between the harvesting and the pre-drying step. The two crops showed a similar profile concerning the fungal frequency, and Fusarium sp. was the prevalent genera (100%) for the sampling sites from both crops. Fumonisins were detected in all samples from the three points of the producing chain (2003 and 2004 crops). The levels ranged from 0.11 to 15.32 microg g(-1)in field samples, from 0.16 to 15.90 microg g(-1)in reception samples, and from 0.02 to 18.78 microg g(-1)in pre-drying samples (2003 crop). Samples from the 2004 crop showed lower contamination and fumonisin levels ranged from 0.07 to 4.78 microg g(-1)in field samples, from 0.03 to 4.09 microg g(-1)in reception samples, and from 0.11 to 11.21 microg g(-1)in pre-drying samples. The mean fumonisin level increased gradually from < or = 5.0 to 19.0 microg g(-1)as the time interval between the harvesting and the pre-drying step increased from 3.22 to 8.89 h (2003 crop). The same profile was observed for samples from the 2004 crop. Fumonisin levels and the time interval (rho = 0.96) showed positive correlation (p < or = 0.05), indicating that delay in the drying process can increase fumonisin levels.

Adherence to Analgesics in Oncology Outpatients: Focus on Taking Analgesics on Time.

PubMed

Oldenmenger, Wendy H; Sillevis Smitt, Peter A E; de Raaf, Pleun J; van der Rijt, Carin C D

2017-06-01

Inadequate adherence to prescribed analgesics may be one of the reasons why patients with cancer experience unrelieved pain. Adherence is directly influenced by patients' barriers about pain management. Patient pain education programs (PEPs) have been developed to reduce patients' barriers and increase patients' adherence to their analgesics. The purpose of this article was to evaluate patients' adherence in patients receiving a pain consult and patient pain education in comparison with patients receiving standard pain treatment (standard care [SC]), to better explore the difficulties in medication adherence in cancer-related pain and the effects of PEP. In 54 adult outpatients with cancer-related pain, patients' adherence to the prescribed around-the-clock analgesics was measured with a Medication Event Monitoring System, in the following time intervals: weeks 1 and 2, weeks 3 and 4, and weeks 7 and 8 after randomization. Adherence was differentiated into taking adherence, taking the correct dose, and taking analgesics at the right time intervals. Taking adherence increased in the intervention group compared to baseline (from 91% to 93%) and decreased in the SC group (from 85% to 78%; P < 0.05). At the end of the study, more patients in the intervention group took their analgesics at the right intervals (78%) than did patients in the SC group (64%, P < 0.05). During the study, patients were more adherent to opioids than to World Health Organization step 1 analgesics. The combined intervention can increase adherence. The true problem in pain management is that patients do not take their prescribed analgesics at the right time intervals. With the detailed adherence information from this study, it is possible to further tailor patient education to the individual patient. © 2016 World Institute of Pain.

Constraining response output on conjunctive fixed-ratio 1 fixed-time reinforcement schedules: Effects on the postreinforcement pause.

PubMed

Lopez, F; Pereira, C

1985-03-01

Two experiments used response-restriction procedures in order to test the independence of the factors determining response rate and the factors determining the size of the postreinforcement pause on interval schedules. Responding was restricted by response-produced blackout or by retracting the lever. In Experiment 1 with a Conjunctive FR 1 FT schedule, the blackout procedure reduced the postreinforcement pause more than the lever-retraction procedure did, and both procedures produced shorter pauses than did the schedule without response restriction. In Experiment 2 the interreinforcement interval was also manipulated, and the size of the pause was an increasing function of the interreinforcement interval, but the rate of increase was lower than that produced by fixed interval schedules of comparable interval durations. The assumption of functional independence of the postreinforcement pause and terminal rate in fixed interval schedules is questioned since data suggest that pause reductions resulted from constraining variation in response number compared to equivalent periodic schedules in which response number was allowed to vary. Copyright © 1985. Published by Elsevier B.V.

Effect of dose and dosage interval on the oral bioavailability of docetaxel in combination with a curcumin self-emulsifying drug delivery system (SEDDS).

PubMed

Yan, Yi-Dong; Marasini, Nirmal; Choi, Young Keun; Kim, Jong Oh; Woo, Jong Soo; Yong, Chul Soon; Choi, Han Gon

2012-09-01

The present study investigated the effects of a curcumin self-emulsifying drug delivery systems (SEDDS) on the pharmacokinetics of orally administered docetaxel in rats. A single dose of docetaxel was orally administered (30 mg/kg) alone or after oral curcumin SEDDS (25, 50, 100 and 150 mg/kg) administration with time intervals of 0, 15 and 30 min, respectively. After oral administration, the C (max) and the area under the plasma concentration-time curve (AUC) of docetaxel were significantly increased (0 min, p < 0.05; 15 and 30 min, p < 0.01) by 2.2, 4.7 and 4.6 times and 2.0, 3.8 and 4.1 times compared to that of control group, respectively, after treatment with curcumin SEDDS (100 mg/kg) for each interval. Moreover, The C (max) of docetaxel was increased by 2.6 and 4.4 times in response to 25 and 50 mg/kg curcumin SEDDS treatment, respectively, the corresponding AUC was increased by about 2.4 and 3.1 times, and consequently the absolute bioavailabilities of docetaxel in these two treatment groups were 7.9 and 10.4%, respectively, which showed a significant increase of about 2.4- and 3.2-fold in comparison to the control value (3.3%). However, no further increase in either AUC or C (max) values of docetaxel was observed as the curcumin SEDDS dose was increased from 50 to 150 mg/kg. It is worth noting that the presence of curcumin SEDDS did not significantly decrease the systemic clearance, which was shown by the almost unchanged terminal half-life (t (1/2)) of docetaxel in all treatment groups. Thus, the enhanced bioavailability of oral docetaxel by curcumin SEDDS seemed to be likely due to an inhibition function of cytochrome P450 (CYP) 3A and P-glycoprotein (Pgp) in the intestines of the rats. However, further in vivo studies are needed to verify these hypotheses.

Development and interval testing of a naturalistic driving methodology to evaluate driving behavior in clinical research.

PubMed

Babulal, Ganesh M; Addison, Aaron; Ghoshal, Nupur; Stout, Sarah H; Vernon, Elizabeth K; Sellan, Mark; Roe, Catherine M

2016-01-01

Background : The number of older adults in the United States will double by 2056. Additionally, the number of licensed drivers will increase along with extended driving-life expectancy. Motor vehicle crashes are a leading cause of injury and death in older adults. Alzheimer's disease (AD) also negatively impacts driving ability and increases crash risk. Conventional methods to evaluate driving ability are limited in predicting decline among older adults. Innovations in GPS hardware and software can monitor driving behavior in the actual environments people drive in. Commercial off-the-shelf (COTS) devices are affordable, easy to install and capture large volumes of data in real-time. However, adapting these methodologies for research can be challenging. This study sought to adapt a COTS device and determine an interval that produced accurate data on the actual route driven for use in future studies involving older adults with and without AD.  Methods : Three subjects drove a single course in different vehicles at different intervals (30, 60 and 120 seconds), at different times of day, morning (9:00-11:59AM), afternoon (2:00-5:00PM) and night (7:00-10pm). The nine datasets were examined to determine the optimal collection interval. Results : Compared to the 120-second and 60-second intervals, the 30-second interval was optimal in capturing the actual route driven along with the lowest number of incorrect paths and affordability weighing considerations for data storage and curation. Discussion : Use of COTS devices offers minimal installation efforts, unobtrusive monitoring and discreet data extraction.  However, these devices require strict protocols and controlled testing for adoption into research paradigms.  After reliability and validity testing, these devices may provide valuable insight into daily driving behaviors and intraindividual change over time for populations of older adults with and without AD.  Data can be aggregated over time to look at changes or adverse events and ascertain if decline in performance is occurring.

Quantitative investigation of resolution increase of free-flow electrophoresis via simple interval sample injection and separation.

PubMed

Shao, Jing; Fan, Liu-Yin; Cao, Cheng-Xi; Huang, Xian-Qing; Xu, Yu-Quan

2012-07-01

Interval free-flow zone electrophoresis (FFZE) has been used to suppress sample band broadening greatly hindering the development of free-flow electrophoresis (FFE). However, there has been still no quantitative study on the resolution increase of interval FFZE. Herein, we tried to make a comparison between bandwidths in interval FFZE and continuous one. A commercial dye with methyl green and crystal violet was well chosen to show the bandwidth. The comparative experiments were conducted under the same sample loading of the model dye (viz. 3.49, 1.75, 1.17, and 0.88 mg/h), the same running time (viz. 5, 10, 15, and 20 min), and the same flux ratio between sample and background buffer (= 10.64 × 10⁻³). Under the given conditions, the experiments demonstrated that (i) the band broadening was evidently caused by hydrodynamic factor in continuous mode, and (ii) the interval mode could clearly eliminate the hydrodynamic broadening existing in continuous mode, greatly increasing the resolution of dye separation. Finally, the interval FFZE was successfully used for the complete separation of two-model antibiotics (herein pyoluteorin and phenazine-1-carboxylic acid coexisting in fermentation broth of a new strain Pseudomonas aeruginosa M18), demonstrating the feasibility of interval FFZE mode for separation of biomolecules. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Interpregnancy interval and risk of autistic disorder.

PubMed

Gunnes, Nina; Surén, Pål; Bresnahan, Michaeline; Hornig, Mady; Lie, Kari Kveim; Lipkin, W Ian; Magnus, Per; Nilsen, Roy Miodini; Reichborn-Kjennerud, Ted; Schjølberg, Synnve; Susser, Ezra Saul; Øyen, Anne-Siri; Stoltenberg, Camilla

2013-11-01

A recent California study reported increased risk of autistic disorder in children conceived within a year after the birth of a sibling. We assessed the association between interpregnancy interval and risk of autistic disorder using nationwide registry data on pairs of singleton full siblings born in Norway. We defined interpregnancy interval as the time from birth of the first-born child to conception of the second-born child in a sibship. The outcome of interest was autistic disorder in the second-born child. Analyses were restricted to sibships in which the second-born child was born in 1990-2004. Odds ratios (ORs) were estimated by fitting ordinary logistic models and logistic generalized additive models. The study sample included 223,476 singleton full-sibling pairs. In sibships with interpregnancy intervals <9 months, 0.25% of the second-born children had autistic disorder, compared with 0.13% in the reference category (≥ 36 months). For interpregnancy intervals shorter than 9 months, the adjusted OR of autistic disorder in the second-born child was 2.18 (95% confidence interval 1.42-3.26). The risk of autistic disorder in the second-born child was also increased for interpregnancy intervals of 9-11 months in the adjusted analysis (OR = 1.71 [95% CI = 1.07-2.64]). Consistent with a previous report from California, interpregnancy intervals shorter than 1 year were associated with increased risk of autistic disorder in the second-born child. A possible explanation is depletion of micronutrients in mothers with closely spaced pregnancies.

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.

System implications of the ambulance arrival-to-patient contact interval on response interval compliance.

PubMed

Campbell, J P; Gratton, M C; Salomone, J A; Lindholm, D J; Watson, W A

1994-01-01

In some emergency medical services (EMS) system designs, response time intervals are mandated with monetary penalties for noncompliance. These times are set with the goal of providing rapid, definitive patient care. The time interval of vehicle at scene-to-patient access (VSPA) has been measured, but its effect on response time interval compliance has not been determined. To determine the effect of the VSPA interval on the mandated code 1 (< 9 min) and code 2 (< 13 min) response time interval compliance in an urban, public-utility model system. A prospective, observational study used independent third-party riders to collect the VSPA interval for emergency life-threatening (code 1) and emergency nonlife-threatening (code 2) calls. The VSPA interval was added to the 9-1-1 call-to-dispatch and vehicle dispatch-to-scene intervals to determine the total time interval from call received until paramedic access to the patient (9-1-1 call-to-patient access). Compliance with the mandated response time intervals was determined using the traditional time intervals (9-1-1 call-to-scene) plus the VSPA time intervals (9-1-1 call-to-patient access). Chi-square was used to determine statistical significance. Of the 216 observed calls, 198 were matched to the traditional time intervals. Sixty-three were code 1, and 135 were code 2. Of the code 1 calls, 90.5% were compliant using 9-1-1 call-to-scene intervals dropping to 63.5% using 9-1-1 call-to-patient access intervals (p < 0.0005). Of the code 2 calls, 94.1% were compliant using 9-1-1 call-to-scene intervals. Compliance decreased to 83.7% using 9-1-1 call-to-patient access intervals (p = 0.012). The addition of the VSPA interval to the traditional time intervals impacts system response time compliance. Using 9-1-1 call-to-scene compliance as a basis for measuring system performance underestimates the time for the delivery of definitive care. This must be considered when response time interval compliances are defined.

Nonelective surgery at night and in-hospital mortality: Prospective observational data from the European Surgical Outcomes Study.

PubMed

van Zaane, Bas; van Klei, Wilton A; Buhre, Wolfgang F; Bauer, Peter; Boerma, E Christiaan; Hoeft, Andreas; Metnitz, Philipp; Moreno, Rui P; Pearse, Rupert; Pelosi, Paolo; Sander, Michael; Vallet, Benoit; Pettilä, Ville; Vincent, Jean-Louis; Rhodes, Andrew

2015-07-01

Evidence suggests that sleep deprivation associated with night-time working may adversely affect performance resulting in a reduction in the safety of surgery and anaesthesia. Our primary objective was to evaluate an association between nonelective night-time surgery and in-hospital mortality. We hypothesised that urgent surgery performed during the night was associated with higher in-hospital mortality and also an increase in the duration of hospital stay and the number of admissions to critical care. A prospective cohort study. This is a secondary analysis of a large database related to perioperative care and outcome (European Surgical Outcome Study). Four hundred and ninety-eight hospitals in 28 European countries. Men and women older than 16 years who underwent nonelective, noncardiac surgery were included according to time of the procedure. None. Primary outcome was in-hospital mortality; the secondary outcome was the duration of hospital stay and critical care admission. Eleven thousand two hundred and ninety patients undergoing urgent surgery were included in the analysis with 636 in-hospital deaths (5.6%). Crude mortality odds ratios (ORs) increased sequentially from daytime [426 deaths (5.3%)] to evening [150 deaths (6.0%), OR 1.14; 95% confidence interval 0.94 to 1.38] to night-time [60 deaths (8.3%), OR 1.62; 95% confidence interval 1.22 to 2.14]. Following adjustment for confounding factors, surgery during the evening (OR 1.09; 95% confidence interval 0.91 to 1.31) and night (OR 1.20; 95% confidence interval 0.9 to 1.6) was not associated with an increased risk of postoperative death. Admittance rate to an ICU increased sequentially from daytime [891 (11.1%)], to evening [347 (13.8%)] to night time [149 (20.6%)]. In patients undergoing nonelective urgent noncardiac surgery, in-hospital mortality was associated with well known risk factors related to patients and surgery, but we did not identify any relationship with the time of day at which the procedure was performed. Clinicaltrials.gov identifier: NCT01203605.

Gravity and Neuronal Adaptation. Neurophysiology of Reflexes from Hypo- to Hypergravity Conditions

NASA Astrophysics Data System (ADS)

Ritzmann, Ramona; Krause, Anne; Freyler, Kathrin; Gollhofer, Albert

2017-02-01

Introduction: For interplanetary and orbital missions in human space flight, knowledge about the gravity-sensitivity of the central nervous system (CNS) is required. The objective of this study was to assess neurophysiological correlates in variable hetero gravity conditions in regard to their timing and shaping. Methods: In ten subjects, peripheral nerve stimulation was used to elicit H-reflexes and M-waves in the M. soleus in Lunar, Martian, Earth and hypergravity. Gravity-dependencies were described by means of reflex latency, inter-peak-interval, duration, stimulation threshold and maximal amplitudes. Experiments were executed during the CNES/ESA/DLR JEPPFs. Results: H-reflex latency, inter-peak-interval and duration decreased with increasing gravitation (P<0.05); likewise, M-wave inter-peak-interval was diminished and latency prolonged with increasing gravity (P<0.05). Stimulation threshold of H-reflexes and M-waves decreased (P<0.05) while maximal amplitudes increased with an increase in gravitation (P<0.05). Conclusion: Adaptations in neurophysiological correlates in hetero gravity are associated with a shift in timing and shaping. For the first time, our results indicate that synaptic and axonal nerve conduction velocity as well as axonal and spinal excitability are diminished with reduced gravitational forces on the Moon and Mars and gradually increased when gravitation is progressively augmented up to hypergravity. Interrelated with the adaptation in threshold we conclude that neuronal circuitries are significantly affected by gravitation. As a consequence, movement control and countermeasures may be biased in extended space missions involving transitions between different force environments.

Reproductive phenology of transgenic Brassica napus cultivars: Effect on intraspecific gene flow.

PubMed

Simard, Marie-Josée; Légère, Anne; Willenborg, Christian J

2009-01-01

Pollen-mediated gene flow in space is well documented and isolation distances are recommended to ensure genetic purity of Brassica napus seed crops. Isolation in time could also contribute to gene flow management but has been little investigated. We assessed the effects of asynchronous and synchronous flowering on intraspecific B. napus gene flow by seeding adjacent plots of transgenic spring canola cultivars, either resistant to glyphosate or glufosinate, over a 0-4 week interval and measuring outcrossing rates and seed-set. Outcrossing rates, evaluated in the center of the first adjacent row, were reduced to the lowest level in plots flowering first when the seeding interval > 2 weeks. Increasing the time gap increased outcrossing rates in plots flowering second up to a seeding interval of two weeks. Flowers that opened during the last week of the flowering period produced fewer seed (< 10% of total seed production) and a smaller fraction of outcrossed seed (-25%). Observed time gap effects were likely caused by extraneous pollen load during the receptivity of productive seed-setting early flowers. Clearly, manipulation of B. napus flowering development through staggered planting dates can contribute to gene flow management. The approach will need to be validated by additional site-years and increased isolation distances.

Reaction time in pilots during intervals of high sustained g.

PubMed

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

2014-11-01

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

Temporal prediction restores the evaluative processing of delayed action feedback: an electrophysiological study.

PubMed

Kimura, Kenta; Kimura, Motohiro

2016-09-28

The evaluative processing of the valence of action feedback is reflected by an event-related brain potential component called feedback-related negativity (FRN) or reward positivity (RewP). Recent studies have shown that FRN/RewP is markedly reduced when the action-feedback interval is long (e.g. 6000 ms), indicating that an increase in the action-feedback interval can undermine the evaluative processing of the valence of action feedback. The aim of the present study was to investigate whether or not such undermined evaluative processing of delayed action feedback could be restored by improving the accuracy of the prediction in terms of the timing of action feedback. With a typical gambling task in which the participant chose one of two cards and received an action feedback indicating monetary gain or loss, the present study showed that FRN/RewP was significantly elicited even when the action-feedback interval was 6000 ms, when an auditory stimulus sequence was additionally presented during the action-feedback interval as a temporal cue. This result suggests that the undermined evaluative processing of delayed action feedback can be restored by increasing the accuracy of the prediction on the timing of the action feedback.

EIVAN - AN INTERACTIVE ORBITAL TRAJECTORY PLANNING TOOL

NASA Technical Reports Server (NTRS)

Brody, A. R.

1994-01-01

The Interactive Orbital Trajectory planning Tool, EIVAN, is a forward looking interactive orbit trajectory plotting tool for use with Proximity Operations (operations occurring within a one kilometer sphere of the space station) and other maneuvers. The result of vehicle burns on-orbit is very difficult to anticipate because of non-linearities in the equations of motion governing orbiting bodies. EIVAN was developed to plot resulting trajectories, to provide a better comprehension of orbital mechanics effects, and to help the user develop heuristics for onorbit mission planning. EIVAN comprises a worksheet and a chart from Microsoft Excel on a Macintosh computer. The orbital path for a user-specified time interval is plotted given operator burn inputs. Fuel use is also calculated. After the thrust parameters (magnitude, direction, and time) are input, EIVAN plots the resulting trajectory. Up to five burns may be inserted at any time in the mission. Twenty data points are plotted for each burn and the time interval can be varied to accommodate any desired time frame or degree of resolution. Since the number of data points for each burn is constant, the mission duration can be increased or decreased by increasing or decreasing the time interval. The EIVAN program runs with Microsoft's Excel for execution on a Macintosh running Macintosh OS. A working knowledge of Excel is helpful, but not imperative, for interacting with EIVAN. The program was developed in 1989.

Effect of the time interval between fusion and activation on epigenetic reprogramming and development of bovine somatic cell nuclear transfer embryos.

PubMed

Liu, Jun; Wang, Yongsheng; Su, Jianmin; Wang, Lijun; Li, Ruizhe; Li, Qian; Wu, Yongyan; Hua, Song; Quan, Fusheng; Guo, Zekun; Zhang, Yong

2013-04-01

Previous studies have shown that the time interval between fusion and activation (FA interval) play an important role in nuclear remodeling and in vitro development of somatic cell nuclear transfer (SCNT) embryos. However, the effects of FA interval on the epigenetic reprogramming and in vivo developmental competence of SCNT embryos remain unknown. In the present study, the effects of different FA intervals (0 h, 2 h, and 4 h) on the epigenetic reprogramming and developmental competence of bovine SCNT embryos were assessed. The results demonstrated that H3 lysine 9 (H3K9ac) levels decreased rapidly after fusion in all three groups. H3K9ac was practically undetectable 2 h after fusion in the 2-h and 4-h FA interval groups. However, H3K9ac was still evidently detectable in the 0-h FA interval group. The H3K9ac levels increased 10 h after fusion in all three groups, but were higher in the 2-h and 4-h FA interval groups than that in the 0-h FA interval group. The methylation levels of the satellite I region in day-7 blastocysts derived from the 2-h or 4-h FA interval groups was similar to that of in vitro fertilization blastocysts and is significantly lower than that of the 0-h FA interval group. SCNT embryos derived from 2-h FA interval group showed higher developmental competence than those from the 0-h and 4-h FA interval groups in terms of cleavage rate, blastocyst formation rate, apoptosis index, and pregnancy and calving rates. Hence, the FA interval is an important factor influencing the epigenetic reprogramming and developmental competence of bovine SCNT embryos.

Functional and histological bladder damage in mice after photodynamic therapy: the influence of sensitiser dose and time of administration.

PubMed Central

Stewart, F. A.; Oussoren, Y.

1993-01-01

The bladders of anaesthetised mice were illuminated with red laser light (630 nm) at intervals of 1 day to 4 weeks after i.p. administration of Photofrin. Light was delivered intravesically by inserting a fibre optic, with a diffusing bulb tip, into the centre of fluid filled bladders. A single light dose of 11.3 J cm-2 applies 1 day after 10 mg kg-1 Photofrin caused a severe acute response, with increased urination frequency (five to seven times control) and hematuria. Recovery was good, however, and by 10 weeks only a mild (approximately two-fold) increase in frequency remained. There was no reduction in the amount of acute bladder damage or in the rate of healing when the interval between Photofrin and light was increased from 1 to 7 days but a 2 to 3 week interval lead to a significant reduction in damage. For an interval of 4 weeks there was only a mild (less than two-fold) increase in urination frequency during the first week. A drug dose of 2.5 mg kg-1 given 1 day before illumination caused transient haematuria but no increase in urination frequency. Doses of 5, 7.5 or 10 mg kg-1 all caused photosensitisation and the amount of bladder damage was drug dose dependent. The bladder seems to be well able to recover from severe acute damage induced by PDT. Occasional incidences of pyelonephritis were seen, however, suggesting that urinary tract infection during the acute period may lead to permanent renal damage. Images Figure 5 PMID:8398691

Effects of an Extended Cage-change Interval on Ammonia Levels and Reproduction in Mongolian Gerbils (Meriones unguiculatus).

PubMed

McCullagh, Elizabeth A; McCullagh, Peter; Klug, Achim; Leszczynski, Jori K; Fong, Derek L

2017-11-01

Prompted by the cage cleanliness of Mongolian gerbils (Meriones unguiculatus), we evaluated a prolonged cage-change interval. We compared the effects of a 2-wk and 6-wk cage-change schedule on ammonia levels, temperature, humidity, and reproductive performance in breeding pairs housed in IVC. We hypothesized that ammonia levels would remain below our threshold for cage changing and that reproductive performance would not be affected. Although ammonia levels increased over time, they remained low (less than 5 ppm) over the 6-wk period. In addition, the 6-wk cage-change interval did not significantly influence reproductive parameters, such as average pup weaning weight, number of litters, and number of pups per litter. We conclude that an extended cage-change interval (6-wk) can be used for gerbils without significant increases in intracage ammonia levels or effects on reproduction.

Role of enamel deminerlization and remineralization on microtensile bond strength of resin composite.

PubMed

Rizvi, Abbas; Zafar, Muhammad S; Al-Wasifi, Yasser; Fareed, Wamiq; Khurshid, Zohaib

2016-01-01

This study is aimed to establish the microtensile bond strength of enamel following exposure to an aerated drink at various time intervals with/without application of remineralization agent. In addition, degree of remineralization and demineralization of tooth enamel has been assessed using polarized light microscopy. Seventy extracted human incisors split into two halves were immersed in aerated beverage (cola drink) for 5 min and stored in saliva until the time of microtensile bond testing. Prepared specimens were divided randomly into two study groups; remineralizing group (n = 70): specimens were treated for remineralization using casein phosphopeptides and amorphous calcium phosphate (CPP-ACP) remineralization agent (Recaldent™; GC Europe) and control group (n = 70): no remineralization treatment; specimens were kept in artificial saliva. All specimens were tested for microtensile bond strength at regular intervals (1 h, 1 days, 2 days, 1 week, and 2 weeks) using a universal testing machine. The results statistically analyzed (P = 0.05) using two-way ANOVA test. Results showed statistically significant increase in bond strength in CPP-ACP tested group (P < 0.05) at all-time intervals. The bond strength of remineralizing group samples at 2 days (~13.64 megapascals [MPa]) is comparable to that of control group after 1 week (~12.44 MPa). CPP-ACP treatment of teeth exposed to an aerated drink provided significant increase in bond strength at a shorter interval compared to teeth exposed to saliva alone.

Behavioral regulation of gravity - Schedule effects under escape-avoidance procedures

NASA Technical Reports Server (NTRS)

Clark, F. C.; Lange, K. O.; Belleville, R. E.

1973-01-01

Squirrel monkeys were restrained in a centrifuge capsule and trained to escape and avoid increases in artificial gravity. During escape-avoidance, lever responses reduced centrifugally simulated gravity or postponed scheduled increases. The effect of variation in the interval of postponement (equal to the duration of decrease produced by escape responses) was studied under a multiple schedule of four components. Three components were gravity escape-avoidance with postponement times of 20, 40, and 60 sec. The fourth component was extinction. Each component was associated with a different auditory stimulus. Rate of responding decreased with increasing postponement time and higher mean g-levels occurred at shorter intervals of postponement. Effects of the schedule parameter on response rate and mean g-level were similar to effects of the schedule on free-operant avoidance and on titration behavior maintained by shock.

Time Determines the Neural Circuit Underlying Associative Fear Learning

PubMed Central

Guimarãis, Marta; Gregório, Ana; Cruz, Andreia; Guyon, Nicolas; Moita, Marta A.

2011-01-01

Ultimately associative learning is a function of the temporal features and relationships between experienced stimuli. Nevertheless how time affects the neural circuit underlying this form of learning remains largely unknown. To address this issue, we used single-trial auditory trace fear conditioning and varied the length of the interval between tone and foot-shock. Through temporary inactivation of the amygdala, medial prefrontal-cortex (mPFC), and dorsal-hippocampus in rats, we tested the hypothesis that different temporal intervals between the tone and the shock influence the neuronal structures necessary for learning. With this study we provide the first experimental evidence showing that temporarily inactivating the amygdala before training impairs auditory fear learning when there is a temporal gap between the tone and the shock. Moreover, imposing a short interval (5 s) between the two stimuli also relies on the mPFC, while learning the association across a longer interval (40 s) becomes additionally dependent on a third structure, the dorsal-hippocampus. Thus, our results suggest that increasing the interval length between tone and shock leads to the involvement of an increasing number of brain areas in order for the association between the two stimuli to be acquired normally. These findings demonstrate that the temporal relationship between events is a key factor in determining the neuronal mechanisms underlying associative fear learning. PMID:22207842

Time from cervical conization to pregnancy and preterm birth.

PubMed

Himes, Katherine P; Simhan, Hyagriv N

2007-02-01

To estimate whether the time interval between cervical conization and subsequent pregnancy is associated with risk of preterm birth. Our study is a case control study nested in a retrospective cohort. Women who underwent colposcopic biopsy or conization with loop electrosurgical excision procedure, large loop excision of the transformation zone, or cold knife cone and subsequently delivered at our hospital were identified with electronic databases. Variables considered as possible confounders included maternal race, age, marital status, payor status, years of education, self-reported tobacco use, history of preterm delivery, and dimensions of cone specimen. Conization was not associated with preterm birth or any subtypes of preterm birth. Among women who underwent conization, those with a subsequent preterm birth had a shorter conization-to-pregnancy interval (337 days) than women with a subsequent term birth (581 days) (P=.004). The association between short conization-to-pregnancy interval and preterm birth remained significant when controlling for confounders including race and cone dimensions. The effect of short conization-to-pregnancy interval on subsequent preterm birth was more persistent among African Americans when compared with white women. Women with a short conization-to-pregnancy interval are at increased risk for preterm birth. Women of reproductive age who must have a conization procedure can be counseled that conceiving within 2 to 3 months of the procedure may be associated with an increased risk of preterm birth. II.

The Effects of Spatial Stimulus-Response Compatibility on Choice Time Production Accuracy and Variability

ERIC Educational Resources Information Center

Rakitin, Brian C.

2005-01-01

Five experiments examined the relations between timing and attention using a choice time production task in which the latency of a spatial choice response is matched to a target interval (3 or 5 s). Experiments 1 and 2 indicated that spatial stimulus-response incompatibility increased nonscalar timing variability without affecting timing accuracy…

Slow wave contraction frequency plateaus in the small intestine are composed of discrete waves of interval increase associated with dislocations.

PubMed

Parsons, Sean P; Huizinga, Jan D

2018-06-03

What is the central question of this study? What is the nature of slow wave driven contraction frequency gradients in the small intestine? What is the main finding and its importance? Frequency plateaus are composed of discrete waves of increased interval, each wave associated with a contraction dislocation. Smooth frequency gradients are generated by localised neural modulation of wave frequency, leading to functionally important wave turbulence. Both patterns are emergent properties of a network of coupled oscillators, the interstitial cells of Cajal. A gut-wide network of interstitial cells of Cajal (ICC) generate electrical oscillations (slow waves) that orchestrate waves of muscle contraction. In the small intestine there is a gradient in slow wave frequency from high at the duodenum to low at the terminal ileum. Time-averaged measurements of frequency have suggested either a smooth or stepped (plateaued) gradient. We measured individual contraction intervals from diameter maps of the mouse small intestine to create interval maps (IMaps). IMaps showed that each frequency plateau was composed of discrete waves of increased interval. Each interval wave originated at a terminating contraction wave, a "dislocation", at the plateau's proximal boundary. In a model chain of coupled phase oscillators, interval wave frequency increased as coupling decreased or as the natural frequency gradient or noise increased. Injuring the intestine at a proximal point to destroy coupling, suppressed distal steps which then reappeared with gap junction block by carbenoxolone. This lent further support to our previous hypothesis that lines of dislocations were fixed by points of low coupling strength. Dislocations induced by electrical field pulses in the intestine and by equivalent phase shift in the model, were associated with interval waves. When the enteric nervous system was active, IMaps showed a chaotic, turbulent pattern of interval change with no frequency steps or plateaus. This probably resulted from local, stochastic release of neurotransmitters. Plateaus, dislocations, interval waves and wave turbulence arise from a dynamic interplay between natural frequency and coupling in the ICC network. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Comparative evaluation of human pulp tissue dissolution by different concentrations of chlorine dioxide, calcium hypochlorite and sodium hypochlorite: An in vitro study

PubMed Central

Taneja, Sonali; Mishra, Neha; Malik, Shubhra

2014-01-01

Introduction: Irrigation plays an indispensable role in removal of tissue remnants and debris from the complicated root canal system. This study compared the human pulp tissue dissolution by different concentrations of chlorine dioxide, calcium hypochlorite and sodium hypochlorite. Materials and Methods: Pulp tissue was standardized to a weight of 9 mg for each sample. In all,60 samples obtained were divided into 6 groups according to the irrigating solution used- 2.5% sodium hypochlorite (NaOCl), 5.25% NaOCl, 5% calcium hypochlorite (Ca(OCl)2), 10% Ca(OCl)2, 5%chlorine dioxide (ClO2) and 13% ClO2. Pulp tissue was placed in each test tube carrying irrigants of measured volume (5ml) according to their specified subgroup time interval: 30 minutes (Subgroup A) and 60 minutes (Subgroup B). The solution from each sample test tube was filtered and was left for drying overnight. The residual weight was calculated by filtration method. Results: Mean tissue dissolution increases with increase in time period. Results showed 5.25% NaOCl to be most effective at both time intervals followed by 2.5% NaOCl at 60 minutes, 10%Ca(OCl)2 and 13% ClO2 at 60 minutes. Least amount of tissue dissolving ability was demonstrated by 5% Ca(OCl)2 and 5% ClO2 at 30 minutes. Distilled water showed no pulp tissue dissolution. Conclusion: Withinthe limitations of the study, NaOCl most efficiently dissolved the pulp tissue at both concentrations and at both time intervals. Mean tissue dissolution by Ca(OCl)2 and ClO2 gradually increased with time and with their increase in concentration. PMID:25506141

Conditioned [corrected] stimulus informativeness governs conditioned stimulus-unconditioned stimulus associability.

PubMed

Ward, Ryan D; Gallistel, C R; Jensen, Greg; Richards, Vanessa L; Fairhurst, Stephen; Balsam, Peter D

2012-07-01

In a conditioning protocol, the onset of the conditioned stimulus ([CS]) provides information about when to expect reinforcement (unconditioned stimulus [US]). There are two sources of information from the CS in a delay conditioning paradigm in which the CS-US interval is fixed. The first depends on the informativeness, the degree to which CS onset reduces the average expected time to onset of the next US. The second depends only on how precisely a subject can represent a fixed-duration interval (the temporal Weber fraction). In three experiments with mice, we tested the differential impact of these two sources of information on rate of acquisition of conditioned responding (CS-US associability). In Experiment 1, we showed that associability (the inverse of trials to acquisition) increased in proportion to informativeness. In Experiment 2, we showed that fixing the duration of the US-US interval or the CS-US interval or both had no effect on associability. In Experiment 3, we equated the increase in information produced by varying the C/T ratio with the increase produced by fixing the duration of the CS-US interval. Associability increased with increased informativeness, but, as in Experiment 2, fixing the CS-US duration had no effect on associability. These results are consistent with the view that CS-US associability depends on the increased rate of reward signaled by CS onset. The results also provide further evidence that conditioned responding is temporally controlled when it emerges.

CS Informativeness Governs CS-US Associability

PubMed Central

Ward, Ryan D.; Gallistel, C. R.; Jensen, Greg; Richards, Vanessa L.; Fairhurst, Stephen; Balsam, Peter D

2012-01-01

In a conditioning protocol, the onset of the conditioned stimulus (CS) provides information about when to expect reinforcement (the US). There are two sources of information from the CS in a delay conditioning paradigm in which the CS-US interval is fixed. The first depends on the informativeness, the degree to which CS onset reduces the average expected time to onset of the next US. The second depends only on how precisely a subject can represent a fixed-duration interval (the temporal Weber fraction). In three experiments with mice, we tested the differential impact of these two sources of information on rate of acquisition of conditioned responding (CS-US associability). In Experiment 1, we show that associability (the inverse of trials to acquisition) increases in proportion to informativeness. In Experiment 2, we show that fixing the duration of the US-US interval or the CS-US interval or both has no effect on associability. In Experiment 3, we equated the increase in information produced by varying the C̅/T̅ ratio with the increase produced by fixing the duration of the CS-US interval. Associability increased with increased informativeness, but, as in Experiment 2, fixing the CS-US duration had no effect on associability. These results are consistent with the view that CS-US associability depends on the increased rate of reward signaled by CS onset. The results also provide further evidence that conditioned responding is temporally controlled when it emerges. PMID:22468633

A novel handheld device for use in remote patient monitoring of heart failure patients--design and preliminary validation on healthy subjects.

PubMed

Pollonini, Luca; Rajan, Nithin O; Xu, Shuai; Madala, Sridhar; Dacso, Clifford C

2012-04-01

Remote patient monitoring (RPM) holds great promise for reducing the burden of congestive heart failure (CHF). Improved sensor technology and effective predictive algorithms can anticipate sudden decompensation events. Enhanced telemonitoring systems would promote patient independence and facilitate communication between patients and their physicians. We report the development of a novel hand-held device, called Blue Box, capable of collecting and wirelessly transmitting key cardiac parameters derived from three integrated biosensors: 2 lead electrocardiogram (ECG), photoplethysmography and bioelectrical impedance (bioimpedance). Blue Box measurements include time intervals between consecutive ECG R-waves (RR interval), time duration of the ECG complex formed by the Q, R and S waves (QRS duration), bioimpedance, heart rate and systolic time intervals. In this study, we recruited 24 healthy subjects to collect several parameters measured by Blue Box and assess their value in correlating with cardiac output measured with Echo-Doppler. Linear correlation between the heart rate measured with Blue Box and cardiac output from Echo-Doppler had a group average correlation coefficient of 0.80. We found that systolic time intervals did not improve the model significantly. However, STIs did inversely correlate with increasing workloads.

Effect of time delay on surgical performance during telesurgical manipulation.

PubMed

Fabrizio, M D; Lee, B R; Chan, D Y; Stoianovici, D; Jarrett, T W; Yang, C; Kavoussi, L R

2000-03-01

Telementoring allows a less experienced surgeon to benefit from an expert surgical consultation, reducing cost, travel, and the learning curve associated with new procedures. However, there are several technical limitations that affect practical applications. One potentially serious problem is the time delay that occurs any time data are transferred across long distances. To date, the effect of time delay on surgical performance has not been studied. A two-phase trial was designed to examine the effect of time delay on surgical performance. In the first phase, a series of tasks was performed, and the numbers of robotic movements required for completion was counted. Programmed incremental time delays were made in audiovisual acquisition and robotic controls. The number of errors made while performing each task at various time delay intervals was noted. In the second phase, a remote surgeon in Baltimore performed the tasks 9000 miles away in Singapore. The number of errors made was recorded. As the time delay increased, the number of operator errors increased. The accuracy needed to perform remote robotic procedures was diminished as the time delay increased. A learning curve did exist for each task, but as the time delay interval increased, it took longer to complete the task. Time delay does affect surgical performance. There is an acceptable delay of <700 msec in which surgeons can compensate for this phenomenon. Clinical studies will be needed to evaluate the true impact of time delay.

A Time Interval of More Than 18 Months Between a Pregnancy and a Roux-en-Y Gastric Bypass Increases the Risk of Iron Deficiency and Anaemia in Pregnancy.

PubMed

Crusell, Mie; Nilas, Lisbeth; Svare, Jens; Lauenborg, Jeannet

2016-10-01

The aim of the study is to explore the impact of time between Roux-en-Y gastric bypass (RYGB) and pregnancy on obstetrical outcome and nutritional derangements. In a retrospective cross-sectional study of pregnant women admitted for antenatal care at two tertiary hospitals, we examined 153 women with RYGB and a singleton pregnancy of at least 24 weeks. The women were stratified according to a pregnancy <18 months (40 women) or ≥18 months (113 women) after RYGB. Main outcome measures were nutritional parameters and glycated haemoglobin 1Ac (HbA1c) in second and third trimester of pregnancy, gestational hypertension, length of pregnancy, mode of delivery and foetal birth weight. The two groups were comparable regarding age, parity and prepregnancy body mass index. The frequency of iron deficiency anaemia (ferritin <12 μg/L and haemoglobin <6.5 mmol/L/10.5 g/dL) was significantly higher in the late group, 29 vs. 8 % in the early group, p = 0.010. No differences were found for vitamin B12, vitamin D and zinc. Median HbA1c was significantly higher in the late group than in the early group (33 vs. 31 mmol/mol, p = 0.027). There were no significant differences in the risk of adverse pregnancy outcome or birth weight between the two groups. A long surgery-to-pregnancy time interval after a RYGB increases the risk of iron deficiency anaemia but not of other nutritional deficits. Time interval does not seem to have an adverse effect on the obstetrical outcome, including intrauterine growth restriction. Specific attention is needed on iron deficit with increasing surgery-to-pregnancy time interval.

B-type natriuretic peptide and echocardiography reflect volume changes during pregnancy

PubMed Central

Burlingame, Janet M.; Yamasato, Kelly; Ahn, Hyeong Jun; Seto, Todd; Tang, W. H. Wilson

2017-01-01

Objective To evaluate B-type natriuretic peptide (BNP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) and cardiac structure and function in normal women through pregnancy and the postpartum. Methods In this prospective observational study, we obtained serial transthoracic echocardiograms, BNP, and NT-proBNP at seven intervals from 6 weeks’ gestation through 12 months postpartum. Women with hypertension or cardiac disease were excluded. Using 6–12 months postpartum as reference for non-pregnant levels, echocardiogram measurements and BNP/NT-proBNP were compared over time using linear mixed models with Tukey-Kramer adjustment for multiple comparisons. Results Of 116 patients, data was available for 78–114 healthy pregnant or postpartum women within each time interval, and 102 patients provided data for ≥ 4 intervals. Compared to 6–12 months postpartum, BNP and NT-proBNP remained stable through pregnancy and delivery, increased within 48 h postpartum (P < 0.0001), then returned to baseline. Left ventricular volume increased within 48 h postpartum (P = 0.021) while left atrial volume increased at 18–24 weeks (P = 0.0002), 30–36 weeks (P < 0.0001) and within 48 h postpartum (P = 0.002). The transmittal early/late diastolic velocity (E/A) ratio, transmittal early/peak mitral annulus diastolic velocity (E/E′) ratio, isovolumic relaxation times, and mitral valve deceleration times were similar within 48 h and 6–12 months postpartum. Conclusion In normal women, BNP/NT-proBNP, left atrial, and left ventricular volumes increase within 48 h postpartum without indications of altered diastolic function. PMID:28195551

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

PubMed Central

Hackenberg, T D; Hineline, P N

1992-01-01

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

Effect of Cypermethrin on the Growth of Ciliate Protozoan Paramecium caudatum.

PubMed

Dutta, Joydeep

2015-01-01

The objective of this study is to assess the effect of cypermethrin on the growth of ciliate protozoan Paramecium caudatum. Monoxenic culture of P. caudatum, were exposed to different doses (0.01, 0.05, 0.1, 0.15, and 0.2 µg/L) of cypermethrin along with control for 24, 48, 72, and 96 h time interval. The total numbers of live and dead cells were counted after trypan blue staining in Neubauer hemocytometer. Marked decrease in the number of living cells with the increase in the concentration of cypermethrin and with increasing exposure time intervals was recorded. The results indicate that cypermethrin is toxic to P. caudatum even at low concentrations when it enters in the aquatic system through runoff.

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.

Temporal Integration of Auditory Information Is Invariant to Temporal Grouping Cues

PubMed

Liu, Andrew S K; Tsunada, Joji; Gold, Joshua I; Cohen, Yale E

2015-01-01

Auditory perception depends on the temporal structure of incoming acoustic stimuli. Here, we examined whether a temporal manipulation that affects the perceptual grouping also affects the time dependence of decisions regarding those stimuli. We designed a novel discrimination task that required human listeners to decide whether a sequence of tone bursts was increasing or decreasing in frequency. We manipulated temporal perceptual-grouping cues by changing the time interval between the tone bursts, which led to listeners hearing the sequences as a single sound for short intervals or discrete sounds for longer intervals. Despite these strong perceptual differences, this manipulation did not affect the efficiency of how auditory information was integrated over time to form a decision. Instead, the grouping manipulation affected subjects' speed-accuracy trade-offs. These results indicate that the temporal dynamics of evidence accumulation for auditory perceptual decisions can be invariant to manipulations that affect the perceptual grouping of the evidence.

Sedimentological and Stable Isotope Changes at the Messinian-Pliocene Boundary Along a West to East Mediterranean Transect.

NASA Astrophysics Data System (ADS)

Pierre, C.; Rouchy, J.; Blanc-Valleron, M.

2001-12-01

During Messinian times, the whole Mediterranean area was submitted to evaporitic conditions which ended by the "Lago-Mare" brackish episode before the reset of open marine conditions in the early Pliocene. These major paleoceanographic changes resulted from regional tectonic reorganizations and global climate changes at this critical time interval, both acting to modify drastically the physiography and the hydrological budget of the Mediterranean basins. There exist outcropping sections and a few deep-sea ODP cores which contain the complete and continuous sedimentary sequence of the Messinian-Pliocene boundary (MPB), making it possible to follow the paleoenvironmental changes at a high resolution scale. We compare here sedimentological and carbonate stable isotope records on three sections for which a high- resolution sampling was applied to the 2 meters thick interval including the MPB. In the Vera section from South Spain, there is no clear change in the carbonate content of the silty clay succession when crossing the MPB. The oxygen and carbon isotopic compositions of calcite both increase by 1 permil across a 40 cm-thick interval which corresponds to the Messinian-Pliocene transition. At ODP Site 968 from the eastern Levantine basin, there is an important sedimentary change between Messinian brown silty clays containing about 20 percent of carbonate and Pliocene gray nannofossil ooze which carbonate content averages 60 percent. Across this 10 cm-thick transitional interval, the oxygen and carbon isotopic compositions of bulk calcite both increase by 4.5 permil. In the Pissouri section from Cyprus, the uppermost Messinian reddish to brown marls with paleosoils are overlain by white Pliocene marls. The carbonate content increases from 20 percent to reach 60 percent across a 40 cm-thick transitional interval. Within this interval corresponding to the MPB, the oxygen and carbon isotopic compositions increase by 4 permil and 2 permil respectively. These results indicate that the MPB is recorded everywhere from W to E Mediterranean by significant and sharp increases in the oxygen and carbon isotopic compositions, which indicate that the early Pliocene marine flooding of the Mediterranean basins was a very abrupt event.

Changes in cancer incidence patterns among a northeastern American Indian population: 1955-1969 versus 1990-2004.

PubMed

Mahoney, Martin C; Va, Puthiery; Stevens, Adrian; Kahn, Amy R; Michalek, Arthur M

2009-01-01

This manuscript examines shifts in patterns of cancer incidence among the Seneca Nation of Indians (SNI) for the interval 1955-1969 compared to 1990-2004. A retrospective cohort design was used to examine cancer incidence among the SNI during 2 time intervals: 1955-1969 and 1990-2004. Person-years at risk were multiplied by cancer incidence rates for New York State, exclusive of New York City, over 5-year intervals. A computer-aided match with the New York State Cancer Registry was used to identify incident cancers. Overall and site-specific standardized incidence ratios (SIRs = observed/expected x 100), and 95% confidence intervals (CIs), were calculated for both time periods. During the earlier interval, deficits in overall cancer incidence were noted among males (SIR = 56, CI 36-82) and females (SIR = 71, CI 50-98), and for female breast cancers (SIR = 21, CI 4-62). During the more recent intervals, deficits in overall cancer incidence persisted among both genders (males SIR = 63, CI 52-77; females SIR = 67, CI 55-80). Deficits were also noted among males for cancers of the lung (SIR = 60, CI 33-98), prostate (SIR = 51, CI = 33-76) and bladder (SIR = 17, CI = 2-61) and among females for breast (SIR = 33, CI = 20-53) and uterus (SIR = 36, CI = 10-92). No cancer sites demonstrated increased incidence. Persons ages 60-69 years, 70-79 years, and ages 80+ years tended to exhibit deficits in overall incidence. Despite marked changes over time, deficits in overall cancer incidence have persisted between the time intervals studied. Tribal-specific cancer data are important for the development and implementation of comprehensive cancer control plans which align with local needs.

Separating the effects of interreinforcement time and number of interreinforcement responses1

PubMed Central

Neuringer, Allen J.; Schneider, Bruce A.

1968-01-01

The relative importance of interreinforcement time and interreinforcement responses was evaluated by varying each independently. To do this, a blackout was presented after each nonreinforced response under both fixed-ratio and fixed-interval schedules of reinforcement. Manipulating the blackout duration under the fixed-ratio schedule caused interreinforcement time to vary without affecting the number of interreinforcement responses. Pigeons' post-reinforcement and post-blackout response latencies were found to increase linearly with interreinforcement time. Under the fixed-interval schedule, the same blackout manipulations changed the number of interreinforcement responses without affecting interreinforcement time. Post-reinforcement and post-blackout response latencies under this condition were approximately constant. These results suggest that responding is controlled by interreinforcement time and is not influenced by the number of responses emitted between reinforcements. PMID:16811313

Coupling between perception and action timing during sensorimotor synchronization.

PubMed

Serrien, Deborah J; Spapé, Michiel M

2010-12-17

Time is an important parameter in behaviour, especially when synchronization with external events is required. To evaluate the nature of the association between perception and action timing, this study introduced pitch accented tones during performance of a sensorimotor tapping task. Furthermore, regularity of the pacing cues was modified by small (subliminal) or large (conscious) timing perturbations. A global analysis across the intervals showed that repeated accented tones increased the tap-tone asynchrony in the regular (control) and irregular (subliminal) trials but not in the irregular trials with awareness of the perturbations. Asynchrony variability demonstrated no effect of accentuation in the regular and subliminal irregular trials, whereas it increased in the conscious irregular trials. A local analysis of the intervals showed that pitch accentuation lengthened the duration of the tapping responses, but only in the irregular trials with large timing perturbations. These data underline that common timing processes are automatically engaged for perception and action, although this arrangement can be overturned by cognitive intervention. Overall, the findings highlight a flexible association between perception and action timing within a functional information processing framework. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Endogenous modulation of low frequency oscillations by temporal expectations

PubMed Central

Cravo, Andre M.; Rohenkohl, Gustavo; Wyart, Valentin

2011-01-01

Recent studies have associated increasing temporal expectations with synchronization of higher frequency oscillations and suppression of lower frequencies. In this experiment, we explore a proposal that low-frequency oscillations provide a mechanism for regulating temporal expectations. We used a speeded Go/No-go task and manipulated temporal expectations by changing the probability of target presentation after certain intervals. Across two conditions, the temporal conditional probability of target events differed substantially at the first of three possible intervals. We found that reactions times differed significantly at this first interval across conditions, decreasing with higher temporal expectations. Interestingly, the power of theta activity (4–8 Hz), distributed over central midline sites, also differed significantly across conditions at this first interval. Furthermore, we found a transient coupling between theta phase and beta power after the first interval in the condition with high temporal expectation for targets at this time point. Our results suggest that the adjustments in theta power and the phase-power coupling between theta and beta contribute to a central mechanism for controlling neural excitability according to temporal expectations. PMID:21900508

The synchronisation of lower limb responses with a variable metronome: the effect of biomechanical constraints on timing.

PubMed

Chen, Hui-Ya; Wing, Alan M; Pratt, David

2006-04-01

Stepping in time with a metronome has been reported to improve pathological gait. Although there have been many studies of finger tapping synchronisation tasks with a metronome, the specific details of the influences of metronome timing on walking remain unknown. As a preliminary to studying pathological control of gait timing, we designed an experiment with four synchronisation tasks, unilateral heel tapping in sitting, bilateral heel tapping in sitting, bilateral heel tapping in standing, and stepping on the spot, in order to examine the influence of biomechanical constraints on metronome timing. These four conditions allow study of the effects of bilateral co-ordination and maintenance of balance on timing. Eight neurologically normal participants made heel tapping and stepping responses in synchrony with a metronome producing 500 ms interpulse intervals. In each trial comprising 40 intervals, one interval, selected at random between intervals 15 and 30, was lengthened or shortened, which resulted in a shift in phase of all subsequent metronome pulses. Performance measures were the speed of compensation for the phase shift, in terms of the temporal difference between the response and the metronome pulse, i.e. asynchrony, and the standard deviation of the asynchronies and interresponse intervals of steady state synchronisation. The speed of compensation decreased with increase in the demands of maintaining balance. The standard deviation varied across conditions but was not related to the compensation speed. The implications of these findings for metronome assisted gait are discussed in terms of a first-order linear correction account of synchronisation.

A joint model of persistent human papillomavirus infection and cervical cancer risk: Implications for cervical cancer screening

PubMed Central

Katki, Hormuzd A.; Cheung, Li C.; Fetterman, Barbara; Castle, Philip E.; Sundaram, Rajeshwari

2014-01-01

Summary New cervical cancer screening guidelines in the US and many European countries recommend that women get tested for human papillomavirus (HPV). To inform decisions about screening intervals, we calculate the increase in precancer/cancer risk per year of continued HPV infection. However, both time to onset of precancer/cancer and time to HPV clearance are interval-censored, and onset of precancer/cancer strongly informatively censors HPV clearance. We analyze this bivariate informatively interval-censored data by developing a novel joint model for time to clearance of HPV and time to precancer/cancer using shared random-effects, where the estimated mean duration of each woman’s HPV infection is a covariate in the submodel for time to precancer/cancer. The model was fit to data on 9,553 HPV-positive/Pap-negative women undergoing cervical cancer screening at Kaiser Permanente Northern California, data that were pivotal to the development of US screening guidelines. We compare the implications for screening intervals of this joint model to those from population-average marginal models of precancer/cancer risk. In particular, after 2 years the marginal population-average precancer/cancer risk was 5%, suggesting a 2-year interval to control population-average risk at 5%. In contrast, the joint model reveals that almost all women exceeding 5% individual risk in 2 years also exceeded 5% in 1 year, suggesting that a 1-year interval is better to control individual risk at 5%. The example suggests that sophisticated risk models capable of predicting individual risk may have different implications than population-average risk models that are currently used for informing medical guideline development. PMID:26556961

A joint model of persistent human papillomavirus infection and cervical cancer risk: Implications for cervical cancer screening.

PubMed

Katki, Hormuzd A; Cheung, Li C; Fetterman, Barbara; Castle, Philip E; Sundaram, Rajeshwari

2015-10-01

New cervical cancer screening guidelines in the US and many European countries recommend that women get tested for human papillomavirus (HPV). To inform decisions about screening intervals, we calculate the increase in precancer/cancer risk per year of continued HPV infection. However, both time to onset of precancer/cancer and time to HPV clearance are interval-censored, and onset of precancer/cancer strongly informatively censors HPV clearance. We analyze this bivariate informatively interval-censored data by developing a novel joint model for time to clearance of HPV and time to precancer/cancer using shared random-effects, where the estimated mean duration of each woman's HPV infection is a covariate in the submodel for time to precancer/cancer. The model was fit to data on 9,553 HPV-positive/Pap-negative women undergoing cervical cancer screening at Kaiser Permanente Northern California, data that were pivotal to the development of US screening guidelines. We compare the implications for screening intervals of this joint model to those from population-average marginal models of precancer/cancer risk. In particular, after 2 years the marginal population-average precancer/cancer risk was 5%, suggesting a 2-year interval to control population-average risk at 5%. In contrast, the joint model reveals that almost all women exceeding 5% individual risk in 2 years also exceeded 5% in 1 year, suggesting that a 1-year interval is better to control individual risk at 5%. The example suggests that sophisticated risk models capable of predicting individual risk may have different implications than population-average risk models that are currently used for informing medical guideline development.

Twenty-eight-year review of childhood renal diseases from renal biopsy data: A single centre in China.

PubMed

Jiang, Mengjie; Xiao, Zizheng; Rong, Liping; Xu, Yuanyuan; Chen, Lizhi; Mo, Ying; Sun, Liangzhong; Sun, Wei; Jiang, Xiaoyun

2016-12-01

The aim of the present study was to investigate the clinicopathologic characteristics of biopsy-proven childhood renal diseases and to compare the trends and changes during two different time intervals between 1984 and 2011 at the First Affiliated Hospital of Sun Yat-sen University in China. We retrospectively analyzed kidney biopsy data from children with renal diseases and compared the data during two time intervals, namely 1984-1997 and 1998-2011. A total of 1313 children were enrolled in the present study. There were 921 children with primary glomerular disease (PGD) and 312 children with secondary glomerular disease (SGD), accounting for 70.1% and 23.8% of participants, respectively. The major clinical manifestation of PGD was nephrotic syndrome (NS), which accounted for 31.2% of cases, while the main aetiology of SGD was lupus nephritis (40.7%). The main biopsy patterns of PGD were IgA nephritis (27.6%), minimal change disease (24.0%), and mesangial proliferative glomerulonephritis (16.9%). PGD was the major class of disease in both time intervals, but the ratio of PGD decreased over time, while the ratio of SGD and other glomerular diseases increased. PGD was also the major class of disease in each age group; however, the incidence of PGD decreased with increasing age. The incidence patterns of paediatric renal diseases changed over the 28-year period of this study. Our results show that different renal diseases characterize different age intervals. Furthermore, there are several associations between clinical presentation and biopsy features in childhood renal disease. © 2015 Asian Pacific Society of Nephrology.

[Changes in heart rate variability after myocardial infarction. Value of Poincareé's diagram].

PubMed

Copie, X; Le Heuzey, J Y; Iliou, M C; Pousset, F; Lavergne, T; Guize, L

1995-11-01

The variability of the heart rate is reduced after myocardial infarction. It then progressively increases, to return to near normal values after several months. However, these changes in heart rate variability occur at the same time as slowing of the heart rate which makes interpretation difficult. Poincaré's diagram is constructed from a Holter recording plotting each RR interval against the preceding RR interval. The authors have developed a geometric approach to this diagram to evaluate parasympathetic tone for a given heart rate. By measuring the dispersion in height of the Poincaré's diagram, the authors evaluate the shor-term variability for a given RR interval. Two 24 hr Holter recordings were performed in 52 patients at one and two weeks after a myocardial infarction. The dispersion in the height of the Poincaré's diagrams was measured at the 10th, 25th, 50th, 75th and 90th percentiles of the total dispersion. The authors have shown an increase in the short-term variability of the shortest RR intervals (1th, 25th and 50th percentiles) which is not observed in the longer RR intervals (75th and 90th percentiles). In conclusion, theres is an increase in the heart rate variability at the shortest RR intervals. This suggests that the recovery of parasympathic tone after myocardial infarction occurs mainly at the fastest heart rates.

Feeding Intervals in Premature Infants ≤1750 g: An Integrative Review.

PubMed

Binchy, Áine; Moore, Zena; Patton, Declan

2018-06-01

The timely establishment of enteral feeds and a reduction in the number of feeding interruptions are key to achieving optimal nutrition in premature infants. Nutritional guidelines vary widely regarding feeding regimens and there is not a widely accepted consensus on the optimal feeding interval. To critically examine the evidence to determine whether there is a relationship to feeding intervals and feeding outcomes in premature infants. A systematic review of the literature in the following databases: PubMed, CINAHL, Embase and the Cochrane Library. The search strategy used the terms infant premature, low birth weight, enteral feeding, feed tolerance and feed intervals. Search results yielded 10 studies involving 1269 infants (birth weight ≤1750 g). No significant differences in feed intolerance, growth, or incidence of necrotizing enterocolitis were observed. Evidence suggests that infants fed at 2 hourly intervals reached full feeds faster than at 3 hourly intervals, had fewer days on parenteral nutrition, and fewer days in which feedings were withheld. Decrease in the volume of gastric residuals and feeding interruptions were observed in the infants fed at 3 hourly intervals than those who were continuously fed. Reducing the feed interval from 3 to 2 hourly increases nurse workload, yet may improve feeding outcomes by reducing the time to achieve full enteral feeding. Studies varied greatly in the definition and management of feeding intolerance and in how outcomes were measured, analyzed, and reported. The term "intermittent" is used widely but can refer to a 2 or 3 hourly interval.

Technical note: Instantaneous sampling intervals validated from continuous video observation for behavioral recording of feedlot lambs.

PubMed

Pullin, A N; Pairis-Garcia, M D; Campbell, B J; Campler, M R; Proudfoot, K L

2017-11-01

When considering methodologies for collecting behavioral data, continuous sampling provides the most complete and accurate data set whereas instantaneous sampling can provide similar results and also increase the efficiency of data collection. However, instantaneous time intervals require validation to ensure accurate estimation of the data. Therefore, the objective of this study was to validate scan sampling intervals for lambs housed in a feedlot environment. Feeding, lying, standing, drinking, locomotion, and oral manipulation were measured on 18 crossbred lambs housed in an indoor feedlot facility for 14 h (0600-2000 h). Data from continuous sampling were compared with data from instantaneous scan sampling intervals of 5, 10, 15, and 20 min using a linear regression analysis. Three criteria determined if a time interval accurately estimated behaviors: 1) ≥ 0.90, 2) slope not statistically different from 1 ( > 0.05), and 3) intercept not statistically different from 0 ( > 0.05). Estimations for lying behavior were accurate up to 20-min intervals, whereas feeding and standing behaviors were accurate only at 5-min intervals (i.e., met all 3 regression criteria). Drinking, locomotion, and oral manipulation demonstrated poor associations () for all tested intervals. The results from this study suggest that a 5-min instantaneous sampling interval will accurately estimate lying, feeding, and standing behaviors for lambs housed in a feedlot, whereas continuous sampling is recommended for the remaining behaviors. This methodology will contribute toward the efficiency, accuracy, and transparency of future behavioral data collection in lamb behavior research.

Risk of metachronous ovarian cancer after ovarian conservation in young women with stage I cervical cancer.

PubMed

Matsuo, Koji; Machida, Hiroko; Horowitz, Max P; Shahzad, Mian M K; Guntupalli, Saketh R; Roman, Lynda D; Wright, Jason D

2017-11-01

While there is an increasing trend of ovarian conservation at the time of surgical treatment for young women with stage I cervical cancer, the risk for subsequent ovarian cancer after ovarian conservation has not been well studied. We sought to examine the incidence of and risk factors for metachronous ovarian cancer among young women with stage I cervical cancer who had ovarian conservation at the time of hysterectomy. The Surveillance, Epidemiology, and End Results Program was used to identify women aged <50 years who underwent hysterectomy with ovarian conservation for stage I cervical cancer from 1983 through 2013 (n = 4365). Time-dependent analysis was performed for ovarian cancer risk after cervical cancer diagnosis. Mean age at cervical cancer diagnosis was 37 years, and the majority of patients had stage IA disease (68.2%) and squamous histology (72.9%). Median follow-up time was 10.8 years, and there were 13 women who developed metachronous ovarian cancer. The 10- and 20-year cumulative incidences of metachronous ovarian cancer were 0.2% (95% confidence interval, 0.1-0.4) and 0.5% (95% confidence interval, 0.2-0.8), respectively. Mean age at the time of diagnosis of metachronous ovarian cancer was 47.5 years, and stage III-IV disease was seen in 55.6%. Age (≥45 vs <45 years, hazard ratio, 4.22; 95% confidence interval, 1.16-15.4; P = .018), ethnicity (non-white vs white, hazard ratio, 4.29; 95% confidence interval, 1.31-14.0; P = .009), cervical cancer histology (adenocarcinoma or adenosquamous vs squamous, hazard ratio, 3.50; 95% confidence interval, 1.17-10.5; P = .028), and adjuvant radiotherapy use (yes vs no, hazard ratio, 3.69; 95% confidence interval, 1.01-13.4; P = .034) were significantly associated with metachronous ovarian cancer risk. The presence of multiple risk factors was associated with a significantly increased risk of metachronous ovarian cancer compared to the no risk factor group: 1 risk factor (hazard ratio range, 2.96-8.43), 2 risk factors (hazard ratio range, 16.6-31.0), and 3-4 risk factors (hazard ratio range, 62.3-109), respectively. Metachronous ovarian cancer risk after ovarian conservation for women with stage I cervical cancer is <1%. Older age, non-white ethnicity, adenocarcinoma or adenosquamous histology, and adjuvant radiotherapy may be associated with an increased metachronous ovarian cancer risk. Copyright © 2017 Elsevier Inc. All rights reserved.

Time‐dependent renewal‐model probabilities when date of last earthquake is unknown

USGS Publications Warehouse

Field, Edward H.; Jordan, Thomas H.

2015-01-01

We derive time-dependent, renewal-model earthquake probabilities for the case in which the date of the last event is completely unknown, and compare these with the time-independent Poisson probabilities that are customarily used as an approximation in this situation. For typical parameter values, the renewal-model probabilities exceed Poisson results by more than 10% when the forecast duration exceeds ~20% of the mean recurrence interval. We also derive probabilities for the case in which the last event is further constrained to have occurred before historical record keeping began (the historic open interval), which can only serve to increase earthquake probabilities for typically applied renewal models.We conclude that accounting for the historic open interval can improve long-term earthquake rupture forecasts for California and elsewhere.

[Structure of maxillary sinus mucous membrane under normal conditions and in odontogenic perforative sinusitis].

PubMed

Baĭdik, O D; Logvinov, S V; Zubarev, S G; Sysoliatin, P G; Gurin, A A

2011-01-01

Methods of light, electron microscopy and immunohistochemistry were used to study the samples of maxillary sinus (MS) mucous membrane (MM) under normal conditions and in odontogenic sinusitis. To study the normal structure, the samples were obtained at autopsy from 26 human corpses 12-24 hours after death. Electron microscopic and immunohistochemical study was performed on biopsies of grossly morphologically unchanged MS MM, obtained during the operations for retention cysts in 6 patients. MS MM in perforative sinusitis was studied using the biopsies obtained from 43 patients. The material is broken into 4 groups depending on perforative sinusitis duration. Under normal conditions, MS MM is lined with a pseudostratified columnar ciliated epithelium. Degenerative changes of ciliated epithelial cells were already detected at short time intervals after MS perforations and become apparent due to reduction of specific volume of mitochondria and, rough endoplasmic reticulum, and increase of nuclear-cytoplasmic ratio. In the globlet cells, the reduction of nuclear-cytoplasmic ratio was associated with the disturbance of the secretory product release. At time intervals exceeding 3 months, epithelium underwent metaplasia into simple cuboidal and stratified squamous keratinized, while in MS MM lamina propria, cellular infiltration was increased. CD4+ cell content in sinus MM gradually increased, while at late periods after perforation occurrence it decreased. Low CD4+ cell count within the epithelium and the absence of muromidase on the surface of MS MM was detected. With the increase of the time interval since MS perforation, the number of CD8+ and CD20+ cells in MS MM was found to increase.

Patient-specific Distraction Regimen to Avoid Growth-rod Failure.

PubMed

Agarwal, Aakash; Jayaswal, Arvind; Goel, Vijay K; Agarwal, Anand K

2018-02-15

A finite element study to establish the relationship between patient's curve flexibility (determined using curve correction under gravity) in juvenile idiopathic scoliosis and the required distraction frequency to avoid growth rod fracture, as a function of time. To perform a parametric analysis using a juvenile scoliotic spine model (single mid-thoracic curve with the apex at the eighth thoracic vertebra) and establish the relationship between curve flexibility (determined using curve correction under gravity) and the distraction interval that allows a higher factor of safety for the growth rods. Previous studies have shown that frequent distraction with smaller magnitude of distractions are less likely to result in rod failure. However there has not been any methodology or a chart provided to apply this knowledge on to the individual patients that undergo the treatment. This study aims to fill in that gap. The parametric study was performed by varying the material properties of the disc, hence altering the axial stiffness of the scoliotic spine model. The stresses on the rod were found to increase with increased axial stiffness of the spine, and this resulted in the increase of required optimal frequency to achieve a factor of safety of two for growth rods. A relationship between the percentage correction in Cobb's angle due to gravity alone, and the required distraction interval for limiting the maximum von Mises stress to 255 MPa on the growth rods was established. The distraction interval required to limit the stresses to the selected nominal value reduces with increase in stiffness of the spine. Furthermore, the appropriate distraction interval reduces for each model as the spine becomes stiffer with time (autofusion). This points to the fact the optimal distraction frequency is a time-dependent variable that must be achieved to keep the maximum von Mises stress under the specified factor of safety. The current study demonstrates the possibility of translating fundamental information from finite element modeling to the clinical arena, for mitigating the occurrence of growth rod fracture, that is, establishing a relationship between optimal distraction interval and curve flexibility (determined using curve correction under gravity). N/A.

Contraction frequency after administration of misoprostol in obese versus nonobese women.

PubMed

Stefely, Erin; Warshak, Carri R

2018-04-30

To examine impact of obesity on contraction frequency following misoprostol. Our hypothesis is that an increased volume of distribution reduces the bioavailability of misoprostol and may be an explanation for reduced efficacy. We examined the contraction frequency as a surrogate marker for bioavailability of misoprostol. We compared the rate of contractions at five time intervals in 313 subjects: prior to administration, and at four intervals post administration. We compared number of contractions in obese versus nonobese. As a planned secondary analysis, we then compared the rate of change in contractions per hour at four time intervals: a repeated measures analysis to compare the rate of change in contractions per hour over the 5-hour window controlling for race (White versus non-White) and parity (primiparous versus multiparous). General linear model and repeated measures analysis were conducted to report the parameter estimates, least square means, difference of least square means, and p values. Nonobese women presented with more contractions at baseline, 7 ± 5 versus 4 ± 5 c/h, p < .001. At all four time intervals after misoprostol administration obese women had fewer contractions per hour. The rate of change in contraction frequency after administration found obese women had a lower rate of increase in contraction frequency over the course of all four hours. We found a least squares means estimate (c/h): first hour (-0.87), p = .08, second hour (-2.43), p = .01, third hour (-1.80), p = .96, and fourth hour (-2.98), p = .007. Obese women have a lower rate of contractions per hour at baseline and at four intervals after misoprostol administration. In addition, the rate of change in the increase in contractions/hour also was reduced in obese women versus nonobese women. This suggests a lower bioavailability of misoprostol in women with a larger volume of distribution which would likely impact the efficacy of misoprostol in obese women when given the same dose of misoprostol. It is unknown if higher misoprostol dosing would increase efficacy of misoprostol in obese women.

Responses in reproductive organs, steroid hormones and CYP450 enzymes in female Mongolian gerbil (Meriones unguiculatus) over time after quinestrol treatment.

PubMed

Su, Qian-Qian; Chen, Yi; Qin, Jiao; Wang, Tong-Liang; Wang, De-Hua; Liu, Quan-Sheng

2017-11-01

The aim of this study was to assess the effects and reversibility of the synthetic estrogen compound, quinestrol, on the reproductive organs, steroid hormones, and drug-metabolizing enzymes CYP3A4 and CYP1A2 in liver and kidney over time after two quinestrol treatments in female Mongolian gerbils (Meriones unguiculatus). Female gerbils were treated with 4mg/kg quinestrol (9 gerbils/group, 3 treated group) (1 control group, 0mg/kg) for 3days and treated again after 25days. Animals were killed for collection of samples at 5, 10 and 15days after the second treatment ending. Two interval quinestrol treatments significantly increased uterine weight, with trend of increase over time, but no change could be detected in ovarian weights. Quinestrol treatment increased progesterone and estradiol levels, both with trend of decline over time. Quinestrol increased liver and kidney weights and total enzyme content of CYP3A4 and CYP1A2, with trend of decline over time. On the basis of reversible changes of detoxification enzymes or organs, interval quinestrol treatment effectively and reversibly influenced the reproductive hormone and organ to some extent. Copyright © 2017 Elsevier Inc. All rights reserved.

Interval Timing Is Preserved Despite Circadian Desynchrony in Rats: Constant Light and Heavy Water Studies.

PubMed

Petersen, Christian C; Mistlberger, Ralph E

2017-08-01

The mechanisms that enable mammals to time events that recur at 24-h intervals (circadian timing) and at arbitrary intervals in the seconds-to-minutes range (interval timing) are thought to be distinct at the computational and neurobiological levels. Recent evidence that disruption of circadian rhythmicity by constant light (LL) abolishes interval timing in mice challenges this assumption and suggests a critical role for circadian clocks in short interval timing. We sought to confirm and extend this finding by examining interval timing in rats in which circadian rhythmicity was disrupted by long-term exposure to LL or by chronic intake of 25% D 2 O. Adult, male Sprague-Dawley rats were housed in a light-dark (LD) cycle or in LL until free-running circadian rhythmicity was markedly disrupted or abolished. The rats were then trained and tested on 15- and 30-sec peak-interval procedures, with water restriction used to motivate task performance. Interval timing was found to be unimpaired in LL rats, but a weak circadian activity rhythm was apparently rescued by the training procedure, possibly due to binge feeding that occurred during the 15-min water access period that followed training each day. A second group of rats in LL were therefore restricted to 6 daily meals scheduled at 4-h intervals. Despite a complete absence of circadian rhythmicity in this group, interval timing was again unaffected. To eliminate all possible temporal cues, we tested a third group of rats in LL by using a pseudo-randomized schedule. Again, interval timing remained accurate. Finally, rats tested in LD received 25% D 2 O in place of drinking water. This markedly lengthened the circadian period and caused a failure of LD entrainment but did not disrupt interval timing. These results indicate that interval timing in rats is resistant to disruption by manipulations of circadian timekeeping previously shown to impair interval timing in mice.

Differences between measured and linearly interpolated synoptic variables over a 12-h period during AVE 4

NASA Technical Reports Server (NTRS)

Dupuis, L. R.; Scoggins, J. R.

1979-01-01

Results of analyses revealed that nonlinear changes or differences formed centers or systems, that were mesosynoptic in nature. These systems correlated well in space with upper level short waves, frontal zones, and radar observed convection, and were very systematic in time and space. Many of the centers of differences were well established in the vertical, extending up to the tropopause. Statistical analysis showed that on the average nonlinear changes were larger in convective areas than nonconvective regions. Errors often exceeding 100 percent were made by assuming variables to change linearly through a 12-h period in areas of thunderstorms, indicating that these nonlinear changes are important in the development of severe weather. Linear changes, however, accounted for more and more of an observed change as the time interval (within the 12-h interpolation period) increased, implying that the accuracy of linear interpolation increased over larger time intervals.

Exercise in pregnancy: an association with placental weight?

PubMed

Hilde, Gunvor; Eskild, Anne; Owe, Katrine Mari; Bø, Kari; Bjelland, Elisabeth K

2017-02-01

Women with high levels of physical exercise have an increased demand for oxygen and nutrients. Thus, in pregnancies of women with high levels of exercise, it is conceivable that the supply of oxygen and nutrients to the placenta is suboptimal, and growth could be impaired. The objective was to study the association of frequency of exercise during pregnancy with placental weight and placental to birthweight ratio. This was a prospective study of 80,515 singleton pregnancies in the Norwegian Mother and Child Cohort Study. Frequency of exercise was self-reported by a questionnaire at pregnancy weeks 17 and 30. Information on placental weight and birthweight was obtained by linkage to the Medical Birth Registry of Norway. Placental weight decreased with increasing frequency of exercise (tests for trend, P < .001). For nonexercisers in pregnancy week 17, the crude mean placental weight was 686.1 g compared with 667.3 g in women exercising ≥6 times weekly (difference, 18.8 g; 95% confidence interval, 12.0-25.5). Likewise, in nonexercisers in pregnancy week 30, crude mean placental weight was 684.9 g compared with 661.6 g in women exercising ≥6 times weekly (difference, 23.3 g; 95% confidence interval, 14.9-31.6). The largest difference in crude mean placental weight was seen between nonexercisers at both time points and women exercising ≥6 times weekly at both time points (difference, 31.7 g; 95% confidence interval, 19.2-44.2). Frequency of exercise was not associated with placental to birthweight ratio. We found decreasing placental weight with increasing frequency of exercise in pregnancy. The difference in placental weight between nonexercisers and women with exercising ≥6 times weekly was small and may have no clinical implications. Copyright © 2016 Elsevier Inc. All rights reserved.

The effects of time compositing on obtaining clear-sky coverage for infrared temperature and moisture profiling from geosynchronous orbit

NASA Technical Reports Server (NTRS)

Shenk, William E.; Hope, William A.

1994-01-01

The impact of time compositing on infrared profiling from geosynchronous orbit was evaluated for two convective outbreak cases. Time compositing is the accumulation of the data from several successive images taken at short intervals to provide a single field of measurements with the temporal resolution equal to the time to take all of the images. This is especially effective when the variability of the measurements is slow compared to the image interval. Time compositing should be able to reduce the interference of clouds for infrared measurments since clouds move and change. The convective outbreak cases were on 4 and 21 May 1990 over the eastern Midwest and southeastern United States, respectively. Geostationary Operational Environmental (GOES) Satellite imagery was used to outline clear areas at hourly intervals by two independent analysts. Time compositing was done every 3 h (1330-1530 UTC; 1630-1830 UTC) and over the full 5-h period. For both cases, a significant increase in coverage was measured with each 3-h compositing (about a factor of 2) and a further increase over the full period (approximately a factor of 3). The increase was especially useful in areas of broken cloud cover where large gaps between potential profiling areas on each image were reduced. To provide information on measurement variability over local areas, the regions where the clear-area analyses were done were subdivided into 0.5 deg latitude-longitude boxes, and if some portion of each box was clear, it was assumed that at least one profile could be obtained within the box. In the largest clear areas, at least some portion was clear every hour. Even in the cloudier regions, multiple clear looks possible during the entire period.

Electrophysiological determinants of hypokalaemia-induced arrhythmogenicity in the guinea-pig heart.

PubMed

Osadchii, O E; Olesen, S P

2009-12-01

Hypokalaemia is an independent risk factor contributing to arrhythmic death in cardiac patients. In the present study, we explored the mechanisms of hypokalaemia-induced tachyarrhythmias by measuring ventricular refractoriness, spatial repolarization gradients, and ventricular conduction time in isolated, perfused guinea-pig heart preparations. Epicardial and endocardial monophasic action potentials from distinct left ventricular (LV) and right ventricular (RV) recording sites were monitored simultaneously with volume-conducted electrocardiogram (ECG) during steady-state pacing and following a premature extrastimulus application at progressively reducing coupling stimulation intervals in normokalaemic and hypokalaemic conditions. Hypokalaemic perfusion (2.5 mm K(+) for 30 min) markedly increased the inducibility of tachyarrhythmias by programmed ventricular stimulation and rapid pacing, prolonged ventricular repolarization and shortened LV epicardial and endocardial effective refractory periods, thereby increasing the critical interval for LV re-excitation. Hypokalaemia increased the RV-to-LV transepicardial repolarization gradients but had no effect on transmural dispersion of APD(90) and refractoriness across the LV wall. As determined by local activation time recordings, the LV-to-RV transepicardial conduction and the LV transmural (epicardial-to-endocardial) conduction were slowed in hypokalaemic heart preparations. This change was attributed to depressed diastolic excitability as evidenced by increased ventricular pacing thresholds. These findings suggest that hypokalaemia-induced arrhythmogenicity is attributed to shortened LV refractoriness, increased critical intervals for LV re-excitation, amplified RV-to-LV transepicardial repolarization gradients and slowed ventricular conduction in the guinea-pig heart.

Stabilization of memory States by stochastic facilitating synapses.

PubMed

Miller, Paul

2013-12-06

Bistability within a small neural circuit can arise through an appropriate strength of excitatory recurrent feedback. The stability of a state of neural activity, measured by the mean dwelling time before a noise-induced transition to another state, depends on the neural firing-rate curves, the net strength of excitatory feedback, the statistics of spike times, and increases exponentially with the number of equivalent neurons in the circuit. Here, we show that such stability is greatly enhanced by synaptic facilitation and reduced by synaptic depression. We take into account the alteration in times of synaptic vesicle release, by calculating distributions of inter-release intervals of a synapse, which differ from the distribution of its incoming interspike intervals when the synapse is dynamic. In particular, release intervals produced by a Poisson spike train have a coefficient of variation greater than one when synapses are probabilistic and facilitating, whereas the coefficient of variation is less than one when synapses are depressing. However, in spite of the increased variability in postsynaptic input produced by facilitating synapses, their dominant effect is reduced synaptic efficacy at low input rates compared to high rates, which increases the curvature of neural input-output functions, leading to wider regions of bistability in parameter space and enhanced lifetimes of memory states. Our results are based on analytic methods with approximate formulae and bolstered by simulations of both Poisson processes and of circuits of noisy spiking model neurons.

Modelling Carbon Emissions in Calluna vulgaris-Dominated Ecosystems when Prescribed Burning and Wildfires Interact.

PubMed

Santana, Victor M; Alday, Josu G; Lee, HyoHyeMi; Allen, Katherine A; Marrs, Rob H

2016-01-01

A present challenge in fire ecology is to optimize management techniques so that ecological services are maximized and C emissions minimized. Here, we modeled the effects of different prescribed-burning rotation intervals and wildfires on carbon emissions (present and future) in British moorlands. Biomass-accumulation curves from four Calluna-dominated ecosystems along a north-south gradient in Great Britain were calculated and used within a matrix-model based on Markov Chains to calculate above-ground biomass-loads and annual C emissions under different prescribed-burning rotation intervals. Additionally, we assessed the interaction of these parameters with a decreasing wildfire return intervals. We observed that litter accumulation patterns varied between sites. Northern sites (colder and wetter) accumulated lower amounts of litter with time than southern sites (hotter and drier). The accumulation patterns of the living vegetation dominated by Calluna were determined by site-specific conditions. The optimal prescribed-burning rotation interval for minimizing annual carbon emissions also differed between sites: the optimal rotation interval for northern sites was between 30 and 50 years, whereas for southern sites a hump-backed relationship was found with the optimal interval either between 8 to 10 years or between 30 to 50 years. Increasing wildfire frequency interacted with prescribed-burning rotation intervals by both increasing C emissions and modifying the optimum prescribed-burning interval for minimum C emission. This highlights the importance of studying site-specific biomass accumulation patterns with respect to environmental conditions for identifying suitable fire-rotation intervals to minimize C emissions.

Behavioral regulation of gravity: schedule effects under escape-avoidance procedures1

PubMed Central

Clark, Fogle C.; Lange, Karl O.; Belleville, Richard E.

1973-01-01

Squirrel monkeys were restrained in a centrifuge capsule and trained to escape and avoid increases in artificial gravity. During escape-avoidance, lever responses reduced centrifugally simulated gravity or postponed scheduled increases. The effect of variation in the interval of postponement (equal to the duration of decrease produced by escape responses) was studied under a multiple schedule of four components. Three components were gravity escape-avoidance with postponement times of 20, 40, and 60 sec. The fourth component was extinction. Each component was associated with a different auditory stimulus. Rate of responding decreased with increasing postponement time and higher mean g-levels occurred at shorter intervals of postponement. Effects of the schedule parameter on response rate and mean g-level were similar to effects of the schedule on free-operant avoidance and on titration behavior maintained by shock. ImagesFig. 1. PMID:4202386

Application of carbon nanotube hold-off voltage for determining gas composition

NASA Technical Reports Server (NTRS)

Schipper, John F. (Inventor); Li, Jing (Inventor)

2009-01-01

Method and system for determining chemical composition of a single-component or multiple-component gas, using a discharge holdoff mechanism. A voltage difference V between two spaced apart electrodes is brought to a selected value and held, the holdoff time interval .DELTA.t(V;ho) required before gas discharge occurs is measured, and the associated electrical current or cumulative electrical charge is measured. As the voltage difference V increases, the time interval length .DELTA.t(V;ho) decreases monotonically. Particular voltage values, V.sub..infin. and V.sub.0, correspond to initial appearance of discharge (.DELTA.t.apprxeq..infin.) and prompt discharge (.DELTA.t.apprxeq.0). The values V.sub..infin. and V.sub.0 and the rate of decrease of .DELTA.t(V;ho) and/or the rate of increase of current or cumulative charge with increasing V are characteristic of one or more gas components present.

Excessive work and risk of haemorrhagic stroke: a nationwide case-control study.

PubMed

Kim, Beom Joon; Lee, Seung-Hoon; Ryu, Wi-Sun; Kim, Chi Kyung; Chung, Jong-Won; Kim, Dohoung; Park, Hong-Kyun; Bae, Hee-Joon; Park, Byung-Joo; Yoon, Byung-Woo

2013-10-01

Adverse effect of excessive work on health has been suggested previously, but it was not documented in cerebrovascular diseases. The authors investigated whether excessive working conditions would associate with increased risk of haemorrhagic stroke. A nationwide matched case-control study database, which contains 940 cases of incident haemorrhagic stroke (498 intracerebral haemorrhages and 442 sub-arachnoid haemorrhages) with 1880 gender- and age- (± 5-year) matched controls, was analysed. Work-related information based on the regular job situation, including type of occupation, regular working time, duration of strenuous activity during regular work and shift work, was gathered through face-to-face interviews. Conditional logistic regression analyses were used for the multivariable analyses. Compared with white-collar workers, blue-collar workers had a higher risk for haemorrhagic stroke (odds ratio, 1.33 [95% confidence interval, 1.06-1.66]). Longer regular working time was associated with increased risk of haemorrhagic stroke [odds ratio, 1.38 (95% confidence interval, 1.05-1.81) for 8-12 h/day; odds ratio, 1.95 (95% confidence interval, 1.33-2.86) for ≥ 13 h/day; compared with ≤ 4 h/day]. Exposure to ≥ 8 h/week of strenuous activity also associated haemorrhagic stroke risk [odds ratio, 1.61 (95% confidence interval, 1.26-2.05); compared with no strenuous activity]. Shift work was not associated with haemorrhagic stroke (P = 0.98). Positive associations between working condition indices and haemorrhagic stroke risk were consistent regardless of haemorrhagic stroke sub-types and current employment status. Blue-collar occupation, longer regular working time and extended duration of strenuous activity during work may relate to an increased risk of haemorrhagic stroke. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.

Longitudinal study of fingerprint recognition.

PubMed

Yoon, Soweon; Jain, Anil K

2015-07-14

Human identification by fingerprints is based on the fundamental premise that ridge patterns from distinct fingers are different (uniqueness) and a fingerprint pattern does not change over time (persistence). Although the uniqueness of fingerprints has been investigated by developing statistical models to estimate the probability of error in comparing two random samples of fingerprints, the persistence of fingerprints has remained a general belief based on only a few case studies. In this study, fingerprint match (similarity) scores are analyzed by multilevel statistical models with covariates such as time interval between two fingerprints in comparison, subject's age, and fingerprint image quality. Longitudinal fingerprint records of 15,597 subjects are sampled from an operational fingerprint database such that each individual has at least five 10-print records over a minimum time span of 5 y. In regard to the persistence of fingerprints, the longitudinal analysis on a single (right index) finger demonstrates that (i) genuine match scores tend to significantly decrease when time interval between two fingerprints in comparison increases, whereas the change in impostor match scores is negligible; and (ii) fingerprint recognition accuracy at operational settings, nevertheless, tends to be stable as the time interval increases up to 12 y, the maximum time span in the dataset. However, the uncertainty of temporal stability of fingerprint recognition accuracy becomes substantially large if either of the two fingerprints being compared is of poor quality. The conclusions drawn from 10-finger fusion analysis coincide with the conclusions from single-finger analysis.

Longitudinal study of fingerprint recognition

PubMed Central

Yoon, Soweon; Jain, Anil K.

2015-01-01

Human identification by fingerprints is based on the fundamental premise that ridge patterns from distinct fingers are different (uniqueness) and a fingerprint pattern does not change over time (persistence). Although the uniqueness of fingerprints has been investigated by developing statistical models to estimate the probability of error in comparing two random samples of fingerprints, the persistence of fingerprints has remained a general belief based on only a few case studies. In this study, fingerprint match (similarity) scores are analyzed by multilevel statistical models with covariates such as time interval between two fingerprints in comparison, subject’s age, and fingerprint image quality. Longitudinal fingerprint records of 15,597 subjects are sampled from an operational fingerprint database such that each individual has at least five 10-print records over a minimum time span of 5 y. In regard to the persistence of fingerprints, the longitudinal analysis on a single (right index) finger demonstrates that (i) genuine match scores tend to significantly decrease when time interval between two fingerprints in comparison increases, whereas the change in impostor match scores is negligible; and (ii) fingerprint recognition accuracy at operational settings, nevertheless, tends to be stable as the time interval increases up to 12 y, the maximum time span in the dataset. However, the uncertainty of temporal stability of fingerprint recognition accuracy becomes substantially large if either of the two fingerprints being compared is of poor quality. The conclusions drawn from 10-finger fusion analysis coincide with the conclusions from single-finger analysis. PMID:26124106

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

PubMed Central

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

2014-01-01

Background The 5 choice serial reaction time task (5CSRTT) is commonly used to assess attention in rodents. We sought to develop a variant of the 5CSRTT that would speed training to objective success criteria, and to test whether this variant could determine attention capability in each subject. New Method Fisher 344 rats were trained to perform a variant of the 5CSRTT in which the duration of visual cue presentation (cue duration) was titrated between trials based upon performance. The cue duration was decreased when the subject made a correct response, or increased with incorrect responses or omissions. Additionally, test day challenges were provided consisting of lengthening the intertrial interval and inclusion of a visual distracting stimulus. Results Rats readily titrated the cue duration to less than 1 sec in 25 training sessions or less (mean ± SEM, 22.9 ± 0.7), and the median cue duration (MCD) was calculated as a measure of attention threshold. Increasing the intertrial interval increased premature responses, decreased the number of trials completed, and increased the MCD. Decreasing the intertrial interval and time allotted for consuming the food reward demonstrated that a minimum of 3.5 sec is required for rats to consume two food pellets and successfully attend to the next trial. Visual distraction in the form of a 3 Hz flashing light increased the MCD and both premature and time out responses. Comparison with existing method The titration variant of the 5CSRTT is a useful method that dynamically measures attention threshold across a wide range of subject performance, and significantly decreases the time required for training. Task challenges produce similar effects in the titration method as reported for the classical procedure. Conclusions The titration 5CSRTT method is an efficient training procedure for assessing attention and can be utilized to assess the limit in performance ability across subjects and various schedule manipulations. PMID:25528113

Mechanical alterations during interval-training treadmill runs in high-level male team-sport players.

PubMed

Girard, Olivier; Brocherie, Franck; Morin, Jean-Benoit; Millet, Grégoire P

2017-01-01

To examine mechanical alterations during interval-training treadmill runs in high-level team-sport players. Within-participants repeated measures. Twenty high-level male field-hockey players performed six 30-s runs at 5.53±0.19ms -1 corresponding to 115% of their velocity associated with maximal oxygen uptake (vVO 2max ) with 30-s passive recovery on an instrumented treadmill. Continuous measurement of running kinetics/kinematics and spring-mass characteristics were performed and values were subsequently averaged over 20s (8th-28ths) for comparison. Contact time (+1.1±4.3%; p=0.044), aerial time (+4.1±5.3%; p=0.001), step length (+2.4±2.2%; p<0.001) along with mean loading rates (+7.1±10.6%; p=0.026) increased from the first to the last interval, whereas step frequency (-2.3±2.1%; p<0.001) decreased. Both centre of mass vertical displacement (+3.0±6.0%; p<0.001) and leg compression (+2.8±9.7%; p=0.036), but not peak vertical forces (0.0±4.1%; p=0.761), increased with fatigue. Vertical stiffness decreased (-2.8±6.9%; p=0.012), whereas leg stiffness did not change across intervals (p=0.149). During interval-training treadmill runs, high-level team-sport players modified their mechanical behaviour towards lower vertical stiffness while preserving a constant leg stiffness. Maintenance of running velocity induced longer step lengths and decreased step frequencies that were also accompanied by increased impact loading rates. These mechanical alterations occurred early during the set. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

National disparities in treatment package time for resected locally advanced head and neck cancer and impact on overall survival.

PubMed

Guttmann, David M; Kobie, Julie; Grover, Surbhi; Lin, Alexander; Lukens, John N; Mitra, Nandita; Rhodes, Karin V; Feng, Weiwei; Swisher-McClure, Samuel

2018-06-01

The purpose of this study was to determine national disparities in head and neck cancer treatment package time (the time interval from surgery through the completion of radiation) and the associated impact on survival. We conducted an observational cohort study using the National Cancer Database of 15 234 patients with resected head and neck cancer who underwent adjuvant radiotherapy from 2004-2012. Predictors of prolonged package time were identified by multivariable linear regression. Survival outcomes were assessed using a multivariable Cox model. Mean package time was 100 days (SD 23). Package time was 7.52 days (95% confidence interval [CI] 6.23-8.81; P < .001) longer with Medicaid versus commercial insurance. Low income and African American race also predicted for longer package times. All-cause mortality increased an average of 4% with each 1 week increase in treatment package time (hazard ratio [HR] 1.04; 95% CI 1.03-1.05; P < .001). Significant national socioeconomic disparities exist in treatment package time. Treatment delays in this setting may contribute to worse survival outcomes. © 2018 Wiley Periodicals, Inc.

Role of enamel deminerlization and remineralization on microtensile bond strength of resin composite

PubMed Central

Rizvi, Abbas; Zafar, Muhammad S.; Al-Wasifi, Yasser; Fareed, Wamiq; Khurshid, Zohaib

2016-01-01

Objective: This study is aimed to establish the microtensile bond strength of enamel following exposure to an aerated drink at various time intervals with/without application of remineralization agent. In addition, degree of remineralization and demineralization of tooth enamel has been assessed using polarized light microscopy. Materials and Methods: Seventy extracted human incisors split into two halves were immersed in aerated beverage (cola drink) for 5 min and stored in saliva until the time of microtensile bond testing. Prepared specimens were divided randomly into two study groups; remineralizing group (n = 70): specimens were treated for remineralization using casein phosphopeptides and amorphous calcium phosphate (CPP-ACP) remineralization agent (Recaldent™; GC Europe) and control group (n = 70): no remineralization treatment; specimens were kept in artificial saliva. All specimens were tested for microtensile bond strength at regular intervals (1 h, 1 days, 2 days, 1 week, and 2 weeks) using a universal testing machine. The results statistically analyzed (P = 0.05) using two-way ANOVA test. Results: Results showed statistically significant increase in bond strength in CPP-ACP tested group (P < 0.05) at all-time intervals. The bond strength of remineralizing group samples at 2 days (~13.64 megapascals [MPa]) is comparable to that of control group after 1 week (~12.44 MPa). Conclusions: CPP-ACP treatment of teeth exposed to an aerated drink provided significant increase in bond strength at a shorter interval compared to teeth exposed to saliva alone. PMID:27403057

Quantifying the statistical complexity of low-frequency fluctuations in semiconductor lasers with optical feedback

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

Tiana-Alsina, J.; Torrent, M. C.; Masoller, C.

Low-frequency fluctuations (LFFs) represent a dynamical instability that occurs in semiconductor lasers when they are operated near the lasing threshold and subject to moderate optical feedback. LFFs consist of sudden power dropouts followed by gradual, stepwise recoveries. We analyze experimental time series of intensity dropouts and quantify the complexity of the underlying dynamics employing two tools from information theory, namely, Shannon's entropy and the Martin, Plastino, and Rosso statistical complexity measure. These measures are computed using a method based on ordinal patterns, by which the relative length and ordering of consecutive interdropout intervals (i.e., the time intervals between consecutive intensitymore » dropouts) are analyzed, disregarding the precise timing of the dropouts and the absolute durations of the interdropout intervals. We show that this methodology is suitable for quantifying subtle characteristics of the LFFs, and in particular the transition to fully developed chaos that takes place when the laser's pump current is increased. Our method shows that the statistical complexity of the laser does not increase continuously with the pump current, but levels off before reaching the coherence collapse regime. This behavior coincides with that of the first- and second-order correlations of the interdropout intervals, suggesting that these correlations, and not the chaotic behavior, are what determine the level of complexity of the laser's dynamics. These results hold for two different dynamical regimes, namely, sustained LFFs and coexistence between LFFs and steady-state emission.« less

Interval breast cancer characteristics before, during and after the transition from screen-film to full-field digital screening mammography.

PubMed

van Bommel, Rob M G; Weber, Roy; Voogd, Adri C; Nederend, Joost; Louwman, Marieke W J; Venderink, Dick; Strobbe, Luc J A; Rutten, Matthieu J C; Plaisier, Menno L; Lohle, Paul N; Hooijen, Marianne J H; Tjan-Heijnen, Vivianne C G; Duijm, Lucien E M

2017-05-05

To determine the proportion of "true" interval cancers and tumor characteristics of interval breast cancers prior to, during and after the transition from screen-film mammography screening (SFM) to full-field digital mammography screening (FFDM). We included all women with interval cancers detected between January 2006 and January 2014. Breast imaging reports, biopsy results and breast surgery reports of all women recalled at screening mammography and of all women with interval breast cancers were collected. Two experienced screening radiologists reviewed the diagnostic mammograms, on which the interval cancers were diagnosed, as well as the prior screening mammograms and determined whether or not the interval cancer had been missed on the most recent screening mammogram. If not missed, the cancer was considered an occult ("true") interval cancer. A total of 442 interval cancers had been diagnosed, of which 144 at SFM with a prior SFM (SFM-SFM), 159 at FFDM with a prior SFM (FFDM-SFM) and 139 at FFDM with a prior FFDM (FFDM-FFDM). The transition from SFM to FFDM screening resulted in the diagnosis of more occult ("true") interval cancers at FFDM-SFM than at SFM-SFM (65.4% (104/159) versus 49.3% (71/144), P < 0.01), but this increase was no longer statistically significant in women who had been screened digitally for the second time (57.6% (80/139) at FFDM-FFDM versus 49.3% (71/144) at SFM-SFM). Tumor characteristics were comparable for the three interval cancer cohorts, except of a lower porportion (75.7 and 78.0% versus 67.2% af FFDM-FFDM, P < 0.05) of invasive ductal cancers at FFDM with prior FFDM. An increase in the proportion of occult interval cancers is observed during the transition from SFM to FFDM screening mammography. However, this increase seems temporary and is no longer detectable after the second round of digital screening. Tumor characteristics and type of surgery are comparable for interval cancers detected prior to, during and after the transition from SFM to FFDM screening mammography, except of a lower proportion of invasive ductal cancers after the transition.

The effects of creatine pyruvate and creatine citrate on performance during high intensity exercise

PubMed Central

Jäger, Ralf; Metzger, Jan; Lautmann, Karin; Shushakov, Vladimir; Purpura, Martin; Geiss, Kurt-Reiner; Maassen, Norbert

2008-01-01

Background A double-blind, placebo-controlled, randomized study was performed to evaluate the effect of oral creatine pyruvate (Cr-Pyr) and creatine citrate (Cr-Cit) supplementation on exercise performance in healthy young athletes. Methods Performance during intermittent handgrip exercise of maximal intensity was evaluated before (pretest) and after (posttest) 28 days of Cr-Pyr (5 g/d, n = 16), Cr-Cit (5 g/d, n = 16) or placebo (pla, 5 g/d, n = 17) intake. Subjects performed ten 15-sec exercise intervals, each followed by 45 sec rest periods. Results Cr-Pyr (p < 0.001) and Cr-Cit (p < 0.01) significantly increased mean power over all intervals. Cr-Cit increased force during the first and second interval (p < 0.01) compared to placebo. The effect of Cr-Cit on force decreased over time and the improvement was not significant at the sixth and ninth interval, whereas Cr-Pyr significantly increased force during all intervals (p < 0.001). Cr-Pyr (p < 0.001) and Cr-Cit (p < 0.01) resulted in an increase in contraction velocity, whereas only Cr-Pyr intake significantly (p < 0.01) increased relaxation velocity. Oxygen consumption measured during rest periods significantly increased with Cr-Pyr (p < 0.05), whereas Cr-Cit and placebo intake did not result in significant improvements. Conclusion It is concluded that four weeks of Cr-Pyr and Cr-Cit intake significantly improves performance during intermittent handgrip exercise of maximal intensity and that Cr-Pyr might benefit endurance, due to enhanced activity of the aerobic metabolism. PMID:18269769

Effect of Cypermethrin on the Growth of Ciliate Protozoan Paramecium caudatum

PubMed Central

Dutta, Joydeep

2015-01-01

Objective: The objective of this study is to assess the effect of cypermethrin on the growth of ciliate protozoan Paramecium caudatum. Materials and Methods: Monoxenic culture of P. caudatum, were exposed to different doses (0.01, 0.05, 0.1, 0.15, and 0.2 µg/L) of cypermethrin along with control for 24, 48, 72, and 96 h time interval. The total numbers of live and dead cells were counted after trypan blue staining in Neubauer hemocytometer. Results: Marked decrease in the number of living cells with the increase in the concentration of cypermethrin and with increasing exposure time intervals was recorded. Conclusion: The results indicate that cypermethrin is toxic to P. caudatum even at low concentrations when it enters in the aquatic system through runoff. PMID:26862268

Out-of-range INR values and outcomes among new warfarin patients with non-valvular atrial fibrillation.

PubMed

Nelson, Winnie W; Wang, Li; Baser, Onur; Damaraju, Chandrasekharrao V; Schein, Jeffrey R

2015-02-01

Although efficacious in stroke prevention in non-valvular atrial fibrillation, many warfarin patients are sub-optimally managed. To evaluate the association of international normalized ratio control and clinical outcomes among new warfarin patients with non-valvular atrial fibrillation. Adult non-valvular atrial fibrillation patients (≥18 years) initiating warfarin treatment were selected from the US Veterans Health Administration dataset between 10/2007 and 9/2012. Valid international normalized ratio values were examined from the warfarin initiation date through the earlier of the first clinical outcome, end of warfarin exposure or death. Each patient contributed multiple in-range and out-of-range time periods. The relative risk ratios of clinical outcomes associated with international normalized ratio control were estimated. 34,346 patients were included for analysis. During the warfarin exposure period, the incidence of events per 100 person-years was highest when patients had international normalized ratio <2:13.66 for acute coronary syndrome; 10.30 for ischemic stroke; 2.93 for transient ischemic attack; 1.81 for systemic embolism; and 4.55 for major bleeding. Poisson regression confirmed that during periods with international normalized ratio <2, patients were at increased risk of developing acute coronary syndrome (relative risk ratio: 7.9; 95 % confidence interval 6.9-9.1), ischemic stroke (relative risk ratio: 7.6; 95 % confidence interval 6.5-8.9), transient ischemic attack (relative risk ratio: 8.2; 95 % confidence interval 6.1-11.2), systemic embolism (relative risk ratio: 6.3; 95 % confidence interval 4.4-8.9) and major bleeding (relative risk ratio: 2.6; 95 % confidence interval 2.2-3.0). During time periods with international normalized ratio >3, patients had significantly increased risk of major bleeding (relative risk ratio: 1.5; 95 % confidence interval 1.2-2.0). In a Veterans Health Administration non-valvular atrial fibrillation population, exposure to out-of-range international normalized ratio values was associated with significantly increased risk of adverse clinical outcomes.

Genomic tools to improve progress and preserve variation for future generations

USDA-ARS?s Scientific Manuscript database

Use of genomic tools has greatly decreased generation intervals and increased genetic progress in dairy cattle, but faster selection cycles can also increase rates of inbreeding per unit of time. Average pedigree inbreeding of Holstein cows increased from 4.6% in 2000 to 5.6% in 2009 to 6.6% in 201...

[Evaluation of immunogenicity and safety of 2 immunizations with allantoic intranasal live influenza vaccine Ultragrivac].

PubMed

Shishkina, L N; Mazurkova, N A; Ternovoĭ, V A; Bulychev, L E; Tumanov, Iu V; Skarnovich, M O; Kabanov, A S; Ryndiuk, N N; Kuzubov, V I; Mironov, A N; Stavskiĭ, E A; Drozdov, I G

2011-01-01

Evaluate reactogenicity, safety and immunogenicity in phase 2 clinical trials of 2 immunization schedules with Ultragrivac--an allantoic intranasal life influenza vaccine based on A/17/ duck/Potsdam/86/92 [17/H5] reassortant strain. 4 groups of volunteers participated in the study: group 1--40 individuals were vaccinated twice with a 10 day interval; group 2--40 individuals were vaccinated twice with a 21 day interval; group 3 (control)--10 individuals received placebo twice with a 10 day interval; group 4 (control)--10 individuals received placebo twice with a 21 day interval. Local (secretory IgA), cellular and humoral immune response were evaluated. Humoral immunity was evaluated by the intensity of increase of geometric mean antibody titers against 2 influenza virus strains A/17/duck/Potsdam/86/92 [17/H5] and A/chicken/Suzdalka/Nov-1 1/2005 (H5N1), and by the level of significant (4 times or more) antibody seroconversions after the vaccination. After the use of Ultragrivac the level of secretory IgA in the nasal cavity of vaccinated volunteers in the groups with revaccination intervals of 10 and 21 days increased significantly. The second immunization with 10 or 21 day intervals significantly increased postvaccinal humoral immune response. Humoral immune response induction after 2 vaccinations with 10 day interval was no less effective than with 21 day interval. Ultragrivac allantoic intranasal live influenza vaccine is areactogenic, harmless for vaccinated individuals, safe for those around, and has immunogenic properties against not only homologous virus A(H5N2), but also against influenza strain A(H5N1).

Electrocardiographic and blood pressure effects of energy drinks and Panax ginseng in healthy volunteers: A randomized clinical trial.

PubMed

Shah, Sachin A; Occiano, Andrew; Nguyen, Tinh An; Chan, Amanda; Sky, Joseph C; Bhattacharyya, Mouchumi; O'Dell, Kate M; Shek, Allen; Nguyen, Nancy N

2016-09-01

Energy drink usage has been linked to emergency room visits and deaths. The objective of the study is to assess the electrocardiographic and blood pressure effects of energy drinks, Panax ginseng and placebo in healthy individuals. This was a randomized, double blinded, placebo controlled, crossover study. Young healthy volunteers with no comorbid conditions consumed 32oz of an energy drink, control drink with 800mg of Panax ginseng or matching placebo-control drink over 45min. Primary endpoints were QTc interval and systolic blood pressure. Secondary endpoints included QT interval, PR interval, QRS duration, heart rate, and diastolic blood pressure. All endpoints were assessed at baseline, 1, 2, 3.5, and 5.5h. A significant increase in QTc interval 2h post energy drink consumption was evident when compared to placebo (3.37±10.7ms and -3.19±11.8ms respectively; p=0.030). Similarly, systolic blood pressure 2h post energy drink consumption increased when compared to placebo (2.00±6.37mmHg and -2.67±5.83mmHg respectively; p=0.014). The PR interval significantly reduced over a 2h period post energy drink use in a clinically non-meaningful manner. Heart rate at 2h was not significantly higher in the energy drink group when compared to others. The QT interval, QRS interval and diastolic blood pressure were not impacted at any time point. Certain energy drinks consumed at a high volume significantly increase the QTc interval and systolic blood pressure by over 6ms and 4mmHg respectively. Panax ginseng does not have a significant impact on ECG or blood pressure parameters. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Association of time-to-surgery with outcomes in clinical stage I-II pancreatic adenocarcinoma treated with upfront surgery.

PubMed

Swords, Douglas S; Zhang, Chong; Presson, Angela P; Firpo, Matthew A; Mulvihill, Sean J; Scaife, Courtney L

2018-04-01

Time-to-surgery from cancer diagnosis has increased in the United States. We aimed to determine the association between time-to-surgery and oncologic outcomes in patients with resectable pancreatic ductal adenocarcinoma undergoing upfront surgery. The 2004-2012 National Cancer Database was reviewed for patients undergoing curative-intent surgery without neoadjuvant therapy for clinical stage I-II pancreatic ductal adenocarcinoma. A multivariable Cox model with restricted cubic splines was used to define time-to-surgery as short (1-14 days), medium (15-42), and long (43-120). Overall survival was examined using Cox shared frailty models. Secondary outcomes were examined using mixed-effects logistic regression models. Of 16,763 patients, time-to-surgery was short in 34.4%, medium in 51.6%, and long in 14.0%. More short time-to-surgery patients were young, privately insured, healthy, and treated at low-volume hospitals. Adjusted hazards of mortality were lower for medium (hazard ratio 0.94, 95% confidence interval, .90, 0.97) and long time-to-surgery (hazard ratio 0.91, 95% confidence interval, 0.86, 0.96) than short. There were no differences in adjusted odds of node positivity, clinical to pathologic upstaging, being unresectable or stage IV at exploration, and positive margins. Medium time-to-surgery patients had higher adjusted odds (odds ratio 1.11, 95% confidence interval, 1.03, 1.20) of receiving an adequate lymphadenectomy than short. Ninety-day mortality was lower in medium (odds ratio 0.75, 95% confidence interval, 0.65, 0.85) and long time-to-surgery (odds ratio 0.72, 95% confidence interval, 0.60, 0.88) than short. In this observational analysis, short time-to-surgery was associated with slightly shorter OS and higher perioperative mortality. These results may suggest that delays for medical optimization and referral to high volume surgeons are safe. Published by Elsevier Inc.

The effect of clomiphene citrate on human preovulatory oocyte maturation in vivo.

PubMed

Seibel, M M; Smith, D M

1989-02-01

Sixty-four infertile women underwent diagnostic laparoscopy in the periovulatory period at time-bracketed intervals following their endogenous luteinizing hormone (LH) surge. Forty-eight of these women were studied during natural cycles and 16 had mild oligoovulation and were administered clomiphene citrate (CC) to regulate their cycles. No patient received human chorionic gonadotropin. No patient was undergoing either in vitro fertilization (IVF) or gamete intrafallopian transfer (GIFT). Follicle puncture was performed and the oocytes were observed immediately for stage of maturation. Oocytes obtained from follicles exposed to CC were found to require an increased interval of time to reach metaphase I compared to oocytes obtained from natural cycles (27.75 +/- 2.2 vs 22.5 hr; mean +/- SE). Furthermore, the interval of time required for metaphase I oocytes to achieve metaphase II was statistically significantly shortened for CC cycles (2.4 hr for CC vs 10 hr for natural cycles. Nevertheless, there was no difference between natural and CC cycles in the time interval between LH surge onset and ovulation. These in vivo findings suggest a direct effect of CC on human oocyte maturation and may help explain the well-established discrepancy between the relatively high ovulation rate and the relatively low conception rate in clomiphene-induced cycles.

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

PubMed

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

2014-05-20

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

The effect of 1/f fluctuation in inter-stimulus intervals on auditory evoked mismatch field.

PubMed

Harada, Nobuyoshi; Masuda, Tadashi; Endo, Hiroshi; Nakamura, Yukihiro; Takeda, Tsunehiro; Tonoike, Mitsuo

2005-05-13

This study focused on the effect of regularity of environmental stimuli on the informational order extracting function of human brain. The regularity of environmental stimuli can be described with the exponent n of the fluctuation 1/f(n). We studied the effect of the exponent of the fluctuation in the inter-stimulus interval (ISI) on the elicitation of auditory evoked mismatch fields (MMF) with two sounds with alternating frequency. ISI times were given by three types of fluctuation, 1/f(0), 1/f(1), 1/f(2), and with a fixed interval (1/f(infinity)). The root mean square (RMS) value of the MMF increased significantly (F(3/9)=4.95, p=0.027) with increases in the exponent of the fluctuation. Increments in the regularity of the fluctuation provoked enhancement of the MMF, which reflected the production of a memory trace, based on the anticipation of the stimulus timing. The gradient of the curve, indicating the ratio of increments between the MMF and the exponent of fluctuation, can express a subject's capability to extract regularity from fluctuating stimuli.

EFFECT ON PERFUSION VALUES OF SAMPLING INTERVAL OF CT PERFUSION ACQUISITIONS IN NEUROENDOCRINE LIVER METASTASES AND NORMAL LIVER

PubMed Central

Ng, Chaan S.; Hobbs, Brian P.; Wei, Wei; Anderson, Ella F.; Herron, Delise H.; Yao, James C.; Chandler, Adam G.

2014-01-01

Objective To assess the effects of sampling interval (SI) of CT perfusion acquisitions on CT perfusion values in normal liver and liver metastases from neuroendocrine tumors. Methods CT perfusion in 16 patients with neuroendocrine liver metastases were analyzed by distributed parameter modeling to yield tissue blood flow, blood volume, mean transit time, permeability, and hepatic arterial fraction, for tumor and normal liver. CT perfusion values for the reference sampling interval of 0.5s (SI0.5) were compared with those of SI datasets of 1s, 2s, 3s and 4s, using mixed-effects model analyses. Results Increases in SI beyond 1s were associated with significant and increasing departures of CT perfusion parameters from reference values at SI0.5 (p≤0.0009). CT perfusion values deviated from reference with increasing uncertainty with increasing SIs. Findings for normal liver were concordant. Conclusion Increasing SIs beyond 1s yield significantly different CT perfusion parameter values compared to reference values at SI0.5. PMID:25626401

Fluctuations in Wikipedia access-rate and edit-event data

NASA Astrophysics Data System (ADS)

Kämpf, Mirko; Tismer, Sebastian; Kantelhardt, Jan W.; Muchnik, Lev

2012-12-01

Internet-based social networks often reflect extreme events in nature and society by drastic increases in user activity. We study and compare the dynamics of the two major complex processes necessary for information spread via the online encyclopedia ‘Wikipedia’, i.e., article editing (information upload) and article access (information viewing) based on article edit-event time series and (hourly) user access-rate time series for all articles. Daily and weekly activity patterns occur in addition to fluctuations and bursting activity. The bursts (i.e., significant increases in activity for an extended period of time) are characterized by a power-law distribution of durations of increases and decreases. For describing the recurrence and clustering of bursts we investigate the statistics of the return intervals between them. We find stretched exponential distributions of return intervals in access-rate time series, while edit-event time series yield simple exponential distributions. To characterize the fluctuation behavior we apply detrended fluctuation analysis (DFA), finding that most article access-rate time series are characterized by strong long-term correlations with fluctuation exponents α≈0.9. The results indicate significant differences in the dynamics of information upload and access and help in understanding the complex process of collecting, processing, validating, and distributing information in self-organized social networks.

Magnitude of increase in QTc interval after initiation of dofetilide in patients with persistent atrial fibrillation is associated with increased rates of pharmacological cardioversion and long-term freedom from recurrent atrial fibrillation.

PubMed

Huang, Henry D; Waks, Jonathan W; Steinhaus, Daniel A; Zimetbaum, Peter

2016-07-01

Dofetilide is a class III antiarrhythmic drug approved for the treatment of atrial fibrillation (AF). Dofetilide-induced corrected QT (QTc) interval prolongation is a surrogate for the degree of drug effect, but the relationships between drug-induced QTc interval prolongation, pharmacological cardioversion (PCV), and freedom from recurrent AF are unclear. The purpose of this study was to assess associations between QTc interval change during dofetilide initiation and PCV and long-term AF recurrence. We performed retrospective analyses of a prospective cohort of patients with AF admitted for dofetilide initiation between 2001 and 2014. Clinical characteristics and electrocardiographic variables were assessed. We evaluated outcomes of successful PCV in patients with persistent AF and time to recurrence of AF in patients with paroxysmal and persistent AF. During the study, 243 patients with persistent AF and 176 patients with paroxysmal AF initiated dofetilide. PCV occurred in 93/243 (41.7%) patients with persistent AF. After multivariable adjustment, QTc interval change was associated with PCV (adjusted odds ratio 1.21; P = .003 per 10-ms QTc increase). Inhospital QTc interval change was associated with long-term freedom from AF in patients with persistent AF (adjusted hazard ratio 0.92; P = .011 at 4 years per 10-ms QTc increase), but not in patients with paroxysmal AF. In patients with persistent AF, PCV was also associated with long-term freedom from recurrent AF (adjusted hazard ratio 0.62; P = .009 at 4 years). The magnitude of QTc interval prolongation during dofetilide initiation is an independent predictor of successful PCV and long-term freedom from arrhythmia in patients with persistent AF. QTc interval change had no association with AF recurrence in patients with paroxysmal AF, suggesting that different mechanisms of arrhythmogenesis may be operant in different AF types. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Measuring the effects of supratherapeutic doses of levofloxacin on healthy volunteers using four methods of QT correction and periodic and continuous ECG recordings.

PubMed

Noel, Gary J; Goodman, Daniel B; Chien, Shuchean; Solanki, Bhavna; Padmanabhan, Mukund; Natarajan, Jaya

2004-05-01

A clinical trial was conducted in healthy volunteers using both periodic and continuous ECG recordings to assess the effect of increasing doses of levofloxacin on the QT and QTc interval. Periodic and continuous ECGs were recorded before and after subjects were dosed with placebo and increasing doses of levofloxacin (500 mg, 1000 mg, 1500 mg) that included doses twice the maximum recommended dose of 750 mg in a double-blind, randomized, four-period, four-sequence crossover trial. Mean heart rate (HR) and the QT and QTc interval after dosing with levofloxacin and placebo were compared, and HR-QT interval relationships defined by linear regression analysis were calculated. After single doses of 1000 and 1500 mg of levofloxacin, HR increased significantly, as measured by periodic and continuous ECG recordings. This transient increase occurred at times of peak plasma concentration and was without symptoms. Mean QT intervals after placebo and mean intervals after levofloxacin were indistinguishable. Using periodic ECG recordings, single doses of 1500 mg were associated with small increases in QTc that were statistically significant. In contrast, an effect on QTc was shown only using the Bazett formula with data obtained from continuous ECG recordings. Together with the finding that levofloxacin does not influence HR-QT relationships, these findings suggest that levofloxacin has little effect on prolonging ventricular repolarization and that small increases in HR associated with high doses of levofloxacin contribute to the drug's apparent effect on QTc. Single doses of 1000 or 1500 mg of levofloxacin transiently increase HR without affecting the uncorrected QT interval. Differences in mean QTc after levofloxacin compared to placebo vary depending on the correction formula used and whether the data analyzed are from periodic or continuous ECG recordings. This work suggests that using continuous ECG recordings in assessing QT/QTc effects of drugs may be of value, particularly with drugs that might influence HR.

Hierarchy of treatment variables affecting outcome of 131I therapy in thyroid cancer patients with lung metastases.

PubMed

Kozak, Oksana V; Sukach, Georgiy G; Korchinskaya, Oksana I; Trembach, Alexander M; Turicina, Viktoria L; Voit, Natalia U

2005-06-01

To assess the correlations between the first 131I activity value, time interval between the courses of radioiodine treatment and the overall number of courses required for total destruction of lung metastases in patients with differentiated thyroid cancer with metastatic lesions in lungs. 27 patients with differentiated thyroid cancer with metastases in lungs have been treated with radioiodine after surgical intervention. Activities administered amounted from 1600 to 7980 MBq. The number of radioiodine courses before total ablation of all metastatic lesions amounted from 1 to 10. Time interval between the 1st and the 2nd courses amounted from 3.5 to 11.5 months (6 months in average). The regression analysis of the data has been made. The exponential model fits the actual number of courses as a function of the first-second activity value and time interval between the courses. The first activity has a decisive influence on the number of courses required for total metastases ablation. The greater was the first activity value, the lesser was the overall number of courses. Increasing time interval between 1st and 2nd courses to 10 months seems to result in reducing the number of courses. Nevertheless even in the case of high activities the probability to undergone less then 3 courses is low. According to the proposed model in thyroid cancer patients with metastases in lungs the first activity should be not lesser than 6000 MBq, time interval between treatments--approximately 10 months. The results of our study suggest that individual factors such as histology, the number and the size of metastases in lymph nodes could not contribute more to the final outcome than the treatment variables, namely the first-second activity and time interval, nor could they affect the hierarchy of the effects revealed for the treatment variables.

The effect of financial incentives on adherence to antipsychotic depot medication: does it change over time?

PubMed

Pavlickova, Hana; Bremner, Stephen A; Priebe, Stefan

2015-08-01

A recent cluster-randomized controlled trial found that offering financial incentives improves adherence to long-acting injectable antipsychotics (LAIs). The present study investigates whether the impact of incentives diminishes over time and whether the improvement in adherence is linked to the amount of incentives offered. Seventy-three teams with 141 patients with psychotic disorders (using ICD-10) were randomized to the intervention or control group. Over 1 year, patients in the intervention group received £15 (US $23) for each LAI, while control patients received treatment as usual. Adherence levels, ie, the percentage of prescribed LAIs that were received, were calculated for quarterly intervals. The amount of incentives offered was calculated from the treatment cycle at baseline. Multilevel models were used to examine the time course of the effect of incentives and the effect of the amount of incentives offered on adherence. Adherence increased in both the intervention and the control group over time by an average of 4.2% per quarterly interval (95% CI, 2.8%-5.6%; P < .001). Despite this general increase, adherence in the intervention group remained improved compared to the control group by between 11% and 14% per quarterly interval. There was no interaction effect between time and treatment group. Further, a higher total amount of incentives was associated with poorer adherence (βbootstrapped = -0.11; 95% CIbootstrapped, -0.20 to -0.01; P = .023). A substantial effect of financial incentives on adherence to LAIs occurs within the first 3 months of the intervention and is sustained over 1 year. A higher total amount of incentives does not increase the effect. ISRCTN.com identifier: ISRCTN77769281 and UKCRN.org identifier: 7033. © Copyright 2015 Physicians Postgraduate Press, Inc.

QT interval correction for drug-induced changes in body temperature during integrated cardiovascular safety assessment in regulatory toxicology studies in dogs: A case study.

PubMed

El Amrani, Abdel-Ilah; El Amrani-Callens, Francine; Loriot, Stéphane; Singh, Pramila; Forster, Roy

2016-01-01

Cardiovascular safety assessment requires accurate evaluation of QT interval, which depends on the length of the cardiac cycle and also on core body temperature (BT). Increases in QT interval duration have been shown to be associated with decreases in BT in dogs. An example of altered QT interval duration associated with changes in body temperature observed during a 4-week regulatory toxicology study in dogs is presented. Four groups of Beagle dogs received the vehicle or test item once on Day 1, followed by a 4-week observation period. Electrocardiogram (ECG) parameters were continuously recorded on Days 1 and 26 by jacketed external telemetry (JET). Core body temperature (BT) was measured with a conventional rectal thermometer at appropriate time-points during the Day 1 recording period. Decreased BT was observed approximately 2h after treatment on Day 1, along with increased QT interval duration corrected according to the Van de Water formula (QTcV), but the effect was no longer observed after correction for changes in BT [QTcVcT=QTcV-14(37.5-BT)] according to the Van der Linde formula. No significant changes in QTcV were reported at the end of the observation period, on Day 26. The present study demonstrates that core body (rectal) temperature can easily be monitored at appropriate time-points during JET recording in regulatory toxicology studies in dogs, in order to correct QT interval duration values for treatment-related changes in BT. The successful application of the Van der Linde formula to correct QTc prolongation for changes in BT was demonstrated. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Power frequency spectrum analysis of surface EMG signals of upper limb muscles during elbow flexion - A comparison between healthy subjects and stroke survivors.

PubMed

Angelova, Silvija; Ribagin, Simeon; Raikova, Rositsa; Veneva, Ivanka

2018-02-01

After a stroke, motor units stop working properly and large, fast-twitch units are more frequently affected. Their impaired functions can be investigated during dynamic tasks using electromyographic (EMG) signal analysis. The aim of this paper is to investigate changes in the parameters of the power/frequency function during elbow flexion between affected, non-affected, and healthy muscles. Fifteen healthy subjects and ten stroke survivors participated in the experiments. Electromyographic data from 6 muscles of the upper limbs during elbow flexion were filtered and normalized to the amplitudes of EMG signals during maximal isometric tasks. The moments when motion started and when the flexion angle reached its maximal value were found. Equal intervals of 0.3407 s were defined between these two moments and one additional interval before the start of the flexion (first one) was supplemented. For each of these intervals the power/frequency function of EMG signals was calculated. The mean (MNF) and median frequencies (MDF), the maximal power (MPw) and the area under the power function (APw) were calculated. MNF was always higher than MDF. A significant decrease in these frequencies was found in only three post-stroke survivors. The frequencies in the first time interval were nearly always the highest among all intervals. The maximal power was nearly zero during first time interval and increased during the next ones. The largest values of MPw and APw were found for the flexor muscles and they increased for the muscles of the affected arm compared to the non-affected one of stroke survivors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Has Ebbinghaus Decayed with Time? The Growth of Recall (Hypermnesia) over Days

ERIC Educational Resources Information Center

Erdelyi, Matthew Hugh; Kleinbard, Jeff

1978-01-01

Recent laboratory work on the recall of pictures has produced a pattern suggesting that memory for certain classes of stimuli may be hypermnesiac rather than amnesiac (Ebbinghaus, 1885/1964), increasing over time and recall attempts. This research tries to determine the magnitude of memory growth over significant time intervals, e.g., a week…

Alteration of Radiosensitivity of Quiescent Cell Populations in Solid Tumors Irradiated with X‐Rays Twice at Various Intervals

PubMed Central

Ono, Koji; Mitsumori, Michihide; Abe, Mitsuyuki

1993-01-01

5‐Bromo‐2′‐deoxyuridine (BUdR) was injected into SCC VII or EMT6/KU tumor‐bearing mice intraperitoneally to label all the proliferating tumor cells. First, the mice were irradiated with X‐rays at a dose of 10 Gy, followed by a dose of 0–20 Gy at 0, 12, 24 or 48 h later. During the interval, no BUdR was injected. Immediately after the second irradiation, the tumors were excised and trypsinized. The micronucleus (MN) frequency in cells without BUdR labeling was determined by means of incubation with cytochalasin‐B (a cytokinesis‐blocker) and immunoftuorescence staining for BUdR. When the tumors were not pretreated with BUdR before the first irradiation, the MN frequency in all tumor cells was determined. To determine the labeling indices of SCC VII and EMT6/KU tumors at the time of the second irradiation, each group also included mice that were continuously administered BUdR until just before the second irradiation using mini‐osmotic pumps which had been implanted subcutaneously 5 days before the first irradiation. The MN frequency of all tumor cell populations obtained immediately after the second irradiation decreased in proportion to the increase in interval time. However, in both tumor systems, the MN frequency of unlabeled cell populations, which could be regarded as quiescent cells in the tumors at the time of the first irradiation, was raised with increase in the interval time. In addition, the labeling index at the second irradiation was higher than that at the first irradiation. These findings support the occurrence of recruitment from quiescent to proliferating state during fractionated irradiation. PMID:8276718

Variability of ionospheric TEC during solar and geomagnetic minima (2008 and 2009): external high speed stream drivers

NASA Astrophysics Data System (ADS)

Verkhoglyadova, O. P.; Tsurutani, B. T.; Mannucci, A. J.; Mlynczak, M. G.; Hunt, L. A.; Runge, T.

2013-02-01

We study solar wind-ionosphere coupling through the late declining phase/solar minimum and geomagnetic minimum phases during the last solar cycle (SC23) - 2008 and 2009. This interval was characterized by sequences of high-speed solar wind streams (HSSs). The concomitant geomagnetic response was moderate geomagnetic storms and high-intensity, long-duration continuous auroral activity (HILDCAA) events. The JPL Global Ionospheric Map (GIM) software and the GPS total electron content (TEC) database were used to calculate the vertical TEC (VTEC) and estimate daily averaged values in separate latitude and local time ranges. Our results show distinct low- and mid-latitude VTEC responses to HSSs during this interval, with the low-latitude daytime daily averaged values increasing by up to 33 TECU (annual average of ~20 TECU) near local noon (12:00 to 14:00 LT) in 2008. In 2009 during the minimum geomagnetic activity (MGA) interval, the response to HSSs was a maximum of ~30 TECU increases with a slightly lower average value than in 2008. There was a weak nighttime ionospheric response to the HSSs. A well-studied solar cycle declining phase interval, 10-22 October 2003, was analyzed for comparative purposes, with daytime low-latitude VTEC peak values of up to ~58 TECU (event average of ~55 TECU). The ionospheric VTEC changes during 2008-2009 were similar but ~60% less intense on average. There is an evidence of correlations of filtered daily averaged VTEC data with Ap index and solar wind speed. We use the infrared NO and CO2 emission data obtained with SABER on TIMED as a proxy for the radiation balance of the thermosphere. It is shown that infrared emissions increase during HSS events possibly due to increased energy input into the auroral region associated with HILDCAAs. The 2008-2009 HSS intervals were ~85% less intense than the 2003 early declining phase event, with annual averages of daily infrared NO emission power of ~ 3.3 × 1010 W and 2.7 × 1010 W in 2008 and 2009, respectively. The roles of disturbance dynamos caused by high-latitude winds (due to particle precipitation and Joule heating in the auroral zones) and of prompt penetrating electric fields (PPEFs) in the solar wind-ionosphere coupling during these intervals are discussed. A correlation between geoeffective interplanetary electric field components and HSS intervals is shown. Both PPEF and disturbance dynamo mechanisms could play important roles in solar wind-ionosphere coupling during prolonged (up to days) external driving within HILDCAA intervals.

Assessment of Micro-Basin Tillage as a Soil and Water Conservation Practice in the Black Soil Region of Northeast China.

PubMed

Sui, Yuanyuan; Ou, Yang; Yan, Baixing; Xu, Xiaohong; Rousseau, Alain N; Zhang, Yu

2016-01-01

Micro-basin tillage is a soil and water conservation practice that requires building individual earth blocks along furrows. In this study, plot experiments were conducted to assess the efficiency of micro-basin tillage on sloping croplands between 2012 and 2013 (5°and 7°). The conceptual, optimal, block interval model was used to design micro-basins which are meant to capture the maximum amount of water per unit area. Results indicated that when compared to the up-down slope tillage, micro-basin tillage could increase soil water content and maize yield by about 45% and 17%, and reduce runoff, sediment and nutrients loads by about 63%, 96% and 86%, respectively. Meanwhile, micro-basin tillage could reduce the peak runoff rates and delay the initial runoff-yielding time. In addition, micro-basin tillage with the optimal block interval proved to be the best one among all treatments with different intervals. Compared with treatments of other block intervals, the optimal block interval treatments increased soil moisture by around 10% and reduced runoff rate by around 15%. In general, micro-basin tillage with optimal block interval represents an effective soil and water conservation practice for sloping farmland of the black soil region.

Assessment of Micro-Basin Tillage as a Soil and Water Conservation Practice in the Black Soil Region of Northeast China

PubMed Central

Sui, Yuanyuan; Ou, Yang; Yan, Baixing; Xu, Xiaohong; Rousseau, Alain N.; Zhang, Yu

2016-01-01

Micro-basin tillage is a soil and water conservation practice that requires building individual earth blocks along furrows. In this study, plot experiments were conducted to assess the efficiency of micro-basin tillage on sloping croplands between 2012 and 2013 (5°and 7°). The conceptual, optimal, block interval model was used to design micro-basins which are meant to capture the maximum amount of water per unit area. Results indicated that when compared to the up-down slope tillage, micro-basin tillage could increase soil water content and maize yield by about 45% and 17%, and reduce runoff, sediment and nutrients loads by about 63%, 96% and 86%, respectively. Meanwhile, micro-basin tillage could reduce the peak runoff rates and delay the initial runoff-yielding time. In addition, micro-basin tillage with the optimal block interval proved to be the best one among all treatments with different intervals. Compared with treatments of other block intervals, the optimal block interval treatments increased soil moisture by around 10% and reduced runoff rate by around 15%. In general, micro-basin tillage with optimal block interval represents an effective soil and water conservation practice for sloping farmland of the black soil region. PMID:27031339

Temporal Integration of Auditory Information Is Invariant to Temporal Grouping Cues1,2,3

PubMed Central

Tsunada, Joji

2015-01-01

Abstract Auditory perception depends on the temporal structure of incoming acoustic stimuli. Here, we examined whether a temporal manipulation that affects the perceptual grouping also affects the time dependence of decisions regarding those stimuli. We designed a novel discrimination task that required human listeners to decide whether a sequence of tone bursts was increasing or decreasing in frequency. We manipulated temporal perceptual-grouping cues by changing the time interval between the tone bursts, which led to listeners hearing the sequences as a single sound for short intervals or discrete sounds for longer intervals. Despite these strong perceptual differences, this manipulation did not affect the efficiency of how auditory information was integrated over time to form a decision. Instead, the grouping manipulation affected subjects’ speed−accuracy trade-offs. These results indicate that the temporal dynamics of evidence accumulation for auditory perceptual decisions can be invariant to manipulations that affect the perceptual grouping of the evidence. PMID:26464975

Climate, canopy disturbance, and radial growth averaging in a second-growth mixed-oak forest in West Virginia, USA

Treesearch

James S. Rentch; B. Desta Fekedulegn; Gary W. Miller

2002-01-01

This study evaluated the use of radial growth averaging as a technique of identifying canopy disturbances in a thinned 55-year-old mixed-oak stand in West Virginia. We used analysis of variance to determine the time interval (averaging period) and lag period (time between thinning and growth increase) that best captured the growth increase associated with different...

Timescale- and Sensory Modality-Dependency of the Central Tendency of Time Perception.

PubMed

Murai, Yuki; Yotsumoto, Yuko

2016-01-01

When individuals are asked to reproduce intervals of stimuli that are intermixedly presented at various times, longer intervals are often underestimated and shorter intervals overestimated. This phenomenon may be attributed to the central tendency of time perception, and suggests that our brain optimally encodes a stimulus interval based on current stimulus input and prior knowledge of the distribution of stimulus intervals. Two distinct systems are thought to be recruited in the perception of sub- and supra-second intervals. Sub-second timing is subject to local sensory processing, whereas supra-second timing depends on more centralized mechanisms. To clarify the factors that influence time perception, the present study investigated how both sensory modality and timescale affect the central tendency. In Experiment 1, participants were asked to reproduce sub- or supra-second intervals, defined by visual or auditory stimuli. In the sub-second range, the magnitude of the central tendency was significantly larger for visual intervals compared to auditory intervals, while visual and auditory intervals exhibited a correlated and comparable central tendency in the supra-second range. In Experiment 2, the ability to discriminate sub-second intervals in the reproduction task was controlled across modalities by using an interval discrimination task. Even when the ability to discriminate intervals was controlled, visual intervals exhibited a larger central tendency than auditory intervals in the sub-second range. In addition, the magnitude of the central tendency for visual and auditory sub-second intervals was significantly correlated. These results suggest that a common modality-independent mechanism is responsible for the supra-second central tendency, and that both the modality-dependent and modality-independent components of the timing system contribute to the central tendency in the sub-second range.

The freckle plot (daily turnaround time chart): a technique for timely and effective quality improvement of test turnaround times.

PubMed

Pellar, T G; Ward, P J; Tuckerman, J F; Henderson, A R

1993-06-01

Test turnaround times are often monitored on a monthly basis. However, such an interval usually means that not all causes for delay in test reporting can be unequivocally identified for institution of remedial action. We have devised a daily chart--the freckle plot--that graphically displays the test turnaround times by laboratory receipt time. Different symbols are used to designate specimens reported within the test's turnaround time limit, those within 10 min beyond that limit, and those well outside the limit. These categories are adjustable to suit different limits of stringency. Freckle plots are produced on a daily basis and can be used to track down causes for test delays. Using the 1-h turnaround time "stat" potassium test as a model, we found 16 causes for test delay, of which 9 were potentially remediable. By applying these remedies, we were able to increase test compliance, in the day shift, from 91.5% (95% confidence interval 88.8%-93.7%) to 97.6% (95% confidence interval 96.4-98.55%), which is significant at P < 10(-7). This daily plot is a useful quality assurance tool, supplementing the more conventional tests used to ensure laboratory quality improvement.

High resolution data acquisition

DOEpatents

Thornton, G.W.; Fuller, K.R.

1993-04-06

A high resolution event interval timing system measures short time intervals such as occur in high energy physics or laser ranging. Timing is provided from a clock, pulse train, and analog circuitry for generating a triangular wave synchronously with the pulse train (as seen in diagram on patent). The triangular wave has an amplitude and slope functionally related to the time elapsed during each clock pulse in the train. A converter forms a first digital value of the amplitude and slope of the triangle wave at the start of the event interval and a second digital value of the amplitude and slope of the triangle wave at the end of the event interval. A counter counts the clock pulse train during the interval to form a gross event interval time. A computer then combines the gross event interval time and the first and second digital values to output a high resolution value for the event interval.

High resolution data acquisition

DOEpatents

Thornton, Glenn W.; Fuller, Kenneth R.

1993-01-01

A high resolution event interval timing system measures short time intervals such as occur in high energy physics or laser ranging. Timing is provided from a clock (38) pulse train (37) and analog circuitry (44) for generating a triangular wave (46) synchronously with the pulse train (37). The triangular wave (46) has an amplitude and slope functionally related to the time elapsed during each clock pulse in the train. A converter (18, 32) forms a first digital value of the amplitude and slope of the triangle wave at the start of the event interval and a second digital value of the amplitude and slope of the triangle wave at the end of the event interval. A counter (26) counts the clock pulse train (37) during the interval to form a gross event interval time. A computer (52) then combines the gross event interval time and the first and second digital values to output a high resolution value for the event interval.

Timing and Trajectory in Rhythm Production

ERIC Educational Resources Information Center

Doumas, Michail; Wing, Alan M.

2007-01-01

The Wing-Kristofferson movement timing model (A. M. Wing & A. B. Kristofferson, 1973a, 1973b) distinguishes central timer and motor implementation processes. Previous studies have shown that increases in interresponse interval (IRI) variability with mean IRI are due to central timer processes, not motor implementation. The authors examine whether…

Comparing neuronal spike trains with inhomogeneous Poisson distribution: evaluation procedure and experimental application in cases of cyclic activity.

PubMed

Fiore, Lorenzo; Lorenzetti, Walter; Ratti, Giovannino

2005-11-30

A procedure is proposed to compare single-unit spiking activity elicited in repetitive cycles with an inhomogeneous Poisson process (IPP). Each spike sequence in a cycle is discretized and represented as a point process on a circle. The interspike interval probability density predicted for an IPP is computed on the basis of the experimental firing probability density; differences from the experimental interval distribution are assessed. This procedure was applied to spike trains which were repetitively induced by opening-closing movements of the distal article of a lobster leg. As expected, the density of short interspike intervals, less than 20-40 ms in length, was found to lie greatly below the level predicted for an IPP, reflecting the occurrence of the refractory period. Conversely, longer intervals, ranging from 20-40 to 100-120 ms, were markedly more abundant than expected; this provided evidence for a time window of increased tendency to fire again after a spike. Less consistently, a weak depression of spike generation was observed for longer intervals. A Monte Carlo procedure, implemented for comparison, produced quite similar results, but was slightly less precise and more demanding as concerns computation time.

Prenatal choline supplementation increases sensitivity to time by reducing non-scalar sources of variance in adult temporal processing

PubMed Central

Cheng, Ruey-Kuang; Meck, Warren H.

2009-01-01

Choline supplementation of the maternal diet has a long-term facilitative effect on timing and temporal memory of the offspring. To further delineate the impact of early nutritional status on interval timing, we examined effects of prenatal-choline supplementation on the temporal sensitivity of adult (6 mo) male rats. Rats that were given sufficient choline in their chow (CON: 1.1 g/kg) or supplemental choline added to their drinking water (SUP: 3.5 g/kg) during embryonic days (ED) 12–17 were trained with a peak-interval procedure that was shifted among 75%, 50%, and 25% probabilities of reinforcement with transitions from 18s –> 36s –>72s temporal criteria. Prenatal-choline supplementation systematically sharpened interval-timing functions by reducing the associative/non-temporal response enhancing effects of reinforcement probability on the Start response threshold, thereby reducing non-scalar sources of variance in the left-hand portion of the Gaussian-shaped response functions. No effect was observed for the Stop response threshold as a function of any of these manipulations. In addition, independence of peak time and peak rate was demonstrated as a function of reinforcement probability for both prenatal-choline supplemented and control rats. Overall, these results suggest that prenatal-choline supplementation facilitates timing by reducing impulsive responding early in the interval, thereby improving the superimposition of peak functions for different temporal criteria. PMID:17996223

Modelling Carbon Emissions in Calluna vulgaris–Dominated Ecosystems when Prescribed Burning and Wildfires Interact

PubMed Central

Santana, Victor M.; Alday, Josu G.; Lee, HyoHyeMi; Allen, Katherine A.; Marrs, Rob H.

2016-01-01

A present challenge in fire ecology is to optimize management techniques so that ecological services are maximized and C emissions minimized. Here, we modeled the effects of different prescribed-burning rotation intervals and wildfires on carbon emissions (present and future) in British moorlands. Biomass-accumulation curves from four Calluna-dominated ecosystems along a north-south gradient in Great Britain were calculated and used within a matrix-model based on Markov Chains to calculate above-ground biomass-loads and annual C emissions under different prescribed-burning rotation intervals. Additionally, we assessed the interaction of these parameters with a decreasing wildfire return intervals. We observed that litter accumulation patterns varied between sites. Northern sites (colder and wetter) accumulated lower amounts of litter with time than southern sites (hotter and drier). The accumulation patterns of the living vegetation dominated by Calluna were determined by site-specific conditions. The optimal prescribed-burning rotation interval for minimizing annual carbon emissions also differed between sites: the optimal rotation interval for northern sites was between 30 and 50 years, whereas for southern sites a hump-backed relationship was found with the optimal interval either between 8 to 10 years or between 30 to 50 years. Increasing wildfire frequency interacted with prescribed-burning rotation intervals by both increasing C emissions and modifying the optimum prescribed-burning interval for minimum C emission. This highlights the importance of studying site-specific biomass accumulation patterns with respect to environmental conditions for identifying suitable fire-rotation intervals to minimize C emissions. PMID:27880840

The matching law in and within groups of rats1

PubMed Central

Graft, D. A.; Lea, S. E. G.; Whitworth, T. L.

1977-01-01

In each of the two experiments, a group of five rats lived in a complex maze containing four small single-lever operant chambers. In two of these chambers, food was available on variable-interval schedules of reinforcement. In Experiment I, nine combinations of variable intervals were used, and the aggregate lever-pressing rates (by the five rats together) were studied. The log ratio of the rates in the two chambers was linearly related to the log ratio of the reinforcement rates in them; this is an instance of Herrnstein's matching law, as generalized by Baum. Summing over the two food chambers, food consumption decreased, and response output increased, as the time required to earn each pellet increased. In Experiment II, the behavior of individual rats was observed by time-sampling on selected days, while different variable-interval schedules were arranged in the two chambers where food was available. Individual lever-pressing rates for the rats were obtained, and their median bore the same “matching” relationship to the reinforcement rates as the group aggregate in Experiment I. There were differences between the rats in their distribution of time and responses between the two food chambers; these differences were correlated with differences in the proportions of reinforcements the rats obtained from each chamber. PMID:16811975

An examination of wilderness first aid knowledge, self-efficacy, and skill retention.

PubMed

Schumann, Scott A; Schimelpfenig, Tod; Sibthorp, Jim; Collins, Rachel H

2012-09-01

The purpose of this study was to examine the retention of wilderness first aid (WFA) knowledge, self-efficacy beliefs, and skills over time in a sample of WFA course participants. Seventy-two open enrollment (volunteer) WFA course participants were assessed at 4 months, 8 months, or 12 months after training. Changes in WFA knowledge and self-efficacy were assessed by written instruments after the course and at the follow-up interval (4, 8, or 12 months). The WFA skills were assessed by a scored medical scenario at the follow-up interval. As the time interval increased, WFA knowledge, self-efficacy, and skill proficiency decreased. The WFA knowledge and self-efficacy beliefs were not highly correlated with skill performance. Without additional training, regular use of the course content, or efforts to refresh thinking on key topics, the ability of WFA students to effectively apply their learning will likely decrease as time from training increases. With respect to these WFA courses, student scores on written tests did not accurately reflect competence in performing practical skills related to a medical scenario. In addition, student self-confidence in the ability to perform such skills did not strongly correlate with actual skills and ability. Copyright © 2012 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

Effects of Emotional Valence and Arousal on Time Perception

PubMed Central

Van Volkinburg, Heather; Balsam, Peter

2016-01-01

We examined the influence of emotional arousal and valence on estimating time intervals. A reproduction task was used in which images from the International Affective Picture System served as the stimuli to be timed. Experiment 1 assessed the effects of positive and negative valence at a moderate arousal level and Experiment 2 replicated Experiment 1 with the addition of a high arousal condition. Overestimation increased as a function of arousal during encoding of times regardless of valence. For images presented during reproduction, overestimation occurred at the moderate arousal level for positive and negative valence but underestimation occurred in the negative valence high arousal condition. The overestimation of time intervals produced by emotional arousal during encoding and during reproduction suggests that emotional stimuli affect temporal information processing in a qualitatively different way during different phases of temporal information processing. PMID:27110491

Disassembly time of deuterium-cluster-fusion plasma irradiated by an intense laser pulse.

PubMed

Bang, W

2015-07-01

Energetic deuterium ions from large deuterium clusters (>10nm diameter) irradiated by an intense laser pulse (>10(16)W/cm(2)) produce DD fusion neutrons for a time interval determined by the geometry of the resulting fusion plasma. We present an analytical solution of this time interval, the plasma disassembly time, for deuterium plasmas that are cylindrical in shape. Assuming a symmetrically expanding deuterium plasma, we calculate the expected fusion neutron yield and compare with an independent calculation of the yield using the concept of a finite confinement time at a fixed plasma density. The calculated neutron yields agree quantitatively with the available experimental data. Our one-dimensional simulations indicate that one could expect a tenfold increase in total neutron yield by magnetically confining a 10-keV deuterium fusion plasma for 10ns.

A simulation model for determining the optimal size of emergency teams on call in the operating room at night.

PubMed

van Oostrum, Jeroen M; Van Houdenhoven, Mark; Vrielink, Manon M J; Klein, Jan; Hans, Erwin W; Klimek, Markus; Wullink, Gerhard; Steyerberg, Ewout W; Kazemier, Geert

2008-11-01

Hospitals that perform emergency surgery during the night (e.g., from 11:00 pm to 7:30 am) face decisions on optimal operating room (OR) staffing. Emergency patients need to be operated on within a predefined safety window to decrease morbidity and improve their chances of full recovery. We developed a process to determine the optimal OR team composition during the night, such that staffing costs are minimized, while providing adequate resources to start surgery within the safety interval. A discrete event simulation in combination with modeling of safety intervals was applied. Emergency surgery was allowed to be postponed safely. The model was tested using data from the main OR of Erasmus University Medical Center (Erasmus MC). Two outcome measures were calculated: violation of safety intervals and frequency with which OR and anesthesia nurses were called in from home. We used the following input data from Erasmus MC to estimate distributions of all relevant parameters in our model: arrival times of emergency patients, durations of surgical cases, length of stay in the postanesthesia care unit, and transportation times. In addition, surgeons and OR staff of Erasmus MC specified safety intervals. Reducing in-house team members from 9 to 5 increased the fraction of patients treated too late by 2.5% as compared to the baseline scenario. Substantially more OR and anesthesia nurses were called in from home when needed. The use of safety intervals benefits OR management during nights. Modeling of safety intervals substantially influences the number of emergency patients treated on time. Our case study showed that by modeling safety intervals and applying computer simulation, an OR can reduce its staff on call without jeopardizing patient safety.

The Isolation of Motivational, Motoric, and Schedule Effects on Operant Performance: A Modeling Approach

PubMed Central

Brackney, Ryan J; Cheung, Timothy H. C; Neisewander, Janet L; Sanabria, Federico

2011-01-01

Dissociating motoric and motivational effects of pharmacological manipulations on operant behavior is a substantial challenge. To address this problem, we applied a response-bout analysis to data from rats trained to lever press for sucrose on variable-interval (VI) schedules of reinforcement. Motoric, motivational, and schedule factors (effort requirement, deprivation level, and schedule requirements, respectively) were manipulated. Bout analysis found that interresponse times (IRTs) were described by a mixture of two exponential distributions, one characterizing IRTs within response bouts, another characterizing intervals between bouts. Increasing effort requirement lengthened the shortest IRT (the refractory period between responses). Adding a ratio requirement increased the length and density of response bouts. Both manipulations also decreased the bout-initiation rate. In contrast, food deprivation only increased the bout-initiation rate. Changes in the distribution of IRTs over time showed that responses during extinction were also emitted in bouts, and that the decrease in response rate was primarily due to progressively longer intervals between bouts. Taken together, these results suggest that changes in the refractory period indicate motoric effects, whereas selective alterations in bout initiation rate indicate incentive-motivational effects. These findings support the use of response-bout analyses to identify the influence of pharmacological manipulations on processes underlying operant performance. PMID:21765544

Measuring the EMS patient access time interval and the impact of responding to high-rise buildings.

PubMed

Morrison, Laurie J; Angelini, Mark P; Vermeulen, Marian J; Schwartz, Brian

2005-01-01

To measure the patient access time interval and characterize its contribution to the total emergency medical services (EMS) response time interval; to compare the patient access time intervals for patients located three or more floors above ground with those less than three floors above or below ground, and specifically in the apartment subgroup; and to identify barriers that significantly impede EMS access to patients in high-rise apartments. An observational study of all patients treated by an emergency medical technician paramedics (EMT-P) crew was conducted using a trained independent observer to collect time intervals and identify potential barriers to access. Of 118 observed calls, 25 (21%) originated from patients three or more floors above ground. The overall median and 90th percentile (95% confidence interval) patient access time intervals were 1.61 (1.27, 1.91) and 3.47 (3.08, 4.05) minutes, respectively. The median interval was 2.73 (2.22, 3.03) minutes among calls from patients located three or more stories above ground compared with 1.25 (1.07, 1.55) minutes among those at lower levels. The patient access time interval represented 23.5% of the total EMS response time interval among calls originating less than three floors above or below ground and 32.2% of those located three or more stories above ground. The most frequently encountered barriers to access included security code entry requirements, lack of directional signs, and inability to fit the stretcher into the elevator. The patient access time interval is significantly long and represents a substantial component of the total EMS response time interval, especially among ambulance calls originating three or more floors above ground. A number of barriers appear to contribute to delayed paramedic access.

Alcohol intake is associated with increased risk of squamous cell carcinoma of the skin: three US prospective cohort studies

PubMed Central

Siiskonen, Satu; Han, Jiali; Li, Tricia; Cho, Eunyoung

2016-01-01

The association between alcohol intake and cutaneous squamous cell carcinoma (cSCC) is unclear. We studied the association between alcohol intake and incident invasive cSCC in three cohorts of women and men with repeated assessments of alcohol intake in the US. Information on alcohol intake was collected repeatedly during follow-up. Cumulative average of alcohol intakes was used. Multivariable Cox proportional hazards models with time-dependent exposure were used to estimate relative risks (RR) and 95% confidence intervals, followed by a meta-analysis. During a follow-up of 4,234,416 person-years, 2,938 cSCC were identified. Alcohol intake was associated with an increased risk of cSCC with a dose-response relationship. Each additional drink (12.8 gram of alcohol) per day was associated with a 22% increased risk of cSCC (RR 1.22, 95% confidence interval: 1.13 to 1.31). White wine consumption of ≥5 times/wk was associated with an increased risk of cSCC (RR 1.31, 95% confidence interval: 1.09 to 1.59). We found no increased risk of cSCC with other alcoholic beverages. The population attributable risk associated with alcohol intake of ≥20 grams/d was 3% of cSCCs. In conclusion, alcohol intake was associated with an elevated risk of cSCC. Among alcoholic beverages, white wine was associated with cSCC. PMID:27145335

Alcohol Intake is Associated with Increased Risk of Squamous Cell Carcinoma of the Skin: Three US Prospective Cohort Studies.

PubMed

Siiskonen, Satu; Han, Jiali; Li, Tricia; Cho, Eunyoung; Nijsten, Tamar; Qureshi, Abrar

2016-01-01

The association between alcohol intake and cutaneous squamous cell carcinoma (cSCC) is unclear. We studied the association between alcohol intake and incident invasive cSCC in three cohorts of women and men with repeated assessments of alcohol intake in the US. Information on alcohol intake was collected repeatedly during follow-up. Cumulative average of alcohol intakes was used. Multivariable Cox proportional hazards models with time-dependent exposure were used to estimate relative risks (RRs) and 95% confidence intervals, followed by a meta-analysis. During a follow-up of 4,234,416 person-years, 2,938 cSCC were identified. Alcohol intake was associated with an increased risk of cSCC with a dose-response relationship. Each additional drink (12.8 gram of alcohol) per day was associated with a 22% increased risk of cSCC (RR 1.22, 95% confidence interval: 1.13-1.31). White wine consumption of ≥5 times/wk was associated with an increased risk of cSCC (RR 1.31, 95% confidence interval: 1.09-1.59). We found no increased risk of cSCC with other alcoholic beverages. The population-attributable risk associated with alcohol intake of ≥20 grams/d was 3% of cSCCs. In conclusion, alcohol intake was associated with an elevated risk of cSCC. Among alcoholic beverages, white wine was associated with cSCC.

Modulation of human time processing by subthalamic deep brain stimulation.

PubMed

Wojtecki, Lars; Elben, Saskia; Timmermann, Lars; Reck, Christiane; Maarouf, Mohammad; Jörgens, Silke; Ploner, Markus; Südmeyer, Martin; Groiss, Stefan Jun; Sturm, Volker; Niedeggen, Michael; Schnitzler, Alfons

2011-01-01

Timing in the range of seconds referred to as interval timing is crucial for cognitive operations and conscious time processing. According to recent models of interval timing basal ganglia (BG) oscillatory loops are involved in time interval recognition. Parkinsońs disease (PD) is a typical disease of the basal ganglia that shows distortions in interval timing. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a powerful treatment of PD which modulates motor and cognitive functions depending on stimulation frequency by affecting subcortical-cortical oscillatory loops. Thus, for the understanding of BG-involvement in interval timing it is of interest whether STN-DBS can modulate timing in a frequency dependent manner by interference with oscillatory time recognition processes. We examined production and reproduction of 5 and 15 second intervals and millisecond timing in a double blind, randomised, within-subject repeated-measures design of 12 PD-patients applying no, 10-Hz- and ≥ 130-Hz-STN-DBS compared to healthy controls. We found under(re-)production of the 15-second interval and a significant enhancement of this under(re-)production by 10-Hz-stimulation compared to no stimulation, ≥ 130-Hz-STN-DBS and controls. Milliseconds timing was not affected. We provide first evidence for a frequency-specific modulatory effect of STN-DBS on interval timing. Our results corroborate the involvement of BG in general and of the STN in particular in the cognitive representation of time intervals in the range of multiple seconds.

Modulation of Human Time Processing by Subthalamic Deep Brain Stimulation

PubMed Central

Timmermann, Lars; Reck, Christiane; Maarouf, Mohammad; Jörgens, Silke; Ploner, Markus; Südmeyer, Martin; Groiss, Stefan Jun; Sturm, Volker; Niedeggen, Michael; Schnitzler, Alfons

2011-01-01

Timing in the range of seconds referred to as interval timing is crucial for cognitive operations and conscious time processing. According to recent models of interval timing basal ganglia (BG) oscillatory loops are involved in time interval recognition. Parkinsońs disease (PD) is a typical disease of the basal ganglia that shows distortions in interval timing. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a powerful treatment of PD which modulates motor and cognitive functions depending on stimulation frequency by affecting subcortical-cortical oscillatory loops. Thus, for the understanding of BG-involvement in interval timing it is of interest whether STN-DBS can modulate timing in a frequency dependent manner by interference with oscillatory time recognition processes. We examined production and reproduction of 5 and 15 second intervals and millisecond timing in a double blind, randomised, within-subject repeated-measures design of 12 PD-patients applying no, 10-Hz- and ≥130-Hz-STN-DBS compared to healthy controls. We found under(re-)production of the 15-second interval and a significant enhancement of this under(re-)production by 10-Hz-stimulation compared to no stimulation, ≥130-Hz-STN-DBS and controls. Milliseconds timing was not affected. We provide first evidence for a frequency-specific modulatory effect of STN-DBS on interval timing. Our results corroborate the involvement of BG in general and of the STN in particular in the cognitive representation of time intervals in the range of multiple seconds. PMID:21931767

Sleep deprivation and time-on-task performance decrement in the rat psychomotor vigilance task.

PubMed

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

2015-03-01

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. 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. The study was conducted in an academic research vivarium. 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. Rats performed the rPVT for 30 min at baseline and after 24 h total sleep deprivation by gentle handling. 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. The rPVT manifests similarities to the hPVT in global performance outcomes, but not in post-sleep deprivation effects of time on task and response-stimulus interval. © 2015 Associated Professional Sleep Societies, LLC.

The benthic macrofauna from the Lower Maastrichtian chalk of Kronsmoor (northern Germany, Saturn quarry): taxonomic outline and palaeoecologic implications

NASA Astrophysics Data System (ADS)

Engelke, Julia; Esser, Klaus J. K.; Linnert, Christian; Mutterlose, Jörg; Wilmsen, Markus

2016-12-01

The benthic macroinvertebrates of the Lower Maastrichtian chalk of Saturn quarry at Kronsmoor (northern Germany) have been studied taxonomically based on more than 1,000 specimens. Two successive benthic macrofossil assemblages were recognised: the lower interval in the upper part of the Kronsmoor Formation (Belemnella obtusa Zone) is characterized by low abundances of macroinvertebrates while the upper interval in the uppermost Kronsmoor and lowermost Hemmoor formations (lower to middle Belemnella sumensis Zone) shows a high macroinvertebrate abundance (eight times more than in the B. obtusa Zone) and a conspicuous dominance of brachiopods. The palaeoecological analysis of these two assemblages indicates the presence of eight different guilds, of which epifaunal suspension feeders (fixo-sessile and libero-sessile guilds), comprising approximately half of the trophic nucleus of the lower interval, increased to a dominant 86% in the upper interval, including a considerable proportion of rhynchonelliform brachiopods. It is tempting to relate this shift from the lower to the upper interval to an increase in nutrient supply and/or a shallowing of the depositional environment but further data including geochemical proxies are needed to fully understand the macrofossil distribution patterns in the Lower Maastrichtian of Kronsmoor.

Burst switching without guard interval in all-optical software-define star intra-data center network

NASA Astrophysics Data System (ADS)

Ji, Philip N.; Wang, Ting

2014-02-01

Optical switching has been introduced in intra-data center networks (DCNs) to increase capacity and to reduce power consumption. Recently we proposed a star MIMO OFDM-based all-optical DCN with burst switching and software-defined networking. Here, we introduce the control procedure for the star DCN in detail for the first time. The timing, signaling, and operation are described for each step to achieve efficient bandwidth resource utilization. Furthermore, the guidelines for the burst assembling period selection that allows burst switching without guard interval are discussed. The star all-optical DCN offers flexible and efficient control for next-generation data center application.

Interval timing under a behavioral microscope: Dissociating motivational and timing processes in fixed-interval performance.

PubMed

Daniels, Carter W; Sanabria, Federico

2017-03-01

The distribution of latencies and interresponse times (IRTs) of rats was compared between two fixed-interval (FI) schedules of food reinforcement (FI 30 s and FI 90 s), and between two levels of food deprivation. Computational modeling revealed that latencies and IRTs were well described by mixture probability distributions embodying two-state Markov chains. Analysis of these models revealed that only a subset of latencies is sensitive to the periodicity of reinforcement, and prefeeding only reduces the size of this subset. The distribution of IRTs suggests that behavior in FI schedules is organized in bouts that lengthen and ramp up in frequency with proximity to reinforcement. Prefeeding slowed down the lengthening of bouts and increased the time between bouts. When concatenated, latency and IRT models adequately reproduced sigmoidal FI response functions. These findings suggest that behavior in FI schedules fluctuates in and out of schedule control; an account of such fluctuation suggests that timing and motivation are dissociable components of FI performance. These mixture-distribution models also provide novel insights on the motivational, associative, and timing processes expressed in FI performance. These processes may be obscured, however, when performance in timing tasks is analyzed in terms of mean response rates.

Ice ingestion with a long rest interval increases the endurance exercise capacity and reduces the core temperature in the heat.

PubMed

Naito, Takashi; Iribe, Yuka; Ogaki, Tetsuro

2017-01-05

The timing in which ice before exercise should be ingested plays an important role in optimizing its success. However, the effects of differences in the timing of ice ingestion before exercise on cycling capacity, and thermoregulation has not been studied. The aim of the present study was to assess the effect of length of time after ice ingestion on endurance exercise capacity in the heat. Seven males ingested 1.25 g kg body mass -1 of ice (0.5 °C) or cold water (4 °C) every 5 min, six times. Under three separate conditions after ice or water ingestion ([1] taking 20 min rest after ice ingestion, [2] taking 5 min rest after ice ingestion, and [3] taking 5 min rest after cold water ingestion), seven physically active male cyclists exercised at 65% of their maximal oxygen uptake to exhaustion in the heat (35 °C, 30% relative humidity). Participants cycled significantly longer following both ice ingestion with a long rest interval (46.0 ± 7.7 min) and that with a short rest interval (38.7 ± 5.7 min) than cold water ingestion (32.3 ± 3.2 min; both p < 0.05), and the time to exhaustion was 16% (p < 0.05) longer for ice ingestion with a long rest interval than that with a short rest interval. Ice ingestion with a long rest interval (-0.55 ± 0.07 °C; both p < 0.05) allowed for a greater drop in the core temperature than both ice ingestion with a short rest interval (-0.36 ± 0.16 °C) and cold water ingestion (-0.11 ± 0.14 °C). Heat storage under condition of ice ingestion with a long rest interval during the pre-exercise period was significantly lower than that observed with a short rest interval (-4.98 ± 2.50 W m -2 ; p < 0.05) and cold water ingestion (2.86 ± 4.44 W m -2 ). Therefore, internal pre-cooling by ice ingestion with a long rest interval had the greatest benefit on exercise capacity in the heat, which is suggested to be driven by a reduced rectal temperature and heat storage before the start of exercise.

Electrogastrographic and autonomic responses during oculovestibular recoupling in flight simulation.

PubMed

Cevette, Michael J; Pradhan, Gaurav N; Cocco, Daniela; Crowell, Michael D; Galea, Anna M; Bartlett, Jennifer; Stepanek, Jan

2014-01-01

Simulator sickness causes vestibulo-autonomic responses that increase sympathetic activity and decrease parasympathetic activity. The purpose of the study was to quantify these responses through electrogastrography and cardiac interbeat intervals during flight simulation. There were 29 subjects that were randomly assigned to 2 parallel arms: (1) oculovestibular recoupling, where galvanic vestibular stimulation was synchronous with the visual field; and (2) control. Electrogastrography and interbeat interval data were collected during baseline, simulation, and post-simulation periods. A simulator sickness questionnaire was administered. Statistically significant differences were observed in percentage of recording time with the dominant frequency of electrogastrography in normogastric and bradygastric domains between the oculovestibular recoupling and control groups. Normogastria was dominant during simulation in the oculovestibular recoupling group. In the control group, the percentage of recording time with the dominant frequency decreased by 22% in normogastria and increased by 20% in bradygastria. The percentage change of the dominant power instability coefficient from baseline to simulation was 26% in the oculovestibular recoupling group vs. 108% in the control group. The power of high-frequency components for interbeat intervals did not change significantly in the oculovestibular recoupling group and was decreased during simulation in the control group. Electrogastrography and interbeat intervals are sensitive indices of autonomic changes in subjects undergoing flight simulation. These data demonstrate the potential of oculovestibular recoupling to stabilize gastric activity and cardiac autonomic changes altered during simulator and motion sickness.

Human's choices in situations of time-based diminishing returns.

PubMed Central

Hackenberg, T D; Axtell, S A

1993-01-01

Three experiments examined adult humans' choices in situations with contrasting short-term and long-term consequences. Subjects were given repeated choices between two time-based schedules of points exchangeable for money: a fixed schedule and a progressive schedule that began at 0 s and increased by 5 s with each point delivered by that schedule. Under "reset" conditions, choosing the fixed schedule not only produced a point but it also reset the requirements of the progressive schedule to 0 s. In the first two experiments, reset conditions alternated with "no-reset" conditions, in which progressive-schedule requirements were independent of fixed-schedule choices. Experiment 1 entailed choices between a progressive-interval schedule and a fixed-interval schedule, the duration of which varied across conditions. Switching from the progressive- to the fixed-interval schedule was systematically related to fixed-interval size in 4 of 8 subjects, and in all subjects occurred consistently sooner in the progressive-schedule sequence under reset than under no-reset procedures. The latter result was replicated in a second experiment, in which choices between progressive- and fixed-interval schedules were compared with choices between progressive- and fixed-time schedules. In Experiment 3, switching patterns under reset conditions were unrelated to variations in intertrial interval. In none of the experiments did orderly choice patterns depend on verbal descriptions of the contingencies or on schedule-controlled response patterns in the presence of the chosen schedules. The overall pattern of results indicates control of choices by temporarily remote consequences, and is consistent with versions of optimality theory that address performance in situations of diminishing returns. PMID:8315364

Long-time uncertainty propagation using generalized polynomial chaos and flow map composition

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

Luchtenburg, Dirk M., E-mail: dluchten@cooper.edu; Brunton, Steven L.; Rowley, Clarence W.

2014-10-01

We present an efficient and accurate method for long-time uncertainty propagation in dynamical systems. Uncertain initial conditions and parameters are both addressed. The method approximates the intermediate short-time flow maps by spectral polynomial bases, as in the generalized polynomial chaos (gPC) method, and uses flow map composition to construct the long-time flow map. In contrast to the gPC method, this approach has spectral error convergence for both short and long integration times. The short-time flow map is characterized by small stretching and folding of the associated trajectories and hence can be well represented by a relatively low-degree basis. The compositionmore » of these low-degree polynomial bases then accurately describes the uncertainty behavior for long integration times. The key to the method is that the degree of the resulting polynomial approximation increases exponentially in the number of time intervals, while the number of polynomial coefficients either remains constant (for an autonomous system) or increases linearly in the number of time intervals (for a non-autonomous system). The findings are illustrated on several numerical examples including a nonlinear ordinary differential equation (ODE) with an uncertain initial condition, a linear ODE with an uncertain model parameter, and a two-dimensional, non-autonomous double gyre flow.« less

Urinary tract infection-like symptom is associated with worse bladder cancer outcomes in the Medicare population: Implications for sex disparities.

PubMed

Richards, Kyle A; Ham, Sandra; Cohn, Joshua A; Steinberg, Gary D

2016-01-01

To determine the time to bladder cancer diagnosis from initial infection-like symptoms and its impact on cancer outcomes. Using Surveillance, Epidemiology and End Results-Medicare, we designed a retrospective cohort study identifying beneficiaries aged ≥ 66 years diagnosed with bladder cancer from 2007 to 2009. Patients were required to have a hematuria or urinary tract infection claim within 1 year of bladder cancer diagnosis (n = 21 216), and have 2 years of prior Medicare data (n = 18 956) without any precedent hematuria, bladder cancer or urinary tract infection claims (n = 12 195). The number of days to bladder cancer diagnosis was measured, as well as the impact of sex and presenting symptom on time to diagnosis, pathology, and oncological outcomes. The mean time to bladder cancer diagnosis was 72.2 days in women versus 58.9 days in men (P < 0.001). A logistic regression model identified the greatest predictors of ≥ pT2 pathology were both women (odds ratio 2.08, 95% confidence interval 1.70-2.55) and men (odds ratio 1.71, 95% confidence interval 1.49-1.97) presenting with urinary tract infection. Cox proportional hazards analysis identified an increased risk of mortality from bladder cancer and all causes in women presenting with urinary tract infection (hazard ratio 1.37, 95% confidence interval 1.10-1.71, and hazard ratio 1.47, 95% confidence interval 1.28-1.69) compared with women with hematuria. Women have a longer interval from urinary tract infection to diagnosis of bladder cancer. Urinary tract infection presentation can adversely affect time to diagnosis, pathology and survival. Time to diagnosis seems not to be an independent predictor of bladder cancer outcomes. © 2015 The Japanese Urological Association.

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.

Measurand transient signal suppressor

NASA Technical Reports Server (NTRS)

Bozeman, Richard J., Jr. (Inventor)

1994-01-01

A transient signal suppressor for use in a controls system which is adapted to respond to a change in a physical parameter whenever it crosses a predetermined threshold value in a selected direction of increasing or decreasing values with respect to the threshold value and is sustained for a selected discrete time interval is presented. The suppressor includes a sensor transducer for sensing the physical parameter and generating an electrical input signal whenever the sensed physical parameter crosses the threshold level in the selected direction. A manually operated switch is provided for adapting the suppressor to produce an output drive signal whenever the physical parameter crosses the threshold value in the selected direction of increasing or decreasing values. A time delay circuit is selectively adjustable for suppressing the transducer input signal for a preselected one of a plurality of available discrete suppression time and producing an output signal only if the input signal is sustained for a time greater than the selected suppression time. An electronic gate is coupled to receive the transducer input signal and the timer output signal and produce an output drive signal for energizing a control relay whenever the transducer input is a non-transient signal which is sustained beyond the selected time interval.

A new model for the estimation of time of death from vitreous potassium levels corrected for age and temperature.

PubMed

Zilg, B; Bernard, S; Alkass, K; Berg, S; Druid, H

2015-09-01

Analysis of potassium concentration in the vitreous fluid of the eye is frequently used by forensic pathologists to estimate the postmortem interval (PMI), particularly when other methods commonly used in the early phase of an investigation can no longer be applied. The postmortem rise in vitreous potassium has been recognized for several decades and is readily explained by a diffusion of potassium from surrounding cells into the vitreous fluid. However, there is no consensus regarding the mathematical equation that best describes this increase. The existing models assume a linear increase, but different slopes and starting points have been proposed. In this study, vitreous potassium levels, and a number of factors that may influence these levels, were examined in 462 cases with known postmortem intervals that ranged from 2h to 17 days. We found that the postmortem rise in potassium followed a non-linear curve and that decedent age and ambient temperature influenced the variability by 16% and 5%, respectively. A long duration of agony and a high alcohol level at the time of death contributed less than 1% variability, and evaluation of additional possible factors revealed no detectable impact on the rise of vitreous potassium. Two equations were subsequently generated, one that represents the best fit of the potassium concentrations alone, and a second that represents potassium concentrations with correction for decedent age and/or ambient temperature. The former was associated with narrow confidence intervals in the early postmortem phase, but the intervals gradually increased with longer PMIs. For the latter equation, the confidence intervals were reduced at all PMIs. Therefore, the model that best describes the observed postmortem rise in vitreous potassium levels includes potassium concentration, decedent age, and ambient temperature. Furthermore, the precision of these equations, particularly for long PMIs, is expected to gradually improve by adjusting the constants as more reference data are added over time. A web application that facilitates this calculation process and allows for such future modifications has been developed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Effect of aspirin in pregnant women is dependent on increase in bleeding time.

PubMed

Dumont, A; Flahault, A; Beaufils, M; Verdy, E; Uzan, S

1999-01-01

Randomized trials with low-dose aspirin to prevent preeclampsia and intrauterine growth restriction have yielded conflicting results. In particular, 3 recent large trials were not conclusive. Study designs, however, varied greatly regarding selection of patients, dose of aspirin, and timing of treatment, all of which can be determinants of the results. Retrospectively analyzing the conditions associated with failure or success of aspirin may therefore help to draw up new hypotheses and prepare for more specific randomized trials. We studied a historical cohort of 187 pregnant women who were considered at high risk for preeclampsia, intrauterine growth restriction, or both and were therefore treated with low-dose aspirin between 1989 and 1994. Various epidemiologic, clinical, and laboratory data were extracted from the files. Univariate and multivariate analyses were performed to search for independent parameters associated with the outcome of pregnancy. Age, parity, weight, height, and race had no influence on the outcome. The success rate was higher when treatment was given because of previous poor pregnancy outcomes than when it was given for other indications, and the patients with successful therapy had started aspirin earlier than had those with therapy failure (17.7 vs 20.0 weeks' gestation, P =.04). After multivariate analysis an increase in Ivy bleeding time after 10 days of treatment by >2 minutes was an independent predictor of a better outcome (odds ratio 0.22, 95% confidence interval 0.09-0.51). Borderline statistical significance was observed for aspirin initiation before 17 weeks' gestation (odds ratio 0.44, 95% confidence interval 0.18-1. 08). Abnormal uterine artery Doppler velocimetric scan at 20-24 weeks' gestation (odds ratio 3.31, 95% confidence interval 1.41-7.7), abnormal umbilical artery Doppler velocimetric scan after 26 weeks' gestation (odds ratio 37.6, 95% confidence interval 3.96-357), and use of antihypertensive therapy (odds ratio 6.06, 95% confidence interval 2.45-15) were independent predictors of poor outcome. Efficacy of aspirin seems optimal when bleeding time increases >/=2 minutes with treatment, indicating a more powerful antiplatelet effect. This suggests that the dose of aspirin should be adjusted according to a biologic marker of the antiplatelet effect. A prospective trial is warranted to test this hypothesis.

Early declaration of death by neurologic criteria results in greater organ donor potential.

PubMed

Resnick, Shelby; Seamon, Mark J; Holena, Daniel; Pascual, Jose; Reilly, Patrick M; Martin, Niels D

2017-10-01

Aggressive management of patients prior to and after determination of death by neurologic criteria (DNC) is necessary to optimize organ recovery, transplantation, and increase the number of organs transplanted per donor (OTPD). The effects of time management are understudied but potentially pivotal component. The objective of this study was to analyze specific time points (time to DNC, time to procurement) and the time intervals between them to better characterize the optimal timeline of organ donation. Using data over a 5-year time period (2011-2015) from the largest US OPO, all patients with catastrophic brain injury and donated transplantable organs were retrospectively reviewed. Active smokers were excluded. Maximum donor potential was seven organs (heart, lungs [2], kidneys [2], liver, and pancreas). Time from admission to declaration of DNC and donation was calculated. Mean time points stratified by specific organ procurement rates and overall OTPD were compared using unpaired t-test. Of 1719 Declaration of Death by Neurologic Criteria organ donors, 381 were secondary to head trauma. Smokers and organs recovered but not transplanted were excluded leaving 297 patients. Males comprised 78.8%, the mean age was 36.0 (±16.8) years, and 87.6% were treated at a trauma center. Higher donor potential (>4 OTPD) was associated with shorter average times from admission to brain death; 66.6 versus 82.2 hours, P = 0.04. Lung donors were also associated with shorter average times from admission to brain death; 61.6 versus 83.6 hours, P = 0.004. The time interval from DNC to donation varied minimally among groups and did not affect donation rates. A shorter time interval between admission and declaration of DNC was associated with increased OTPD, especially lungs. Further research to identify what role timing plays in the management of the potential organ donor and how that relates to donor management goals is needed. Copyright © 2017 Elsevier Inc. All rights reserved.

Optimization of the Reconstruction Interval in Neurovascular 4D-CTA Imaging

PubMed Central

Hoogenboom, T.C.H.; van Beurden, R.M.J.; van Teylingen, B.; Schenk, B.; Willems, P.W.A.

2012-01-01

Summary Time resolved whole brain CT angiography (4D-CTA) is a novel imaging technology providing information regarding blood flow. One of the factors that influence the diagnostic value of this examination is the temporal resolution, which is affected by the gantry rotation speed during acquisition and the reconstruction interval during post-processing. Post-processing determines the time spacing between two reconstructed volumes and, unlike rotation speed, does not affect radiation burden. The data sets of six patients who underwent a cranial 4D-CTA were used for this study. Raw data was acquired using a 320-slice scanner with a rotation speed of 2 Hz. The arterial to venous passage of an intravenous contrast bolus was captured during a 15 s continuous scan. The raw data was reconstructed using four different reconstruction-intervals: 0.2, 0.3, 0.5 and 1.0 s. The results were rated by two observers using a standardized score sheet. The appearance of each lesion was rated correctly in all readings. Scoring for quality of temporal resolution revealed a stepwise improvement from the 1.0 s interval to the 0.3 s interval, while no discernable improvement was noted between the 0.3 s and 0.2 s interval. An increase in temporal resolution may improve the diagnostic quality of cranial 4D-CTA. Using a rotation speed of 0.5 s, the optimal reconstruction interval appears to be 0.3 s, beyond which, changes can no longer be discerned. PMID:23217631

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

Computational aspects of real-time simulation of rotary-wing aircraft. M.S. Thesis

NASA Technical Reports Server (NTRS)

Houck, J. A.

1976-01-01

A study was conducted to determine the effects of degrading a rotating blade element rotor mathematical model suitable for real-time simulation of rotorcraft. Three methods of degradation were studied, reduction of number of blades, reduction of number of blade segments, and increasing the integration interval, which has the corresponding effect of increasing blade azimuthal advance angle. The three degradation methods were studied through static trim comparisons, total rotor force and moment comparisons, single blade force and moment comparisons over one complete revolution, and total vehicle dynamic response comparisons. Recommendations are made concerning model degradation which should serve as a guide for future users of this mathematical model, and in general, they are in order of minimum impact on model validity: (1) reduction of number of blade segments; (2) reduction of number of blades; and (3) increase of integration interval and azimuthal advance angle. Extreme limits are specified beyond which a different rotor mathematical model should be used.

Effects of rotor model degradation on the accuracy of rotorcraft real time simulation

NASA Technical Reports Server (NTRS)

Houck, J. A.; Bowles, R. L.

1976-01-01

The effects are studied of degrading a rotating blade element rotor mathematical model to meet various real-time simulation requirements of rotorcraft. Three methods of degradation were studied: reduction of number of blades, reduction of number of blade segments, and increasing the integration interval, which has the corresponding effect of increasing blade azimuthal advance angle. The three degradation methods were studied through static trim comparisons, total rotor force and moment comparisons, single blade force and moment comparisons over one complete revolution, and total vehicle dynamic response comparisons. Recommendations are made concerning model degradation which should serve as a guide for future users of this mathematical model, and in general, they are in order of minimum impact on model validity: (1) reduction of number of blade segments, (2) reduction of number of blades, and (3) increase of integration interval and azimuthal advance angle. Extreme limits are specified beyond which the rotating blade element rotor mathematical model should not be used.

Effects of increasing time delays on pitch-matching accuracy in trained singers and untrained individuals.

PubMed

Estis, Julie M; Coblentz, Joana K; Moore, Robert E

2009-07-01

Trained singers (TS) generally demonstrate accurate pitch matching, but this ability varies within the general population. Pitch-matching accuracy, given increasing silence intervals of 5, 15, and 25 seconds between target tones and vocal matches, was investigated in TS and untrained individuals. A relationship between pitch discrimination and pitch matching was also examined. Thirty-two females (20-30 years) were grouped based on individual vocal training and performance in an immediate pitch-matching task. Participants matched target pitches following time delays, and completed a pitch discrimination task, which required the classification of two tones as same or different. TS and untrained accurate participants performed comparably on all pitch-matching tasks, while untrained inaccurate participants performed significantly less accurately than the other two groups. Performances declined across groups as intervals of silence increased, suggesting degradation of pitch matching as pitch memory was taxed. A significant relationship between pitch discrimination and pitch matching was revealed across participants.

The Estimation of Short Time Intervals as a Function of Age and Metronome Pacing.

ERIC Educational Resources Information Center

Kline, Donald W.; And Others

1980-01-01

The time judgments of the older participants were significantly and systematically determined by a metronome rate. Results are consistent with the notion of increased field-dependence among older persons and suggest that their greater social conformity and their inability to ignore irrelevant stimuli might also be explicable. (Author)

Influence of northwest Pacific productivity on North Pacific Intermediate Water oxygen concentrations during the Bølling-Ållerød interval (14.7-12.9 ka)

USGS Publications Warehouse

Crusius, John; Pedersen, Thomas F.; Kienast, Stephanie; Keigwin, Lloyd D.; Labeyrie, Laurent

2004-01-01

Elevated productivity in the northwest Pacific is suggested as a new possible control driving past intervals of low-O2 intermediate water along the western continental margin of North America. According to this mechanism, O2 consumption would occur near the site of formation of North Pacific Intermediate Water (NPIW), due to increased respiration of organic carbon in response to a high-productivity event. Evidence is provided for such a productivity increase during the Bølling-Ållerød interval (14.7–12.9 ka), a time when laminated sediments were deposited along the northern California margin. By this mechanism, low-O2 events in intermediate waters off the western North American margin could occur without significant changes in the rate of NPIW ventilation.

Effects of varied doses of psilocybin on time interval reproduction in human subjects.

PubMed

Wackermann, Jirí; Wittmann, Marc; Hasler, Felix; Vollenweider, Franz X

2008-04-11

Action of a hallucinogenic substance, psilocybin, on internal time representation was investigated in two double-blind, placebo-controlled studies: Experiment 1 with 12 subjects and graded doses, and Experiment 2 with 9 subjects and a very low dose. The task consisted in repeated reproductions of time intervals in the range from 1.5 to 5s. The effects were assessed by parameter kappa of the 'dual klepsydra' model of internal time representation, fitted to individual response data and intra-individually normalized with respect to initial values. The estimates kappa were in the same order of magnitude as in earlier studies. In both experiments, kappa was significantly increased by psilocybin at 90 min from the drug intake, indicating a higher loss rate of the internal duration representation. These findings are tentatively linked to qualitative alterations of subjective time in altered states of consciousness.

Disassembly time of deuterium-cluster-fusion plasma irradiated by an intense laser pulse

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

Bang, W.

Energetic deuterium ions from large deuterium clusters (>10 nm diameter) irradiated by an intense laser pulse (>10¹⁶ W/cm²) produce DD fusion neutrons for a time interval determined by the geometry of the resulting fusion plasma. We show an analytical solution of this time interval, the plasma disassembly time, for deuterium plasmas that are cylindrical in shape. Assuming a symmetrically expanding deuterium plasma, we calculate the expected fusion neutron yield and compare with an independent calculation of the yield using the concept of a finite confinement time at a fixed plasma density. The calculated neutron yields agree quantitatively with the availablemore » experimental data. Our one-dimensional simulations indicate that one could expect a tenfold increase in total neutron yield by magnetically confining a 10 - keV deuterium fusion plasma for 10 ns.« less

Disassembly time of deuterium-cluster-fusion plasma irradiated by an intense laser pulse

DOE PAGES

Bang, W.

2015-07-02

Energetic deuterium ions from large deuterium clusters (>10 nm diameter) irradiated by an intense laser pulse (>10¹⁶ W/cm²) produce DD fusion neutrons for a time interval determined by the geometry of the resulting fusion plasma. We show an analytical solution of this time interval, the plasma disassembly time, for deuterium plasmas that are cylindrical in shape. Assuming a symmetrically expanding deuterium plasma, we calculate the expected fusion neutron yield and compare with an independent calculation of the yield using the concept of a finite confinement time at a fixed plasma density. The calculated neutron yields agree quantitatively with the availablemore » experimental data. Our one-dimensional simulations indicate that one could expect a tenfold increase in total neutron yield by magnetically confining a 10 - keV deuterium fusion plasma for 10 ns.« less

Triatomine Infestation in Guatemala: Spatial Assessment after Two Rounds of Vector Control

PubMed Central

Manne, Jennifer; Nakagawa, Jun; Yamagata, Yoichi; Goehler, Alexander; Brownstein, John S.; Castro, Marcia C.

2012-01-01

In 2000, the Guatemalan Ministry of Health initiated a Chagas disease program to control Rhodnius prolixus and Triatoma dimidiata by periodic house spraying with pyrethroid insecticides to characterize infestation patterns and analyze the contribution of programmatic practices to these patterns. Spatial infestation patterns at three time points were identified using the Getis-Ord Gi*(d) test. Logistic regression was used to assess predictors of reinfestation after pyrethroid insecticide administration. Spatial analysis showed high and low clusters of infestation at three time points. After two rounds of spray, 178 communities persistently fell in high infestation clusters. A time lapse between rounds of vector control greater than 6 months was associated with 1.54 (95% confidence interval = 1.07–2.23) times increased odds of reinfestation after first spray, whereas a time lapse of greater than 1 year was associated with 2.66 (95% confidence interval = 1.85–3.83) times increased odds of reinfestation after first spray compared with localities where the time lapse was less than 180 days. The time lapse between rounds of vector control should remain under 1 year. Spatial analysis can guide targeted vector control efforts by enabling tracking of reinfestation hotspots and improved targeting of resources. PMID:22403315

Ratio-based lengths of intervals to improve fuzzy time series forecasting.

PubMed

Huarng, Kunhuang; Yu, Tiffany Hui-Kuang

2006-04-01

The objective of this study is to explore ways of determining the useful lengths of intervals in fuzzy time series. It is suggested that ratios, instead of equal lengths of intervals, can more properly represent the intervals among observations. Ratio-based lengths of intervals are, therefore, proposed to improve fuzzy time series forecasting. Algebraic growth data, such as enrollments and the stock index, and exponential growth data, such as inventory demand, are chosen as the forecasting targets, before forecasting based on the various lengths of intervals is performed. Furthermore, sensitivity analyses are also carried out for various percentiles. The ratio-based lengths of intervals are found to outperform the effective lengths of intervals, as well as the arbitrary ones in regard to the different statistical measures. The empirical analysis suggests that the ratio-based lengths of intervals can also be used to improve fuzzy time series forecasting.

Time-resolved speckle effects on the estimation of laser-pulse arrival times

NASA Technical Reports Server (NTRS)

Tsai, B.-M.; Gardner, C. S.

1985-01-01

A maximum-likelihood (ML) estimator of the pulse arrival in laser ranging and altimetry is derived for the case of a pulse distorted by shot noise and time-resolved speckle. The performance of the estimator is evaluated for pulse reflections from flat diffuse targets and compared with the performance of a suboptimal centroid estimator and a suboptimal Bar-David ML estimator derived under the assumption of no speckle. In the large-signal limit the accuracy of the estimator was found to improve as the width of the receiver observational interval increases. The timing performance of the estimator is expected to be highly sensitive to background noise when the received pulse energy is high and the receiver observational interval is large. Finally, in the speckle-limited regime the ML estimator performs considerably better than the suboptimal estimators.

Importance of the Time Interval between Bowel Preparation and Colonoscopy in Determining the Quality of Bowel Preparation for Full-Dose Polyethylene Glycol Preparation

PubMed Central

Kim, Tae Kyung; Kim, Hyung Wook; Kim, Su Jin; Ha, Jong Kun; Jang, Hyung Ha; Hong, Young Mi; Park, Su Bum; Choi, Cheol Woong; Kang, Dae Hwan

2014-01-01

Background/Aims The quality of bowel preparation (QBP) is the important factor in performing a successful colonoscopy. Several factors influencing QBP have been reported; however, some factors, such as the optimal preparation-to-colonoscopy time interval, remain controversial. This study aimed to determine the factors influencing QBP and the optimal time interval for full-dose polyethylene glycol (PEG) preparation. Methods A total of 165 patients who underwent colonoscopy from June 2012 to August 2012 were prospectively evaluated. The QBP was assessed using the Ottawa Bowel Preparation Scale (Ottawa) score according to several factors influencing the QBP were analyzed. Results Colonoscopies with a time interval of 5 to 6 hours had the best Ottawa score in all parts of the colon. Patients with time intervals of 6 hours or less had the better QBP than those with time intervals of more than 6 hours (p=0.046). In the multivariate analysis, the time interval (odds ratio, 1.897; 95% confidence interval, 1.006 to 3.577; p=0.048) was the only significant contributor to a satisfactory bowel preparation. Conclusions The optimal time was 5 to 6 hours for the full-dose PEG method, and the time interval was the only significant contributor to a satisfactory bowel preparation. PMID:25368750

Race and time from diagnosis to radical prostatectomy: does equal access mean equal timely access to the operating room?--Results from the SEARCH database.

PubMed

Bañez, Lionel L; Terris, Martha K; Aronson, William J; Presti, Joseph C; Kane, Christopher J; Amling, Christopher L; Freedland, Stephen J

2009-04-01

African American men with prostate cancer are at higher risk for cancer-specific death than Caucasian men. We determine whether significant delays in management contribute to this disparity. We hypothesize that in an equal-access health care system, time interval from diagnosis to treatment would not differ by race. We identified 1,532 African American and Caucasian men who underwent radical prostatectomy (RP) from 1988 to 2007 at one of four Veterans Affairs Medical Centers that comprise the Shared Equal-Access Regional Cancer Hospital (SEARCH) database with known biopsy date. We compared time from biopsy to RP between racial groups using linear regression adjusting for demographic and clinical variables. We analyzed risk of potential clinically relevant delays by determining odds of delays >90 and >180 days. Median time interval from diagnosis to RP was 76 and 68 days for African Americans and Caucasian men, respectively (P = 0.004). After controlling for demographic and clinical variables, race was not associated with the time interval between diagnosis and RP (P = 0.09). Furthermore, race was not associated with increased risk of delays >90 (P = 0.45) or >180 days (P = 0.31). In a cohort of men undergoing RP in an equal-access setting, there was no significant difference between racial groups with regard to time interval from diagnosis to RP. Thus, equal-access includes equal timely access to the operating room. Given our previous finding of poorer outcomes among African Americans, treatment delays do not seem to explain these observations. Our findings need to be confirmed in patients electing other treatment modalities and in other practice settings.

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…

Measuring happiness in individuals with profound multiple disabilities.

PubMed

Darling, Joseph A; Circo, Deborah K

2015-12-01

This quantitative study assessed whether presentation of preferred items and activities during multiple periods of the day (and over multiple days) increased indices of happiness (over time/sustained) in individuals with PMD. A multiple baseline design across participants was utilized to measure changes in indices of happiness of the participants. Participants were recruited from an adult day activity program specializing in providing assistance to individuals with disabilities. For Mary, baseline indices of happiness were 26.67% of intervals, increasing 6.76% during intervention to 33.43%. For Caleb, baseline indices of happiness were 20.84% of intervals, increasing 6.34% during intervention to 27.18%. For Mark, baseline indices of happiness were 40.00% of intervals, increasing 12.75% during intervention to 52.75%. Overall interobserver agreement was 82.8%, with interobserver agreement observations occurring during 63.04% of the observations. The results of the investigation demonstrated that presenting preferred items and activities increased the indices of happiness compared to baseline rates of indices of happiness. Results may have been more robust if the participants were assessed for overall responsiveness patterns prior to the initiation of measurement of indices of happiness. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cardiotachometer displays heart rate on a beat-to-beat basis

NASA Technical Reports Server (NTRS)

Rasquin, J. R.; Smith, H. E.; Taylor, R. A.

1974-01-01

Electronics for this system may be chosen so that complete calculation and display may be accomplished in a few milliseconds, far less than even the fastest heartbeat interval. Accuracy may be increased, if desired, by using higher-frequency timing oscillator, although this will require large capacity registers at increased cost.

An operational definition of a statistically meaningful trend.

PubMed

Bryhn, Andreas C; Dimberg, Peter H

2011-04-28

Linear trend analysis of time series is standard procedure in many scientific disciplines. If the number of data is large, a trend may be statistically significant even if data are scattered far from the trend line. This study introduces and tests a quality criterion for time trends referred to as statistical meaningfulness, which is a stricter quality criterion for trends than high statistical significance. The time series is divided into intervals and interval mean values are calculated. Thereafter, r(2) and p values are calculated from regressions concerning time and interval mean values. If r(2) ≥ 0.65 at p ≤ 0.05 in any of these regressions, then the trend is regarded as statistically meaningful. Out of ten investigated time series from different scientific disciplines, five displayed statistically meaningful trends. A Microsoft Excel application (add-in) was developed which can perform statistical meaningfulness tests and which may increase the operationality of the test. The presented method for distinguishing statistically meaningful trends should be reasonably uncomplicated for researchers with basic statistics skills and may thus be useful for determining which trends are worth analysing further, for instance with respect to causal factors. The method can also be used for determining which segments of a time trend may be particularly worthwhile to focus on.

Improving photoprotection attitudes in the tropics: sunburn vs vitamin D.

PubMed

Silva, Abel A

2014-01-01

The ultraviolet radiation of type B (the UVB) stimulates both the production of vitamin D (VD) and the incorporation of erythema dose (ED). The UVA also contributes to ED. The turning point between the benefit of producing VD and the harm of incorporating ED cannot be determined easily. However, the casual behavior regarding the exposure to the Sun can be changed in order to improve the protoprotection attitudes and create a trend towards benefit. In the case, people living in the low latitudes should exposure themselves to the Sun for a determined time interval within the noon time and avoid the Sun in other periods. This would produce an adequate amount of VD through the VD dose (207-214 J m(-2)) against minimum ED (≈105 J m(-2)) for skin type II. For it, unprotected forearms and hands must be exposed to the noon Sun (cloudless) for 11 min (winter) and 5 min (summer). The exposure at other times different from noon can represent increases of up to 24% in ED and up to 12 times in the time interval to be in the Sun in relation to the minimum amounts of both ED and time interval at noon. © 2014 The American Society of Photobiology.

The curious influence of timing on the magical experience evoked by conjuring tricks involving false transfer: decay of amodal object permanence?

PubMed

Beth, Tessa; Ekroll, Vebjørn

2015-07-01

In magic tricks involving false transfer, the conjurer typically creates the illusion of transferring a coin from one hand into the other, which is then closed into a fist, while in reality the coin is kept hidden in the first hand. The magical experience occurs when the closed fist of the second hand is opened and shown to be empty. According to professional magicians, the magical experience evoked by this kind of tricks becomes noticeably weaker when the time interval between the false transfer and the opening of the fist increases. This observation is surprising, given that neither the length of this interval nor any obvious factors associated with it can be expected to change the spectators' intellectual conviction regarding the true location of the coin. We performed a controlled psychological experiment and obtained results corroborating these informal observations. Increasing the temporal interval from 1 to 32 s led to an average reduction of the strength of the magical experience of 38%. We discuss potential explanations of this curious phenomenon in terms of object persistence, object files and temporal amodal completion.

Assessment of atrial electromechanical interval and P wave dispersion in patients with polycystic ovary syndrome.

PubMed

Bayır, Pınar Türker; Güray, Ümit; Duyuler, Serkan; Demirkan, Burcu; Kayaalp, Oya; Kanat, Selçuk; Güray, Yeşim

2016-02-01

Polycystic ovary syndrome (PCOS) is associated with increased cardiovascular risk, including ischemic stroke. Prolonged atrial electromechanical interval (EMI) is related to increased atrial fibrillation (AF) risk. The aim of the study is to evaluate atrial EMI and electrocardiographic P-wave indices related to increased AF risk in patients with PCOS. Forty PCOS patients diagnosed on the basis of the Rotterdam criteria and 20 age-matched controls were prospectively included. patients with atrioventricular or intraventricular conduction abnormalities, dysrhythmia or taking antiarrhythmic drugs, atherosclerotic heart disease, cardiomyopathies, valvular lesions, pericardial disease, a history of pulmonary emboli or pulmonary hypertension, and abnormal thyroid function were excluded. Intra and interatrial EMI were measured by tissue Doppler imaging and P-wave dispersion (Pd) was calculated on 12-lead electrocardiography (ECG). The Isovolumetric relaxation time was the interval between the aortic valve closure artifact at the end of the LV outflow envelope and the mitral valve opening artifact at the beginning of the mitral E wave. Patients with PCOS had significantly higher interatrial [38 (24-65) ms vs. 16 (9-19) ms p<0.001], left-sided intra-atrial (14.8±6.1 vs. 7±1.7 ms, p<0.001), and right-sided intra-atrial (22.3±8.1 vs. 8.6±3.6 ms, p<0.001) EMI compared with the control group. Pd was significantly greater in the PCOS group compared with control group [45 (27-60) ms vs. 30 (26-38) ms, p<0.001]. Echocardiographic parameters of atrial EMI were significantly correlated with body mass index, Pd, and isovolumetric relaxation time in patients with PCOS. PCOS is associated with prolonged inter- and intra-atrial conduction times, which are related to increased AF risk.

Effects of atomoxetine on the QT interval in healthy CYP2D6 poor metabolizers

PubMed Central

Loghin, Corina; Haber, Harry; Beasley, Charles M; Kothare, Prajakti A; Kauffman, Lynnette; April, John; Jin, Ling; Allen, Albert J; Mitchell, Malcolm I

2013-01-01

Aim The effects of atomoxetine (20 and 60 mg twice daily), 400 mg moxifloxacin and placebo on QTc in 131 healthy CYP2D6 poor metabolizer males were compared. Methods Atomoxetine doses were selected to result in plasma concentrations that approximated expected plasma concentrations at both the maximum recommended dose and at a supratherapeutic dose in CYP2D6 extensive metabolizers. Ten second electrocardiograms were obtained for time-matched baseline on days −2 and −1, three time points after dosing on day 1 for moxifloxacin and five time points on day 7 for atomoxetine and placebo. Maximum mean placebo-subtracted change from baseline model-corrected QT (QTcM) on day 7 was the primary endpoint. Results QTcM differences for atomoxetine 20 and 60 mg twice daily were 0.5 ms (upper bound of the one-sided 95% confidence interval 2.2 ms) and 4.2 ms (upper bound of the one-sided 95% confidence interval 6.0 ms), respectively. As plasma concentration of atomoxetine increased, a statistically significant increase in QTc was observed. The moxifloxacin difference from placebo met the a priori definition of non-inferiority. Maximum mean placebo-subtracted change from baseline QTcM for moxifloxacin was 4.8 ms and this difference was statistically significant. Moxifloxacin plasma concentrations were below the concentrations expected from the literature. However, the slope of the plasma concentration−QTc change observed was consistent with the literature. Conclusion Atomoxetine was not associated with a clinically significant change in QTc. However, a statistically significant increase in QTc was associated with increasing plasma concentrations. PMID:22803597

Ambulatory aortic blood pressure, wave reflections and pulse wave velocity are elevated during the third in comparison to the second interdialytic day of the long interval in chronic haemodialysis patients

PubMed Central

Koutroumbas, Georgios; Georgianos, Panagiotis I.; Sarafidis, Pantelis A.; Protogerou, Athanase; Karpetas, Antonios; Vakianis, Pantelis; Raptis, Vassilios; Liakopoulos, Vassilios; Panagoutsos, Stylianos; Syrganis, Christos; Passadakis, Ploumis

2015-01-01

Background Increased arterial stiffness and aortic blood pressure (BP) are independent predictors of cardiovascular outcomes in end-stage renal disease. The 3-day interdialytic interval is associated with elevated risk of cardiovascular morbidity and mortality in haemodialysis. This study investigated differences in ambulatory aortic BP and arterial stiffness between the second and third day of the long interdialytic interval. Methods Ambulatory BP monitoring with Mobil-O-Graph monitor (IEM, Stolberg, Germany) was performed in 55 haemodialysis patients during a 3-day interval. Mobil-O-Graph records oscillometric brachial BP and pulse waves and calculates aortic BP and augmentation index (AIx) as measure of wave reflections, and pulse wave velocity (PWV) as measure of arterial stiffness. Results Ambulatory aortic systolic blood pressure (SBP) and diastolic blood pressure (DBP) were higher during the third versus second interdialytic day (123.6 ± 17.0 versus 118.5 ± 17.1 mmHg, P < 0.001; 81.5 ± 11.8 versus 78 ± 11.9 mmHg, P < 0.001, respectively). Similar differences were noted for brachial BP. Ambulatory AIx and PWV were also significantly increased during the third versus second day (30.5 ± 9.9 versus 28.8 ± 9.9%, P < 0.05; 9.6 ± 2.3 versus 9.4 ± 2.3 m/s, P < 0.001, respectively). Differences between Days 2 and 3 remained significant when day-time and night-time periods were compared separately. Aortic SBP and DBP, AIx and PWV showed gradual increases from the end of dialysis session onwards. Interdialytic weight gain was a strong determinant of the increase in the above parameters. Conclusions This study showed significantly higher ambulatory aortic BP, AIx and PWV levels during the third compared with the second interdialytic day. These findings support a novel pathway for increased cardiovascular risk during the third interdialytic day in haemodialysis. PMID:25920919

Resting and postexercise heart rate variability in professional handball players.

PubMed

Kayacan, Yildirim; Yildiz, Sedat

2016-03-01

The aim of this study was to evaluate heart rate variability (HRV) in professional handball players during rest and following a 5 min mild jogging exercise. For that purpose, electrocardiogram (ECG) of male handball players (N.=12, mean age 25±3.95 years) and sedentary controls (N.=14, mean age 23.5±2.95 years) were recorded for 5 min at rest and just after 5 min of mild jogging. ECGs were recorded and following HRV parameters were calculated: time-domain variables such as heart rate (HR), average normal-to-normal RR intervals, standard deviation of normal-to-normal RR intervals, square root of the mean of the squares of differences between adjacent NN intervals, percentage of differences between adjacent NN intervals that are greater than 50 milliseconds (pNN50), and frequency-domain variables such as very low frequency, low (LF) and high frequency (HF) of the power and LF/HF ratio. Unpaired t-test was used to find out differences among groups while paired t-test was used for comparison of each group for pre- and postjogging HRV. Pearson correlations were carried out to find out the relationships between the parameters. Blood pressures were not different between handball players and sedentary controls but exercise increased systolic blood pressure (P<0.01). HR was increased with exercise (P<0.001) and was slower in handball players (P<0.01). QTc was increased with exercise (P<0.001) and was higher in handball players (P<0.001). Exercise decreased pNN50 values in both groups but LF/HF ratio increased only in sedentary subjects. In conclusion, results of the HRV parameters show that sympathovagal balance does not appear to change in handball players in response to a mild, short-time (5 min) jogging exercise. However, in sedentary subjects, either the sympathetic regulation of the autonomous nervous system increased or vagal withdrawal occurred.

Effects of psilocybin on time perception and temporal control of behaviour in humans.

PubMed

Wittmann, Marc; Carter, Olivia; Hasler, Felix; Cahn, B Rael; Grimberg, Ulrike; Spring, Philipp; Hell, Daniel; Flohr, Hans; Vollenweider, Franz X

2007-01-01

Hallucinogenic psilocybin is known to alter the subjective experience of time. However, there is no study that systematically investigated objective measures of time perception under psilocybin. Therefore, we studied dose-dependent effects of the serotonin (5-HT)2A/1A receptor agonist psilocybin (4-phosphoryloxy-N, N-dimethyltryptamine) on temporal processing, employing tasks of temporal reproduction, sensorimotor synchronization and tapping tempo. To control for cognitive and subjective changes, we assessed spatial working memory and conscious experience. Twelve healthy human volunteers were tested under placebo, medium (115 microg/kg), and high (250 microg/kg) dose conditions, in a double-blind experimental design. Psilocybin was found to significantly impair subjects' ability to (1) reproduce interval durations longer than 2.5 sec, (2) to synchronize to inter-beat intervals longer than 2 sec and (3) caused subjects to be slower in their preferred tapping rate. These objective effects on timing performance were accompanied by working-memory deficits and subjective changes in conscious state, namely increased reports of 'depersonalization' and 'derealization' phenomena including disturbances in subjective 'time sense.' Our study is the first to systematically assess the impact of psilocybin on timing performance on standardized measures of temporal processing. Results indicate that the serotonin system is selectively involved in duration processing of intervals longer than 2 to 3 seconds and in the voluntary control of the speed of movement. We speculate that psilocybin's selective disruption of longer intervals is likely to be a product of interactions with cognitive dimensions of temporal processing -presumably via 5-HT2A receptor stimulation.

Combining Speed Information Across Space

NASA Technical Reports Server (NTRS)

Verghese, Preeti; Stone, Leland S.

1995-01-01

We used speed discrimination tasks to measure the ability of observers to combine speed information from multiple stimuli distributed across space. We compared speed discrimination thresholds in a classical discrimination paradigm to those in an uncertainty/search paradigm. Thresholds were measured using a temporal two-interval forced-choice design. In the discrimination paradigm, the n gratings in each interval all moved at the same speed and observers were asked to choose the interval with the faster gratings. Discrimination thresholds for this paradigm decreased as the number of gratings increased. This decrease was not due to increasing the effective stimulus area as a control experiment that increased the area of a single grating did not show a similar improvement in thresholds. Adding independent speed noise to each of the n gratings caused thresholds to decrease at a rate similar to the original no-noise case, consistent with observers combining an independent sample of speed from each grating in both the added- and no-noise cases. In the search paradigm, observers were asked to choose the interval in which one of the n gratings moved faster. Thresholds in this case increased with the number of gratings, behavior traditionally attributed to an input bottleneck. However, results from the discrimination paradigm showed that the increase was not due to observers' inability to process these gratings. We have also shown that the opposite trends of the data in the two paradigms can be predicted by a decision theory model that combines independent samples of speed information across space. This demonstrates that models typically used in classical detection and discrimination paradigms are also applicable to search paradigms. As our model does not distinguish between samples in space and time, it predicts that discrimination performance should be the same regardless of whether the gratings are presented in two spatial intervals or two temporal intervals. Our last experiment largely confirmed this prediction.

Using Solar Radio Burst Integrated Fluxes to Predict Energetic Proton Flux Increases.

DTIC Science & Technology

1982-08-31

Energy Density, ET, of the radio burst, an integration across the frequency interval of the time-integrated radio fluxes at each frequency, was found to...integrated flux or energy at five frequencies in the 600- to 8800-MHz frequency interval and related them to the peak proton flux of the associated... energy of the burst normalized to its peak flux. One other characteristic of the radio burst to which Croom 13 referred was the total energy density, ET

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.

Qualitative Research in the CJA/RCV: An 18-Year Analysis (1995-2012).

PubMed

Humble, Áine M; Green, Maureen

2016-03-01

Some researchers have suggested that qualitative research is increasing in the gerontology field, but little systematic analysis has tested this assertion. Using the Canadian Journal on Aging/La Revue canadienne du vieillissement as a case study, we analysed articles reporting on original research from 1995 to 2012. One in four articles were qualitative, and results in three-year intervals show a clear increase in qualitative research findings during this 18-year time frame: (a) 1995-1997: 10 per cent; (b) 1998-2000: 19 per cent; (c) 2001-2003: 25 per cent; (d) 2004-2006: 25 per cent; (e) 2007-2009: 29 per cent; and (f) 2010-2012: 43 per cent. In all time intervals (with the exception of 2004-2006), French language articles were more likely to use a qualitative research design compared to English language articles. Topics, methodologies, and data collection strategies are also discussed.

Enhancing quantum sensing sensitivity by a quantum memory

PubMed Central

Zaiser, Sebastian; Rendler, Torsten; Jakobi, Ingmar; Wolf, Thomas; Lee, Sang-Yun; Wagner, Samuel; Bergholm, Ville; Schulte-Herbrüggen, Thomas; Neumann, Philipp; Wrachtrup, Jörg

2016-01-01

In quantum sensing, precision is typically limited by the maximum time interval over which phase can be accumulated. Memories have been used to enhance this time interval beyond the coherence lifetime and thus gain precision. Here, we demonstrate that by using a quantum memory an increased sensitivity can also be achieved. To this end, we use entanglement in a hybrid spin system comprising a sensing and a memory qubit associated with a single nitrogen-vacancy centre in diamond. With the memory we retain the full quantum state even after coherence decay of the sensor, which enables coherent interaction with distinct weakly coupled nuclear spin qubits. We benchmark the performance of our hybrid quantum system against use of the sensing qubit alone by gradually increasing the entanglement of sensor and memory. We further apply this quantum sensor-memory pair for high-resolution NMR spectroscopy of single 13C nuclear spins. PMID:27506596

High-intensity interval training: Modulating interval duration in overweight/obese men.

PubMed

Smith-Ryan, Abbie E; Melvin, Malia N; Wingfield, Hailee L

2015-05-01

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. 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. Twenty-five men [body mass index (BMI) > 25 kg · m(2)] 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). 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. HIIT may be an effective short-term strategy to improve cardiorespiratory fitness and IN sensitivity in overweight males.

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

Interval Timing Accuracy and Scalar Timing in C57BL/6 Mice

PubMed Central

Buhusi, Catalin V.; Aziz, Dyana; Winslow, David; Carter, Rickey E.; Swearingen, Joshua E.; Buhusi, Mona C.

2010-01-01

In many species, interval timing behavior is accurate—appropriate estimated durations—and scalar—errors vary linearly with estimated durations. While accuracy has been previously examined, scalar timing has not been yet clearly demonstrated in house mice (Mus musculus), raising concerns about mouse models of human disease. We estimated timing accuracy and precision in C57BL/6 mice, the most used background strain for genetic models of human disease, in a peak-interval procedure with multiple intervals. Both when timing two intervals (Experiment 1) or three intervals (Experiment 2), C57BL/6 mice demonstrated varying degrees of timing accuracy. Importantly, both at individual and group level, their precision varied linearly with the subjective estimated duration. Further evidence for scalar timing was obtained using an intraclass correlation statistic. This is the first report of consistent, reliable scalar timing in a sizable sample of house mice, thus validating the PI procedure as a valuable technique, the intraclass correlation statistic as a powerful test of the scalar property, and the C57BL/6 strain as a suitable background for behavioral investigations of genetically engineered mice modeling disorders of interval timing. PMID:19824777

Assessment of cardiac time intervals using high temporal resolution real-time spiral phase contrast with UNFOLDed-SENSE.

PubMed

Kowalik, Grzegorz T; Knight, Daniel S; Steeden, Jennifer A; Tann, Oliver; Odille, Freddy; Atkinson, David; Taylor, Andrew; Muthurangu, Vivek

2015-02-01

To develop a real-time phase contrast MR sequence with high enough temporal resolution to assess cardiac time intervals. The sequence utilized spiral trajectories with an acquisition strategy that allowed a combination of temporal encoding (Unaliasing by fourier-encoding the overlaps using the temporal dimension; UNFOLD) and parallel imaging (Sensitivity encoding; SENSE) to be used (UNFOLDed-SENSE). An in silico experiment was performed to determine the optimum UNFOLD filter. In vitro experiments were carried out to validate the accuracy of time intervals calculation and peak mean velocity quantification. In addition, 15 healthy volunteers were imaged with the new sequence, and cardiac time intervals were compared to reference standard Doppler echocardiography measures. For comparison, in silico, in vitro, and in vivo experiments were also carried out using sliding window reconstructions. The in vitro experiments demonstrated good agreement between real-time spiral UNFOLDed-SENSE phase contrast MR and the reference standard measurements of velocity and time intervals. The protocol was successfully performed in all volunteers. Subsequent measurement of time intervals produced values in keeping with literature values and good agreement with the gold standard echocardiography. Importantly, the proposed UNFOLDed-SENSE sequence outperformed the sliding window reconstructions. Cardiac time intervals can be successfully assessed with UNFOLDed-SENSE real-time spiral phase contrast. Real-time MR assessment of cardiac time intervals may be beneficial in assessment of patients with cardiac conditions such as diastolic dysfunction. © 2014 Wiley Periodicals, Inc.

The Effects of High Intensity Interval Training vs Steady State Training on Aerobic and Anaerobic Capacity

PubMed Central

Foster, Carl; Farland, Courtney V.; Guidotti, Flavia; Harbin, Michelle; Roberts, Brianna; Schuette, Jeff; Tuuri, Andrew; Doberstein, Scott T.; Porcari, John P.

2015-01-01

High intensity interval training (HIIT) has become an increasingly popular form of exercise due to its potentially large effects on exercise capacity and small time requirement. This study compared the effects of two HIIT protocols vs steady-state training on aerobic and anaerobic capacity following 8-weeks of training. Fifty-five untrained college-aged subjects were randomly assigned to three training groups (3x weekly). Steady-state (n = 19) exercised (cycle ergometer) 20 minutes at 90% of ventilatory threshold (VT). Tabata (n = 21) completed eight intervals of 20s at 170% VO2max/10s rest. Meyer (n = 15) completed 13 sets of 30s (20 min) @ 100% PVO2 max/ 60s recovery, average PO = 90% VT. Each subject did 24 training sessions during 8 weeks. Results: There were significant (p < 0.05) increases in VO2max (+19, +18 and +18%) and PPO (+17, +24 and +14%) for each training group, as well as significant increases in peak (+8, + 9 and +5%) & mean (+4, +7 and +6%) power during Wingate testing, but no significant differences between groups. Measures of the enjoyment of the training program indicated that the Tabata protocol was significantly less enjoyable (p < 0.05) than the steady state and Meyer protocols, and that the enjoyment of all protocols declined (p < 0.05) across the duration of the study. The results suggest that although HIIT protocols are time efficient, they are not superior to conventional exercise training in sedentary young adults. Key points Steady state training equivalent to HIIT in untrained students Mild interval training presents very similar physiologic challenge compared to steady state training HIIT (particularly very high intensity variants were less enjoyable than steady state or mild interval training Enjoyment of training decreases across the course of an 8 week experimental training program PMID:26664271

The Effects of High Intensity Interval Training vs Steady State Training on Aerobic and Anaerobic Capacity.

PubMed

Foster, Carl; Farland, Courtney V; Guidotti, Flavia; Harbin, Michelle; Roberts, Brianna; Schuette, Jeff; Tuuri, Andrew; Doberstein, Scott T; Porcari, John P

2015-12-01

High intensity interval training (HIIT) has become an increasingly popular form of exercise due to its potentially large effects on exercise capacity and small time requirement. This study compared the effects of two HIIT protocols vs steady-state training on aerobic and anaerobic capacity following 8-weeks of training. Fifty-five untrained college-aged subjects were randomly assigned to three training groups (3x weekly). Steady-state (n = 19) exercised (cycle ergometer) 20 minutes at 90% of ventilatory threshold (VT). Tabata (n = 21) completed eight intervals of 20s at 170% VO2max/10s rest. Meyer (n = 15) completed 13 sets of 30s (20 min) @ 100% PVO2 max/ 60s recovery, average PO = 90% VT. Each subject did 24 training sessions during 8 weeks. There were significant (p < 0.05) increases in VO2max (+19, +18 and +18%) and PPO (+17, +24 and +14%) for each training group, as well as significant increases in peak (+8, + 9 and +5%) & mean (+4, +7 and +6%) power during Wingate testing, but no significant differences between groups. Measures of the enjoyment of the training program indicated that the Tabata protocol was significantly less enjoyable (p < 0.05) than the steady state and Meyer protocols, and that the enjoyment of all protocols declined (p < 0.05) across the duration of the study. The results suggest that although HIIT protocols are time efficient, they are not superior to conventional exercise training in sedentary young adults. Key pointsSteady state training equivalent to HIIT in untrained studentsMild interval training presents very similar physiologic challenge compared to steady state trainingHIIT (particularly very high intensity variants were less enjoyable than steady state or mild interval trainingEnjoyment of training decreases across the course of an 8 week experimental training program.

Early changes in myocardial repolarization and coronary perfusion after cardiopulmonary bypass surgery for ASD repair in children.

PubMed

Aburawi, Elhadi H; Souid, Abdul-Kader; Liuba, Petru; Zoubeidi, Taoufik; Pesonen, Erkki

2013-09-10

In adults, impaired myocardial repolarization and increased risk of arrhythmia are known consequences of open heart surgery. Little is known, however, about post-operative consequences of cardiopulmonary bypass surgery in children. The aim of this study was to assess ventricular repolarization and coronary perfusion after bypass surgery for atrial septal defect (ASD) repair in children. Twelve patients with ASD were assessed one day before and 5-6 days after ASD repair. Myocardial repolarization (corrected QT interval, QTc, QT dispersion, QTd, and PQ interval) was determined on 12-lead electrocardiograms. Coronary flow in proximal left anterior descending artery (peak flow velocity in diastole, PFVd) was assessed by transthoracic Doppler echocardiography. Ten of the 12 (83%) children had normal myocardial repolarization before and after surgery. After surgery, QTc increased 1-9% in 5 (42%) patients, decreased 2-11% in 5 (42%) patients and did not change in 2 (16%) patients. Post-op QTc positively correlated with bypass time (R=0.686, p=0.014) and changes in PFVd (R=0.741, p=0.006). After surgery, QTd increased 33-67% in 4 (33%) patients, decreased 25-50% in 6 patients (50%) and did not change in 2 (16%) patients. After surgery, PQ interval increased 5-30% in 4 (33%) patients, decreased 4-29% in 6 (50%) patients and did not change in 1 (8%) patient. Post-op PQ positively correlated with bypass time (R=0.636, p=0.027). As previously reported, PFVd significantly increased after surgery (p<0.001). Changes in QTc, PQ and PFVd are common in young children undergoing surgery for ASD repair. Post-op QTc significantly correlates with bypass time, suggesting prolonged cardiopulmonary bypass may impair ventricular repolarization. Post-op QTc significantly correlates with PFVd changes, suggesting increased coronary flow may also impair ventricular repolarization. The clinical significance and reversibility of these alternations require further investigations.

Uptake of recommended common reference intervals for chemical pathology in Australia.

PubMed

Jones, Graham Rd; Koetsier, Sabrina

2017-05-01

Background Reference intervals are a vital part of reporting numerical pathology results. It is known, however, that variation in reference intervals between laboratories is common, even when analytical methods support common reference intervals. In response to this, in Australia, the Australasian Association of Clinical Biochemists together with the Royal College of Pathologists of Australasia published in 2014 a set of recommended common reference intervals for 11 common serum analytes (sodium, potassium, chloride, bicarbonate, creatinine male, creatinine female, calcium, calcium adjusted for albumin, phosphate, magnesium, lactate dehydrogenase, alkaline phosphatase and total protein). Methods Uptake of recommended common reference intervals in Australian laboratories was assessed using data from four annual cycles of the RCPAQAP reference intervals external quality assurance programme. Results Over three years, from 2013 to 2016, the use of the recommended upper and lower reference limits has increased from 40% to 83%. Nearly half of the intervals in use by enrolled laboratories in 2016 have been changed in this time period, indicating an active response to the guidelines. Conclusions These data support the activities of the Australasian Association of Clinical Biochemists and Royal College of Pathologists of Australasia in demonstrating a change in laboratory behaviour to reduce unnecessary variation in reference intervals and thus provide a consistent message to doctor and patients irrespective of the laboratory used.

Prediction of mortality rates using a model with stochastic parameters

NASA Astrophysics Data System (ADS)

Tan, Chon Sern; Pooi, Ah Hin

2016-10-01

Prediction of future mortality rates is crucial to insurance companies because they face longevity risks while providing retirement benefits to a population whose life expectancy is increasing. In the past literature, a time series model based on multivariate power-normal distribution has been applied on mortality data from the United States for the years 1933 till 2000 to forecast the future mortality rates for the years 2001 till 2010. In this paper, a more dynamic approach based on the multivariate time series will be proposed where the model uses stochastic parameters that vary with time. The resulting prediction intervals obtained using the model with stochastic parameters perform better because apart from having good ability in covering the observed future mortality rates, they also tend to have distinctly shorter interval lengths.

Long-Term Memory: A Natural Mechanism for the Clustering of Extreme Events and Anomalous Residual Times in Climate Records

NASA Astrophysics Data System (ADS)

Bunde, Armin; Eichner, Jan F.; Kantelhardt, Jan W.; Havlin, Shlomo

2005-01-01

We study the statistics of the return intervals between extreme events above a certain threshold in long-term persistent records. We find that the long-term memory leads (i)to a stretched exponential distribution of the return intervals, (ii)to a pronounced clustering of extreme events, and (iii)to an anomalous behavior of the mean residual time to the next event that depends on the history and increases with the elapsed time in a counterintuitive way. We present an analytical scaling approach and demonstrate that all these features can be seen in long climate records. The phenomena should also occur in heartbeat records, Internet traffic, and stock market volatility and have to be taken into account for an efficient risk evaluation.

Dating of Early Subdural Haematoma: A Correlative Clinico-Radiological Study

PubMed Central

Rao, Murali Gundu; Khandelwal, Niranjan; Sharma, Suresh Kumar

2016-01-01

Introduction Determination of post-traumatic interval remains one of the foremost important goals of any forensic investigation related to human crimes. The estimation of time since injury in cases of subdural haemorrhage has been studied only by a few investigators on the histological and radiological front. Aim The purpose of this study was to determine the post-traumatic interval of Subdural Haemorrhage (SDH) based on Hounsfield Unit measurements (HU) on Computed Tomography (CT) in surviving victims of head injury. Materials and Methods The study included a total of 100 cases of closed head injury with subdural haemorrhage. The Post-traumatic Time Interval (PTI) varied from 0.5 hours to a maximum of 249 hours, with a mean of 54.2 hours. Results Statistically significant results were obtained between the HU measurements of the SDH and the post-traumatic intervals and were found to be statistically significant. A rough attempt was made to determine the effect of haematoma volume on attenuation and was found out to be statistically insignificant. Conclusion The density of the subdural haematoma decreases with increase in the post-traumatic interval that concurs with the limited number of studies being conducted in the past. We concluded that further sorting of cases could be done according to its age with additional research and uniformity in the methodology. PMID:27190831

The effect of age at first calving and calving interval on productive life and lifetime profit in korean holsteins.

PubMed

Do, Changhee; Wasana, Nidarshani; Cho, Kwanghyun; Choi, Yunho; Choi, Taejeong; Park, Byungho; Lee, Donghee

2013-11-01

This study was performed to estimate the effect of age at first calving and first two calving intervals on productive life and life time profit in Korean Holsteins. Reproduction data of Korean Holsteins born from 1998 to 2004 and lactation data from 276,573 cows with birth and last dry date that calved between 2000 and 2010 were used for the analysis. Lifetime profit increased with the days of life span. Regression of Life Span on Lifetime profit indicated that there was an increase of 3,800 Won (approximately $3.45) of lifetime profit per day increase in life span. This is evidence that care of each cow is necessary to improve net return and important for farms maintaining profitable cows. The estimates of heritability of age at first calving, first two calving intervals, days in milk for lifetime, lifespan, milk income and lifetime profit were 0.111, 0.088, 0.142, 0.140, 0.143, 0.123, and 0.102, respectively. The low heritabilities indicated that the productive life and economical traits include reproductive and productive characteristics. Age at first calving and interval between first and second calving had negative genetic correlation with lifetime profit (-0.080 and -0.265, respectively). Reducing age at first calving and first calving interval had a positive effect on lifetime profit. Lifetime profit increased to approximately 2,600,000 (2,363.6) from 800,000 Won ($727.3) when age at first calving decreased to (22.3 month) from (32.8 month). Results suggested that reproductive traits such as age at first calving and calving interval might affect various economical traits and consequently influenced productive life and profitability of cows. In conclusion, regard of the age at first calving must be taken with the optimum age at first calving for maximum lifetime profit being 22.5 to 23.5 months. Moreover, considering the negative genetic correlation of first calving interval with lifetime profit, it should be reduced against the present trend of increase.

The Effect of Age at First Calving and Calving Interval on Productive Life and Lifetime Profit in Korean Holsteins

PubMed Central

Do, Changhee; Wasana, Nidarshani; Cho, Kwanghyun; Choi, Yunho; Choi, Taejeong; Park, Byungho; Lee, Donghee

2013-01-01

This study was performed to estimate the effect of age at first calving and first two calving intervals on productive life and life time profit in Korean Holsteins. Reproduction data of Korean Holsteins born from 1998 to 2004 and lactation data from 276,573 cows with birth and last dry date that calved between 2000 and 2010 were used for the analysis. Lifetime profit increased with the days of life span. Regression of Life Span on Lifetime profit indicated that there was an increase of 3,800 Won (approximately $3.45) of lifetime profit per day increase in life span. This is evidence that care of each cow is necessary to improve net return and important for farms maintaining profitable cows. The estimates of heritability of age at first calving, first two calving intervals, days in milk for lifetime, lifespan, milk income and lifetime profit were 0.111, 0.088, 0.142, 0.140, 0.143, 0.123, and 0.102, respectively. The low heritabilities indicated that the productive life and economical traits include reproductive and productive characteristics. Age at first calving and interval between first and second calving had negative genetic correlation with lifetime profit (−0.080 and −0.265, respectively). Reducing age at first calving and first calving interval had a positive effect on lifetime profit. Lifetime profit increased to approximately 2,600,000 (2,363.6) from 800,000 Won ($727.3) when age at first calving decreased to (22.3 month) from (32.8 month). Results suggested that reproductive traits such as age at first calving and calving interval might affect various economical traits and consequently influenced productive life and profitability of cows. In conclusion, regard of the age at first calving must be taken with the optimum age at first calving for maximum lifetime profit being 22.5 to 23.5 months. Moreover, considering the negative genetic correlation of first calving interval with lifetime profit, it should be reduced against the present trend of increase. PMID:25049735

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.

Development of Automatic Control of Bayer Plant Digestion

NASA Astrophysics Data System (ADS)

Riffaud, J. P.

Supervisory computer control has been achieved in Alcan's Bayer Plants at Arvida, Quebec, Canada. The purpose of the automatic control system is to stabilize and consequently increase, the alumina/caustic ratio within the digester train and in the blow-off liquor. Measurements of the electrical conductivity of the liquor are obtained from electrodeless conductivity meters. These signals, along with several others are scanned by the computer and converted to engineering units, using specific relationships which are updated periodically for calibration purposes. On regular time intervals, values of ratio are compared to target values and adjustments are made to the bauxite flow entering the digesters. Dead time compensation included in the control algorithm enables a faster rate for corrections. Modification of production rate is achieved through careful timing of various flow changes. Calibration of the conductivity meters is achieved by sampling at intervals the liquor flowing through them, and analysing it with a thermometric titrator. Calibration of the thermometric titrator is done at intervals with a standard solution. Calculations for both calibrations are performed by computer from data entered by the analyst. The computer was used for on-line data collection, modelling of the digester system, calculation of disturbances and simulation of control strategies before implementing the most successful strategy in the Plant. Control of ratio has been improved by the integrated system, resulting in increased Plant productivity.

Decreasing triage time: effects of implementing a step-wise ESI algorithm in an EHR.

PubMed

Villa, Stephen; Weber, Ellen J; Polevoi, Steven; Fee, Christopher; Maruoka, Andrew; Quon, Tina

2018-06-01

To determine if adapting a widely-used triage scale into a computerized algorithm in an electronic health record (EHR) shortens emergency department (ED) triage time. Before-and-after quasi-experimental study. Urban, tertiary care hospital ED. Consecutive adult patient visits between July 2011 and June 2013. A step-wise algorithm, based on the Emergency Severity Index (ESI-5) was programmed into the triage module of a commercial EHR. Duration of triage (triage interval) for all patients and change in percentage of high acuity patients (ESI 1 and 2) completing triage within 15 min, 12 months before-and-after implementation of the algorithm. Multivariable analysis adjusted for confounders; interrupted time series demonstrated effects over time. Secondary outcomes examined quality metrics and patient flow. About 32 546 patient visits before and 33 032 after the intervention were included. Post-intervention patients were slightly older, census was higher and admission rate slightly increased. Median triage interval was 5.92 min (interquartile ranges, IQR 4.2-8.73) before and 2.8 min (IQR 1.88-4.23) after the intervention (P < 0.001). Adjusted mean triage interval decreased 3.4 min (95% CI: -3.6, -3.2). The proportion of high acuity patients completing triage within 15 min increased from 63.9% (95% CI 62.5, 65.2%) to 75.0% (95% CI 73.8, 76.1). Monthly time series demonstrated immediate and sustained improvement following the intervention. Return visits within 72 h and door-to-balloon time were unchanged. Total length of stay was similar. The computerized triage scale improved speed of triage, allowing more high acuity patients to be seen within recommended timeframes, without notable impact on quality.

Ultra-short heart rate variability recording reliability: The effect of controlled paced breathing.

PubMed

Melo, Hiago M; Martins, Thiago C; Nascimento, Lucas M; Hoeller, Alexandre A; Walz, Roger; Takase, Emílio

2018-06-04

Recent studies have reported that Heart Rate Variability (HRV) indices remain reliable even during recordings shorter than 5 min, suggesting the ultra-short recording method as a valuable tool for autonomic assessment. However, the minimum time-epoch to obtain a reliable record for all HRV domains (time, frequency, and Poincare geometric measures), as well as the effect of respiratory rate on the reliability of these indices remains unknown. Twenty volunteers had their HRV recorded in a seated position during spontaneous and controlled respiratory rhythms. HRV intervals with 1, 2, and 3 min were correlated with the gold standard period (6-min duration) and the mean values of all indices were compared in the two respiratory rhythm conditions. rMSSD and SD1 were more reliable for recordings with ultra-short duration at all time intervals (r values from 0.764 to 0.950, p < 0.05) for spontaneous breathing condition, whereas the other indices require longer recording time to obtain reliable values. The controlled breathing rhythm evokes stronger r values for time domain indices (r values from 0.83 to 0.99, p < 0.05 for rMSSD), but impairs the mean values replicability of domains across most time intervals. Although the use of standardized breathing increases the correlations coefficients, all HRV indices showed an increase in mean values (t values from 3.79 to 14.94, p < 0.001) except the RR and HF that presented a decrease (t = 4.14 and 5.96, p < 0.0001). Our results indicate that proper ultra-short-term recording method can provide a quick and reliable source of cardiac autonomic nervous system assessment. © 2018 Wiley Periodicals, Inc.

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

NASA Technical Reports Server (NTRS)

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

2001-01-01

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

A time-parallel approach to strong-constraint four-dimensional variational data assimilation

NASA Astrophysics Data System (ADS)

Rao, Vishwas; Sandu, Adrian

2016-05-01

A parallel-in-time algorithm based on an augmented Lagrangian approach is proposed to solve four-dimensional variational (4D-Var) data assimilation problems. The assimilation window is divided into multiple sub-intervals that allows parallelization of cost function and gradient computations. The solutions to the continuity equations across interval boundaries are added as constraints. The augmented Lagrangian approach leads to a different formulation of the variational data assimilation problem than the weakly constrained 4D-Var. A combination of serial and parallel 4D-Vars to increase performance is also explored. The methodology is illustrated on data assimilation problems involving the Lorenz-96 and the shallow water models.

The role of ultrasound guidance in pediatric caudal block

PubMed Central

Erbüyün, Koray; Açıkgöz, Barış; Ok, Gülay; Yılmaz, Ömer; Temeltaş, Gökhan; Tekin, İdil; Tok, Demet

2016-01-01

Objectives: To compare the time interval of the procedure, possible complications, post-operative pain levels, additional analgesics, and nurse satisfaction in ultrasonography-guided and standard caudal block applications. Methods: This retrospective study was conducted in Celal Bayar University Hospital, Manisa, Turkey, between January and December 2014, included 78 pediatric patients. Caudal block was applied to 2 different groups; one with ultrasound guide, and the other using the standard method. Results: The time interval of the procedure was significantly shorter in the standard application group compared with ultrasound-guided group (p=0.020). Wong-Baker FACES Pain Rating Scale values obtained at the 90th minute was statistically lower in the standard application group compared with ultrasound-guided group (p=0.035). No statistically significant difference was found on the other parameters between the 2 groups. The shorter time interval of the procedure at standard application group should not be considered as a distinctive mark by the pediatric anesthesiologists, because this time difference was as short as seconds. Conclusion: Ultrasound guidance for caudal block applications would neither increase nor decrease the success of the treatment. However, ultrasound guidance should be needed in cases where the detection of sacral anatomy is difficult, especially by palpations. PMID:26837396

Atmospheric Fluctuation Measurements with the Palomar Testbed Interferometer

NASA Astrophysics Data System (ADS)

Linfield, R. P.; Lane, B. F.; Colavita, M. M.; PTI Collaboration

Observations of bright stars with the Palomar Testbed Interferometer, at a wavelength of 2.2 microns, have been used to measure atmospheric delay fluctuations. The delay structure function Dτ(Δ t) was calculated for 66 scans (each >= 120s in length) on seven nights in 1997 and one in 1998. For all except one scan, Dτ exhibited a clean power law shape over the time interval 50-500 msec. Over shorter time intervals, the effect of the delay line servo loop corrupts Dτ. Over longer time intervals (usually starting at > 1s), the slope of Dτ decreases, presumably due to some combination of saturation e.g. finite turbulent layer thickness) and the effect of the finite wind speed crossing time on our 110 m baseline. The mean power law slopes for the eight nights ranged from 1.16 to 1.36, substantially flatter than the value of 1.67 for three dimensional Kolmogorov turbulence. Such sub-Kolmogorov slopes will result in atmospheric seeling (θ) that improves rapidly with increasing wavelength: θ propto λ1-(2β), where β is the observed power law slope of Dτ. The atmospheric errors in astrometric measurements with an interferometer will average down more quickly than in the Kolmogorov case.

The impact of early outcome events on the effect of tranexamic acid in post-partum haemorrhage: an exploratory subgroup analysis of the WOMAN trial.

PubMed

Brenner, Amy; Shakur-Still, Haleema; Chaudhri, Rizwana; Fawole, Bukola; Arulkumaran, Sabaratnam; Roberts, Ian

2018-06-07

In severe post-partum haemorrhage, death can occur within hours of bleeding onset so interventions to control the bleeding must be given immediately. In clinical trials of treatments for life-threatening bleeding, established treatments are given priority and the trial treatment is usually given last. However, enrolling patients in whom severe maternal morbidity or death is imminent or inevitable at the time of randomisation may dilute the effects of a trial treatment. We conducted an exploratory analysis of data from the WOMAN trial, an international, randomised placebo-controlled trial of the effects of tranexamic acid on death and surgical intervention in 20,060 women with post-partum haemorrhage. We assessed the impact of early maternal death or hysterectomy due to exsanguination on the effect of tranexamic acid on each of these respective outcomes. We conducted repeated analyses excluding patients with these outcomes at increasing intervals from the time of randomisation. We quantified treatment effects using risk ratios (RR) and 99% confidence intervals (CI) and prepared cumulative failure plots. Among 14,923 women randomised within 3 h of delivery (7518 tranexamic acid and 7405 placebo), there were 216 bleeding deaths (1.5%) and 383 hysterectomies due to bleeding (2.8%). After excluding deaths from exsanguination at increasing time intervals following randomization, there was a significant reduction in the risk of death due to bleeding with tranexamic acid (RR = 0.41; 99% CI 0.19-0.89). However, after excluding hysterectomies at increasing time intervals post-randomization, there was no reduction in the risk of hysterectomy due to bleeding with tranexamic acid (RR = 0.79; 99% CI 0.33-1.86). Findings from this analysis provide further evidence that tranexamic acid reduces the risk of death from exsanguination in women who experience postpartum haemorrhage. It is uncertain whether tranexamic acid reduces the risk of hysterectomy for bleeding after excluding early hysterectomies. ISRCTN trial registration number ISRCTN76912190, 8 Dec 2008; ClinicalTrials.gov number NCT00872469, 30 March 2009; PACTR number PACTR201007000192283, 9 Feb 2010; EudraCT number 2008-008441-38, 8 Dec 2010 (retrospectively registered).

Characterizing the variability of benthic foraminifera in the northeastern Gulf of Mexico following the Deepwater Horizon event (2010-2012).

PubMed

Schwing, P T; O'Malley, B J; Romero, I C; Martínez-Colón, M; Hastings, D W; Glabach, M A; Hladky, E M; Greco, A; Hollander, D J

2017-01-01

Following the Deepwater Horizon (DWH) event in 2010 subsurface hydrocarbon intrusions (1000-1300 m) and an order of magnitude increase in flocculent hydrocarbon deposition caused increased concentrations of hydrocarbons in continental slope sediments. This study sought to characterize the variability [density, Fisher's alpha (S), equitability (E), Shannon (H)] of benthic foraminifera following the DWH event. A series of sediment cores were collected at two sites in the northeastern Gulf of Mexico from 2010 to 2012. At each site, three cores were utilized for benthic faunal analysis, organic geochemistry, and redox metal chemistry, respectively. The surface intervals (∼0-10 mm) of the sedimentary records collected in December 2010 at DSH08 and February 2011 at PCB06 were characterized by significant decreases in foraminiferal density, S, E, and H, relative to the down-core intervals as well as previous surveys. Non-metric multidimensional scaling (nMDS) analysis suggested that a 3-fold increase in polycyclic aromatic hydrocarbon (PAH) concentration in the surface interval, relative to the down-core interval, was the environmental driver of benthic foraminiferal variability. These records suggested that the benthic foraminiferal recovery time, following an event such as the DWH, was on the order of 1-2 years.

Intact interval timing in circadian CLOCK mutants.

PubMed

Cordes, Sara; Gallistel, C R

2008-08-28

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.

A pan-Precambrian link between deglaciation and environmental oxidation

USGS Publications Warehouse

Raub, T.J.; Kirschvink, J.L.

2007-01-01

Despite a continuous increase in solar luminosity to the present, Earth’s glacial record appears to become more frequent, though less severe, over geological time. At least two of the three major Precambrian glacial intervals were exceptionally intense, with solid evidence for widespread sea ice on or near the equator, well within a “Snowball Earth” zone produced by ice-albedo runaway in energy-balance models. The end of the first unambiguously low-latitude glaciation, the early Paleoproterozoic Makganyene event, is associated intimately with the first solid evidence for global oxygenation, including the world’s largest sedimentary manganese deposit. Subsequent low-latitude deglaciations during the Cryogenian interval of the Neoproterozoic Era are also associated with progressive oxidation, and these young Precambrian ice ages coincide with the time when basal animal phyla were diversifying. However, specifically testing hypotheses of cause and effect between Earth’s Neoproterozoic biosphere and glaciation is complicated because large and rapid True Polar Wander events appear to punctuate Neoproterozoic time and may have episodically dominated earlier and later intervals as well, rendering geographic reconstruction and age correlation challenging except for an exceptionally well-defined global paleomagnetic database.

Da-Chaihu-Tang alters the pharmacokinetics of nifedipine in rats and a treatment regimen to avoid this.

PubMed

He, Ju-Xiu; Ohno, Kenji; Tang, Jun; Hattori, Masao; Tani, Tadato; Akao, Teruaki

2014-11-01

To investigate the influence of co-administrated Da-Chaihu-Tang (DCT; a traditional Chinese formulation) on the pharmacokinetics of nifedipine, as well as the safe optimal dosing interval to avoid the adverse interactions. A single dose of DCT was administered with nifedipine simultaneously, 2 h before, 30 min before or 30 min after nifedipine administration. Pharmacokinetics of nifedipine with or without DCT were compared. The influences of DCT on nifedipine intestinal mucosal and hepatic metabolism were studied by using rat in-vitro everted jejunal sac model and hepatic microsomes. A simultaneous co-administration of DCT significantly increased the area under concentration-time curve from time zero to infinity (AUC0-inf ) of nifedipine. In-vitro mechanism investigations revealed that DCT inhibited both the intestinal and the hepatic metabolism of nifedipine. Further study on the optimal dosing interval for nifedipine and DCT revealed that administration of DCT 30 min before or after nifedipine did not significantly change the AUC of nifedipine. The bioavailability of nifedipine is significantly increased by a simultaneous oral co-administration of DCT. This increase is caused by the inhibitory effect of DCT on both the intestinal mucosal and the hepatic metabolism of nifedipine. The dose interval between DCT and nifedipine needs to be set for over 30 min to avoid such drug-drug interactions. © 2014 Royal Pharmaceutical Society.

Emergency Department Overcrowding and Ambulance Turnaround Time

PubMed Central

Lee, Yu Jin; Shin, Sang Do; Lee, Eui Jung; Cho, Jin Seong; Cha, Won Chul

2015-01-01

Objective The aims of this study were to describe overcrowding in regional emergency departments in Seoul, Korea and evaluate the effect of crowdedness on ambulance turnaround time. Methods This study was conducted between January 2010 and December 2010. Patients who were transported by 119-responding ambulances to 28 emergency centers within Seoul were eligible for enrollment. Overcrowding was defined as the average occupancy rate, which was equal to the average number of patients staying in an emergency department (ED) for 4 hours divided by the number of beds in the ED. After selecting groups for final analysis, multi-level regression modeling (MLM) was performed with random-effects for EDs, to evaluate associations between occupancy rate and turnaround time. Results Between January 2010 and December 2010, 163,659 patients transported to 28 EDs were enrolled. The median occupancy rate was 0.42 (range: 0.10-1.94; interquartile range (IQR): 0.20-0.76). Overcrowded EDs were more likely to have older patients, those with normal mentality, and non-trauma patients. Overcrowded EDs were more likely to have longer turnaround intervals and traveling distances. The MLM analysis showed that an increase of 1% in occupancy rate was associated with 0.02-minute decrease in turnaround interval (95% CI: 0.01 to 0.03). In subgroup analyses limited to EDs with occupancy rates over 100%, we also observed a 0.03 minute decrease in turnaround interval per 1% increase in occupancy rate (95% CI: 0.01 to 0.05). Conclusions In this study, we found wide variation in emergency department crowding in a metropolitan Korean city. Our data indicate that ED overcrowding is negatively associated with turnaround interval with very small practical significance. PMID:26115183

A Long-Term Dissipation of the EUV He ii (30.4 nm) Segmentation in Full-Disk Solar Images

NASA Astrophysics Data System (ADS)

Didkovsky, Leonid

2018-06-01

Some quiet-Sun days observed by the Atmospheric Imaging Assembly (AIA) on-board the Solar Dynamics Observatory (SDO) during the time interval in 2010 - 2017 were used to continue our previous analyses reported by Didkovsky and Gurman ( Solar Phys. 289, 153, 2014a) and Didkovsky, Wieman, and Korogodina ( Solar Phys. 292, 32, 2017). The analysis consists of determining and comparing spatial spectral ratios (spectral densities over some time interval) from spatial (segmentation-cell length) power spectra. The ratios were compared using modeled compatible spatial frequencies for spectra from the Extreme ultraviolet Imaging Telescope (EIT) on-board the Solar and Heliospheric Observatory (SOHO) and from AIA images. With the new AIA data added to the EIT data we analyzed previously, the whole time interval from 1996 to 2017 reported here is approximately the length of two "standard" solar cycles (SC). The spectral ratios of segmentation-cell dimension structures show a significant and steady increase with no detected indication of SC-related returns to the values that characterize the SC minima. This increase in spatial power at high spatial frequencies is interpreted as a dissipation of medium-size EUV network structures to smaller-size structures in the transition region. Each of the latest ratio changes for 2010 through 2017 spectra calculated for a number of consecutive short-term intervals has been converted into monthly mean ratio (MMR) changes. The MMR values demonstrate variable sign and magnitudes, thus confirming the solar nature of the changes. These changes do not follow a "typical" trend of instrumental degradation or a long-term activity profile from the He ii (30.4 nm) irradiance measured by the Extreme ultraviolet Spectrophotometer (ESP) either. The ESP is a channel of the Extreme ultraviolet Variability Experiment (EVE) on-board SDO.

Fertility time trends in dairy herds in northern Portugal.

PubMed

Rocha, A; Martins, A; Carvalheira, J

2010-10-01

The economics of dairy production are in great part dictated by the reproductive efficiency of the herds. Many studies have reported a widespread decrease in fertility of dairy cows. In a previous work (Rocha et al. 2001), we found a very poor oestrus detection rate (38%), and consequently a delayed calving to 1st AI and calving to conception intervals. However, a good conception rate at 1st AI was noted (51%) resulting in a low number of inseminations per pregnancy (IAP) (1.4). Here, results from a subsequent fertility time trend assessment study carried out in the same region for cows born from 1992 to 2002 are reported. Statistical linear models were used to analyse the data. Estimate linear contrasts of least square means were computed from each model. The number of observations per studied index varied from 12,130 (culling rate) to 57,589 (non-return rate). Mean age at first calving was 28.9 ± 0.14 months, without (p > 0.05) variation over time. There was a small, but significant (p < 0.05), deterioration of all other parameters. Non-return rates at 90 days and calving rate at 1st AI decreased 0.3% per trimester, with a consequent increase of 0.04 IA/parturition. Oestrus detection rate decreased 0.13% per year, and calving at 1st AI and calving-conception intervals increased 0.17 and 0.07 days/year respectively, while intercalving interval increased 1.7 days per year. From 12,130 cows calving, only 1,816 had a 4th lactation (85% culling/losses). The data was not meant to draw conclusions on the causes for the decreased fertility over time, but an increase of milk production from 6537 kg to 8590 kg (305 days) from 1996 to 2002 is probably one factor to take into consideration. Specific measures to revert or slow down this trend of decreasing fertility are warranted. Available strategies are discussed. © 2009 Blackwell Verlag GmbH.

Six Sessions of Sprint Interval Training Improves Running Performance in Trained Athletes.

PubMed

Koral, Jerome; Oranchuk, Dustin J; Herrera, Roberto; Millet, Guillaume Y

2018-03-01

Koral, J, Oranchuk, DJ, Herrera, R, and Millet, GY. Six sessions of sprint interval training improves running performance in trained athletes. J Strength Cond Res 32(3): 617-623, 2018-Sprint interval training (SIT) is gaining popularity with endurance athletes. Various studies have shown that SIT allows for similar or greater endurance, strength, and power performance improvements than traditional endurance training but demands less time and volume. One of the main limitations in SIT research is that most studies were performed in a laboratory using expensive treadmills or ergometers. The aim of this study was to assess the performance effects of a novel short-term and highly accessible training protocol based on maximal shuttle runs in the field (SIT-F). Sixteen (12 male, 4 female) trained trail runners completed a 2-week procedure consisting of 4-7 bouts of 30 seconds at maximal intensity interspersed by 4 minutes of recovery, 3 times a week. Maximal aerobic speed (MAS), time to exhaustion at 90% of MAS before test (Tmax at 90% MAS), and 3,000-m time trial (TT3000m) were evaluated before and after training. Data were analyzed using a paired samples t-test, and Cohen's (d) effect sizes were calculated. Maximal aerobic speed improved by 2.3% (p = 0.01, d = 0.22), whereas peak power (PP) and mean power (MP) increased by 2.4% (p = 0.009, d = 0.33) and 2.8% (p = 0.002, d = 0.41), respectively. TT3000m was 6% shorter (p < 0.001, d = 0.35), whereas Tmax at 90% MAS was 42% longer (p < 0.001, d = 0.74). Sprint interval training in the field significantly improved the 3,000-m run, time to exhaustion, PP, and MP in trained trail runners. Sprint interval training in the field is a time-efficient and cost-free means of improving both endurance and power performance in trained athletes.

Six Sessions of Sprint Interval Training Improves Running Performance in Trained Athletes

PubMed Central

Oranchuk, Dustin J.; Herrera, Roberto; Millet, Guillaume Y.

2018-01-01

Abstract Koral, J, Oranchuk, DJ, Herrera, R, and Millet, GY. Six sessions of sprint interval training improves running performance in trained athletes. J Strength Cond Res 32(3): 617–623, 2018—Sprint interval training (SIT) is gaining popularity with endurance athletes. Various studies have shown that SIT allows for similar or greater endurance, strength, and power performance improvements than traditional endurance training but demands less time and volume. One of the main limitations in SIT research is that most studies were performed in a laboratory using expensive treadmills or ergometers. The aim of this study was to assess the performance effects of a novel short-term and highly accessible training protocol based on maximal shuttle runs in the field (SIT-F). Sixteen (12 male, 4 female) trained trail runners completed a 2-week procedure consisting of 4–7 bouts of 30 seconds at maximal intensity interspersed by 4 minutes of recovery, 3 times a week. Maximal aerobic speed (MAS), time to exhaustion at 90% of MAS before test (Tmax at 90% MAS), and 3,000-m time trial (TT3000m) were evaluated before and after training. Data were analyzed using a paired samples t-test, and Cohen's (d) effect sizes were calculated. Maximal aerobic speed improved by 2.3% (p = 0.01, d = 0.22), whereas peak power (PP) and mean power (MP) increased by 2.4% (p = 0.009, d = 0.33) and 2.8% (p = 0.002, d = 0.41), respectively. TT3000m was 6% shorter (p < 0.001, d = 0.35), whereas Tmax at 90% MAS was 42% longer (p < 0.001, d = 0.74). Sprint interval training in the field significantly improved the 3,000-m run, time to exhaustion, PP, and MP in trained trail runners. Sprint interval training in the field is a time-efficient and cost-free means of improving both endurance and power performance in trained athletes. PMID:29076961

The Anaesthetic-ECT Time Interval in Electroconvulsive Therapy Practice--Is It Time to Time?

PubMed

Gálvez, Verònica; Hadzi-Pavlovic, Dusan; Wark, Harry; Harper, Simon; Leyden, John; Loo, Colleen K

2016-01-01

Because most common intravenous anaesthetics used in ECT have anticonvulsant properties, their plasma-brain concentration at the time of seizure induction might affect seizure expression. The quality of ECT seizure expression has been repeatedly associated with efficacy outcomes. The time interval between the anaesthetic bolus injection and the ECT stimulus (anaesthetic-ECT time interval) will determine the anaesthetic plasma-brain concentration when the ECT stimulus is administered. The aim of this study was to examine the effect of the anaesthetic-ECT time interval on ECT seizure quality and duration. The anaesthetic-ECT time interval was recorded in 771 ECT sessions (84 patients). Right unilateral brief pulse ECT was applied. Anaesthesia given was propofol (1-2 mg/kg) and succinylcholine (0.5-1.0 mg/kg). Seizure quality indices (slow wave onset, amplitude, regularity, stereotypy and post-ictal suppression) and duration were rated through a structured rating scale by a single blinded trained rater. Linear Mixed Effects Models analysed the effect of the anaesthetic-ECT time interval on seizure quality indices, controlling for propofol dose (mg), ECT charge (mC), ECT session number, days between ECT, age (years), initial seizure threshold (mC) and concurrent medication. Longer anaesthetic-ECT time intervals lead to significantly higher quality seizures (p < 0.001 for amplitude, regularity, stereotypy and post-ictal suppression). These results suggest that the anaesthetic-ECT time interval is an important factor to consider in ECT practice. This time interval should be extended to as long as practically possible to facilitate the production of better quality seizures. Close collaboration between the anaesthetist and the psychiatrist is essential. Copyright © 2015 Elsevier Inc. All rights reserved.

Brainstem auditory evoked responses in man. 1: Effect of stimulus rise-fall time and duration

NASA Technical Reports Server (NTRS)

Hecox, K.; Squires, N.; Galambos, R.

1975-01-01

Short latency (under 10 msec) responses elicited by bursts of white noise were recorded from the scalps of human subjects. Response alterations produced by changes in the noise burst duration (on-time), inter-burst interval (off-time), and onset and offset shapes were analyzed. The latency of the most prominent response component, wave V, was markedly delayed with increases in stimulus rise time but was unaffected by changes in fall time. Increases in stimulus duration, and therefore in loudness, resulted in a systematic increase in latency. This was probably due to response recovery processes, since the effect was eliminated with increases in stimulus off-time. The amplitude of wave V was insensitive to changes in signal rise and fall times, while increasing signal on-time produced smaller amplitude responses only for sufficiently short off-times. It was concluded that wave V of the human auditory brainstem evoked response is solely an onset response.

Reference intervals and longitudinal changes in copeptin and MR-proADM concentrations during pregnancy.

PubMed

Joosen, Annemiek M C P; van der Linden, Ivon J M; Schrauwen, Lianne; Theeuwes, Alisia; de Groot, Monique J M; Ermens, Antonius A M

2017-11-27

Vasopressin and adrenomedullin and their stable by-products copeptin and midregional part of proadrenomedullin (MR-proADM) are promising biomarkers for the development of preeclampsia. However, clinical use is hampered by the lack of trimester-specific reference intervals. We therefore estimated reference intervals for copeptin and MR-proADM in disease-free Dutch women throughout pregnancy. Apparently healthy low risk pregnant women were recruited. Exclusion criteria included current or past history of endocrine disease, multiple pregnancy, use of medication known to influence thyroid function and current pregnancy as a result of hormonal stimulation. Women who miscarried, developed hyperemesis gravidarum, hypertension, pre-eclampsia, hemolysis elevated liver enzymes and low platelets, diabetes or other disease, delivered prematurely or had a small for gestational age neonate were excluded from analyses. Blood samples were collected at 9-13 weeks (n=98), 27-29 weeks (n=94) and 36-39 weeks (n=91) of gestation and at 4-13 weeks post-partum (PP) (n=89). Sixty-two women had complete data during pregnancy and PP. All analyses were performed on a Kryptor compact plus. Copeptin increases during pregnancy, but 97.5th percentiles remain below the non-pregnant upper reference limit (URL) provided by the manufacturer. MR-proADM concentrations increase as well during pregnancy. In trimesters 2 and 3 the 97.5th percentiles are over three times the non-pregnant URL provided by the manufacturer. Trimester- and assay-specific reference intervals for copeptin and MR-proADM should be used. In addition, consecutive measurements and the time frame between measurements should be considered as the differences seen with or in advance of preeclampsia can be expected to be relatively small compared to the reference intervals.

Effect of 6-8 weeks of oral ursodeoxycholic acid administration on serum concentrations of fasting and postprandial bile acids and biochemical analytes in healthy dogs.

PubMed

Deitz, Krysta L; Makielski, Kelly M; Williams, Jackie M; Lin, Hui; Morrison, Jo Ann

2015-09-01

Ursodeoxycholic acid (UDCA) is commonly used for the treatment of hepatobiliary disease. UDCA is a bile acid that can be detected in the bile acid assay. Its effect on biochemical analytes is unknown. The aim of this study was to determine the effect of 6-8 weeks of UDCA administration on fasting and postprandial concentrations of serum bile acids (SBA), cholesterol, triglycerides, bilirubin, and liver enzyme activities in healthy dogs. Twenty healthy dogs received UDCA for 6-8 weeks. CBC, biochemistry profile, urinalysis, fasting and postprandial SBA, and hepatobiliary ultrasound examination were performed prior to starting UDCA (timepoint 0) and after 6-8 weeks of therapy, while animals were still receiving UDCA (timepoint 1). Timepoint 0 and timepoint 1 values were compared with a paired t-test. SBA were remeasured 72 hours after UDCA discontinuation. Only mean fasting SBA at timepoint 1 increased significantly (P = .03) from timepoint 0 (2.26 μmol/L at time 0 and 3.81 μmol/L at time 1) but were not elevated above the normal reference interval (0-9 μmol/L). Two dogs had timepoint 1 fasting SBA above the reference interval (10 and 11.7 μmol/L). One dog had timepoint 1 postprandial SBA above the reference interval at 20.1 μmol/L (reference interval 0-17 μmol/L). Repeat SBA 72 hours after UDCA discontinuation were normal. Long-term administration of UDCA to healthy dogs may increase fasting SBA above pretreatment values (typically within the reference interval). Long-term administration of UDCA to healthy dogs does not alter liver enzyme activities, and bilirubin, cholesterol, or triglyceride concentrations. © 2015 American Society for Veterinary Clinical Pathology.

Effect of dose timing in relation to food intake on systemic exposure to blonanserin.

PubMed

Saruwatari, Junji; Yasui-Furukori, Norio; Inoue, Yoshimasa; Kaneko, Sunao

2010-09-01

Blonanserin is a novel potent dopamine D(2) and serotonin 5-HT(2) antagonist for treating schizophrenia. The aim of this study was to investigate prandial effects on systemic exposure to blonanserin in healthy volunteers, with particular attention paid to the effect of dose timing relative to meal intake. Volunteers received a single 2-mg oral dose of blonanserin under the following conditions: fasting, 30 min before eating a standard meal; or 30 min or 2 or 4 h after eating the meal. Plasma concentrations of blonanserin were measured using validated high-performance liquid chromatography coupled with tandem mass spectrometry. Ratios and 90% confidence intervals of the geometric means compared with the fasting condition indicated that the maximum concentrations of blonanserin (C(max)) significantly increased with dosing 30 min before meal intake, and 30 min and 2 and 4 h after meal intake, yielding by 330%, 239%, 272%, and 138%, respectively. The truncated area under the concentration-time curve (AUC(last)) also increased by 386%, 201%, 256%, and 155%, respectively. There was no difference in values of the time to reach maximum concentration between the fasting and the four fed states. Food intake increased the systemic exposure to blonanserin for all time intervals investigated in this study. The marked effect of food on the bioavailability of blonanserin should be taken into account in its dosing schedules.

Palbociclib has no clinically relevant effect on the QTc interval in patients with advanced breast cancer.

PubMed

Durairaj, Chandrasekar; Ruiz-Garcia, Ana; Gauthier, Eric R; Huang, Xin; Lu, Dongrui R; Hoffman, Justin T; Finn, Richard S; Joy, Anil A; Ettl, Johannes; Rugo, Hope S; Zheng, Jenny; Wilner, Keith D; Wang, Diane D

2018-03-01

The aim of this study was to assess the potential effects of palbociclib in combination with letrozole on QTc. PALOMA-2, a phase 3, randomized, double-blind, placebo-controlled trial, compared palbociclib plus letrozole with placebo plus letrozole in postmenopausal women with estrogen receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer. The study included a QTc evaluation substudy carried out as a definitive QT interval prolongation assessment for palbociclib. Time-matched triplicate ECGs were performed at 0, 2, 4, 6, and 8 h at baseline (Day 0) and on Cycle 1 Day 14. Additional ECGs were collected from all patients for safety monitoring. The QT interval was corrected for heart rate using Fridericia's correction (QTcF), Bazett's correction (QTcB), and a study-specific correction factor (QTcS). In total, 666 patients were randomized 2 : 1 to palbociclib plus letrozole or placebo plus letrozole. Of these, 125 patients were enrolled in the QTc evaluation substudy. No patients in the palbociclib plus letrozole arm of the substudy (N=77) had a maximum postbaseline QTcS or QTcF value of ≥ 480 ms, or a maximum increase from clock time-matched baseline for QTcS or QTcF values of ≥ 60 ms. The upper bounds of the one-sided 95% confidence interval for the mean change from time-matched baseline for QTcS, QTcF, and QTcB at all time points and at steady-state Cmax following repeated administration of 125 mg palbociclib were less than 10 ms. Palbociclib, when administered with letrozole at the recommended therapeutic dosing regimen, did not prolong the QT interval to a clinically relevant extent.

Music enhances performance and perceived enjoyment of sprint interval exercise.

PubMed

Stork, Matthew J; Kwan, Matthew Y W; Gibala, Martin J; Martin Ginis, Kathleen A

2015-05-01

Interval exercise training can elicit physiological adaptations similar to those of traditional endurance training, but with reduced time. However, the intense nature of specific protocols, particularly the "all-out" efforts characteristic of sprint interval training (SIT), may be perceived as being aversive. The purpose of this study was to determine whether listening to self-selected music can reduce the potential aversiveness of an acute session of SIT by improving affect, motivation, and enjoyment, and to examine the effects of music on performance. Twenty moderately active adults (22 ± 4 yr) unfamiliar with interval exercise completed an acute session of SIT under two different conditions: music and no music. The exercise consisted of four 30-s "all-out" Wingate Anaerobic Test bouts on a cycle ergometer, separated by 4 min of rest. Peak and mean power output, RPE, affect, task motivation, and perceived enjoyment of the exercise were measured. Mixed-effects models were used to evaluate changes in dependent measures over time and between the two conditions. Peak and mean power over the course of the exercise session were higher in the music condition (coefficient = 49.72 [SE = 13.55] and coefficient = 23.65 [SE = 11.30]; P < 0.05). A significant time by condition effect emerged for peak power (coefficient = -12.31 [SE = 4.95]; P < 0.05). There were no between-condition differences in RPE, affect, or task motivation. Perceived enjoyment increased over time and was consistently higher in the music condition (coefficient = 7.00 [SE = 3.05]; P < 0.05). Music enhances in-task performance and enjoyment of an acute bout of SIT. Listening to music during intense interval exercise may be an effective strategy for facilitating participation in, and adherence to, this form of training.

Methoxyflurane anesthesia augments the chronotropic and dromotropic effects of verapamil.

PubMed

Jamali, F; Mayo, P R

1999-01-01

Inhalation anesthetics have been shown to have electrical suppressant effects on excitable membranes such as the cardiac conduction system. Therefore, the anesthetized patient or laboratory animal may respond differently to cardiac drugs when compared with their conscious counterparts. The purpose of this study was to assess the effects of anesthesia with methoxyflurane (MF) on the dromotropic and chronotropic effects of verapamil (VER) in the rat. A lead I ECG was measured using subcutaneous electrodes placed both axilli and over the xyphoid process in male Sprague-Dawley rats. Dromotropic effect was measured using the PR-interval which indicated the electrical spread across the atria to the AV-node and chronotropic effects were determined using RR-interval. A total of six animals were randomized to receive 10 mg/kg s.c. of verapamil in the presence or absence of general anesthesia containing methoxyflurane. In addition, PR-interval and RR-intervals were determined in the presence of only methoxyflurane and at rest without any drug exposure. The time for the ECG to normalize after exposure to methoxyflurane and/or verapamil was also determined. Exposure to verapamil alone resulted in a 5% prolongation in PR-interval and 6% prolongation in RR-interval. Methoxyflurane alone had a larger effect than verapamil demonstrating a 14.5% prolongation in PR-interval and a 12.3% in RR-interval which was statistically significant. The combination of MF + VER resulted in a synergistic prolongation in PR-interval to 28. 7% while the effect on RR-interval was additive with an increase to 17.6%. The time for the ECG to normalize after exposure to VER, MF and VER + MF was 37.5 15.1 min, 69.8 5.3 min, and 148.5 +/- 6.6 min respectively. General anesthesia with MF enhances the dromotropic and chronotropic effect of VER. This should be considered when MF-anesthesia is used in experimental procedure.

Cool episode and platform demise in the Early Aptian: New insights on the links between climate and carbonate production

NASA Astrophysics Data System (ADS)

Bonin, Aurélie; Pucéat, Emmanuelle; Vennin, Emmanuelle; Mattioli, Emanuela; Aurell, Marcos; Joachimski, Michael; Barbarin, Nicolas; Laffont, Rémi

2016-01-01

The Early Aptian encountered several crises in neritic and pelagic carbonate production, major perturbations in the carbon cycle, and an oceanic anoxic event (OAE1a). Yet the causal links between these perturbations and climate changes remain poorly understood, partly because temperature records spanning the Early Aptian interval are still scant. We present new δ18O data from well-preserved bivalves from a carbonate platform of the Galve subbasin (Spain) that document a major cooling event postdating most of OAE1a. Our data show that cooling postdates the global platform demise and cannot have triggered this event that occurred during the warmest interval. The warmest temperatures coincide with the time equivalent of OAE1a and with platform biotic assemblages dominated by microbialites at Aliaga as well as on other Tethyan platforms. Coral-dominated assemblages then replace microbialites during the subsequent cooling. Nannoconids are absent during most of the time equivalent of the OAE1a, probably related to the well-known crisis affecting this group. Yet they present a transient recovery in the upper part of this interval with an increase in both size and abundance during the cool interval portion that postdates OAE1a. An evolution toward cooler and drier climatic conditions may have induced the regional change from microbial to coral assemblages as well as nannoconids size and abundance increase by limiting continent-derived input of nutrients.

Time-Based Loss in Visual Short-Term Memory is from Trace Decay, not Temporal Distinctiveness

PubMed Central

Ricker, Timothy J.; Spiegel, Lauren R.; Cowan, Nelson

2014-01-01

There is no consensus as to why forgetting occurs in short-term memory tasks. In past work, we have shown that forgetting occurs with the passage of time, but there are two classes of theories that can explain this effect. In the present work, we investigate the reason for time-based forgetting by contrasting the predictions of temporal distinctiveness and trace decay in the procedure in which we have observed such loss, involving memory for arrays of characters or letters across several seconds. The first theory, temporal distinctiveness, predicts that increasing the amount of time between trials will lead to less proactive interference, resulting in less forgetting across a retention interval. In the second theory, trace decay, temporal distinctiveness between trials is irrelevant to the loss over a retention interval. Using visual array change detection tasks in four experiments, we find small proactive interference effects on performance under some specific conditions, but no concomitant change in the effect of a retention interval. We conclude that trace decay is the more suitable class of explanations of the time-based forgetting in short-term memory that we have observed, and we suggest the need for further clarity in what the exact basis of that decay may be. PMID:24884646

Environmental changes in the Tule Lake basin, Siskiyou and Modoc Counties, California, from 3 to 2 million years before present

USGS Publications Warehouse

Adam, David P.; Bradbury, J. Platt; Rieck, Hugh J.; Sarna-Wojcicki, Andrei M.

1990-01-01

Pollen and diatom analyses of a core from the town of Tulelake, Siskiyou County, California, for the period between 3 and 2 Ma reveal a paleoclimatic and paleolimnologic sequence recording a long, warm time interval that lasted from about 2.9 to 2.6 Ma and had a short, cooler interval within it. During this warm interval, the regional vegetation surrounding ancient Tule Lake was a mixed coniferous forest, and Tule Lake was a warm monomictic lake. Approximate modern analogs for this Pliocene fossil record at Tulelake are found at least 2 degrees farther south. The Tulelake warm interval appears to have correlatives in the North Atlantic oxygen isotope record and in the pollen record of the Reuverian in the Netherlands. An interval beginning at about 2.4 Ma was characterized at Tule Lake by slow sedimentation, by changes in the relative amounts of algae in the lake, and by an increase in the maximum percentages of Artemisia pollen.

Resolution of hypertension and proteinuria after preeclampsia.

PubMed

Berks, Durk; Steegers, Eric A P; Molas, Marek; Visser, Willy

2009-12-01

To estimate the time required for hypertension and proteinuria to resolve after preeclampsia, and to estimate how this time to resolution correlates with the levels of blood pressure and proteinuria during preeclampsia and prolonging pregnancy after the development of preeclampsia. This is a historic prospective cohort study of 205 preeclamptic women who were admitted between 1990 and 1992 at the Erasmus MC Medical Centre, Rotterdam, The Netherlands. Data were collected at 1.5, 3, 6, 12, 18, and 24 months after delivery. Hypertension was defined as a blood pressure 140/90 mm Hg or higher or use of antihypertensive drugs. Proteinuria was defined as 0.3 g/d or more. Resolution of hypertension and proteinuria were analyzed with the Turnbull extension to the Kaplan-Meier procedure. Correlations were calculated with an accelerated failure time model. At 3 months postpartum, 39% of women still had hypertension, which decreased to 18% at 2 years postpartum. Resolution time increased by 60% (P<.001) for every 10-mm Hg increase in maximal systolic blood pressure, 40% (P=.044) for every 10-mm Hg increase in maximal diastolic blood pressure, and 3.6% (P=.001) for every 1-day increase in the diagnosis-to-delivery interval. At 3 months postpartum, 14% still had proteinuria, which decreased to 2% at 2 years postpartum. Resolution time increased by 16% (P=.001) for every 1-g/d increase in maximal proteinuria. Gestational age at onset of preeclampsia was not correlated with resolution time of hypertension and proteinuria. The severity of preeclampsia and the time interval between diagnosis and delivery are associated with postpartum time to resolution of hypertension and proteinuria. After preeclampsia, it can take up to 2 years for hypertension and proteinuria to resolve. Therefore, the authors suggest that further invasive diagnostic tests for underlying renal disease may be postponed until 2 years postpartum. III.

Analysis of the deconstruction of Dyke Marsh, George Washington Memorial Parkway, Virginia-Progression, geologic and manmade causes, and effective restoration scenarios

USGS Publications Warehouse

Litwin, Ronald J.; Smoot, Joseph P.; Pavich, Milan J.; Markewich, Helaine W.; Oberg, Erik; Helwig, Ben; Steury, Brent; Santucci, Vincent L.; Durika, Nancy J.; Rybicki, Nancy B.; Engelhardt, Katharina M.; Sanders, Geoffrey; Verardo, Stacey; Elmore, Andrew J.; Gilmer, Joseph

2011-01-01

Photoanalysis of time-sequence aerial photographs of Dyke Marsh enabled us to calculate shoreline erosion estimates for this marsh over 19 years (1987-2006), as well as to quantify overall marsh acreage for 6 calendar years spanning an ~70 year interval (1937-2006). Photo overlay of a historic map enabled us to extend our whole-marsh acreage calculations back to 1883. Both sets of analyses were part of a geologic framework study in support of current efforts by the National Park Service (NPS) to restore this urban wetland. Two time intervals were selected for our shoreline erosion analyses, based on image quality and availability: 1987 to 2002, and 2002 to 2006. The more recent time interval shows a marked increase in erosion in the southern part of Dyke Marsh, following a wave-induced breach of a small peninsula that had protected its southern shoreline. Field observations and analyses of annual aerial imagery between 1987 and 2006 revealed a progressive increase in wave-induced erosion that presently is deconstructing Hog Island Gut, the last significant tidal creek network within the Dyke Marsh. These photo analyses documented an overall average westward shoreline loss of 6.0 to 7.8 linear feet per year along the Potomac River during this 19-year time interval. Additionally, photographic evidence documented that lateral erosion now is capturing existing higher order tributaries in the Hog Island Gut. Wave-driven stream piracy is fragmenting the remaining marsh habitat, and therefore its connectivity, relatively rapidly, causing the effective mouth of the Hog Island Gut tidal network to retreat headward visibly over the past several decades. Based on our estimates of total marsh area in the Dyke Marsh derived from 1987 aerial imagery, as much as 12 percent of the central part of the marsh has eroded in the 19 year period we studied (or ~7.5 percent of the original ~78.8 acres of 1987 marshland). Shoreline loss estimates for marsh parcels north and south of our study area have not yet been analyzed, although annual aerial photos from 1987 to 2002 confirm visible progressive shoreline loss in those areas over this same time interval.

Prevalence of dry eye syndrome in an adult population.

PubMed

Hashemi, Hassan; Khabazkhoob, Mehdi; Kheirkhah, Ahmad; Emamian, Mohammad Hassan; Mehravaran, Shiva; Shariati, Mohammad; Fotouhi, Akbar

2014-04-01

To determine the prevalence of dry eye syndrome in the general 40- to 64-year-old population of Shahroud, Iran. Population-based cross-sectional study. Through cluster sampling, 6311 people were selected and 5190 participated. Assessment of dry eye was done in a random subsample of 1008 people. Subjective assessment for dry eye syndrome was performed using Ocular Surface Disease Index questionnaire. In addition, the following objective tests of dry eye syndrome were employed: Schirmer test, tear break-up time, and fluorescein and Rose Bengal staining using the Oxford grading scheme. Those with an Ocular Surface Disease Index score ≥23 were considered symptomatic, and dry eye syndrome was defined as having symptoms and at least one positive objective sign. The prevalence of dry eye syndrome was 8.7% (95% confidence interval 6.9-10.6). Assessment of signs showed an abnormal Schirmer score in 17.8% (95% confidence interval 15.5-20.0), tear break-up time in 34.2% (95% confidence interval 29.5-38.8), corneal fluorescein staining (≥1) in 11.3% (95% confidence interval 8.5-14.1) and Rose Bengal staining (≥3 for cornea and/or conjunctiva) in 4.9% (95% confidence interval 3.4-6.5). According to the Ocular Surface Disease Index scores, 18.3% (95% confidence interval 15.9-20.6) had dry eye syndrome symptoms. The prevalence of dry eye syndrome was significantly higher in women (P = 0.010) and not significantly associated with age (P = 0.291). The objective dry eye syndrome signs significantly increased with age. Based on the findings, the prevalence of dry eye syndrome in the studied population is in the mid-range. The prevalence is higher in women. Also, objective tests tend to turn abnormal at higher age. Pterygium is associated with dry eye syndrome and increased its symptoms. © 2013 Royal Australian and New Zealand College of Ophthalmologists.

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

PubMed

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

2013-11-01

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 on 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. Copyright © 2013 Elsevier Ltd. All rights reserved.

Excitability of the motor system: A transcranial magnetic stimulation study on singing and speaking.

PubMed

Royal, Isabelle; Lidji, Pascale; Théoret, Hugo; Russo, Frank A; Peretz, Isabelle

2015-08-01

The perception of movements is associated with increased activity in the human motor cortex, which in turn may underlie our ability to understand actions, as it may be implicated in the recognition, understanding and imitation of actions. Here, we investigated the involvement and lateralization of the primary motor cortex (M1) in the perception of singing and speech. Transcranial magnetic stimulation (TMS) was applied independently for both hemispheres over the mouth representation of the motor cortex in healthy participants while they watched 4-s audiovisual excerpts of singers producing a 2-note ascending interval (singing condition) or 4-s audiovisual excerpts of a person explaining a proverb (speech condition). Subjects were instructed to determine whether a sung interval/written proverb, matched a written interval/proverb. During both tasks, motor evoked potentials (MEPs) were recorded from the contralateral mouth muscle (orbicularis oris) of the stimulated motor cortex compared to a control task. Moreover, to investigate the time course of motor activation, TMS pulses were randomly delivered at 7 different time points (ranging from 500 to 3500 ms after stimulus onset). Results show that stimulation of the right hemisphere had a similar effect on the MEPs for both the singing and speech perception tasks, whereas stimulation of the left hemisphere significantly differed in the speech perception task compared to the singing perception task. Furthermore, analysis of the MEPs in the singing task revealed that they decreased for small musical intervals, but increased for large musical intervals, regardless of which hemisphere was stimulated. Overall, these results suggest a dissociation between the lateralization of M1 activity for speech perception and for singing perception, and that in the latter case its activity can be modulated by musical parameters such as the size of a musical interval. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

[Impact of a PACS/RIS-integrated speech recognition system on radiology reporting time and report availability].

PubMed

Trumm, C G; Glaser, C; Paasche, V; Crispin, A; Popp, P; Küttner, B; Francke, M; Nissen-Meyer, S; Reiser, M

2006-04-01

Quantification of the impact of a PACS/RIS-integrated speech recognition system (SRS) on the time expenditure for radiology reporting and on hospital-wide report availability (RA) in a university institution. In a prospective pilot study, the following parameters were assessed for 669 radiographic examinations (CR): 1. time requirement per report dictation (TED: dictation time (s)/number of images [examination] x number of words [report]) with either a combination of PACS/tape-based dictation (TD: analog dictation device/mini-cassette/transcription) or PACS/RIS/speech recognition system (RR: remote recognition/transcription and OR: online recognition/self-correction by radiologist), respectively, and 2. the Report Turnaround Time (RTT) as the time interval from the entry of the first image into the PACS to the available RIS/HIS report. Two equal time periods were chosen retrospectively from the RIS database: 11/2002 - 2/2003 (only TD) and 11/2003 - 2/2004 (only RR or OR with speech recognition system [SRS]). The mid-term (> or = 24 h, 24 h intervals) and short-term (< 24 h, 1 h intervals) RA after examination completion were calculated for all modalities and for CR, CT, MR and XA/DS separately. The relative increase in the mid-term RA (RIMRA: related to total number of examinations in each time period) and increase in the short-term RA (ISRA: ratio of available reports during the 1st to 24th hour) were calculated. Prospectively, there was a significant difference between TD/RR/OR (n = 151/257/261) regarding mean TED (0.44/0.54/0.62 s [per word and image]) and mean RTT (10.47/6.65/1.27 h), respectively. Retrospectively, 37 898/39 680 reports were computed from the RIS database for the time periods of 11/2002 - 2/2003 and 11/2003 - 2/2004. For CR/CT there was a shift of the short-term RA to the first 6 hours after examination completion (mean cumulative RA 20 % higher) with a more than three-fold increase in the total number of available reports within 24 hours (all modalities). The RIMRA for CR/CT/MR was 3.1/5.8/4.0 in the first 24 hours, and 2.0 for XA/DS in the second 24-hour interval. In comparison to tape-based dictation, an SRS results in a significantly higher primary time expenditure and a modified report dictation workflow. In a university institution, a PACS/RIS-integrated SRS achieves a marked improvement in both short- and mid-term RA which eventually results in an improvement in patient care.

Sex Differences in the Age of Peak Marathon Race Time.

PubMed

Nikolaidis, Pantelis T.; Rosemann, Thomas; Knechtle, Beat

2018-04-30

Recent studies showed that women were older than men when achieving their fastest marathon race time. These studies, however, investigated a limited sample of athletes. We investigated the age of peak marathon performance in a large sample of female and male marathon finishers by using data from all finishers. We analyzed the age of peak marathon performance in 1-year and 5-year age intervals of 451,637 runners (i.e. 168,702 women and 282,935 men) who finished the ‘New York City Marathon’ between 2006 and 2016, using analysis of variance and non-linear regression analysis. During these 11 years, men were faster and older than women, the participation of women increased disproportionately to that of men resulting in a decrease of the male-to-female ratio, and relatively more women participated in the younger age groups. Most women were in the age group 30-34 years and most men in the age group 40-44 years. The fastest race time was shown at 29.7 years in women and 34.8 years in men in the 1-year age intervals, and in age group 30-34 years in women and 35-39 years in men in the 5-year age intervals. In contrast to existing findings reporting a higher age of peak marathon performance in women compared to men, we found that women achieved their best marathon race time ~5 years earlier in life than men in both 1-year and 5-year age intervals. Female athletes and their coaches should plan to achieve their fastest marathon race time at the age of ~30 years.

Job strain as a risk factor for leisure-time physical inactivity: an individual-participant meta-analysis of up to 170,000 men and women: the IPD-Work Consortium.

PubMed

Fransson, Eleonor I; Heikkilä, Katriina; Nyberg, Solja T; Zins, Marie; Westerlund, Hugo; Westerholm, Peter; Väänänen, Ari; Virtanen, Marianna; Vahtera, Jussi; Theorell, Töres; Suominen, Sakari; Singh-Manoux, Archana; Siegrist, Johannes; Sabia, Séverine; Rugulies, Reiner; Pentti, Jaana; Oksanen, Tuula; Nordin, Maria; Nielsen, Martin L; Marmot, Michael G; Magnusson Hanson, Linda L; Madsen, Ida E H; Lunau, Thorsten; Leineweber, Constanze; Kumari, Meena; Kouvonen, Anne; Koskinen, Aki; Koskenvuo, Markku; Knutsson, Anders; Kittel, France; Jöckel, Karl-Heinz; Joensuu, Matti; Houtman, Irene L; Hooftman, Wendela E; Goldberg, Marcel; Geuskens, Goedele A; Ferrie, Jane E; Erbel, Raimund; Dragano, Nico; De Bacquer, Dirk; Clays, Els; Casini, Annalisa; Burr, Hermann; Borritz, Marianne; Bonenfant, Sébastien; Bjorner, Jakob B; Alfredsson, Lars; Hamer, Mark; Batty, G David; Kivimäki, Mika

2012-12-15

Unfavorable work characteristics, such as low job control and too high or too low job demands, have been suggested to increase the likelihood of physical inactivity during leisure time, but this has not been verified in large-scale studies. The authors combined individual-level data from 14 European cohort studies (baseline years from 1985-1988 to 2006-2008) to examine the association between unfavorable work characteristics and leisure-time physical inactivity in a total of 170,162 employees (50% women; mean age, 43.5 years). Of these employees, 56,735 were reexamined after 2-9 years. In cross-sectional analyses, the odds for physical inactivity were 26% higher (odds ratio = 1.26, 95% confidence interval: 1.15, 1.38) for employees with high-strain jobs (low control/high demands) and 21% higher (odds ratio = 1.21, 95% confidence interval: 1.11, 1.31) for those with passive jobs (low control/low demands) compared with employees in low-strain jobs (high control/low demands). In prospective analyses restricted to physically active participants, the odds of becoming physically inactive during follow-up were 21% and 20% higher for those with high-strain (odds ratio = 1.21, 95% confidence interval: 1.11, 1.32) and passive (odds ratio = 1.20, 95% confidence interval: 1.11, 1.30) jobs at baseline. These data suggest that unfavorable work characteristics may have a spillover effect on leisure-time physical activity.

Job Strain as a Risk Factor for Leisure-Time Physical Inactivity: An Individual-Participant Meta-Analysis of Up to 170,000 Men and Women

PubMed Central

Fransson, Eleonor I.; Heikkilä, Katriina; Nyberg, Solja T.; Zins, Marie; Westerlund, Hugo; Westerholm, Peter; Väänänen, Ari; Virtanen, Marianna; Vahtera, Jussi; Theorell, Töres; Suominen, Sakari; Singh-Manoux, Archana; Siegrist, Johannes; Sabia, Séverine; Rugulies, Reiner; Pentti, Jaana; Oksanen, Tuula; Nordin, Maria; Nielsen, Martin L.; Marmot, Michael G.; Magnusson Hanson, Linda L.; Madsen, Ida E. H.; Lunau, Thorsten; Leineweber, Constanze; Kumari, Meena; Kouvonen, Anne; Koskinen, Aki; Koskenvuo, Markku; Knutsson, Anders; Kittel, France; Jöckel, Karl-Heinz; Joensuu, Matti; Houtman, Irene L.; Hooftman, Wendela E.; Goldberg, Marcel; Geuskens, Goedele A.; Ferrie, Jane E.; Erbel, Raimund; Dragano, Nico; De Bacquer, Dirk; Clays, Els; Casini, Annalisa; Burr, Hermann; Borritz, Marianne; Bonenfant, Sébastien; Bjorner, Jakob B.; Alfredsson, Lars; Hamer, Mark; Batty, G. David; Kivimäki, Mika

2012-01-01

Unfavorable work characteristics, such as low job control and too high or too low job demands, have been suggested to increase the likelihood of physical inactivity during leisure time, but this has not been verified in large-scale studies. The authors combined individual-level data from 14 European cohort studies (baseline years from 1985–1988 to 2006–2008) to examine the association between unfavorable work characteristics and leisure-time physical inactivity in a total of 170,162 employees (50% women; mean age, 43.5 years). Of these employees, 56,735 were reexamined after 2–9 years. In cross-sectional analyses, the odds for physical inactivity were 26% higher (odds ratio = 1.26, 95% confidence interval: 1.15, 1.38) for employees with high-strain jobs (low control/high demands) and 21% higher (odds ratio = 1.21, 95% confidence interval: 1.11, 1.31) for those with passive jobs (low control/low demands) compared with employees in low-strain jobs (high control/low demands). In prospective analyses restricted to physically active participants, the odds of becoming physically inactive during follow-up were 21% and 20% higher for those with high-strain (odds ratio = 1.21, 95% confidence interval: 1.11, 1.32) and passive (odds ratio = 1.20, 95% confidence interval: 1.11, 1.30) jobs at baseline. These data suggest that unfavorable work characteristics may have a spillover effect on leisure-time physical activity. PMID:23144364

Important Role of Menarche in Development of Estrogen Receptor-Negative Breast Cancer in African American Women.

PubMed

Ambrosone, Christine B; Zirpoli, Gary; Hong, Chi-Chen; Yao, Song; Troester, Melissa A; Bandera, Elisa V; Schedin, Pepper; Bethea, Traci N; Borges, Virginia; Park, Song-Yi; Chandra, Dhyan; Rosenberg, Lynn; Kolonel, Laurence N; Olshan, Andrew F; Palmer, Julie R

2015-09-01

Menarche is a critical time point for diverging fates of mammary cells of origin. African American women have young age at menarche, which could be associated with their high rates of estrogen receptor-negative (ER-) breast cancer. In the AMBER Consortium, using harmonized data from 4426 African American women with breast cancer and 17 474 controls, we used polytomous logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for ages at menarche and first live birth (FLB), and the interval between, in relation to ER+ and ER- breast cancer. All statistical tests were two-sided. Risk of ER- breast cancer was reduced with later age at menarche among both parous and nulliparous women (≥15 vs <11 years OR = 0.62, 95% CI = 0.48 to 0.81 and OR = 0.56, 95% CI = 0.29 to 1.10, respectively), with no effect of age at FLB. For ER+ breast cancer, the inverse association was weaker among nulliparous women. While longer intervals between menarche and FLB were associated with increased risk of ER+ breast cancer in a dose-response fashion (OR for 20 year interval = 1.39, 95% CI = 1.08 to 1.79, P trend = .003), ER- risk was only increased for intervals up to 14 years and not beyond (P trend = .33). While ER- breast cancer risk was markedly reduced in women with a late age at menarche, there was not a clear pattern of increased risk with longer interval between menarche and FLB, as was observed for ER+ breast cancer. These findings indicate that etiologic pathways involving adolescence and pregnancy may differ for ER- and ER+ breast cancer. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

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.

Adaptive Changes After 2 Weeks of 10-s Sprint Interval Training With Various Recovery Times.

PubMed

Olek, Robert A; Kujach, Sylwester; Ziemann, Ewa; Ziolkowski, Wieslaw; Waz, Piotr; Laskowski, Radoslaw

2018-01-01

Purpose: The aim of this study was to compare the effect of applying two different rest recovery times in a 10-s sprint interval training session on aerobic and anaerobic capacities as well as skeletal muscle enzyme activities. Methods: Fourteen physically active but not highly trained male subjects (mean maximal oxygen uptake 50.5 ± 1.0 mlO 2 ·kg -1 ·min -1 ) participated in the study. The training protocol involved a series of 10-s sprints separated by either 1-min (SIT10:1) or 4-min (SIT10:4) of recovery. The number of sprints progressed from four to six over six sessions separated by 1-2 days rest. Pre and post intervention anthropometric measurements, assessment of aerobic, anaerobic capacity and muscle biopsy were performed. In the muscle samples maximal activities of citrate synthase (CS), 3-hydroxyacylCoA dehydrogenase (HADH), carnitine palmitoyl-transferase (CPT), malate dehydrogenase (MDH), and its mitochondrial form (mMDH), as well as lactate dehydrogenase (LDH) were determined. Analysis of variance was performed to determine changes between conditions. Results: Maximal oxygen uptake improved significantly in both training groups, by 13.6% in SIT10:1 and 11.9% in SIT10:4, with no difference between groups. Wingate anaerobic test results indicated main effect of time for total work, peak power output and mean power output, which increased significantly and similarly in both groups. Significant differences between training groups were observed for end power output, which increased by 10.8% in SIT10:1, but remained unchanged in SIT10:4. Both training protocols induced similar increase in CS activity (main effect of time p < 0.05), but no other enzymes. Conclusion: Sprint interval training protocols induce metabolic adaptation over a short period of time, and the reduced recovery between bouts may attenuate fatigue during maximal exercise.

Complications following incident stroke resulting in readmissions: an analysis of data from three Scottish health surveys.

PubMed

Ponomarev, Dmitry; Miller, Claire; Govan, Lindsay; Haig, Caroline; Wu, Olivia; Langhorne, Peter

2015-08-01

Stroke is widely recognized as the major contributor to morbidity and mortality in the United Kingdom. We analyzed the data obtained from the three consecutive Scottish Health Surveys and the Scottish Morbidity records, with the aim of identifying risk factors for, and timing of, common poststroke complications. There were 19434 individuals sampled during three Scottish Health Surveys in 1995, 1998, and 2001. For these individuals their morbidity and mortality outcomes were obtained in 2007. Incident stroke prevalence, risk factors for a range of poststroke complications, and average times until such complications in the sample were established. Of the total of 168 incident stroke admissions (0·86% of the survey), 16·1% people died during incident stroke hospitalization. Of the remaining 141 stroke survivors, 75·2% were rehospitalized at least once. The most frequent reason for readmission after stroke was a cardiovascular complication (28·6%), median time until event 1412 days, followed by infection (17·3%, median 1591 days). The risk of cardiovascular readmission was higher in those with 'poor' self-assessed health (odds ratio 7·70; 95% confidence interval 1·64-43·27), smokers (odds ratio 4·24; 95% confidence interval 1·11-21·59), and doubled with every five years increase in age (odds ratio 1·97; 95% confidence interval 1·46-2·65). 'Poor' self-assessed health increased chance of readmission for infection (odds ratio 14·11; 95% confidence interval 2·27-276·56). Cardiovascular events and infections are the most frequent poststroke complications resulting in readmissions. The time period until event provides a possibility to focus monitoring on those people at risk of readmission and introduce preventative measures, thereby reducing readmission-associated costs. © 2013 The Authors. International Journal of Stroke © 2013 World Stroke Organization.

Effects of 4-Week Training Intervention with Unknown Loads on Power Output Performance and Throwing Velocity in Junior Team Handball Players.

PubMed

Sabido, Rafael; Hernández-Davó, Jose Luis; Botella, Javier; Moya, Manuel

2016-01-01

To compare the effect of 4-week unknown vs known loads strength training intervention on power output performance and throwing velocity in junior team handball players. Twenty-eight junior team-handball players (17.2 ± 0.6 years, 1.79 ± 0.07 m, 75.6 ± 9.4 kg)were divided into two groups (unknown loads: UL; known loads: KL). Both groups performed two sessions weekly consisting of four sets of six repetitions of the bench press throw exercise, using the 30%, 50% and 70% of subjects' individual 1 repetition maximum (1RM). In each set, two repetitions with each load were performed, but the order of the loads was randomised. In the KL group, researchers told the subjects the load to mobilise prior each repetition, while in the UL group, researchers did not provide any information. Maximal dynamic strength (1RM bench press), power output (with 30, 50 and 70% of 1RM) and throwing velocity (7 m standing throw and 9 m jumping throw) were assessed pre- and post-training intervention. Both UL and KL group improved similarly their 1RM bench press as well as mean and peak power with all loads. There were significant improvements in power developed in all the early time intervals measured (150 ms) with the three loads (30, 50, 70% 1RM) in the UL group, while KL only improved with 30% 1RM (all the time intervals) and with 70% 1RM (at certain time intervals). Only the UL group improved throwing velocity in both standing (4.7%) and jumping (5.3%) throw (p > 0.05). The use of unknown loads has led to greater gains in power output in the early time intervals as well as to increases in throwing velocity compared with known loads. Therefore unknown loads are of significant practical use to increase both strength and in-field performance in a short period of training.

Stride-to-stride variability and complexity between novice and experienced runners during a prolonged run at anaerobic threshold speed.

PubMed

Mo, Shiwei; Chow, Daniel H K

2018-05-19

Motor control, related to running performance and running related injuries, is affected by progression of fatigue during a prolonged run. Distance runners are usually recommended to train at or slightly above anaerobic threshold (AT) speed for improving performance. However, running at AT speed may result in accelerated fatigue. It is not clear how one adapts running gait pattern during a prolonged run at AT speed and if there are differences between runners with different training experience. To compare characteristics of stride-to-stride variability and complexity during a prolonged run at AT speed between novice runners (NR) and experienced runners (ER). Both NR (n = 17) and ER (n = 17) performed a treadmill run for 31 min at his/her AT speed. Stride interval dynamics was obtained throughout the run with the middle 30 min equally divided into six time intervals (denoted as T1, T2, T3, T4, T5 and T6). Mean, coefficient of variation (CV) and scaling exponent alpha of stride intervals were calculated for each interval of each group. This study revealed mean stride interval significantly increased with running time in a non-linear trend (p<0.001). The stride interval variability (CV) maintained relatively constant for NR (p = 0.22) and changed nonlinearly for ER (p = 0.023) throughout the run. Alpha was significantly different between groups at T2, T5 and T6, and nonlinearly changed with running time for both groups with slight differences. These findings provided insights into how the motor control system adapts to progression of fatigue and evidences that long-term training enhances motor control. Although both ER and NR could regulate gait complexity to maintain AT speed throughout the prolonged run, ER also regulated stride interval variability to achieve the goal. Copyright © 2018. Published by Elsevier B.V.

Working times of elastomeric impression materials determined by dimensional accuracy.

PubMed

Tan, E; Chai, J; Wozniak, W T

1996-01-01

The working times of five poly(vinyl siloxane) impression materials were estimated by evaluating the dimensional accuracy of stone dies of impressions of a standard model made at successive time intervals. The stainless steel standard model was represented by two abutments having known distances between landmarks in three dimensions. Three dimensions in the x-, y-, and z-axes of the stone dies were measured with a traveling microscope. A time interval was rejected as being within the working time if the percentage change of the resultant dies, in any dimension, was statistically different from those measured from stone dies from previous time intervals. The absolute dimensions of those dies from the rejected time interval also must have exceeded all those from previous time intervals. Results showed that the working times estimated with this method generally were about 30 seconds longer than those recommended by the manufacturers.

Single-channel autocorrelation functions: the effects of time interval omission.

PubMed Central

Ball, F G; Sansom, M S

1988-01-01

We present a general mathematical framework for analyzing the dynamic aspects of single channel kinetics incorporating time interval omission. An algorithm for computing model autocorrelation functions, incorporating time interval omission, is described. We show, under quite general conditions, that the form of these autocorrelations is identical to that which would be obtained if time interval omission was absent. We also show, again under quite general conditions, that zero correlations are necessarily a consequence of the underlying gating mechanism and not an artefact of time interval omission. The theory is illustrated by a numerical study of an allosteric model for the gating mechanism of the locust muscle glutamate receptor-channel. PMID:2455553

Precise time technology for selected Air Force systems: Present status and future requirements

NASA Technical Reports Server (NTRS)

Yannoni, N. F.

1981-01-01

Precise time and time interval (PTTI) technology is becoming increasingly significant to Air Force operations as digital techniques find expanded utility in military missions. Timing has a key role in the function as well as in navigation. A survey of the PTTI needs of several Air Force systems is presented. Current technology supporting these needs was reviewed and new requirements are emphasized for systems as they transfer from initial development to final operational deployment.

Noninvasive Ph-telemetric Measurement of Gastrointestinal Function

NASA Technical Reports Server (NTRS)

Tietze, Karen J.

1991-01-01

The purpose of this study was to gain experience with and validate the Heidelberg pH-telemetric methodology in order to determine if the pH-telemetric methodology would be a useful noninvasive measure of gastrointestinal transit time for future ground-based and in-flight drug evaluation studies. The Heidelberg pH metering system is a noninvasive, nonradioactive telemetric system that, following oral ingestion, continuously measures intraluminal pH of the stomach, duodenum, small bowel, ileocecal junction, and large bowel. Gastrointestinal motility profiles were obtained in normal volunteers using the lactulose breath-hydrogen and Heidelberg pH metering techniques. All profiles were obtained in the morning after an overnight fast. Heidelberg pH profiles were obtained in the fasting and fed states; lactulose breath-hydrogen profiles were obtained after a standard breakfast. Mouth-to-cecum transit time was measured as the interval from administration of lactulose (30 ml; 20 g) to a sustained increase in breath-hydrogen of 10 ppm or more. Gastric emptying time was measured as the interval from the administration of the Heidelberg capsule to a sustained increase in pH of three units or more.

Risk factors for brachial plexus injury in a large cohort with shoulder dystocia.

PubMed

Volpe, Katherine A; Snowden, Jonathan M; Cheng, Yvonne W; Caughey, Aaron B

2016-11-01

To examine birthweight and other predictors of brachial plexus injury (BPI) among births complicated by shoulder dystocia. A retrospective cohort study of term births complicated by shoulder dystocia in California between 1997 and 2006. Birthweight at time of delivery was stratified into 500-g intervals. Women were further stratified by diabetes status, parity, and race/ethnicity. The perinatal outcome of BPI was assessed. This study included 62,762 deliveries complicated by shoulder dystocia, of which 3168 (5 %) resulted in BPI. The association between birthweight and BPI remained significant regardless of confounders. Each increasing birthweight interval was associated with an increasing risk of BPI compared with 3000-3499-g birthweight. Race/ethnicity, diabetes, and parity were also independently associated with BPI. Increasing birthweight increases the risk of BPI among births with shoulder dystocia, independent of advanced maternal age, race, parity, gestational diabetes, or operative vaginal delivery.

Alcohol References on Undergraduate Males’ Facebook Profiles

PubMed Central

Egan, Katie G.; Moreno, Megan A.

2011-01-01

Perceived peer alcohol use is a predictor of consumption in college males; frequent references to alcohol on Facebook may encourage alcohol consumption. Content analysis of college males’ Facebook profiles identified references to alcohol. The average age of 225 identified profiles was 19.9 years. Alcohol references were present on 85.3% of the profiles; the prevalence of alcohol was similar across each undergraduate grade. The average number of alcohol references per profile was 8.5 but increased with undergraduate year (p = .003; confidence interval = 1.5, 7.5). Students who were of legal drinking age referenced alcohol 4.5 times more than underage students, and an increase in number of Facebook friends was associated with an increase in displayed alcohol references (p < .001; confidence interval = 0.009, 0.02). Facebook is widely used in the college population; widespread alcohol displays on Facebook may influence social norms and cause increases in male college students’ alcohol use. PMID:21406490

Lacosamide cardiac safety: a thorough QT/QTc trial in healthy volunteers.

PubMed

Kropeit, D; Johnson, M; Cawello, W; Rudd, G D; Horstmann, R

2015-11-01

To determine whether lacosamide prolongs the corrected QT interval (QTc). In this randomized, double-blind, positive- and placebo-controlled, parallel-design trial, healthy volunteers were randomized to lacosamide 400 mg/day (maximum-recommended daily dose, 6 days), lacosamide 800 mg/day (supratherapeutic dose, 6 days), placebo (6 days), or moxifloxacin 400 mg/day (3 days). Variables included maximum time-matched change from baseline in QT interval individually corrected for heart rate ([HR] QTcI), other ECG parameters, pharmacokinetics (PK), and safety/tolerability. The QTcI mean maximum difference from placebo was -4.3 ms and -6.3 ms for lacosamide 400 and 800 mg/day; upper limits of the 2-sided 90% confidence interval were below the 10 ms non-inferiority margin (-0.5 and -2.5 ms, respectively). Placebo-corrected QTcI for moxifloxacin was +10.4 ms (lower 90% confidence bound >0 [6.6 ms]), which established assay sensitivity for this trial. As lacosamide did not increase QTcI, the trial is considered a negative QTc trial. There was no dose-related or clinically relevant effect on QRS duration. HR increased from baseline by ~5 bpm with lacosamide 800 mg/day versus placebo. Placebo-subtracted mean increases in PR interval at tmax were 7.3 ms (400 mg/day) and 11.9 ms (800 mg/day). There were no findings of second-degree or higher atrioventricular block. Adverse events (AEs) were dose related and most commonly involved the nervous and gastrointestinal systems. Lacosamide (≤ 800 mg/day) did not prolong the QTc interval. Lacosamide caused a small, dose-related increase in mean PR interval that was not associated with AEs. Cardiac, overall safety, and PK profiles for lacosamide in healthy volunteers were consistent with those observed in patients with partial-onset seizures. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

An investigation of articulatory setting using real-time magnetic resonance imaging

PubMed Central

Ramanarayanan, Vikram; Goldstein, Louis; Byrd, Dani; Narayanan, Shrikanth S.

2013-01-01

This paper presents an automatic procedure to analyze articulatory setting in speech production using real-time magnetic resonance imaging of the moving human vocal tract. The procedure extracts frames corresponding to inter-speech pauses, speech-ready intervals and absolute rest intervals from magnetic resonance imaging sequences of read and spontaneous speech elicited from five healthy speakers of American English and uses automatically extracted image features to quantify vocal tract posture during these intervals. Statistical analyses show significant differences between vocal tract postures adopted during inter-speech pauses and those at absolute rest before speech; the latter also exhibits a greater variability in the adopted postures. In addition, the articulatory settings adopted during inter-speech pauses in read and spontaneous speech are distinct. The results suggest that adopted vocal tract postures differ on average during rest positions, ready positions and inter-speech pauses, and might, in that order, involve an increasing degree of active control by the cognitive speech planning mechanism. PMID:23862826

Exercise training improves autonomic profiles in patients with Charcot-Marie-Tooth disease.

PubMed

El Mhandi, Lhassan; Pichot, Vincent; Calmels, Paul; Gautheron, Vincent; Roche, Frédéric; Féasson, Léonard

2011-11-01

The effect of an interval exercise training (ITE) program on heart rate variability (HRV) was studied in 8 patients with Charcot-Marie-Tooth (CMT) disease and 8 healthy controls. At baseline, all subjects underwent ambulatory 24-hour Holter electrocardiographic (ECG) monitoring to evaluate HRV. HRV analysis was repeated on CMT patients after they completed a 24-week ITE program on a cycle ergometer. Before exercise, all HRV indices were lower in patients compared with controls, and the difference reached statistical significance for pNN50 (percent of differences between adjacent R-R intervals exceeding 50 ms). After ITE, time- and frequency-domain indices were significantly improved, particularly at night (+8% mean R-R interval, +95% pNN50, 52% reduction in low/high-frequency ratio). We observed significant increases in some of the time and frequency parameters, and values sometimes exceeded those of controls at baseline. Our results suggest that ITE improves HRV modulation in CMT patients by enhancing parasympathetic activity. Copyright © 2011 Wiley Periodicals, Inc.

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

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

Vujovic, Olga, E-mail: olga.vujovic@lhsc.on.ca; Yu, Edward; Cherian, Anil

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, distantmore » 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.« less

Teaching Students to Request the Continuation of Routine Activities by Using Time Delay and Decreasing Physical Assistance in the Context of Chain Interruption.

ERIC Educational Resources Information Center

Gee, Kathleen; And Others

1991-01-01

Three students (ages 5-10) with profound intellectual, sensory, and physical disabilities were taught to activate a communication device to request the continuation of activities in which they were involved. The intervention consisted of a consistent response interval and increasing time delay paired with decreasing physical assistance in…

Monkeys time their pauses of movement and not their movement-kinematics during a synchronization-continuation rhythmic task.

PubMed

Donnet, Sophie; Bartolo, Ramon; Fernandes, José Maria; Cunha, João Paulo Silva; Prado, Luis; Merchant, Hugo

2014-05-01

A critical question in tapping behavior is to understand whether the temporal control is exerted on the duration and trajectory of the downward-upward hand movement or on the pause between hand movements. In the present study, we determined the duration of both the movement execution and pauses of monkeys performing a synchronization-continuation task (SCT), using the speed profile of their tapping behavior. We found a linear increase in the variance of pause-duration as a function of interval, while the variance of the motor implementation was relatively constant across intervals. In fact, 96% of the variability of the duration of a complete tapping cycle (pause + movement) was due to the variability of the pause duration. In addition, we performed a Bayesian model selection to determine the effect of interval duration (450-1,000 ms), serial-order (1-6 produced intervals), task phase (sensory cued or internally driven), and marker modality (auditory or visual) on the duration of the movement-pause and tapping movement. The results showed that the most important parameter used to successfully perform the SCT was the control of the pause duration. We also found that the kinematics of the tapping movements was concordant with a stereotyped ballistic control of the hand pressing the push-button. The present findings support the idea that monkeys used an explicit timing strategy to perform the SCT, where a dedicated timing mechanism controlled the duration of the pauses of movement, while also triggered the execution of fixed movements across each interval of the rhythmic sequence. Copyright © 2014 the American Physiological Society.

Cardiac interbeat interval dynamics from childhood to senescence : comparison of conventional and new measures based on fractals and chaos theory

NASA Technical Reports Server (NTRS)

Pikkujamsa, S. M.; Makikallio, T. H.; Sourander, L. B.; Raiha, I. J.; Puukka, P.; Skytta, J.; Peng, C. K.; Goldberger, A. L.; Huikuri, H. V.

1999-01-01

BACKGROUND: New methods of R-R interval variability based on fractal scaling and nonlinear dynamics ("chaos theory") may give new insights into heart rate dynamics. The aims of this study were to (1) systematically characterize and quantify the effects of aging from early childhood to advanced age on 24-hour heart rate dynamics in healthy subjects; (2) compare age-related changes in conventional time- and frequency-domain measures with changes in newly derived measures based on fractal scaling and complexity (chaos) theory; and (3) further test the hypothesis that there is loss of complexity and altered fractal scaling of heart rate dynamics with advanced age. METHODS AND RESULTS: The relationship between age and cardiac interbeat (R-R) interval dynamics from childhood to senescence was studied in 114 healthy subjects (age range, 1 to 82 years) by measurement of the slope, beta, of the power-law regression line (log power-log frequency) of R-R interval variability (10(-4) to 10(-2) Hz), approximate entropy (ApEn), short-term (alpha(1)) and intermediate-term (alpha(2)) fractal scaling exponents obtained by detrended fluctuation analysis, and traditional time- and frequency-domain measures from 24-hour ECG recordings. Compared with young adults (<40 years old, n=29), children (<15 years old, n=27) showed similar complexity (ApEn) and fractal correlation properties (alpha(1), alpha(2), beta) of R-R interval dynamics despite lower spectral and time-domain measures. Progressive loss of complexity (decreased ApEn, r=-0.69, P<0.001) and alterations of long-term fractal-like heart rate behavior (increased alpha(2), r=0.63, decreased beta, r=-0.60, P<0.001 for both) were observed thereafter from middle age (40 to 60 years, n=29) to old age (>60 years, n=29). CONCLUSIONS: Cardiac interbeat interval dynamics change markedly from childhood to old age in healthy subjects. Children show complexity and fractal correlation properties of R-R interval time series comparable to those of young adults, despite lower overall heart rate variability. Healthy aging is associated with R-R interval dynamics showing higher regularity and altered fractal scaling consistent with a loss of complex variability.

Heart-Rate Variability During Deep Sleep in World-Class Alpine Skiers: A Time-Efficient Alternative to Morning Supine Measurements.

PubMed

Herzig, David; Testorelli, Moreno; Olstad, Daniela Schäfer; Erlacher, Daniel; Achermann, Peter; Eser, Prisca; Wilhelm, Matthias

2017-05-01

It is increasingly popular to use heart-rate variability (HRV) to tailor training for athletes. A time-efficient method is HRV assessment during deep sleep. To validate the selection of deep-sleep segments identified by RR intervals with simultaneous electroencephalography (EEG) recordings and to compare HRV parameters of these segments with those of standard morning supine measurements. In 11 world-class alpine skiers, RR intervals were monitored during 10 nights, and simultaneous EEGs were recorded during 2-4 nights. Deep sleep was determined from the HRV signal and verified by delta power from the EEG recordings. Four further segments were chosen for HRV determination, namely, a 4-h segment from midnight to 4 AM and three 5-min segments: 1 just before awakening, 1 after waking in supine position, and 1 in standing after orthostatic challenge. Training load was recorded every day. A total of 80 night and 68 morning measurements of 9 athletes were analyzed. Good correspondence between the phases selected by RR intervals vs those selected by EEG was found. Concerning root-mean-squared difference of successive RR intervals (RMSSD), a marker for parasympathetic activity, the best relationship with the morning supine measurement was found in deep sleep. HRV is a simple tool for approximating deep-sleep phases, and HRV measurement during deep sleep could provide a time-efficient alternative to HRV in supine position.

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.

Pediatric magnet ingestions: the dark side of the force.

PubMed

Brown, Julie C; Otjen, Jeffrey P; Drugas, George T

2014-05-01

Pediatric magnet ingestions are increasing. Commercial availability of rare-earth magnets poses a serious health risk. This study defines incidence, characteristics, and management of ingestions over time. Cases were identified by searching radiology reports from June 2002 to December 2012 at a children's hospital and verified by chart and imaging review. Relative risk (RR) regressions determined changes in incidence and interventions over time. In all, 98% of ingestions occurred since 2006; 57% involved multiple magnets. Median age was 8 years (range 0 to 18); 0% of single and 56% of multiple ingestions required intervention. Compared with 2007 to 2009, ingestions increased from 2010 to 2012 (RR = 1.9, 95% confidence interval 1.2 to 3.0). Intervention proportion was unchanged (RR = .94, 95% confidence interval .4 to 2.2). Small spherical magnets comprised 26.8% of ingestions since 2010; 86% involved multiple magnets and 47% required intervention. Pediatric magnet ingestions and interventions have increased. Multiple ingestions prompt more imaging and surgical interventions. Magnet safety standards are needed to decrease risk to children. Copyright © 2014 Elsevier Inc. All rights reserved.

Measuring discharge with ADCPs: Inferences from synthetic velocity profiles

USGS Publications Warehouse

Rehmann, C.R.; Mueller, D.S.; Oberg, K.A.

2009-01-01

Synthetic velocity profiles are used to determine guidelines for sampling discharge with acoustic Doppler current profilers (ADCPs). The analysis allows the effects of instrument characteristics, sampling parameters, and properties of the flow to be studied systematically. For mid-section measurements, the averaging time required for a single profile measurement always exceeded the 40 s usually recommended for velocity measurements, and it increased with increasing sample interval and increasing time scale of the large eddies. Similarly, simulations of transect measurements show that discharge error decreases as the number of large eddies sampled increases. The simulations allow sampling criteria that account for the physics of the flow to be developed. ?? 2009 ASCE.

A high-order time-accurate interrogation method for time-resolved PIV

NASA Astrophysics Data System (ADS)

Lynch, Kyle; Scarano, Fulvio

2013-03-01

A novel method is introduced for increasing the accuracy and extending the dynamic range of time-resolved particle image velocimetry (PIV). The approach extends the concept of particle tracking velocimetry by multiple frames to the pattern tracking by cross-correlation analysis as employed in PIV. The working principle is based on tracking the patterned fluid element, within a chosen interrogation window, along its individual trajectory throughout an image sequence. In contrast to image-pair interrogation methods, the fluid trajectory correlation concept deals with variable velocity along curved trajectories and non-zero tangential acceleration during the observed time interval. As a result, the velocity magnitude and its direction are allowed to evolve in a nonlinear fashion along the fluid element trajectory. The continuum deformation (namely spatial derivatives of the velocity vector) is accounted for by adopting local image deformation. The principle offers important reductions of the measurement error based on three main points: by enlarging the temporal measurement interval, the relative error becomes reduced; secondly, the random and peak-locking errors are reduced by the use of least-squares polynomial fits to individual trajectories; finally, the introduction of high-order (nonlinear) fitting functions provides the basis for reducing the truncation error. Lastly, the instantaneous velocity is evaluated as the temporal derivative of the polynomial representation of the fluid parcel position in time. The principal features of this algorithm are compared with a single-pair iterative image deformation method. Synthetic image sequences are considered with steady flow (translation, shear and rotation) illustrating the increase of measurement precision. An experimental data set obtained by time-resolved PIV measurements of a circular jet is used to verify the robustness of the method on image sequences affected by camera noise and three-dimensional motions. In both cases, it is demonstrated that the measurement time interval can be significantly extended without compromising the correlation signal-to-noise ratio and with no increase of the truncation error. The increase of velocity dynamic range scales more than linearly with the number of frames included for the analysis, which supersedes by one order of magnitude the pair correlation by window deformation. The main factors influencing the performance of the method are discussed, namely the number of images composing the sequence and the polynomial order chosen to represent the motion throughout the trajectory.

Use of mobile phones in Norway and risk of intracranial tumours.

PubMed

Klaeboe, Lars; Blaasaas, Karl Gerhard; Tynes, Tore

2007-04-01

To test the hypothesis that exposure to radio-frequency electromagnetic fields from mobile phones increases the incidence of gliomas, meningiomas and acoustic neuromas in adults. The incident cases were of patients aged 19-69 years who were diagnosed during 2001-2002 in Southern Norway. Population controls were selected and frequency-matched for age, sex, and residential area. Detailed information about mobile phone use was collected from 289 glioma (response rate 77%), 207 meningioma patients (71%), and 45 acoustic neuroma patients (68%) and from 358 (69%) controls. For regular mobile phone use, defined as use on average at least once a week or more for at least 6 months, the odds ratio was 0.6 (95% confidence interval 0.4-0.9) for gliomas, 0.8 (95% confidence interval 0.5-1.1) for meningiomas and 0.5 (95% confidence interval 0.2-1.0) for acoustic neuromas. Similar results were found with mobile phone use for 6 years or more for gliomas and acoustic neuromas. An exception was meningiomas, where the odds ratio was 1.2 (95% confidence interval 0.6-2.2). Furthermore, no increasing trend was observed for gliomas or acoustic neuromas by increasing duration of regular use, the time since first regular use or cumulative use of mobile phones. The results from the present study indicate that use of mobile phones is not associated with an increased risk of gliomas, meningiomas or acoustic neuromas.

Relativity and the TRS-80.

ERIC Educational Resources Information Center

Levin, Sidney

1984-01-01

Presents the listing (TRS-80) for a computer program which derives the relativistic equation (employing as a model the concept of a moving clock which emits photons at regular intervals) and calculates transformations of time, mass, and length with increasing velocities (Einstein-Lorentz transformations). (JN)

Buffered coscheduling for parallel programming and enhanced fault tolerance

DOEpatents

Petrini, Fabrizio [Los Alamos, NM; Feng, Wu-chun [Los Alamos, NM

2006-01-31

A computer implemented method schedules processor jobs on a network of parallel machine processors or distributed system processors. Control information communications generated by each process performed by each processor during a defined time interval is accumulated in buffers, where adjacent time intervals are separated by strobe intervals for a global exchange of control information. A global exchange of the control information communications at the end of each defined time interval is performed during an intervening strobe interval so that each processor is informed by all of the other processors of the number of incoming jobs to be received by each processor in a subsequent time interval. The buffered coscheduling method of this invention also enhances the fault tolerance of a network of parallel machine processors or distributed system processors

Cardiovascular Outcomes after a Respiratory Tract Infection among Adults with Non-Cystic Fibrosis Bronchiectasis: A General Population-based Study.

PubMed

Navaratnam, Vidya; Root, Adrian A; Douglas, Ian; Smeeth, Liam; Hubbard, Richard B; Quint, Jennifer K

2018-03-01

Studies suggest that adults with bronchiectasis are at increased risk of cardiovascular comorbidities. We aimed to quantify the relative risk of incident cardiovascular events after a respiratory tract infection among adults with bronchiectasis. Using UK electronic primary care records, we conducted a within-person comparison using the self-controlled case series method. We calculated the relative risk of first-time cardiovascular events (either first myocardial infarction or stroke) after a respiratory tract infection compared with the individual's baseline risk. Our cohort consisted of 895 adult men and women with non-cystic fibrosis bronchiectasis with a first myocardial infarction or stroke and at least one respiratory tract infection. There was an increased rate of first-time cardiovascular events in the 91-day period after a respiratory tract infection (incidence rate ratio, 1.56; 95% confidence interval, 1.20-2.02). The rate of a first cardiovascular event was highest in the first 3 days after a respiratory tract infection (incidence rate ratio, 2.73; 95% confidence interval, 1.41-5.27). These data suggest that respiratory tract infections are strongly associated with a transient increased risk of first-time myocardial infarction or stroke among people with bronchiectasis. As respiratory tract infections are six times more common in people with bronchiectasis than the general population, the increased risk has a disproportionately greater impact in these individuals. These findings may have implications for including cardiovascular risk modifications in airway infection treatment pathways in this population.

An outbreak of mud-wrestling-induced pustular dermatitis in college students. Dermatitis palaestrae limosae.

PubMed

Adler, A I; Altman, J

1993-01-27

To investigate an outbreak of gram-negative folliculitis in relation to a common exposure, mud wrestling, and identify risk factors for dermatitis among those who mud wrestled. Case-control study. University of Washington, Seattle. Two college-residence groups of students. Cultures from affected students and from mud similar to that used for wrestling yielded Enterobacteriaceae. The odds ratio associated with mud wrestling was 79.5 (95% confidence interval, 13.9 to 895.4). Increased time spent wrestling was associated with increased risk. Skin trauma during wrestling or immersion in the mud increased the risk of infection (odds ratio, 23.1; 95% confidence interval, 1.7 to 1440.4). Mud wrestling is one cause of pustular follicular dermatitis. Trauma to the skin may be a necessary cofactor for the development of infection.

Does the risk of peritoneal dialysis-associated peritonitis vary by time on treatment?

PubMed

Perl, Jeffrey; Parpia, Sameer; Nessim, Sharon J

2016-04-01

Early retraining of patients/caregivers at 3 months after peritoneal dialysis (PD) initiation is recommended to prevent peritonitis. We sought to better understand if the risk of peritonitis was highest early after the initiation of PD and if the risk varied by time on therapy and by organism. Using the multicenter Canadian Baxter POET database, we studied 4,247 incident PD patients. Time on dialysis was divided into 3-month intervals over the first 2 years on PD, with 0 - 3 months serving as the reference period. After creating several organism categories (all organisms, coagulase-negative staphylococcus (CNS), Staphylococcus aureus, streptococcus, Gramnegative, culture-negative, and yeast), time to first peritonitis was analyzed by Kaplan-Meier analysis and using smooth hazard plots. The risk of peritonitis for each of these categories over time was then analyzed in a multivariable model after adjusting for potential confounding variables. The overall risk of peritonitis (all organisms) was greatest in the first 3 months on PD compared with all subsequent 3-month intervals (p = 0.001). Organism-specific analyses revealed an increased risk of culture-negative peritonitis in the first 3 months (p < 0.001) but no increased risk of CNS peritonitis or any of the other pre-specified organism categories. The overall risk of peritonitis was greatest in the first 3 months on PD and was largely driven by an increased risk of culture-negative peritonitis but not by CNS. Better understanding of this increased early peritonitis risk is warranted in order to develop strategies aimed at its prevention.

Evaluating Protocol Lifecycle Time Intervals in HIV/AIDS Clinical Trials

PubMed Central

Schouten, Jeffrey T.; Dixon, Dennis; Varghese, Suresh; Cope, Marie T.; Marci, Joe; Kagan, Jonathan M.

2014-01-01

Background Identifying efficacious interventions for the prevention and treatment of human diseases depends on the efficient development and implementation of controlled clinical trials. Essential to reducing the time and burden of completing the clinical trial lifecycle is determining which aspects take the longest, delay other stages, and may lead to better resource utilization without diminishing scientific quality, safety, or the protection of human subjects. Purpose In this study we modeled time-to-event data to explore relationships between clinical trial protocol development and implementation times, as well as identify potential correlates of prolonged development and implementation. Methods We obtained time interval and participant accrual data from 111 interventional clinical trials initiated between 2006 and 2011 by NIH’s HIV/AIDS Clinical Trials Networks. We determined the time (in days) required to complete defined phases of clinical trial protocol development and implementation. Kaplan-Meier estimates were used to assess the rates at which protocols reached specified terminal events, stratified by study purpose (therapeutic, prevention) and phase group (pilot/phase I, phase II, and phase III/ IV). We also examined several potential correlates to prolonged development and implementation intervals. Results Even though phase grouping did not determine development or implementation times of either therapeutic or prevention studies, overall we observed wide variation in protocol development times. Moreover, we detected a trend toward phase III/IV therapeutic protocols exhibiting longer developmental (median 2 ½ years) and implementation times (>3years). We also found that protocols exceeding the median number of days for completing the development interval had significantly longer implementation. Limitations The use of a relatively small set of protocols may have limited our ability to detect differences across phase groupings. Some timing effects present for a specific study phase may have been masked by combining protocols into phase groupings. Presence of informative censoring, such as withdrawal of some protocols from development if they began showing signs of lost interest among investigators, complicates interpretation of Kaplan-Meier estimates. Because this study constitutes a retrospective examination over an extended period of time, it does not allow for the precise identification of relative factors impacting timing. Conclusions Delays not only increase the time and cost to complete clinical trials, but they also diminish their usefulness by failing to answer research questions in time. We believe that research analyzing the time spent traversing defined intervals across the clinical trial protocol development and implementation continuum can stimulate business process analyses and reengineering efforts that could lead to reductions in the time from clinical trial concept to results, thereby accelerating progress in clinical research. PMID:24980279

The effect of methylphenidate and rearing environment on behavioral inhibition in adult male rats.

PubMed

Hill, Jade C; Covarrubias, Pablo; Terry, Joel; Sanabria, Federico

2012-01-01

The ability to withhold reinforced responses-behavioral inhibition-is impaired in various psychiatric conditions including Attention Deficit Hyperactivity Disorder (ADHD). Methodological and analytical limitations have constrained our understanding of the effects of pharmacological and environmental factors on behavioral inhibition. To determine the effects of acute methylphenidate (MPH) administration and rearing conditions (isolated vs. pair-housed) on behavioral inhibition in adult rats. Inhibitory capacity was evaluated using two response-withholding tasks, differential reinforcement of low rates (DRL) and fixed minimum interval (FMI) schedules of reinforcement. Both tasks made sugar pellets contingent on intervals longer than 6 s between consecutive responses. Inferences on inhibitory and timing capacities were drawn from the distribution of withholding times (interresponse times, or IRTs). MPH increased the number of intervals produced in both tasks. Estimates of behavioral inhibition increased with MPH dose in FMI and with social isolation in DRL. Nonetheless, burst responding in DRL and the divergence of DRL data relative to past studies, among other limitations, undermined the reliability of DRL data as the basis for inferences on behavioral inhibition. Inhibitory capacity was more precisely estimated from FMI than from DRL performance. Based on FMI data, MPH, but not a socially enriched environment, appears to improve inhibitory capacity. The highest dose of MPH tested, 8 mg/kg, did not reduce inhibitory capacity but reduced the responsiveness to waiting contingencies. These results support the use of the FMI schedule, complemented with appropriate analytic techniques, for the assessment of behavioral inhibition in animal models.

The Influence of Prior Choices on Current Choice

PubMed Central

de la Piedad, Xochitl; Field, Douglas; Rachlin, Howard

2006-01-01

Three pigeons chose between random-interval (RI) and tandem, continuous-reinforcement, fixed-interval (crf-FI) reinforcement schedules by pecking either of two keys. As long as a pigeon pecked on the RI key, both keys remained available. If a pigeon pecked on the crf-FI key, then the RI key became unavailable and the crf-FI timer began to time out. With this procedure, once the RI key was initially pecked, the prospective value of both alternatives remained constant regardless of time spent pecking on the RI key without reinforcement (RI waiting time). Despite this constancy, the rate at which pigeons switched from the RI to the crf-FI decreased sharply as RI waiting time increased. That is, prior choices influenced current choice—an exercise effect. It is argued that such influence (independent of reinforcement contingencies) may serve as a sunk-cost commitment device in self-control situations. In a second experiment, extinction was programmed if RI waiting time exceeded a certain value. Rate of switching to the crf-FI first decreased and then increased as the extinction point approached, showing sensitivity to both prior choices and reinforcement contingencies. In a third experiment, crf-FI availability was limited to a brief window during the RI waiting time. When constrained in this way, switching occurred at a high rate regardless of when, during the RI waiting time, the crf-FI became available. PMID:16602373

Retrospective study evaluating dose standards for infliximab in patients with rheumatoid arthritis at Hospital Israelita Albert Einstein, São Paulo, Brazil.

PubMed

Scheinberg, Morton; Goldenberg, José; Feldman, Daniel P; Nóbrega, João Luiz

2008-08-01

We determined, in our surrounding environment, the proportion of patients being treated with infliximab who required a therapeutic scheme escalation (an infliximab dose increase surpassing the level of 3 mg/kg every 8 weeks and/or a decrease on the current between infusions' interval). This was a study of the retrospective analysis of data from the 41 rheumatoid arthritis (RA) patients receiving an infliximab therapy at the Albert Einstein Israelita Hospital, from January 2001 up to December 2005. A questionnaire was applied to these patients, assessing their clinical and laboratory data, adverse events, and individual information regarding the infliximab administration. Therapeutic dose information was available in 68% (28/41) of the RA patients, with 46% of these (13/28) receiving a dose increase, and 30% (8/27) experiencing a shortening of the between infusions' interval. The average final infliximab dose (4.21 mg/kg) was significantly greater than their average initial dose (3.29 mg/kg). The average time intervals between the initial and final infusions, though shortened, were not significantly different. A proportion of 73% (30/41) of these patients demonstrated improvement in at least one of the assessed clinical parameters, and 50% of these patients (15/30) experienced a dose increase, while 20% (6/30) experienced shortening of the between treatments' interval. A total of 20% (8/41) of the original patients experienced adverse events. Although infliximab is effective in the control of RA, dose adjustment and/or shortening of the between treatments' interval is frequently required.

Effect of postmortem time interval on in vitro culture potential of goat skin tissues stored at room temperature.

PubMed

Singh, Mahipal; Ma, Xiaoling; Sharma, Anil

2012-09-01

Animal cloning using somatic cell nuclear transfer technology has renewed the interest in postmortem tissue storage, since these tissues can be used to reintroduce the lost genes back into the breeding pool in animal agriculture, preserve the genetic diversity, and revive the endangered species. However, for successful cloning of animals, integrity of nuclear DNA is essential. Cell viability and their potential to in vitro culture ensure nuclear integrity. The aim of this study was to determine the limits of postmortem time interval within which live cells can be recovered from goat skin tissues. To test the postmortem tissue storage limits, we cultured 2-3 mm(2) skin pieces (n = 70) from the ears of three breeds of goats (n = 7) after 0, 2, 4, and 6 days of postmortem storage at 24°C. After 10 days of culture, outgrowth of fibroblast-like cells (>50 cells) around the explants was scored. All the explants irrespective of breed displayed outgrowth of cells on the dish containing fresh tissues (i.e., day 0 of storage). However, the number of explants exhibiting outgrowth reduced with increasing time interval. Only 53.85 % explants displayed outgrowth after 2 days of tissue storage. The number of explants displaying outgrowth was much smaller after 4 (16.67 %) and 6 days (13.3 %) of storage. In general, the number of outgrowing cells per explant, on a given day, also decreased with increasing postmortem storage time interval. To test the differences between cell cultures, we established secondary cultures from one of the goats exhibiting outgrowth of cells after 6 days of tissue storage and compared them to similar cells from fresh tissues. Comparison of both the cell lines revealed similar cell morphology and growth curves and had doubling times of 23.04 and 22.56 h, respectively. These results suggest that live cells can be recovered from goat (and perhaps other animal) tissues stored at room temperature even after 6 days of their death with comparable growth profiles and, thus, can be used for tissue banking for preservation of superior genetics, genetic diversity, and cloning of animals.

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.

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.

The prelaying interval of emperor geese on the Yukon-Kuskokwim Delta, Alaska

USGS Publications Warehouse

Hupp, Jerry W.; Schmutz, J.A.; Ely, Craig R.

2006-01-01

We marked 136 female Emperor Geese (Chen canagica) in western Alaska with VHF or satellite (PTT) transmitters from 1999 to 2003 to monitor their spring arrival and nest initiation dates on the Yukon Delta, and to estimate prelaying interval lengths once at the nesting area. Ninety-two females with functional transmitters returned to the Yukon Delta in the spring after they were marked, and we located the nests of 35 of these individuals. Prelaying intervals were influenced by when snow melted in the spring and individual arrival dates on the Yukon Delta. The median prelaying interval was 15 days (range = 12-19 days) in a year when snow melted relatively late, and 11 days (range = 4-16 days) in two warmer years when snow melted earlier. In years when snow melted earlier, prelaying intervals of <12 days for 11 of 15 females suggested they initiated rapid follicle development on spring staging areas. The prelaying interval declined by approximately 0.4 days and nest initiation date increased approximately 0.5 days for each day a female delayed her arrival. Thus, females that arrived first on the Yukon Delta had prelaying intervals up to four days longer, yet they nested up to five days earlier, than females that arrived last. The proximity of spring staging areas on the Alaska Peninsula to nesting areas on the Yukon Delta may enable Emperor Geese to alter timing of follicle development depending on annual conditions, and to invest nutrients acquired from both areas in eggs during their formation. Plasticity in timing of follicle development is likely advantageous in a variable environment where melting of snow cover in the spring can vary by 2-3 weeks annually. ?? The Cooper Ornithological Society 2006.

a New Approach for Accuracy Improvement of Pulsed LIDAR Remote Sensing Data

NASA Astrophysics Data System (ADS)

Zhou, G.; Huang, W.; Zhou, X.; He, C.; Li, X.; Huang, Y.; Zhang, L.

2018-05-01

In remote sensing applications, the accuracy of time interval measurement is one of the most important parameters that affect the quality of pulsed lidar data. The traditional time interval measurement technique has the disadvantages of low measurement accuracy, complicated circuit structure and large error. A high-precision time interval data cannot be obtained in these traditional methods. In order to obtain higher quality of remote sensing cloud images based on the time interval measurement, a higher accuracy time interval measurement method is proposed. The method is based on charging the capacitance and sampling the change of capacitor voltage at the same time. Firstly, the approximate model of the capacitance voltage curve in the time of flight of pulse is fitted based on the sampled data. Then, the whole charging time is obtained with the fitting function. In this method, only a high-speed A/D sampler and capacitor are required in a single receiving channel, and the collected data is processed directly in the main control unit. The experimental results show that the proposed method can get error less than 3 ps. Compared with other methods, the proposed method improves the time interval accuracy by at least 20 %.

The influence of hunger on meal to pellet intervals in barred owls

USGS Publications Warehouse

Duke, G.E.; Fuller, M.R.; Huberty, B.J.

1980-01-01

1. Barred owls fed at a sub-maintenance (SM) level had significantly (P < 0.01) longer meal to pellet intervals (MPI)/g eaten/kg body weight (BW) than those fed at an above maintenance (AM) level; MPI/g per kg for owls fed at a maintenance (M) level was intermediate but significantly (P < 0.01) different from both SM and AM.2. During SM feeding, MPI/g per kg gradually increased.3. The proportion of a meal occurring in a pellet was less in “hungry” owls whether losing weight (SM) or gaining (AM) as compared to owls maintaining their normal body weight (M).4. SM fed owls appear to be able to increase digestion time as well as thoroughness of digestion.

The effect of interval tubal sterilization on sexual interest and pleasure.

PubMed

Costello, Caroline; Hillis, Susan D; Marchbanks, Polly A; Jamieson, Denise J; Peterson, Herbert B

2002-09-01

To determine if interval tubal sterilization leads to a change in female sexual interest or pleasure and to identify predictors of a positive or negative effect. Our study population comprised 4576 women enrolled in a prospective, multicenter cohort study between 1978 and 1983. Potential demographic, clinical, and surgical predictors of sexual outcome were tested for significant variation from the overall pattern of unchanged, increased, and decreased sexual interest and pleasure. Over 80% of the 4576 study women reported no consistent change in either sexual interest (80.0%) or pleasure (81.7%) after interval tubal sterilization. Among women with consistent change, positive effects were reported ten and 15 times more often than negative effects for sexual interest and pleasure, respectively. All subgroups of women, except for those with poststerilization regret, were significantly (P <.05) more likely to experience increased rather than decreased interest or pleasure. Women with poststerilization regret were the subgroup most likely to have a negative effect; in multivariate analyses, poststerilization regret was the only factor to be a predictor for decreased interest (odds ratio 4.0) and decreased pleasure (odds ratio 5.1). Similarly, women reporting regret were significantly less likely to report increased interest or pleasure. Whether the regret or the decreased sexual interest or pleasure occurred first is unclear. Interval tubal ligation is unlikely to result in changed sexual interest or pleasure. Among those with change, the majority experienced positive sexual effects.

Characterizing the weathering induced changes in optical performance and properties of poly(ethylene-terephthalate) via MaPd:RTS spectroscopy

NASA Astrophysics Data System (ADS)

Gordon, Devin A.; DeNoyer, Lin; Meyer, Corey W.; Sweet, Noah W.; Burns, David M.; Bruckman, Laura S.; French, Roger H.

2017-08-01

Poly(ethylene-terephthalate) (PET) film is widely used in photovoltaic module backsheets for its dielectric break- down strength, and in applications requiring high optical clarity for its high transmission in the visible region. However, PET degrades and loses optical clarity under exposure to ultraviolet (UV) irradiance, heat, and moisture. Stabilizers are often included in PET formulation to increase its longevity; however, even these are subject to degradation and further reduce optical clarity. To study the weathering induced changes in the optical properties in PET films, samples of a UV-stabilized grade of PET were exposed to heat, moisture, and UV irradiance as prescribed by ASTM-G154 Cycle 4 for 168 hour time intervals. UV-Vis reflection and transmission spectra were collected via Multi-Angle, Polarization-Dependent, Reflection, Transmission, and Scattering (MaPd:RTS) spectroscopy after each exposure interval. The resulting spectra were used to calculate the complex index of refraction throughout the UV-Vis spectral region via an iterative optimization process based upon the Fresnel equations. The index of refraction and extinction coefficient were found to vary throughout the UV-Vis region with time under exposure. The spectra were also used to investigate changes in light scattering behavior with increasing exposure time. The intensity of scattered light was found to increase at higher angles with time under exposure.

Effect of P.G. 600 on the timing of ovulation in gilts treated with altrenogest.

PubMed

Horsley, B R; Estienne, M J; Harper, A F; Purcell, S H; Baitis, H K; Beal, W E; Knight, J W

2005-07-01

We previously reported that ovulation rate, but not pregnancy rate or litter size at d 30 after mating, was enhanced by treatment with P.G. 600 (400 IU of PMSG and 200 IU of hCG, Intervet America, Inc., Millsboro, DE) in gilts fed the orally active progestin, altrenogest (Matrix, Intervet America, Inc.) to synchronize estrus. We hypothesized that in addition to increasing ovulation rate, P.G. 600 may have altered the timing of ovulation. Therefore, mating gilts 12 and 24 h after first detection of estrus, as is common in the swine industry, may not have been the optimal breeding regimen, and as a consequence, pregnancy rate and litter size were not altered. The objective of the present study was to determine the effect of P.G. 600 on the timing of ovulation in gilts treated with altrenogest. Randomly cycling, crossbred gilts (5.5 mo old, 117 kg BW, and 14.7 mm of backfat) were fed a diet containing altrenogest (15 mg/d) for 18 d. Twenty-four hours after altrenogest withdrawal, gilts received i.m. injections of P.G. 600 (n = 25) or saline (n = 25). Gilts were checked for estrus at 8-h intervals. After first detection of estrus, transrectal ultrasonography was performed at 8-h intervals to determine the time of ovulation. Gilts were killed 9 to 11 d after the onset of estrus to determine ovulation rate. All gilts displayed estrus by 7 d after treatment with P.G. 600 or saline. Compared with saline, P.G. 600 increased (P = 0.07) ovulation rate (14.8 vs. 17.5, respectively; SE = 1.1). The intervals from injection to estrus (110.9 vs. 98.4; SE = 2.7 h; P < 0.01) and injection to ovulation (141.9 vs. 128.6; SE = 3.2 h; P < 0.01) were greater in gilts treated with saline than in gilts treated with P.G. 600. Duration of estrus (54.4 vs. 53.7; SE = 2.5 h), the estrus-to-ovulation interval (30.2 vs. 31.7; SE = 2.2 h), and the time of ovulation as a percentage of estrus duration (55.8 vs. 57.5; SE = 3.0%) did not differ for the P.G. 600 and saline-injected gilts, respectively. In summary, P.G. 600 advanced the onset of estrus and ovulation following termination of altrenogest treatment and increased ovulation rate; however, treatment of gilts with P.G. 600 had no effect on the timing of ovulation relative to the onset of estrus.

Recurrence time statistics for finite size intervals

NASA Astrophysics Data System (ADS)

Altmann, Eduardo G.; da Silva, Elton C.; Caldas, Iberê L.

2004-12-01

We investigate the statistics of recurrences to finite size intervals for chaotic dynamical systems. We find that the typical distribution presents an exponential decay for almost all recurrence times except for a few short times affected by a kind of memory effect. We interpret this effect as being related to the unstable periodic orbits inside the interval. Although it is restricted to a few short times it changes the whole distribution of recurrences. We show that for systems with strong mixing properties the exponential decay converges to the Poissonian statistics when the width of the interval goes to zero. However, we alert that special attention to the size of the interval is required in order to guarantee that the short time memory effect is negligible when one is interested in numerically or experimentally calculated Poincaré recurrence time statistics.

CT-1-CP-induced ventricular electrical remodeling in mice.

PubMed

Chen, Shu-fen; Wei, Tao-zhi; Rao, Li-ya; Xu, Ming-guang; Dong, Zhan-ling

2015-02-01

The chronic effects of carboxyl-terminal polypeptide of Cardiotrophin-1 (CT-1-CP) on ventricular electrical remodeling were investigated. CT-1-CP, which contains 16 amino acids in sequence of the C-terminal of Cardiotrophin-1, was selected and synthesized, and then administered to Kunming mice (aged 5 weeks) by intraperitoneal injection (500 ng·g⁻¹·day⁻¹) (4 groups, n=10 and female: male=1:1 in each group) for 1, 2, 3 and 4 weeks, respectively. The control group (n=10, female: male=1:1) was injected by physiological saline for 4 weeks. The epicardial monophasic action potential (MAP) was recorded by using a contact-type MAP electrode placed vertically on the left ventricular (LV) epicardium surface, and the electrocardiogram (ECG) signal in lead II was monitored synchronously. ECG intervals (RR, PR, QRS and QT) and the amplitude of MAP (Am), the maximum upstroke velocity (Vmax), as well as action potential durations (APDs) at different repolarization levels (APD30, APD50, APD70, and APD90) of MAP were determined and analyzed in detail. There were no significant differences in RR and P intervals between CT-1-CP-treated groups and control group, but the PR segment and the QRS complex were greater in the former than in the latter (F=2.681 and 5.462 respectively, P<0.05). Though QT interval and the corrected QT interval (QTc) were shorter in CT-1-CP-treated groups than in control group, the QT dispersion (QTd) of them was greater in the latter than in the former (F=3.090, P<0.05) and increased with the time. The ECG monitoring synchronously with the MAP showed that the compression of MAP electrode on the left ventricular epicardium induced performance similar to myocardium ischemia. As compared with those before chest-opening, the PR segment and QT intervals remained basically unchanged in control group, but prolonged significantly in all CT-1-CP-treated groups and the prolongation of QT intervals increased gradually along with the time of exposure to CT-1-CP. The QRS complex had no significant change in control group, one-week and three-week CT-1-CP-treated groups, but prolonged significantly in two-week and four-week CT-1-CP-treated groups. Interestingly, the QTd after chest-opening was significantly greater than that before chest-opening in control group (t=5.242, P<0.01), but decreased along with the time in CT-1-CP-treated groups. The mean MAP amplitude, Vmax and APD were greater in CT-1-CP-treated groups than those in control group, and became more obvious along with the time. The APD in four CT-1-CP-treat groups was prolonged mainly in middle to final repolarization phase. The difference among these groups became significant in middle phase (APD50) (F=6.076, P<0.01) and increased furthermore in late and final phases (APD70: F=10.054; APD90: F=18.691, P<0.01) along with the time of injection of CT-1-CP. The chronic action of CT-1-CP might induce the adapting alteration in cardiac conductivity and ventricular repolarization. The amplitude and the Vmax of the anterior LV epicardial MAP increased obviously, and the APD prolonged mainly in late and final phase of repolarization.

Fast transfer of crossmodal time interval training.

PubMed

Chen, Lihan; Zhou, Xiaolin

2014-06-01

Sub-second time perception is essential for many important sensory and perceptual tasks including speech perception, motion perception, motor coordination, and crossmodal interaction. This study investigates to what extent the ability to discriminate sub-second time intervals acquired in one sensory modality can be transferred to another modality. To this end, we used perceptual classification of visual Ternus display (Ternus in Psychol Forsch 7:81-136, 1926) to implicitly measure participants' interval perception in pre- and posttests and implemented an intra- or crossmodal sub-second interval discrimination training protocol in between the tests. The Ternus display elicited either an "element motion" or a "group motion" percept, depending on the inter-stimulus interval between the two visual frames. The training protocol required participants to explicitly compare the interval length between a pair of visual, auditory, or tactile stimuli with a standard interval or to implicitly perceive the length of visual, auditory, or tactile intervals by completing a non-temporal task (discrimination of auditory pitch or tactile intensity). Results showed that after fast explicit training of interval discrimination (about 15 min), participants improved their ability to categorize the visual apparent motion in Ternus displays, although the training benefits were mild for visual timing training. However, the benefits were absent for implicit interval training protocols. This finding suggests that the timing ability in one modality can be rapidly acquired and used to improve timing-related performance in another modality and that there may exist a central clock for sub-second temporal processing, although modality-specific perceptual properties may constrain the functioning of this clock.

Effects of high-intensity interval training on cardiometabolic risk factors in overweight/obese women

PubMed Central

Smith-Ryan, Abbie E.; Trexler, Eric T.; Wingfield, Hailee; Blue, Malia N.M.

2016-01-01

The purpose of this study was to evaluate two practical interval training protocols on cardiorespiratory fitness, lipids, and body composition in overweight/obese women. Thirty women (mean ± SD; Weight: 88.1 ± 15.9 kg; BMI: 32.0 ± 6.0 kg·m2) were randomly assigned to ten 1-minute high-intensity intervals (90%VO2peak, 1min recovery), or five 2-minute high-intensity intervals (80-100% VO2peak, 1 min recovery), or control. Peak oxygen uptake (VO2peak), peak power output, body composition, and fasting blood lipids were evaluated before and after 3 weeks of training, completed 3 days per week. Results from ANCOVA analyses demonstrated no significant training group differences for any primary variables (p>0.05). When training groups were collapsed, 1MIN and 2MIN resulted in a significant increase in peak power output (∆18.9 ± 8.5 watts; p=0.014) and time to exhaustion (∆55.1 ± 16.4 sec; p=0.001); non-significant increase in VO2peak (∆2.36 ± 1.34 ml·kg−1·min−1; p=0.185); and a significant decrease in fat mass (∆−1.96 ± 0.99kg; p=0.011). Short-term interval exercise training may be effective for decreasing fat mass and improving exercise tolerance in overweight and obese women. PMID:26934687

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

Time-resolved magnetic resonance angiography (MRA) at 3.0 Tesla for evaluation of hemodynamic characteristics of vascular malformations: description of distinct subgroups.

PubMed

Hammer, Simone; Uller, Wibke; Manger, Florentine; Fellner, Claudia; Zeman, Florian; Wohlgemuth, Walter A

2017-01-01

Quantitative evaluation of hemodynamic characteristics of arteriovenous and venous malformations using time-resolved magnetic resonance angiography (MRA) at 3.0 Tesla. Time-resolved MRA with interleaved stochastic trajectories (TWIST) at 3.0 Tesla was studied in 83 consecutive patients with venous malformations (VM) and arteriovenous malformations (AVM). Enhancement characteristics were calculated as percentage increase of signal intensity above baseline over time. Maximum percentage signal intensity increase (signal max ), time intervals between onset of arterial enhancement and lesion enhancement (t onset ), and time intervals between beginning of lesion enhancement and maximum percentage of lesion enhancement (t max ) were analyzed. All AVMs showed a high-flow hemodynamic pattern. Two significantly different (p < 0.001) types of venous malformations emerged: VMs with arteriovenous fistulas (AVF) (median signal max 737 %, IQR [interquartile range] = 511 - 1182 %; median t onset 5 s, IQR = 5 - 10 s; median t max 35 s, IQR = 26 - 40 s) and without AVFs (median signal max 284 %, IQR = 177-432 %; median t onset 23 s, IQR = 15 - 30 s; median t max 60 s, IQR = 55 - 75 s). Quantitative evaluation of time-resolved MRA at 3.0 Tesla provides hemodynamic characterization of vascular malformations. VMs can be subclassified into two hemodynamic subgroups due to presence or absence of AVFs. • Time-resolved MRA at 3.0 Tesla provides quantitative hemodynamic characterization of vascular malformations. • Malformations significantly differ in time courses of enhancement and signal intensity increase. • AVMs show a distinctive high-flow hemodynamic pattern. • Two significantly different types of VMs emerged: VMs with and without AVFs.

Birth spacing and fertility limitation: a behavioral analysis of a nineteenth century frontier population.

PubMed

Anderton, D L; Bean, L L

1985-05-01

Our analysis of changing birth interval distributions over the course of a fertility transition from natural to controlled fertility has examined three closely related propositions. First, within both natural fertility populations (identified at the aggregate level) and cohorts following the onset of fertility limitation, we hypothesized that substantial groups of women with long birth intervals across the individually specified childbearing careers could be identified. That is, even during periods when fertility behavior at the aggregate level is consistent with a natural fertility regime, birth intervals at all parities are inversely related to completed family size. Our tabular analysis enables us to conclude that birth spacing patterns are parity dependent; there is stability in CEB-parity specific mean and birth interval variance over the entire transition. Our evidence does not suggest that the early group of women limiting and spacing births was marked by infecundity. Secondly, the transition appears to be associated with an increasingly larger proportion of women shifting to the same spacing schedules associated with smaller families in earlier cohorts. Thirdly, variations in birth spacing by age of marriage indicate that changes in birth intervals over time are at least indirectly associated with age of marriage, indicating an additional compositional effect. The evidence we have presented on spacing behavior does not negate the argument that parity-dependent stopping behavior was a powerful factor in the fertility transition. Our data also provide evidence of attempts to truncate childbearing. Specifically, the smaller the completed family size, the longer the ultimate birth interval; and ultimate birth intervals increase across cohorts controlling CEB and parity. But spacing appears to represent an additional strategy of fertility limitation. Thus, it may be necessary to distinguish spacing and stopping behavior if one wishes to clarify behavioral patterns within a population (Edlefsen, 1981; Friedlander et al., 1980; Rodriguez and Hobcraft, 1980). Because fertility transition theories imply increased attempts to limit family sizes, it is important to examine differential behavior within subgroups achieving different family sizes. It is this level of analysis which we have attempted to achieve in utilizing parity-specific birth intervals controlled by children ever born.(ABSTRACT TRUNCATED AT 400 WORDS)

Prolongation of atrio-ventricular node conduction in a rabbit model of ischaemic cardiomyopathy: Role of fibrosis and connexin remodelling.

PubMed

Nisbet, Ashley M; Camelliti, Patrizia; Walker, Nicola L; Burton, Francis L; Cobbe, Stuart M; Kohl, Peter; Smith, Godfrey L

2016-05-01

Conduction abnormalities are frequently associated with cardiac disease, though the mechanisms underlying the commonly associated increases in PQ interval are not known. This study uses a chronic left ventricular (LV) apex myocardial infarction (MI) model in the rabbit to create significant left ventricular dysfunction (LVD) 8weeks post-MI. In vivo studies established that the PQ interval increases by approximately 7ms (10%) with no significant change in average heart rate. Optical mapping of isolated Langendorff perfused rabbit hearts recapitulated this result: time to earliest activation of the LV was increased by 14ms (16%) in the LVD group. Intra-atrial and LV transmural conduction times were not altered in the LVD group. Isolated AVN preparations from the LVD group demonstrated a significantly longer conduction time (by approximately 20ms) between atrial and His electrograms than sham controls across a range of pacing cycle lengths. This difference was accompanied by increased effective refractory period and Wenckebach cycle length, suggesting significantly altered AVN electrophysiology post-MI. The AVN origin of abnormality was further highlighted by optical mapping of the isolated AVN. Immunohistochemistry of AVN preparations revealed increased fibrosis and gap junction protein (connexin43 and 40) remodelling in the AVN of LVD animals compared to sham. A significant increase in myocyte-non-myocyte connexin co-localization was also observed after LVD. These changes may increase the electrotonic load experienced by AVN muscle cells and contribute to slowed conduction velocity within the AVN. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Place avoidance learning and memory in a jumping spider.

PubMed

Peckmezian, Tina; Taylor, Phillip W

2017-03-01

Using a conditioned passive place avoidance paradigm, we investigated the relative importance of three experimental parameters on learning and memory in a salticid, Servaea incana. Spiders encountered an aversive electric shock stimulus paired with one side of a two-sided arena. Our three parameters were the ecological relevance of the visual stimulus, the time interval between trials and the time interval before test. We paired electric shock with either a black or white visual stimulus, as prior studies in our laboratory have demonstrated that S. incana prefer dark 'safe' regions to light ones. We additionally evaluated the influence of two temporal features (time interval between trials and time interval before test) on learning and memory. Spiders exposed to the shock stimulus learned to associate shock with the visual background cue, but the extent to which they did so was dependent on which visual stimulus was present and the time interval between trials. Spiders trained with a long interval between trials (24 h) maintained performance throughout training, whereas spiders trained with a short interval (10 min) maintained performance only when the safe side was black. When the safe side was white, performance worsened steadily over time. There was no difference between spiders tested after a short (10 min) or long (24 h) interval before test. These results suggest that the ecological relevance of the stimuli used and the duration of the interval between trials can influence learning and memory in jumping spiders.

Estimation of postmortem interval based on colony development time for Anoplolepsis longipes (Hymenoptera: Formicidae).

PubMed

Goff, M L; Win, B H

1997-11-01

The postmortem interval for a set of human remains discovered inside a metal tool box was estimated using the development time required for a stratiomyid fly (Diptera: Stratiomyidae), Hermetia illucens, in combination with the time required to establish a colony of the ant Anoplolepsis longipes (Hymenoptera: Formicidae) capable of producing alate (winged) reproductives. This analysis resulted in a postmortem interval estimate of 14 + months, with a period of 14-18 months being the most probable time interval. The victim had been missing for approximately 18 months.

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.

Monitoring molecular interactions using photon arrival-time interval distribution analysis

DOEpatents

Laurence, Ted A [Livermore, CA; Weiss, Shimon [Los Angels, CA

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.

Acute haemodynamic effects of felodipine and verapamil in man, singly and with metoprolol.

PubMed

Rönn, O; Bengtsson, B; Edgar, B; Raner, S

1985-01-01

In a single-blind randomised study in 9 healthy men we compared the acute haemodynamic effects of the calcium antagonists felodipine and verapamil, singly and in combination with metoprolol. Three different cumulative intravenous doses of 0.25, 0.75 and 1.5 mg felodipine and of 2.0, 4.0 and 8.0 mg verapamil or placebo were given as constant infusions over 5 minutes on 3 occasions and were followed by intravenous metoprolol (15 mg). Felodipine caused a significant and dose-dependent decrease in the total peripheral resistance, and an increase in the forearm blood flow by 8, 48 and 163% with progressively increasing doses showing that the drug is a potent arteriolar vasodilator. A significant and dose-dependent increase in heart rate and a decrease in the pre-ejection period/left ventricular ejection time (PEP/LVET) ratio of up to 15% was also recorded, mainly reflecting a reflexogenic increase in the sympathetic tone. Total peripheral resistance, forearm blood flow, heart rate and the systolic time intervals were mainly unchanged after verapamil, whereas the PQ interval was prolonged. Metoprolol given after the 2 calcium antagonists caused a decrease in heart rate and blood flow and an increase in the total peripheral resistance and PEP/LVET ratio. The tolerability was good to all infusions.

Brainstem auditory evoked responses in man. 1: Effect of stimulus rise-fall time and duration

NASA Technical Reports Server (NTRS)

Hecox, K.; Squires, N.; Galambos, R.

1975-01-01

Short latency (under 10 msec) evoked responses elicited by bursts of white noise were recorded from the scalp of human subjects. Response alterations produced by changes in the noise burst duration (on-time) inter-burst interval (off-time), and onset and offset shapes are reported and evaluated. The latency of the most prominent response component, wave V, was markedly delayed with increases in stimulus rise-time but was unaffected by changes in fall-time. The amplitude of wave V was insensitive to changes in signal rise-and-fall times, while increasing signal on-time produced smaller amplitude responses only for sufficiently short off-times. It is concluded that wave V of the human auditory brainstem evoked response is solely an onset response.

A biophysical model examining the role of low-voltage-activated potassium currents in shaping the responses of vestibular ganglion neurons.

PubMed

Hight, Ariel E; Kalluri, Radha

2016-08-01

The vestibular nerve is characterized by two broad groups of neurons that differ in the timing of their interspike intervals; some fire at highly regular intervals, whereas others fire at highly irregular intervals. Heterogeneity in ion channel properties has been proposed as shaping these firing patterns (Highstein SM, Politoff AL. Brain Res 150: 182-187, 1978; Smith CE, Goldberg JM. Biol Cybern 54: 41-51, 1986). Kalluri et al. (J Neurophysiol 104: 2034-2051, 2010) proposed that regularity is controlled by the density of low-voltage-activated potassium currents (IKL). To examine the impact of IKL on spike timing regularity, we implemented a single-compartment model with three conductances known to be present in the vestibular ganglion: transient sodium (gNa), low-voltage-activated potassium (gKL), and high-voltage-activated potassium (gKH). Consistent with in vitro observations, removing gKL depolarized resting potential, increased input resistance and membrane time constant, and converted current step-evoked firing patterns from transient (1 spike at current onset) to sustained (many spikes). Modeled neurons were driven with a time-varying synaptic conductance that captured the random arrival times and amplitudes of glutamate-driven synaptic events. In the presence of gKL, spiking occurred only in response to large events with fast onsets. Models without gKL exhibited greater integration by responding to the superposition of rapidly arriving events. Three synaptic conductance were modeled, each with different kinetics to represent a variety of different synaptic processes. In response to all three types of synaptic conductance, models containing gKL produced spike trains with irregular interspike intervals. Only models lacking gKL when driven by rapidly arriving small excitatory postsynaptic currents were capable of generating regular spiking. Copyright © 2016 the American Physiological Society.

Modified 30-second Sit to Stand test predicts falls in a cohort of institutionalized older veterans

PubMed Central

Chassé, Kathleen

2017-01-01

Physical function performance tests, including sit to stand tests and Timed Up and Go, assess the functional capacity of older adults. Their ability to predict falls warrants further investigation. The objective was to determine if a modified 30-second Sit to Stand test that allowed upper extremity use and Timed Up and Go test predicted falls in institutionalized Veterans. Fifty-three older adult Veterans (mean age = 91 years, 49 men) residing in a long-term care hospital completed modified 30-second Sit to Stand and Timed Up and Go tests. The number of falls over one year was collected. The ability of modified 30-second Sit to Stand or Timed Up and Go to predict if participants had fallen was examined using logistic regression. The ability of these tests to predict the number of falls was examined using negative binomial regression. Both analyses controlled for age, history of falls, cognition, and comorbidities. The modified 30-second Sit to Stand was significantly (p < 0.05) related to if participants fell (odds ratio = 0.75, 95% confidence interval = 0.58, 0.97) and the number of falls (incidence rate ratio = 0.82, 95% confidence interval = 0.68, 0.98); decreased repetitions were associated with increased number of falls. Timed Up and Go was not significantly (p > 0.05) related to if participants fell (odds ratio = 1.03, 95% confidence interval = 0.96, 1.10) or the number of falls (incidence rate ratio = 1.01, 95% confidence interval = 0.98, 1.05). The modified 30-second Sit to Stand that allowed upper extremity use offers an alternative method to screen for fall risk in older adults in long-term care. PMID:28464024

Modified 30-second Sit to Stand test predicts falls in a cohort of institutionalized older veterans.

PubMed

Applebaum, Eva V; Breton, Dominic; Feng, Zhuo Wei; Ta, An-Tchi; Walsh, Kayley; Chassé, Kathleen; Robbins, Shawn M

2017-01-01

Physical function performance tests, including sit to stand tests and Timed Up and Go, assess the functional capacity of older adults. Their ability to predict falls warrants further investigation. The objective was to determine if a modified 30-second Sit to Stand test that allowed upper extremity use and Timed Up and Go test predicted falls in institutionalized Veterans. Fifty-three older adult Veterans (mean age = 91 years, 49 men) residing in a long-term care hospital completed modified 30-second Sit to Stand and Timed Up and Go tests. The number of falls over one year was collected. The ability of modified 30-second Sit to Stand or Timed Up and Go to predict if participants had fallen was examined using logistic regression. The ability of these tests to predict the number of falls was examined using negative binomial regression. Both analyses controlled for age, history of falls, cognition, and comorbidities. The modified 30-second Sit to Stand was significantly (p < 0.05) related to if participants fell (odds ratio = 0.75, 95% confidence interval = 0.58, 0.97) and the number of falls (incidence rate ratio = 0.82, 95% confidence interval = 0.68, 0.98); decreased repetitions were associated with increased number of falls. Timed Up and Go was not significantly (p > 0.05) related to if participants fell (odds ratio = 1.03, 95% confidence interval = 0.96, 1.10) or the number of falls (incidence rate ratio = 1.01, 95% confidence interval = 0.98, 1.05). The modified 30-second Sit to Stand that allowed upper extremity use offers an alternative method to screen for fall risk in older adults in long-term care.

Time-based loss in visual short-term memory is from trace decay, not temporal distinctiveness.

PubMed

Ricker, Timothy J; Spiegel, Lauren R; Cowan, Nelson

2014-11-01

There is no consensus as to why forgetting occurs in short-term memory tasks. In past work, we have shown that forgetting occurs with the passage of time, but there are 2 classes of theories that can explain this effect. In the present work, we investigate the reason for time-based forgetting by contrasting the predictions of temporal distinctiveness and trace decay in the procedure in which we have observed such loss, involving memory for arrays of characters or letters across several seconds. The 1st theory, temporal distinctiveness, predicts that increasing the amount of time between trials will lead to less proactive interference, resulting in less forgetting across a retention interval. In the 2nd theory, trace decay, temporal distinctiveness between trials is irrelevant to the loss over a retention interval. Using visual array change detection tasks in 4 experiments, we find small proactive interference effects on performance under some specific conditions, but no concomitant change in the effect of a retention interval. We conclude that trace decay is the more suitable class of explanations of the time-based forgetting in short-term memory that we have observed, and we suggest the need for further clarity in what the exact basis of that decay may be. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Ambulatory aortic blood pressure, wave reflections and pulse wave velocity are elevated during the third in comparison to the second interdialytic day of the long interval in chronic haemodialysis patients.

PubMed

Koutroumbas, Georgios; Georgianos, Panagiotis I; Sarafidis, Pantelis A; Protogerou, Athanase; Karpetas, Antonios; Vakianis, Pantelis; Raptis, Vassilios; Liakopoulos, Vassilios; Panagoutsos, Stylianos; Syrganis, Christos; Passadakis, Ploumis

2015-12-01

Increased arterial stiffness and aortic blood pressure (BP) are independent predictors of cardiovascular outcomes in end-stage renal disease. The 3-day interdialytic interval is associated with elevated risk of cardiovascular morbidity and mortality in haemodialysis. This study investigated differences in ambulatory aortic BP and arterial stiffness between the second and third day of the long interdialytic interval. Ambulatory BP monitoring with Mobil-O-Graph monitor (IEM, Stolberg, Germany) was performed in 55 haemodialysis patients during a 3-day interval. Mobil-O-Graph records oscillometric brachial BP and pulse waves and calculates aortic BP and augmentation index (AIx) as measure of wave reflections, and pulse wave velocity (PWV) as measure of arterial stiffness. Ambulatory aortic systolic blood pressure (SBP) and diastolic blood pressure (DBP) were higher during the third versus second interdialytic day (123.6 ± 17.0 versus 118.5 ± 17.1 mmHg, P < 0.001; 81.5 ± 11.8 versus 78 ± 11.9 mmHg, P < 0.001, respectively). Similar differences were noted for brachial BP. Ambulatory AIx and PWV were also significantly increased during the third versus second day (30.5 ± 9.9 versus 28.8 ± 9.9%, P < 0.05; 9.6 ± 2.3 versus 9.4 ± 2.3 m/s, P < 0.001, respectively). Differences between Days 2 and 3 remained significant when day-time and night-time periods were compared separately. Aortic SBP and DBP, AIx and PWV showed gradual increases from the end of dialysis session onwards. Interdialytic weight gain was a strong determinant of the increase in the above parameters. This study showed significantly higher ambulatory aortic BP, AIx and PWV levels during the third compared with the second interdialytic day. These findings support a novel pathway for increased cardiovascular risk during the third interdialytic day in haemodialysis. © The Author 2015. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

Regulation of muscle stiffness during periodic length changes in the isolated abdomen of the hermit crab.

PubMed

Chapple, W D

1997-09-01

Reflex activation of the ventral superficial muscles (VSM) in the abdomen of the hermit crab, Pagurus pollicarus, was studied using sinusoidal and stochastic longitudinal vibration of the muscle while recording the length and force of the muscle and the spike times of three exciter motoneurons. In the absence of vibration, the interspike interval histograms of the two larger motoneurons were bimodal; cutting sensory nerves containing most of the mechanoreceptor input removed the short interval peak in the histogram, indicating that the receptors are important in maintaining tonic firing. Vibration of the muscle evoked a reflex increase in motoneuron frequency that habituated after an initial peak but remained above control levels for the duration of stimulation. Motoneuron frequency increased with root mean square (rms) stimulus amplitude. Average stiffness during stimulation was about two times the stiffness of passive muscle. The reflex did not alter muscle dynamics. Estimated transfer functions were calculated from the fast Fourier transform of length and force signals. Coherence was >0.9 for the frequency range of 3-35 Hz. Stiffness magnitude gradually increased over this range in both reflex activated and passive muscle; phase was between 10 and 20 degrees. Reflex stiffness decreased with increasing stimulus amplitudes, but at larger amplitudes, this decrease was much less pronounced; in this range stiffness was regulated by the reflex. The sinusoidal frequency at which reflex bursts were elicited was approximately 6 Hz, consistent with previous measurements using ramp stretch. During reflex excitation, there was an increase in amplitude of the short interval peak in the interspike interval histogram; this was reduced when the majority of afferent pathways was removed. A phase histogram of motoneuron firing during sinusoidal vibration had a peak at approximately 110 ms, also suggesting that an important component of the reflex is via direct projections from the mechanoreceptors. These results are consistent with the hypothesis that a robust feedforward regulation of abdominal stiffness during continuous disturbances is achieved by mechanoreceptors signalling the absolute value of changing forces; habituation of the reflex, its high-threshold for low frequency disturbances and the activation kinetics of the muscle further modify reflex dynamics.

A centralized mailed program with stepped increases of support increases time in compliance with colorectal cancer screening guidelines over 5 years: A randomized trial.

PubMed

Green, Beverly B; Anderson, Melissa L; Cook, Andrea J; Chubak, Jessica; Fuller, Sharon; Meenan, Richard T; Vernon, Sally W

2017-11-15

Screening over many years is required to optimize reductions in colorectal cancer (CRC) mortality. However, no prior trials have compared strategies for obtaining long-term adherence. Systems of Support to Increase Colorectal Cancer Screening and Follow-Up was implemented in an integrated health care organization in Washington State. Between 2008 and 2009, 4675 individuals aged 50 to 74 years were randomized to receive the usual care (UC), which included clinic-based strategies to increase CRC screening (arm 1), or, in years 1 and 2, mailings with a call-in number for colonoscopy and mailed fecal tests (arm 2), mailings plus brief telephone assistance (arm 3), or mailings and assistance plus nurse navigation (arm 4). Active-intervention subjects (those in arms 2, 3, and 4 combined) who were still eligible for CRC screening were randomized to mailings being stopped or continued in years 3 and 5. The time in compliance with CRC screening over 5 years was compared for persons assigned to any intervention and persons assigned to UC. Screening tests contributed time on the basis of national guidelines for screening intervals (fecal tests annually, sigmoidoscopy every 5 years, and colonoscopy every 10 years). All participants contributed data, but they were censored at disenrollment, death, the age of 76 years, or a diagnosis of CRC. Compared with UC participants, intervention participants had 31% more adjusted covered time over 5 years (incidence rate ratio, 1.31; 95% confidence interval, 1.25-1.37; covered time, 47.5% vs 62.1%). Fecal testing accounted for almost all additional covered time. In a health care organization with clinic-based activities to increase CRC screening, a centralized program led to increased CRC screening adherence over 5 years. Longer term data on screening adherence and its impact on CRC outcomes are needed. Cancer 2017;123:4472-80. © 2017 American Cancer Society. © 2017 American Cancer Society.

Heinrich Events in the Southern Hemisphere: A Tropical Trigger?

NASA Astrophysics Data System (ADS)

Farmer, E. C.; Choi, W. S.; Quadri, M.

2006-12-01

Heinrich events, or periodic pulses of ice-rafted debris into the North Atlantic, have long been envisioned as having a high-latitude trigger. This trigger is most often cited as internal ice-sheet dynamics. McIntyre and Molfino (1996) proposed a tropical trigger for Heinrich Events: they suggested that precession-related strengthening of the North African monsoonal atmospheric circulation would alter oceanic circulation in such a way as to reduce heat transport to the high latitudes. Discovery of possible evidence (Mg/Ca ratios and faunal abundance) for Heinrich Event 1 (H1) in the Benguela upwelling region (Farmer et al. 2005) stimulated a search for a Heinrich Event 2 (H2) signal. From the review by Hemming (2004), we estimated the time horizon in which we would expect to find H2 as 22.4 - 26.8 ka. We extrapolated the published ODP1084B age model (Farmer et al. 2005) to estimate the depth interval of this time horizon, and counted the relative abundance of the four dominant species of planktonic foraminifera (G. inflata, G. bulloides, N. pachyderma right- and left-coiling) in each sample within this interval. We found an interval spanning five centimeters, or approximately 22.9 to 23.1 ka, in which the relative abundance of N. pachyderma (left-coiling) rose to a an average of 31.5%. Compared to the average level of 23.5% in the surrounding samples, and our pooled standard deviation of 3.4%, this shift appears significant. Increases in relative abundance of N. pachyderma (left-coiling) in earlier intervals are associated with decreased Mg/Ca-based sea surface temperatures (SSTs) and are inferred to be a likely result of increased upwelling (Farmer et al. 2005). Although this new interval is shorter than would be expected from Heinrich event studies elsewhere, the shift in relative abundance of N. pachyderma (left-coiling) is consistent with an H2 signal. Better age control is needed to constrain the timing of this event, however, and data from an additional proxy such as Mg/Ca is needed to confirm the signal.

Cure rate model with interval censored data.

PubMed

Kim, Yang-Jin; Jhun, Myoungshic

2008-01-15

In cancer trials, a significant fraction of patients can be cured, that is, the disease is completely eliminated, so that it never recurs. In general, treatments are developed to both increase the patients' chances of being cured and prolong the survival time among non-cured patients. A cure rate model represents a combination of cure fraction and survival model, and can be applied to many clinical studies over several types of cancer. In this article, the cure rate model is considered in the interval censored data composed of two time points, which include the event time of interest. Interval censored data commonly occur in the studies of diseases that often progress without symptoms, requiring clinical evaluation for detection (Encyclopedia of Biostatistics. Wiley: New York, 1998; 2090-2095). In our study, an approximate likelihood approach suggested by Goetghebeur and Ryan (Biometrics 2000; 56:1139-1144) is used to derive the likelihood in interval censored data. In addition, a frailty model is introduced to characterize the association between the cure fraction and survival model. In particular, the positive association between the cure fraction and the survival time is incorporated by imposing a common normal frailty effect. The EM algorithm is used to estimate parameters and a multiple imputation based on the profile likelihood is adopted for variance estimation. The approach is applied to the smoking cessation study in which the event of interest is a smoking relapse and several covariates including an intensive care treatment are evaluated to be effective for both the occurrence of relapse and the non-smoking duration. Copyright (c) 2007 John Wiley & Sons, Ltd.

Investigation of kinetics and absorption isotherm models for hydroponic phytoremediation of waters contaminated with sulfate.

PubMed

Saber, Ali; Tafazzoli, Milad; Mortazavian, Soroosh; James, David E

2018-02-01

Two common wetland plants, Pampas Grass (Cortaderia selloana) and Lucky Bamboo (Dracaena sanderiana), were used in hydroponic cultivation systems for the treatment of simulated high-sulfate wastewaters. Plants in initial experiments at pH 7.0 removed sulfate more efficiently compared to the same experimental conditions at pH 6.0. Results at sulfate concentrations of 50, 200, 300, 600, 900, 1200, 1500 and 3000 mg/L during three consecutive 7-day treatment periods with 1-day rest intervals, showed decreasing trends of both removal efficiencies and uptake rates with increasing sulfate concentrations from the first to the second to the third 7-day treatment periods. Removed sulfate masses per unit dry plant mass, calculated after 23 days, showed highest removal capacity at 600 mg/L sulfate for both plants. A Langmuir-type isotherm best described sulfate uptake capacity of both plants. Kinetic studies showed that compared to pseudo first-order kinetics, pseudo-second order kinetic models slightly better described sulfate uptake rates by both plants. The Elovich kinetic model showed faster rates of attaining equilibrium at low sulfate concentrations for both plants. The dimensionless Elovich model showed that about 80% of sulfate uptake occurred during the first four days' contact time. Application of three 4-day contact times with 2-day rest intervals at high sulfate concentrations resulted in slightly higher uptakes compared to three 7-day contact times with 1-day rest intervals, indicating that pilot-plant scale treatment systems could be sized with shorter contact times and longer rest-intervals. Copyright © 2017 Elsevier Ltd. All rights reserved.

Is physical activity differentially associated with different types of sedentary pursuits?

PubMed

Feldman, Debbie Ehrmann; Barnett, Tracie; Shrier, Ian; Rossignol, Michel; Abenhaim, Lucien

2003-08-01

To determine whether there is a relationship between the time adolescents spend in physical activity and time they spend in different sedentary pursuits: watching television, playing video games, working on computers, doing homework, and reading, taking into account the effect of part-time work on students' residual time. Cross-sectional cohort design. Seven hundred forty-three high school students from 2 inner-city public schools and 1 private school. Students completed a self-administered questionnaire that addressed time spent in physical activity, time spent in sedentary pursuits, musculoskeletal pain, and psychosocial issues and were also measured for height and weight. Main Outcome Measure Level of physical activity (low, moderate, high). There were more girls than boys in the low and moderate physical activity groups and more boys than girls in the high activity group. Ordinal logistic regression showed that increased time spent in "productive sedentary behavior" (reading or doing homework and working on computers) was associated with increased physical activity (odds ratio, 1.7; 95% confidence interval, 1.2-2.4), as was time spent working (odds ratio, 1.3; 95% confidence interval, 1.2-1.4). Time spent watching television and playing video games was not associated with decreased physical activity. Physical activity was not inversely associated with watching television or playing video games, but was positively associated with productive sedentary behavior and part-time work. Some students appear capable of managing their time better than others. Future studies should explore the ability of students to manage their time and also determine what characteristics are conducive to better time management.

Fixed-interval matching-to-sample: intermatching time and intermatching error runs1

PubMed Central

Nelson, Thomas D.

1978-01-01

Four pigeons were trained on a matching-to-sample task in which reinforcers followed either the first matching response (fixed interval) or the fifth matching response (tandem fixed-interval fixed-ratio) that occurred 80 seconds or longer after the last reinforcement. Relative frequency distributions of the matching-to-sample responses that concluded intermatching times and runs of mismatches (intermatching error runs) were computed for the final matching responses directly followed by grain access and also for the three matching responses immediately preceding the final match. Comparison of these two distributions showed that the fixed-interval schedule arranged for the preferential reinforcement of matches concluding relatively extended intermatching times and runs of mismatches. Differences in matching accuracy and rate during the fixed interval, compared to the tandem fixed-interval fixed-ratio, suggested that reinforcers following matches concluding various intermatching times and runs of mismatches influenced the rate and accuracy of the last few matches before grain access, but did not control rate and accuracy throughout the entire fixed-interval period. PMID:16812032

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.

The Time Is Up: Compression of Visual Time Interval Estimations of Bimodal Aperiodic Patterns

PubMed Central

Duarte, Fabiola; Lemus, Luis

2017-01-01

The ability to estimate time intervals subserves many of our behaviors and perceptual experiences. However, it is not clear how aperiodic (AP) stimuli affect our perception of time intervals across sensory modalities. To address this question, we evaluated the human capacity to discriminate between two acoustic (A), visual (V) or audiovisual (AV) time intervals of trains of scattered pulses. We first measured the periodicity of those stimuli and then sought for correlations with the accuracy and reaction times (RTs) of the subjects. We found that, for all time intervals tested in our experiment, the visual system consistently perceived AP stimuli as being shorter than the periodic (P) ones. In contrast, such a compression phenomenon was not apparent during auditory trials. Our conclusions are: first, the subjects exposed to P stimuli are more likely to measure their durations accurately. Second, perceptual time compression occurs for AP visual stimuli. Lastly, AV discriminations are determined by A dominance rather than by AV enhancement. PMID:28848406

The Lambert-Beer law in time domain form and its application.

PubMed

Mosorov, Volodymyr

2017-10-01

The majority of current radioisotope gauges utilize measurements of intensity for a chosen sampling time interval using a detector. Such an approach has several disadvantages: temporal resolution of the gauge is fixed and the accuracy of the measurements is not the same for different count rate. The solution can be the use of a stronger radioactive source, but it will be conflicted with ALARA (As Low As Reasonably Achievable) principle. Therefore, the article presents an alternative approach which is based on modified Lambert-Beer law. The basis of the approach is the registration of time intervals instead of the registration of counts. It allows to increase the temporal resolution of a gauge without the necessity of using a stronger radioactive source and the accuracy of the measurements will not depend on count rate. Copyright © 2017 Elsevier Ltd. All rights reserved.

Landscape Change Detected Over A 60 Year Period In The Arctic National Wildlife Refuge, Alaska, Using High Resolution Aerial Photographs And Satellite Images

NASA Astrophysics Data System (ADS)

Jorgenson, J. C.; Jorgenson, M. T.; Boldenow, M.; Orndahl, K. M.

2016-12-01

We documented landscape change over a 60 year period in the Arctic National Wildlife Refuge in northeastern Alaska using aerial photographs and satellite images. We used a stratified random sample to allow inference to the whole refuge (78,050 km2), with five random sites in each of seven ecoregions. Each site (2 km2) had a systematic grid of 100 points for a total of 3500 points. We chose study sites in the overlap area covered by acceptable imagery in three time periods: aerial photographs from 1947 - 1955 and 1978 - 1988, Quick Bird and IKONOS satellite images from 2000 - 2007.At each point a 10 meter radius circle was visually evaluated in ARC-MAP for each time period for vegetation type, disturbance, presence of ice wedge polygon microtopography and surface water. A landscape change category was assigned to each point based on differences detected between the three periods. Change types were assigned for time interval 1, interval 2 and overall. Additional explanatory variables included elevation, slope, aspect, geology, physiography and temperature. Overall, 23% of points changed over the study period. Fire was the most common change agent, affecting 28% of the Boreal Forest points. The next most common change was degradation of soil ice wedges (thermokarst), detected at 12% of the points on the North Slope Tundra. The other most common changes included increase in cover of trees or shrubs (7% of Boreal Forest and Brooks Range points) and erosion or deposition on river floodplains and at the Beaufort Sea coast. Changes on the North Slope Tundra tended to be related to landscape wetting, mainly thermokarst. Changes in the Boreal Forest tended to involve landscape drying, including fire, reduced area of lakes and tree increase on wet sites. The second time interval coincided with a shift towards a warmer climate and had greater change in several categories including thermokarst, lake changes and tree and shrub increase.

The impact of peritoneal dialysis-related peritonitis on mortality in peritoneal dialysis patients.

PubMed

Ye, Hongjian; Zhou, Qian; Fan, Li; Guo, Qunying; Mao, Haiping; Huang, Fengxian; Yu, Xueqing; Yang, Xiao

2017-06-05

Results concerning the association between peritoneal dialysis-related peritonitis and mortality in peritoneal dialysis patients are inconclusive, with one potential reason being that the time-dependent effect of peritonitis has rarely been considered in previous studies. This study aimed to evaluate whether peritonitis has a negative impact on mortality in a large cohort of peritoneal dialysis patients. We also assessed the changing impact of peritonitis on patient mortality with respect to duration of follow-up. This retrospective cohort study included incident patients who started peritoneal dialysis from 1 January 2006 to 31 December 2011. Episodes of peritonitis were recorded at the time of onset, and peritonitis was parameterized as a time-dependent variable for analysis. We used the Cox regression model to assess whether peritonitis has a negative impact on mortality. A total of 1321 patients were included. The mean age was 48.1 ± 15.3 years, 41.3% were female, and 23.5% with diabetes mellitus. The median (interquartile) follow-up time was 34 (21-48) months. After adjusting for confounders, peritonitis was independently associated with 95% increased risk of all-cause mortality (hazard ratio, 1.95; 95% confidence interval: 1.46-2.60), 90% increased risk of cardiovascular mortality (hazard ratio, 1.90; 95% confidence interval: 1.28-2.81) and near 4-fold increased risk of infection-related mortality (hazard ratio, 4.94; 95% confidence interval: 2.47-9.86). Further analyses showed that peritonitis was not significantly associated with mortality within 2 years of peritoneal dialysis initiation, but strongly influenced mortality in patients dialysed longer than 2 years. Peritonitis was independently associated with higher risk of all-cause, cardiovascular and infection-related mortality in peritoneal dialysis patients, and its impact on mortality was more significant in patients with longer peritoneal dialysis duration.

Method and apparatus for assessing cardiovascular risk

NASA Technical Reports Server (NTRS)

Albrecht, Paul (Inventor); Bigger, J. Thomas (Inventor); Cohen, Richard J. (Inventor)

1998-01-01

The method for assessing risk of an adverse clinical event includes detecting a physiologic signal in the subject and determining from the physiologic signal a sequence of intervals corresponding to time intervals between heart beats. The long-time structure of fluctuations in the intervals over a time period of more than fifteen minutes is analyzed to assess risk of an adverse clinical event. In a preferred embodiment, the physiologic signal is an electrocardiogram and the time period is at least fifteen minutes. A preferred method for analyzing the long-time structure variability in the intervals includes computing the power spectrum and fitting the power spectrum to a power law dependence on frequency over a selected frequency range such as 10.sup.-4 to 10.sup.-2 Hz. Characteristics of the long-time structure fluctuations in the intervals is used to assess risk of an adverse clinical event.

Improvement of ECM Techniques through Implementation of a Genetic Algorithm

DTIC Science & Technology

2008-03-01

Range Gate Pull-Off (RGPO), where pulse returns are time - delayed to induce an increase in target distance, and Velocity Gate Pull-Off (VGPO), which...estima- tion, the assumption given is that the signal is a stationary, bandlimited process, 13 where the time delay will be fixed for each interval [11...This configuration, known as a transponder system with constant gain, uses time delayed copies of the original to rebroadcast back into the environment

Mammal extinctions, body size, and paleotemperature

USGS Publications Warehouse

Bown, T.M.; Holroyd, P.A.; Rose, K.D.

1994-01-01

There is a general inverse relationship between the natural logarithm of tooth area (a body size indicator) of some fossil mammals and paleotemperature during approximately 2.9 million years of the early Eocene in the Bighorn Basin of northwest Wyoming. When mean temperatures became warmer, tooth areas tended to become smaller. During colder times, larger species predominated; these generally became larger or remained the same size. Paleotemperature trends also markedly affected patterns of local (and, perhaps, regional) extinction and immigration. New species appeared as immigrants during or near the hottest (smaller forms) and coldest (larger forms) intervals. Paleotemperature trend reversals commonly resulted in the ultimate extinction of both small forms (during cooling intervals) and larger forms (during warming intervals). These immigrations and extinctions mark faunal turnovers that were also modulated by sharp increases in sediment accumulation rate.

The spike trains of inhibited pacemaker neurons seen through the magnifying glass of nonlinear analyses.

PubMed

Segundo, J P; Sugihara, G; Dixon, P; Stiber, M; Bersier, L F

1998-12-01

This communication describes the new information that may be obtained by applying nonlinear analytical techniques to neurobiological time-series. Specifically, we consider the sequence of interspike intervals Ti (the "timing") of trains recorded from synaptically inhibited crayfish pacemaker neurons. As reported earlier, different postsynaptic spike train forms (sets of timings with shared properties) are generated by varying the average rate and/or pattern (implying interval dispersions and sequences) of presynaptic spike trains. When the presynaptic train is Poisson (independent exponentially distributed intervals), the form is "Poisson-driven" (unperturbed and lengthened intervals succeed each other irregularly). When presynaptic trains are pacemaker (intervals practically equal), forms are either "p:q locked" (intervals repeat periodically), "intermittent" (mostly almost locked but disrupted irregularly), "phase walk throughs" (intermittencies with briefer regular portions), or "messy" (difficult to predict or describe succinctly). Messy trains are either "erratic" (some intervals natural and others lengthened irregularly) or "stammerings" (intervals are integral multiples of presynaptic intervals). The individual spike train forms were analysed using attractor reconstruction methods based on the lagged coordinates provided by successive intervals from the time-series Ti. Numerous models were evaluated in terms of their predictive performance by a trial-and-error procedure: the most successful model was taken as best reflecting the true nature of the system's attractor. Each form was characterized in terms of its dimensionality, nonlinearity and predictability. (1) The dimensionality of the underlying dynamical attractor was estimated by the minimum number of variables (coordinates Ti) required to model acceptably the system's dynamics, i.e. by the system's degrees of freedom. Each model tested was based on a different number of Ti; the smallest number whose predictions were judged successful provided the best integer approximation of the attractor's true dimension (not necessarily an integer). Dimensionalities from three to five provided acceptable fits. (2) The degree of nonlinearity was estimated by: (i) comparing the correlations between experimental results and data from linear and nonlinear models, and (ii) tuning model nonlinearity via a distance-weighting function and identifying the either local or global neighborhood size. Lockings were compatible with linear models and stammerings were marginal; nonlinear models were best for Poisson-driven, intermittent and erratic forms. (3) Finally, prediction accuracy was plotted against increasingly long sequences of intervals forecast: the accuracies for Poisson-driven, locked and stammering forms were invariant, revealing irregularities due to uncorrelated noise, but those of intermittent and messy erratic forms decayed rapidly, indicating an underlying deterministic process. The excellent reconstructions possible for messy erratic and for some intermittent forms are especially significant because of their relatively low dimensionality (around 4), high degree of nonlinearity and prediction decay with time. This is characteristic of chaotic systems, and provides evidence that nonlinear couplings between relatively few variables are the major source of the apparent complexity seen in these cases. This demonstration of different dimensions, degrees of nonlinearity and predictabilities provides rigorous support for the categorization of different synaptically driven discharge forms proposed earlier on the basis of more heuristic criteria. This has significant implications. (1) It demonstrates that heterogeneous postsynaptic forms can indeed be induced by manipulating a few presynaptic variables. (2) Each presynaptic timing induces a form with characteristic dimensionality, thus breaking up the preparation into subsystems such that the physical variables in each operate as one

Altered Running Economy Directly Translates to Altered Distance-Running Performance.

PubMed

Hoogkamer, Wouter; Kipp, Shalaya; Spiering, Barry A; Kram, Rodger

2016-11-01

Our goal was to quantify if small (1%-3%) changes in running economy quantitatively affect distance-running performance. Based on the linear relationship between metabolic rate and running velocity and on earlier observations that added shoe mass increases metabolic rate by ~1% per 100 g per shoe, we hypothesized that adding 100 and 300 g per shoe would slow 3000-m time-trial performance by 1% and 3%, respectively. Eighteen male sub-20-min 5-km runners completed treadmill testing, and three 3000-m time trials wearing control shoes and identical shoes with 100 and 300 g of discreetly added mass. We measured rates of oxygen consumption and carbon dioxide production and calculated metabolic rates for the treadmill tests, and we recorded overall running time for the time trials. Adding mass to the shoes significantly increased metabolic rate at 3.5 m·s by 1.11% per 100 g per shoe (95% confidence interval = 0.88%-1.35%). While wearing the control shoes, participants ran the 3000-m time trial in 626.1 ± 55.6 s. Times averaged 0.65% ± 1.36% and 2.37% ± 2.09% slower for the +100-g and +300-g shoes, respectively (P < 0.001). On the basis of a linear fit of all the data, 3000-m time increased 0.78% per added 100 g per shoe (95% confidence interval = 0.52%-1.04%). Adding shoe mass predictably degrades running economy and slows 3000-m time-trial performance proportionally. Our data demonstrate that laboratory-based running economy measurements can accurately predict changes in distance-running race performance due to shoe modifications.

Changes in mitochondrial function and mitochondria associated protein expression in response to 2-weeks of high intensity interval training

PubMed Central

Vincent, Grace; Lamon, Séverine; Gant, Nicholas; Vincent, Peter J.; MacDonald, Julia R.; Markworth, James F.; Edge, Johann A.; Hickey, Anthony J. R.

2015-01-01

Purpose: High-intensity short-duration interval training (HIT) stimulates functional and metabolic adaptation in skeletal muscle, but the influence of HIT on mitochondrial function remains poorly studied in humans. Mitochondrial metabolism as well as mitochondrial-associated protein expression were tested in untrained participants performing HIT over a 2-week period. Methods: Eight males performed a single-leg cycling protocol (12 × 1 min intervals at 120% peak power output, 90 s recovery, 4 days/week). Muscle biopsies (vastus lateralis) were taken pre- and post-HIT. Mitochondrial respiration in permeabilized fibers, citrate synthase (CS) activity and protein expression of peroxisome proliferator-activated receptor gamma coactivator (PGC-1α) and respiratory complex components were measured. Results: HIT training improved peak power and time to fatigue. Increases in absolute oxidative phosphorylation (OXPHOS) capacities and CS activity were observed, but not in the ratio of CCO to the electron transport system (CCO/ETS), the respiratory control ratios (RCR-1 and RCR-2) or mitochondrial-associated protein expression. Specific increases in OXPHOS flux were not apparent after normalization to CS, indicating that gross changes mainly resulted from increased mitochondrial mass. Conclusion: Over only 2 weeks HIT significantly increased mitochondrial function in skeletal muscle independently of detectable changes in mitochondrial-associated and mitogenic protein expression. PMID:25759671

Welfare, maternal work, and on-time childhood vaccination rates.

PubMed

Sohn, Min-Woong; Yoo, Joan; Oh, Elissa H; Amsden, Laura B; Holl, Jane L

2011-12-01

To examine effects of Temporary Assistance for Needy Families welfare cash assistance and maternal work requirements on "on-time" childhood vaccination rates. A stratified random sample of Illinois children from low-income families affected by welfare reform was monitored from 1997 to 2004. Medical records from pediatricians' offices and Medicaid claims data were used to identify the timeliness of 18 recommended vaccinations. Random-intercept logistic models were used to estimate on-time vaccine administration as a function of welfare receipt and maternal work with adjustment for characteristics of the children and mothers and time-varying covariates pertaining to the administration window for each recommended vaccine dose. Of all recommended vaccinations, 55.9% were administered on time. On-time vaccination rates were higher when families were receiving welfare than not (57.4% vs 52.8%). Children in families that either were receiving welfare or had working mothers were 1.7 to 2.1 times more likely to receive vaccinations on time compared with children in families that were not receiving welfare and did not have working mothers. When vaccine doses were stratified according to welfare status, maternal work was associated with decreased on-time vaccination rates (odds ratio: 0.73 [95% confidence interval: 0.59-0.90]) when families received welfare but increased on-time vaccination rates (odds ratio: 1.68 [95% confidence interval: 1.27-2.22]) when they did not receive welfare. These results indicate that maternal work requirements of Temporary Assistance for Needy Families had negative effects on timely administration of childhood vaccinations, although receipt of welfare itself was associated with increased on-time rates.

α7 Nicotinic acetylcholine receptors and temporal memory: Synergistic effects of combining prenatal choline and nicotine on reinforcement-induced resetting of an interval clock

PubMed Central

Cheng, Ruey-Kuang; Meck, Warren H.; Williams, Christina L.

2006-01-01

We previously showed that prenatal choline supplementation could increase the precision of timing and temporal memory and facilitate simultaneous temporal processing in mature and aged rats. In the present study, we investigated the ability of adult rats to selectively control the reinforcement-induced resetting of an internal clock as a function of prenatal drug treatments designed to affect the α7 nicotinic acetylcholine receptor (α7 nAChR). Male Sprague-Dawley rats were exposed to prenatal choline (CHO), nicotine (NIC), methyllycaconitine (MLA), choline + nicotine (CHO + NIC), choline + nicotine + methyllycaconitine (CHO + NIC + MLA), or a control treatment (CON). Beginning at 4-mo-of-age, rats were trained on a peak-interval timing procedure in which food was available at 10-, 30-, and 90-sec criterion durations. At steady-state performance there were no differences in timing accuracy, precision, or resetting among the CON, MLA, and CHO + NIC + MLA treatments. It was observed that the CHO and NIC treatments produced a small, but significant increase in timing precision, but no change in accuracy or resetting. In contrast, the CHO + NIC prenatal treatment produced a dramatic increase in timing precision and selective control of the resetting mechanism with no change in overall timing accuracy. The synergistic effect of combining prenatal CHO and NIC treatments suggests an organizational change in α7 nAChR function that is dependent upon a combination of selective and nonselective nAChR stimulation during early development. PMID:16547161

Intrauterine instillation of diluted seminal plasma at oocyte pick-up does not increase the IVF pregnancy rate: a double-blind, placebo controlled, randomized study.

PubMed

von Wolff, M; Rösner, S; Germeyer, A; Jauckus, J; Griesinger, G; Strowitzki, T

2013-12-01

Does intrauterine application of diluted seminal plasma (SP) at the time of ovum pick-up improve the pregnancy rate by ≥14% in IVF treatment? Intrauterine instillation of diluted SP at the time of ovum pick-up is unlikely to increase the pregnancy rate by ≥14% in IVF. SP modulates endometrial function, and sexual intercourse around the time of embryo transfer has been suggested to increase the likelihood of pregnancy. A previous randomized double-blind pilot study demonstrated a strong trend towards increased pregnancy rates following the intracervical application of undiluted SP. As this study was not conclusive and as the finding could have been confounded by sexual intercourse, the intrauterine application of diluted SP was investigated in the present trial. A single-centre, prospective, double-blind, placebo-controlled, randomized, superiority trial on women undergoing IVF was conducted from April 2007 until February 2012 at the University Department of Gynaecological Endocrinology and Reproductive Medicine, Heidelberg, Germany. The study was powered to detect an 14% increase in the clinical pregnancy rate and two sequential tests were planned using the Pocock spending function. At the first interim analysis, 279 women had been randomly assigned to intrauterine diluted SP (20% SP in saline from the patients' partner) (n = 138) or placebo (n = 141) at the time of ovum pick-up. The clinical pregnancy rate per randomized patient was 37/138 (26.8%) in the SP group and 41/141 (29.1%) in the placebo group (difference: -2.3%, 95% confidence interval of the difference: -12.7 to +8.2%; P = 0.69). The live birth rate per randomized patient was 28/138 (20.3%) in the SP group and 33/141 (23.4%) in the placebo group (difference: -3.1%, 95% confidence interval of the difference: -12.7 to +6.6%; P = 0.56). It was decided to terminate the trial due to futility at the first interim analysis, at a conditional power of 62%. The confidence interval of the difference remains wide, thus clinically relevant differences cannot reliably be excluded based on this single study. The results of this study cast doubt on the validity of the concept that SP increases endometrial receptivity and thus implantation in humans. Funding was provided by the department's own research facilities. DRKS00004615.

Hourly differences in air pollution and risk of respiratory disease in the elderly: a time-stratified case-crossover study.

PubMed

Yorifuji, Takashi; Suzuki, Etsuji; Kashima, Saori

2014-08-13

Epidemiological studies have shown adverse effects of short-term exposure to air pollution on respiratory disease outcomes; however, few studies examined this association on an hourly time scale. We evaluated the associations between hourly changes in air pollution and the risk of respiratory disease in the elderly, using the time of the emergency call as the disease onset for each case. We used a time-stratified case-crossover design. Study participants were 6,925 residents of the city of Okayama, Japan, aged 65 or above who were taken to hospital emergency rooms between January 2006 and December 2010 for onset of respiratory disease. We calculated city-representative hourly average concentrations of air pollutants from several monitoring stations. By using conditional logistic regression models, we estimated odds ratios per interquartile-range increase in each pollutant by exposure period prior to emergency call, adjusting for hourly ambient temperature, hourly relative humidity, and weekly numbers of reported influenza cases aged ≥60. Suspended particulate matter (SPM) exposure 24 to <72 hours prior to the onset and ozone exposure 48 to <96 hours prior to the onset were associated with the increased risk of respiratory disease. For example, following one interquartile-range increase, odds ratios were 1.05 (95% confidence interval: 1.01, 1.09) for SPM exposure 24 to <48 hours prior to the onset and 1.13 (95% confidence interval: 1.04, 1.23) for ozone exposure 72 to <96 hours prior to the onset. Sulfur dioxide (SO2) exposure 0 to <24 hours prior to onset was associated with the increased risk of pneumonia and influenza: odds ratio was 1.07 per one interquartile-range increase (95% confidence interval: 1.00, 1.14). Elevated risk for pneumonia and influenza of SO2 was observed at shorter lags (i.e., 8-18 hours) than the elevated risks for respiratory disease of SPM or ozone. Overall, the effect estimates for chronic obstructive pulmonary disease and allied conditions were equivocal. This study provides further evidence that hourly changes in air pollution exposure increase the risks of respiratory disease, and that SO2 may be related with more immediate onset of the disease than other pollutants.

Responses of heart rate and blood pressure to KC-135 hyper-gravity

NASA Technical Reports Server (NTRS)

Satake, Hirotaka; Matsunami, Ken'ichi; Reschke, Millard F.

1992-01-01

Many investigators have clarified the effects of hyper gravitational-inertial forces (G) upon the cardiovascular system, using the centrifugal apparatus with short rotating radius. We investigated the cardiovascular responses to KC-135 hyper-G flight with negligibly small angular velocity. Six normal, healthy subjects 29 to 40 years old (5 males and 1 female) took part in this experiment. Hyper gravitational-inertial force was generated by the KC-135 hyper-G flight, flown in a spiral path with a very long radius of 1.5 miles. Hyper-G was sustained for 3 minutes with 1.8 +Gz in each session and was repeatedly exposed to very subject sitting on a chair 5 times. The preliminary results of blood pressure and R-R interval are discussed. An exposure of 1.8 +Gz stress resulted in a remarkable increase of systolic and diastolic blood pressure, while the pulse pressure did not change and remained equal to the control level regardless of an exposure of hyper-G. These results in blood pressure indicate an increase of resistance in the peripheral vessels, when an exposure of hyper-G was applied. The R-R interval was calculated from ECG. R-R interval in all subjects was changed but not systematically, and R-R interval became obviously shorter during the hyper-G period than during the 1 +Gz control period although R-R interval varied widely in some cases. The coefficient of variation of R-R interval was estimated to determine the autonomic nerve activity, but no significant change was detectable.

A modeling and simulation approach to characterize methadone QT prolongation using pooled data from five clinical trials in MMT patients.

PubMed

Florian, J; Garnett, C E; Nallani, S C; Rappaport, B A; Throckmorton, D C

2012-04-01

Pharmacokinetic (PK)-pharmacodynamic modeling and simulation were used to establish a link between methadone dose, concentrations, and Fridericia rate-corrected QT (QTcF) interval prolongation, and to identify a dose that was associated with increased risk of developing torsade de pointes. A linear relationship between concentration and QTcF described the data from five clinical trials in patients on methadone maintenance treatment (MMT). A previously published population PK model adequately described the concentration-time data, and this model was used for simulation. QTcF was increased by a mean (90% confidence interval (CI)) of 17 (12, 22) ms per 1,000 ng/ml of methadone. Based on this model, doses >120 mg/day would increase the QTcF interval by >20 ms. The model predicts that 1-3% of patients would have ΔQTcF >60 ms, and 0.3-2.0% of patients would have QTcF >500 ms at doses of 160-200 mg/day. Our predictions are consistent with available observational data and support the need for electrocardiogram (ECG) monitoring and arrhythmia risk factor assessment in patients receiving methadone doses >120 mg/day.

Individualized Infliximab Treatment Guided by Patient-managed eHealth in Children and Adolescents with Inflammatory Bowel Disease.

PubMed

Carlsen, Katrine; Houen, Gunnar; Jakobsen, Christian; Kallemose, Thomas; Paerregaard, Anders; Riis, Lene B; Munkholm, Pia; Wewer, Vibeke

2017-09-01

To individualize timing of infliximab (IFX) treatment in children and adolescents with inflammatory bowel disease (IBD) using a patient-managed eHealth program. Patients with IBD, 10 to 17 years old, treated with IFX were prospectively included. Starting 4 weeks after their last infusion, patients reported a weekly symptom score and provided a stool sample for fecal calprotectin analysis. Based on symptom scores and fecal calprotectin results, the eHealth program calculated a total inflammation burden score that determined the timing of the next IFX infusion (4-12 wk after the previous infusion). Quality of Life was scored by IMPACT III. A control group was included to compare trough levels of IFX antibodies and concentrations and treatment intervals. Patients and their parents evaluated the eHealth program. There were 29 patients with IBD in the eHealth group and 21 patients with IBD in the control group. During the control period, 94 infusions were provided in the eHealth group (mean interval 9.5 wk; SD 2.3) versus 105 infusions in the control group (mean interval 6.9 wk; SD 1.4). Treatment intervals were longer in the eHealth group (P < 0.001). Quality of Life did not change during the study. Appearance of IFX antibodies did not differ between the 2 groups. Eighty percent of patients reported increased disease control and 63% (86% of parents) reported an improved knowledge of the disease. Self-managed, eHealth-individualized timing of IFX treatments, with treatment intervals of 4 to 12 weeks, was accompanied by no significant development of IFX antibodies. Patients reported better control and improved knowledge of their IBD.

Moderate Recovery Unnecessary to Sustain High Stroke Volume during Interval Training. A Brief Report

PubMed Central

Stanley, Jamie; Buchheit, Martin

2014-01-01

It has been suggested that the time spent at a high stroke volume (SV) is important for improving maximal cardiac function. The aim of this study was to examine the effect of recovery intensity on cardiovascular parameters during a typical high-intensity interval training (HIIT) session in fourteen well-trained cyclists. Oxygen consumption (VO2), heart rate (HR), SV, cardiac output (Qc), and oxygenation of vastus lateralis (TSI) were measured during a HIIT (3×3-min work period, 2 min of recovery) session on two occasions. VO2, HR and Qc were largely higher during moderate-intensity (60%) compared with low-intensity (30%) (VO2, effect size; ES = +2.6; HR, ES = +2.8; Qc, ES = +2.2) and passive (HR, ES = +2.2; Qc, ES = +1.7) recovery. By contrast, there was no clear difference in SV between the three recovery conditions, with the SV during the two active recovery periods not being substantially different than during exercise (60%, ES = −0.1; 30%, ES = −0.2). To conclude, moderate-intensity recovery may not be required to maintain a high SV during HIIT. Key points Moderate-intensity recovery periods may not be necessary to maintain high stroke volume during the exercise intervals of HIIT. Stroke volume did not surpass the levels attained during the exercise intervals during the recovery periods of HIIT. The practical implication of these finding is that reducing the intensity of the recovery period during a HIIT protocol may prolong the time to exhaustion, potentially allowing completion of additional high-intensity intervals increasing the time accumulated at maximal cardiac output. PMID:24790495

The error and bias of supplementing a short, arid climate, rainfall record with regional vs. global frequency analysis

NASA Astrophysics Data System (ADS)

Endreny, Theodore A.; Pashiardis, Stelios

2007-02-01

SummaryRobust and accurate estimates of rainfall frequencies are difficult to make with short, and arid-climate, rainfall records, however new regional and global methods were used to supplement such a constrained 15-34 yr record in Cyprus. The impact of supplementing rainfall frequency analysis with the regional and global approaches was measured with relative bias and root mean square error (RMSE) values. Analysis considered 42 stations with 8 time intervals (5-360 min) in four regions delineated by proximity to sea and elevation. Regional statistical algorithms found the sites passed discordancy tests of coefficient of variation, skewness and kurtosis, while heterogeneity tests revealed the regions were homogeneous to mildly heterogeneous. Rainfall depths were simulated in the regional analysis method 500 times, and then goodness of fit tests identified the best candidate distribution as the general extreme value (GEV) Type II. In the regional analysis, the method of L-moments was used to estimate location, shape, and scale parameters. In the global based analysis, the distribution was a priori prescribed as GEV Type II, a shape parameter was a priori set to 0.15, and a time interval term was constructed to use one set of parameters for all time intervals. Relative RMSE values were approximately equal at 10% for the regional and global method when regions were compared, but when time intervals were compared the global method RMSE had a parabolic-shaped time interval trend. Relative bias values were also approximately equal for both methods when regions were compared, but again a parabolic-shaped time interval trend was found for the global method. The global method relative RMSE and bias trended with time interval, which may be caused by fitting a single scale value for all time intervals.

Time to brain imaging in acute stroke is improving: secondary analysis of the INSTINCT trial.

PubMed

Sauser, Kori; Burke, James F; Levine, Deborah A; Scott, Phillip A; Meurer, William J

2014-01-01

Patients with acute ischemic stroke benefit from rapid evaluation and treatment, and timely brain imaging is a necessary component. We determined the effect of a targeted behavioral intervention on door-to-imaging time (DIT) among patients with ischemic stroke treated with tissue-type plasminogen activator. Second, we examined the variation in DIT accounted for by patient-level and hospital-level factors. The Increasing Stroke Treatment through Interventional behavioral Change Tactics (INSTINCT) trial was a cluster-randomized, controlled trial involving 24 Michigan hospitals. The intervention aimed to increase tissue-type plasminogen activator utilization. Detailed chart abstractions collected data for 557 patients with ischemic stroke. We used a series of hierarchical linear mixed-effects models to evaluate the effect of the intervention on DIT (difference-in-differences analysis) and used patient-level and hospital-level explanatory variables to decompose variation in DIT. DIT improved over time, without a difference between intervention and control hospitals (intervention: 23.7-19.3 minutes, control: 28.9-19.2 minutes; P=0.56). Adjusted DIT was faster in patients who arrived by ambulance (7.2 minutes; 95% confidence interval, 4.1-10.2), had severe strokes (1.0 minute per +5-point National Institutes of Health Stroke Scale; 95% confidence interval, 0.1-2.0), and presented in the postintervention period (4.9 minutes; 95% confidence interval, 2.3-7.4). After accounting for these factors, 13.8% of variation in DIT was attributable to hospital. Neither hospital stroke volume nor stroke center status was associated with DIT. Performance on DIT improved similarly in intervention and control hospitals, suggesting that nonintervention factors explain the improvement. Hospital-level factors explain a modest proportion of variation in DIT, but further research is needed to identify the hospital-level factors responsible.

Use of Self-Matching to Control for Stable Patient Characteristics While Addressing Time-Varying Confounding on Treatment Effect: A Case Study of Older Intensive Care Patients.

PubMed

Han, Ling; Pisani, M A; Araujo, K L B; Allore, Heather G

Exposure-crossover design offers a non-experimental option to control for stable baseline confounding through self-matching while examining causal effect of an exposure on an acute outcome. This study extends this approach to longitudinal data with repeated measures of exposure and outcome using data from a cohort of 340 older medical patients in an intensive care unit (ICU). The analytic sample included 92 patients who received ≥1 dose of haloperidol, an antipsychotic medication often used for patients with delirium. Exposure-crossover design was implemented by sampling the 3-day time segments prior ( Induction) and posterior ( Subsequent) to each treatment episode of receiving haloperidol. In the full cohort, there was a trend of increasing delirium severity scores (Mean±SD: 4.4±1.7) over the course of the ICU stay. After exposure-crossover sampling, the delirium severity score decreased from the Induction (4.9) to the Subsequent (4.1) intervals, with the treatment episode falling in-between (4.5). Based on a GEE Poisson model accounting for self-matching and within-subject correlation, the unadjusted mean delirium severity scores was -0.55 (95% CI: -1.10, -0.01) points lower for the Subsequent than the Induction intervals. The association diminished by 32% (-0.38, 95%CI: -0.99, 0.24) after adjusting only for ICU confounding, while being slightly increased by 7% (-0.60, 95%CI: -1.15, -0.04) when adjusting only for baseline characteristics. These results suggest that longitudinal exposure-crossover design is feasible and capable of partially removing stable baseline confounding through self-matching. Loss of power due to eliminating treatment-irrelevant person-time and uncertainty around allocating person-time to comparison intervals remain methodological challenges.

The stability of M(max) and H (max) amplitude over time.

PubMed

McNulty, Penelope A; Shiner, Christine T; Thayaparan, Ganesha K; Burke, David

2012-05-01

The stability of the maximal muscle response (M(max)) is critical to H reflex methodology. It has previously been reported that the amplitude of M(max) declines over time. If reproducible, this finding would have implications for all experimental studies that normalise the output of the motoneurone pool against the M wave. We investigated the effect of time on changes in M(max) and the maximal H reflex (H(max)) evoked at 4-s intervals over 60 min. To identify an influence of homosynaptic depression, we extended the interstimulus interval to 10 s and the time to 100 min. Two recording montages over soleus were used to ensure that interelectrode distance was not a critical factor. The soleus M(max) and H reflex were evoked by stimulation of the tibial nerve in the popliteal fossa in 7 subjects who sat with the knee flexed to 30° and the ankle plantar flexed by ~30°. We found no change in the pooled data for M(max), H(max), a reflex 50% of maximal, or the current required to produce it. However, one subject had a statistically significant increase in M(max) and a concurrent decrease in H(max) regardless of the interstimulus interval. On average, there was no change in the H(max)/M(max) ratio over time. While both M(max) and H(max) may change in response to many factors, these results suggest that, typically, time is not one of them.

Intrafraction Prostate Translations and Rotations During Hypofractionated Robotic Radiation Surgery: Dosimetric Impact of Correction Strategies and Margins

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

Water, Steven van de, E-mail: s.vandewater@erasmusmc.nl; Valli, Lorella; Alma Mater Studiorum, Department of Physics and Astronomy, Bologna University, Bologna

Purpose: To investigate the dosimetric impact of intrafraction prostate motion and the effect of robot correction strategies for hypofractionated CyberKnife treatments with a simultaneously integrated boost. Methods and Materials: A total of 548 real-time prostate motion tracks from 17 patients were available for dosimetric simulations of CyberKnife treatments, in which various correction strategies were included. Fixed time intervals between imaging/correction (15, 60, 180, and 360 seconds) were simulated, as well as adaptive timing (ie, the time interval reduced from 60 to 15 seconds in case prostate motion exceeded 3 mm or 2° in consecutive images). The simulated extent of robot corrections was alsomore » varied: no corrections, translational corrections only, and translational corrections combined with rotational corrections up to 5°, 10°, and perfect rotational correction. The correction strategies were evaluated for treatment plans with a 0-mm or 3-mm margin around the clinical target volume (CTV). We recorded CTV coverage (V{sub 100%}) and dose-volume parameters of the peripheral zone (boost), rectum, bladder, and urethra. Results: Planned dose parameters were increasingly preserved with larger extents of robot corrections. A time interval between corrections of 60 to 180 seconds provided optimal preservation of CTV coverage. To achieve 98% CTV coverage in 98% of the treatments, translational and rotational corrections up to 10° were required for the 0-mm margin plans, whereas translational and rotational corrections up to 5° were required for the 3-mm margin plans. Rectum and bladder were spared considerably better in the 0-mm margin plans. Adaptive timing did not improve delivered dose. Conclusions: Intrafraction prostate motion substantially affected the delivered dose but was compensated for effectively by robot corrections using a time interval of 60 to 180 seconds. A 0-mm margin required larger extents of additional rotational corrections than a 3-mm margin but resulted in lower doses to rectum and bladder.« less

Talofibular interval changes after acute ankle sprain: a stress ultrasonography study of ankle laxity.

PubMed

Croy, Theodore; Saliba, Susan; Saliba, Ethan; Anderson, Mark W; Hertel, Jay

2013-11-01

Quantifying talocrural joint laxity after ankle sprain is problematic. Stress ultrasonography (US) can image the lateral talocrural joint and allow the measurement of the talofibular interval, which may suggest injury to the anterior talofibular ligament (ATFL). The acute talofibular interval changes after lateral ankle sprain are unknown. Twenty-five participants (9 male, 16 female; age 21.8 ± 3.2 y, height 167.8 ± 34.1 cm, mass 72.7 ± 13.8 kg) with 27 acute, lateral ankle injuries underwent bilateral stress US imaging at baseline (<7 d) and on the affected ankle at 3 wk and 6 wk from injury in 3 ankle conditions: neutral, anterior drawer, and inversion. Talofibular interval (mm) was measured using imaging software and self-reported function (activities of daily living [ADL] and sports) by the Foot and Ankle Ability Measure (FAAM). The talofibular interval increased with anterior-drawer stress in the involved ankle (22.65 ± 3.75 mm; P = .017) over the uninvolved ankle (19.45 ± 2.35 mm; limb × position F1,26 = 4.9, P = .035) at baseline. Inversion stress also resulted in greater interval changes (23.41 ± 2.81 mm) than in the uninvolved ankles (21.13 ± 2.08 mm). A main effect for time was observed for inversion (F2,52 = 4.3, P = .019, 21.93 ± 2.24 mm) but not for anterior drawer (F2,52 = 3.1, P = .055, 21.18 ± 2.34 mm). A significant reduction in the talofibular interval took place between baseline and week 3 inversion measurements only (F1,26 = 5.6, P = .026). FAAM-ADL and sports results increased significantly from baseline to wk 3 (21.9 ± 16.2, P < .0001 and 23.8 ± 16.9, P < .0001) and from wk 3 to wk 6 (2.5 ± 4.4, P = .009 and 10.5 ± 13.2, P = .001). Stress US methods identified increased talofibular interval changes suggestive of talocrural laxity and ATFL injury using anterior drawer and inversion stress that, despite significant improvements in self-reported function, only marginally improved during the 6 wk after ankle sprain. Stress US provides a safe, repeatable, and quantifiable method of measuring the talofibular interval and may augment manual stress examinations in acute ankle injuries.

Characterization of Cardiac Time Intervals in Healthy Bonnet Macaques (Macaca radiata) by Using an Electronic Stethoscope

PubMed Central

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

2011-01-01

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

Remembering Places in Space: A Human Analog Study of the Morris Water Maze

NASA Astrophysics Data System (ADS)

Fitting, Sylvia; Allen, Gary L.; Wedell, Douglas H.

We conducted a human analog study of the Morris Water Maze, with individuals indicating a remembered location in a 3 m diameter arena over different intervals of time and with different memory loads. The primary focus of the study was to test a theory of how varying cue location and number of cues affects memory for spatial location. As expected, memory performance, as measured by proximity to the actual location, was negatively affected by increasing memory load, increasing delay interval, and decreasing the number of cues. As memory performance decremented, bias effects increased and were in accordance with the cue-based memory model described by Fitting, Wedell and Allen (2005). Specifically, remembered locations were biased toward the nearest cue and error decreased with more cues. These results demonstrate that localization processes that apply to small two-dimensional task fields may generalize to a larger traversable task field.

Short communication: use of a mechanical brush by Holstein dairy cattle around parturition.

PubMed

Newby, Nathalie C; Duffield, Todd F; Pearl, David L; Leslie, Ken E; LeBlanc, Stephen J; von Keyserlingk, Marina A G

2013-04-01

Grooming is a normal behavior that may contribute to relief of stress. The purpose of this study was to investigate the effect of access to a mechanical brush on auto-grooming behavior in parturient cows. The hypothesis was that cows would increase the total time spent scratching using the brush if they had access to a brush around the time of calving, whereas auto-grooming would be lower for the brush group compared with the no-brush group. The use of a mechanical brush was analyzed both in a group-housed pen (72 to 48 h before calving) and in an individual maternity pen (6h before to 6h after calving) in 16 multiparous Holstein cows. In the maternity pen, cows were randomly assigned to have access to the brush or not. The provision of a mechanical brush in the individual maternity pen did not change the amount of time spent auto-grooming but cows did use the brush before calving and after the calf was removed. Despite being housed in pens containing a brush, cows failed to use it when the calf was present. However, cows with access to a brush spent more time licking their calves in the first hour postcalving (β=8.7 min; 95% confidence interval: 1.5, 15.8) than cows that did not have access to a brush. Regardless of treatment, cows increased the time spent auto-grooming and scratching following separation of their newborn calf (β=1.4 min; 95% confidence interval: 0.46, 2.3 and β=0.07 min; 95% confidence interval: 0.02, 0.12, respectively). Further research is warranted to investigate possible benefits of mechanical brush devices at the time of calving, particularly for cows that experience difficult calving and require manual or mechanical assistance. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Method and system for benchmarking computers

DOEpatents

Gustafson, John L.

1993-09-14

A testing system and method for benchmarking computer systems. The system includes a store containing a scalable set of tasks to be performed to produce a solution in ever-increasing degrees of resolution as a larger number of the tasks are performed. A timing and control module allots to each computer a fixed benchmarking interval in which to perform the stored tasks. Means are provided for determining, after completion of the benchmarking interval, the degree of progress through the scalable set of tasks and for producing a benchmarking rating relating to the degree of progress for each computer.

Fractal analyses reveal independent complexity and predictability of gait

PubMed Central

Dierick, Frédéric; Nivard, Anne-Laure

2017-01-01

Locomotion is a natural task that has been assessed for decades and used as a proxy to highlight impairments of various origins. So far, most studies adopted classical linear analyses of spatio-temporal gait parameters. Here, we use more advanced, yet not less practical, non-linear techniques to analyse gait time series of healthy subjects. We aimed at finding more sensitive indexes related to spatio-temporal gait parameters than those previously used, with the hope to better identify abnormal locomotion. We analysed large-scale stride interval time series and mean step width in 34 participants while altering walking direction (forward vs. backward walking) and with or without galvanic vestibular stimulation. The Hurst exponent α and the Minkowski fractal dimension D were computed and interpreted as indexes expressing predictability and complexity of stride interval time series, respectively. These holistic indexes can easily be interpreted in the framework of optimal movement complexity. We show that α and D accurately capture stride interval changes in function of the experimental condition. Walking forward exhibited maximal complexity (D) and hence, adaptability. In contrast, walking backward and/or stimulation of the vestibular system decreased D. Furthermore, walking backward increased predictability (α) through a more stereotyped pattern of the stride interval and galvanic vestibular stimulation reduced predictability. The present study demonstrates the complementary power of the Hurst exponent and the fractal dimension to improve walking classification. Our developments may have immediate applications in rehabilitation, diagnosis, and classification procedures. PMID:29182659

Smoked marijuana effects on tobacco cigarette smoking behavior.

PubMed

Kelly, T H; Foltin, R W; Rose, A J; Fischman, M W; Brady, J V

1990-03-01

The effects of marijuana smoke exposure on several measures of tobacco cigarette smoking behavior were examined. Eight healthy adult male volunteers, who smoked both tobacco and marijuana cigarettes, participated in residential studies, lasting 10 to 15 days, designed to measure the effects of marijuana smoke exposure on a range of behavioral variables. Tobacco cigarettes were available throughout the day (9:00 A.M. until midnight). Each day was divided into a private period (9:00 A.M. to 5:00 P.M.), during which subjects were socially isolated, and a social period (5:00 P.M. to midnight), during which subjects could interact. Under blind conditions, subjects smoked placebo and active marijuana cigarettes (0%, 1.3%, 2.3%, or 2.7% delta 9-tetrahydrocannabinol) four times daily (9:45 A.M., 1:30 P.M., 5:00 P.M. and 8:30 P.M.). Each subject was exposed to both placebo and one active dose over 2- to 5-consecutive-day intervals, and dose conditions (i.e., placebo or active) alternated throughout the study. Active marijuana smoking significantly decreased the number of daily tobacco smoking bouts, increased inter-bout intervals and decreased inter-puff intervals. Marijuana decreased the number of tobacco smoking bouts by delaying the initiation of tobacco cigarette smoking immediately after marijuana smoking, whereas decreases in inter-puff intervals were unrelated to the time of marijuana smoking. No consistent interactions between marijuana effects and social or private periods (i.e., time of day) were observed.

Intracellular Calcium and the Mechanism of Anodal Supernormal Excitability in Langendorff Perfused Rabbit Ventricles

PubMed Central

Joung, Boyoung; Park, Hyung-Wook; Maruyama, Mitsunori; Tang, Liang; Song, Juan; Han, Seongwook; Piccirillo, Gianfranco; Weiss, James N.; Lin, Shien-Fong; Chen, Peng-Sheng

2012-01-01

Background Anodal stimulation hyperpolarizes cell membrane and increases intracellular Ca2+ (Cai) transient. This study tested the hypothesis that The maximum slope of Cai decline (–(dCai/dt)max) corresponds to the timing of anodal dip on the strength-interval curve and the initiation of repetitive responses and ventricular fibrillation (VF) after a premature stimulus (S2). Methods and Results We simultaneously mapped membrane potential (Vm) and Cai in 23 rabbit ventricles. A dip was observed on the anodal strength-interval curve. During the anodal dip, ventricles were captured by anodal break excitation directly under the S2 electrode. The Cai following anodal stimuli is larger than that following cathodal stimuli. The S1-S2 intervals of the anodal dip (203 ± 10 ms) coincided with the -(dCai/dt)max (199 ± 10 ms, p=NS). BAPTA-AM (n=3), INCX inhibition by low extracellular Na+ (n=3), and combined ryanodine and thapsigargin infusion (n=2) eliminated the anodal supernormality. Strong S2 during the relative refractory period (n=5) induced 29 repetitive responses and 10 VF episodes. The interval between S2 and the first non-driven beat was coincidental with the time of -(dCai/dt)max. Conclusions Larger Cai transient and INCX activation induced by anodal stimulation produces anodal supernormality. Time of maximum INCX activation is coincidental to the induction of non- driven beats from the Cai sinkhole after a strong premature stimulation. PMID:21301131

Is breast compression associated with breast cancer detection and other early performance measures in a population-based breast cancer screening program?

PubMed

Moshina, Nataliia; Sebuødegård, Sofie; Hofvind, Solveig

2017-06-01

We aimed to investigate early performance measures in a population-based breast cancer screening program stratified by compression force and pressure at the time of mammographic screening examination. Early performance measures included recall rate, rates of screen-detected and interval breast cancers, positive predictive value of recall (PPV), sensitivity, specificity, and histopathologic characteristics of screen-detected and interval breast cancers. Information on 261,641 mammographic examinations from 93,444 subsequently screened women was used for analyses. The study period was 2007-2015. Compression force and pressure were categorized using tertiles as low, medium, or high. χ 2 test, t tests, and test for trend were used to examine differences between early performance measures across categories of compression force and pressure. We applied generalized estimating equations to identify the odds ratios (OR) of screen-detected or interval breast cancer associated with compression force and pressure, adjusting for fibroglandular and/or breast volume and age. The recall rate decreased, while PPV and specificity increased with increasing compression force (p for trend <0.05 for all). The recall rate increased, while rate of screen-detected cancer, PPV, sensitivity, and specificity decreased with increasing compression pressure (p for trend <0.05 for all). High compression pressure was associated with higher odds of interval breast cancer compared with low compression pressure (1.89; 95% CI 1.43-2.48). High compression force and low compression pressure were associated with more favorable early performance measures in the screening program.

Effects of high-intensity interval cycling performed after resistance training on muscle strength and hypertrophy.

PubMed

Tsitkanou, S; Spengos, K; Stasinaki, A-N; Zaras, N; Bogdanis, G; Papadimas, G; Terzis, G

2017-11-01

Aim of the study was to investigate whether high-intensity interval cycling performed immediately after resistance training would inhibit muscle strength increase and hypertrophy expected from resistance training per se. Twenty-two young men were assigned into either resistance training (RE; N = 11) or resistance training plus high-intensity interval cycling (REC; N = 11). Lower body muscle strength and rate of force development (RFD), quadriceps cross-sectional area (CSA) and vastus lateralis muscle architecture, muscle fiber type composition and capillarization, and estimated aerobic capacity were evaluated before and after 8 weeks of training (2 times per week). Muscle strength and quadriceps CSA were significantly and similarly increased after both interventions. Fiber CSA increased significantly and similarly after both RE (type I: 13.6 ± 3.7%, type IIA: 17.6 ± 4.4%, type IIX: 23.2 ± 5.7%, P < 0.05) and REC (type I: 10.0 ± 2.7%, type IIA: 14.8 ± 4.3% type IIX: 20.8 ± 6.0%, P < 0.05). In contrast, RFD decreased and fascicle angle increased (P < 0.05) only after REC. Capillary density and estimated aerobic capacity increased (P < 0.05) only after REC. These results suggest that high-intensity interval cycling performed after heavy-resistance exercise may not inhibit resistance exercise-induced muscle strength/hypertrophy after 2 months of training, while it prompts aerobic capacity and muscle capillarization. The addition of high-intensity cycling after heavy-resistance exercise may decrease RFD partly due to muscle architectural changes. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of number of cows in estrus and confinement area on estrous behavior of beef cows.

PubMed

Floyd, L N; Lents, C A; White, F J; Wettemann, R P

2009-06-01

Mature Angus and Angus x Hereford cows were used to determine the effects of confinement area and number of cows in estrus on estrous behavior. During each of 2 replicates, 32 nonpregnant, nonlactating cows were maintained in a drylot (60 x 100 m) or in a pasture (12 ha). Estrous cycles were synchronized with 2 injections of PGF(2alpha) 10 to 14 d apart at the initiation of the experiment. Thereafter, PGF(2alpha) was administered between d 6 and 18 of the estrous cycle so that 1, 2 to 3, 4 to 6, or > or = 7 cows were in estrus at the same time. Concentrations of progesterone were quantified in plasma at treatment to ensure cows had a normal response to PGF(2alpha). Duration of estrus and the number of mounts received during estrus were recorded by HeatWatch. If any part of estrus for a cow occurred at the same time as estrus for another cow, the cow was considered to have concurrent estrus with the other cow. Cows in the drylot had a shorter (P < 0.02; 61.8 +/- 3.1 h) interval to estrus after PGF(2alpha) compared with cows on pasture (72.8 +/- 3.3 h). The interval to estrus was longer (P < 0.07) when cows were treated with PGF(2alpha) on d 10 to 13 (76.7 +/- 3.3 h) of the estrous cycle than when treated on d 6 to 9 (62.3 +/- 4.7 h) or d 14 to 18 (62.9 +/- 3.6 h). Increasing the number of cows concurrently in estrus increased the number of mounts each cow received per estrus (P < 0.001) and the duration of estrus (P < 0.01). When only 1 cow was in estrus, she received 11.0 +/- 6.2 mounts during 11.6 +/- 1.5 h. When > or = 7 cows were in estrus at the same time, each cow received 50.4 +/- 3.2 mounts during 17.3 +/- 0.8 h. Cows in drylot were in estrus longer (P < 0.04; 16.4 +/- 0.8 h) than cows on pasture (14.2 +/- 0.7 h). Duration of the longest interval between mounts received decreased (P < 0.002) as the number of cows in estrus at one time increased (5.3 +/- 0.7 h for 1 estrous cow; 2.6 +/- 0.3 h when > or = 7 cows were in estrus). We conclude that increasing the number of beef cows in estrus at the same time will increase the number of times a cow is mounted and the duration of estrus. The increase in estrous behavior associated with more cows in estrus could increase the number of estrous cows detected with infrequent visual observation.

Effect of cimetidine and ranitidine on pharmacokinetics and pharmacodynamics of a single dose of dofetilide

PubMed Central

Abel, Samantha; Nichols, Donald J; Brearley, Christopher J; Eve, Malcolm D

2000-01-01

Aims The aim of this open-label, placebo-controlled, randomized, four-period crossover study was to determine the effects of cimetidine and ranitidine on the pharmacokinetics and pharmacodynamics of a single dose of dofetilide. Methods Twenty healthy male subjects received 100 or 400 mg twice daily of cimetidine, 150 mg twice daily of ranitidine, or placebo for 4 days. On the second day, a single oral 500 μg dose of dofetilide was administered immediately after the morning doses of cimetidine, ranitidine, or placebo. Treatment periods were separated by 1–2 weeks. Pharmacokinetic parameters were determined from plasma and urinary dofetilide concentrations; prolongation of the QTc interval was determined from three-lead electrocardiograms. Results Ranitidine did not significantly affect the pharmacokinetics or pharmacodynamics of dofetilide; however, a dose-dependent increase in exposure to dofetilide was observed with cimetidine. When dofetilide was administered with 100 and 400 mg of cimetidine, the area under the plasma concentration-time curve of dofetilide increased by 11% and 48% and the maximum plasma dofetilide concentration increased by 11% and 29%, respectively. The respective cimetidine doses reduced renal clearance of dofetilide by 13% and 33% and nonrenal clearance by 5% and 21%. Dofetilide-induced prolongation of the QTc interval was enhanced by cimetidine; the mean maximum change in QTc interval from baseline was increased by 22% and 33% with 100 and 400 mg of cimetidine, respectively. However, the relationship between the prolongation of the QTc interval and plasma dofetilide concentrations was unaffected by cimetidine or ranitidine; a 1 ng ml−1 increase in plasma dofetilide concentration produced a 17–19 ms prolongation of the QTc interval. Dofetilide was well tolerated, with no treatment-related adverse events or laboratory abnormalities. Conclusions These results suggest that cimetidine increased dofetilide exposure by inhibiting renal tubular dofetilide secretion, whereas ranitidine did not. This effect is not an H2-receptor antagonist class effect but is specific to cimetidine. If therapy with an H2-receptor antagonist is required, it is recommended that cimetidine at all doses be avoided; since ranitidine has no effect on dofetilide pharmacokinetics or prolongation of the QTc interval, it can be seen as a suitable alternative. PMID:10606839

Optimal methods for fitting probability distributions to propagule retention time in studies of zoochorous dispersal.

PubMed

Viana, Duarte S; Santamaría, Luis; Figuerola, Jordi

2016-02-01

Propagule retention time is a key factor in determining propagule dispersal distance and the shape of "seed shadows". Propagules dispersed by animal vectors are either ingested and retained in the gut until defecation or attached externally to the body until detachment. Retention time is a continuous variable, but it is commonly measured at discrete time points, according to pre-established sampling time-intervals. Although parametric continuous distributions have been widely fitted to these interval-censored data, the performance of different fitting methods has not been evaluated. To investigate the performance of five different fitting methods, we fitted parametric probability distributions to typical discretized retention-time data with known distribution using as data-points either the lower, mid or upper bounds of sampling intervals, as well as the cumulative distribution of observed values (using either maximum likelihood or non-linear least squares for parameter estimation); then compared the estimated and original distributions to assess the accuracy of each method. We also assessed the robustness of these methods to variations in the sampling procedure (sample size and length of sampling time-intervals). Fittings to the cumulative distribution performed better for all types of parametric distributions (lognormal, gamma and Weibull distributions) and were more robust to variations in sample size and sampling time-intervals. These estimated distributions had negligible deviations of up to 0.045 in cumulative probability of retention times (according to the Kolmogorov-Smirnov statistic) in relation to original distributions from which propagule retention time was simulated, supporting the overall accuracy of this fitting method. In contrast, fitting the sampling-interval bounds resulted in greater deviations that ranged from 0.058 to 0.273 in cumulative probability of retention times, which may introduce considerable biases in parameter estimates. We recommend the use of cumulative probability to fit parametric probability distributions to propagule retention time, specifically using maximum likelihood for parameter estimation. Furthermore, the experimental design for an optimal characterization of unimodal propagule retention time should contemplate at least 500 recovered propagules and sampling time-intervals not larger than the time peak of propagule retrieval, except in the tail of the distribution where broader sampling time-intervals may also produce accurate fits.

Factors influencing pre-hospital care time intervals in Iran: a qualitative study.

PubMed

Khorasani-Zavareh, Davoud; Mohammadi, Reza; Bohm, Katarina

2018-06-23

Pre-hospital time management provides better access to victims of road traffic crashes (RTCs) and can help minimize preventable deaths, injuries and disabilities. While most studies have been focused on measuring various time intervals in the pre-hospital phase, to our best knowledge there is no study exploring the barriers and facilitators that affects these various intervals qualitatively. The present study aimed to explore factors affecting various time intervals relating to road traffic incidents in the pre-hospital phase and provides suggestions for improvements in Iran. The study was conducted during 2013-2014 at both the national and local level in Iran. Overall, 18 face-to-face interviews with emergency medical services (EMS) personnel were used for data collection. Qualitative content analysis was employed to analyze the data. The most important barriers in relation to pre-hospital intervals were related to the manner of cooperation by members of the public with the EMS and their involvement at the crash scene, as well as to pre-hospital system factors, including the number and location of EMS facilities, type and number of ambulances and manpower. These factors usually affect how rapidly the EMS can arrive at the scene of the crash and how quickly victims can be transferred to hospital. These two categories have six main themes: notification interval; activation interval; response interval; on-scene interval; transport interval; and delivery interval. Despite more focus on physical resources, cooperation from members of the public needs to be taken in account in order to achieve better pre-hospital management of the various intervals, possibly through the use of public education campaigns.

Trends in risk factor prevalence and management before first stroke: data from the South London Stroke Register 1995-2011.

PubMed

Marshall, Iain J; Wang, Yanzhong; McKevitt, Christopher; Rudd, Anthony G; Wolfe, Charles D A

2013-07-01

Vascular risk factors are suboptimally managed internationally. This study investigated time trends in risk factors diagnosed before stroke and their treatment, and factors associated with appropriate medication use. A total of 4416 patients with a first stroke were registered in the population-based South London Stroke Register from 1995 to 2011. Previously diagnosed risk factors and usual medications were collected from patients' primary care and hospital records. Trends and associations were assessed using multivariate logistic regression. Seventy-two percent of patients were diagnosed previously with 1 or more risk factors; 30% had diagnosed risk factors that were untreated. Hypercholesterolemia increased significantly during the study period; myocardial infarction and transient ischemic attack prevalences decreased. Antiplatelet prescription increased in atrial fibrillation (AF), myocardial infarction, and transient ischemic attack (AF, 37%-51%, P<0.001; myocardial infarction, 48%-69%, P<0.001; transient ischemic attack, 49%-61%, P=0.015). Anticoagulant prescription for AF showed a nonsignificant increase (12%-23%; P=0.059). Fewer older patients with AF were prescribed anticoagulants (age, >85 versus <65 years; adjusted relative risk, 0.19; 95% confidence interval, 0.08-0.41). Black ethnicity (adjusted relative risk, 1.17; 95% confidence interval, 1.10-1.23) and female sex (adjusted relative risk, 1.09; 95% confidence interval, 1.03-1.15) were associated with increased antihypertensive drug prescription; other medications did not vary by ethnicity or sex. Antiplatelet and cholesterol-lowering treatment prescribing have improved significantly over time; however, only a minority with AF received anticoagulants, and this did not improve significantly. Overall, 30% of strokes occurred in patients with previously diagnosed but untreated risk factors.

Advanced analysis of finger-tapping performance: a preliminary study.

PubMed

Barut, Cağatay; Kızıltan, Erhan; Gelir, Ethem; Köktürk, Fürüzan

2013-06-01

The finger-tapping test is a commonly employed quantitative assessment tool used to measure motor performance in the upper extremities. This task is a complex motion that is affected by external stimuli, mood and health status. The complexity of this task is difficult to explain with a single average intertap-interval value (time difference between successive tappings) which only provides general information and neglects the temporal effects of the aforementioned factors. This study evaluated the time course of average intertap-interval values and the patterns of variation in both the right and left hands of right-handed subjects using a computer-based finger-tapping system. Cross sectional study. Thirty eight male individuals aged between 20 and 28 years (Mean±SD = 22.24±1.65) participated in the study. Participants were asked to perform single-finger-tapping test for 10 seconds of test period. Only the results of right-handed (RH) 35 participants were considered in this study. The test records the time of tapping and saves data as the time difference between successive tappings for further analysis. The average number of tappings and the temporal fluctuation patterns of the intertap-intervals were calculated and compared. The variations in the intertap-interval were evaluated with the best curve fit method. An average tapping speed or tapping rate can reliably be defined for a single-finger tapping test by analysing the graphically presented data of the number of tappings within the test period. However, a different presentation of the same data, namely the intertap-interval values, shows temporal variation as the number of tapping increases. Curve fitting applications indicate that the variation has a biphasic nature. The measures obtained in this study reflect the complex nature of the finger-tapping task and are suggested to provide reliable information regarding hand performance. Moreover, the equation reflects both the variations in and the general patterns associated with the task.

Interval stability for complex systems

NASA Astrophysics Data System (ADS)

Klinshov, Vladimir V.; Kirillov, Sergey; Kurths, Jürgen; Nekorkin, Vladimir I.

2018-04-01

Stability of dynamical systems against strong perturbations is an important problem of nonlinear dynamics relevant to many applications in various areas. Here, we develop a novel concept of interval stability, referring to the behavior of the perturbed system during a finite time interval. Based on this concept, we suggest new measures of stability, namely interval basin stability (IBS) and interval stability threshold (IST). IBS characterizes the likelihood that the perturbed system returns to the stable regime (attractor) in a given time. IST provides the minimal magnitude of the perturbation capable to disrupt the stable regime for a given interval of time. The suggested measures provide important information about the system susceptibility to external perturbations which may be useful for practical applications. Moreover, from a theoretical viewpoint the interval stability measures are shown to bridge the gap between linear and asymptotic stability. We also suggest numerical algorithms for quantification of the interval stability characteristics and demonstrate their potential for several dynamical systems of various nature, such as power grids and neural networks.

Levofloxacin can be used effectively as a positive control in thorough QT/QTc studies in healthy volunteers

PubMed Central

Taubel, Jorg; Naseem, Asif; Harada, Tomohiko; Wang, Duolao; Arezina, Radivoj; Lorch, Ulrike; Camm, A John

2010-01-01

AIMS To characterize the effects of levofloxacin on QT interval in healthy subjects and the most appropriate oral positive control treatments for International Conference on Harmonization (ICH) E14 QT/QTc studies. METHODS Healthy subjects received a single dose of levofloxacin (1000 or 1500 mg), moxifloxacin (400 mg) or placebo in a four-period crossover design. Digital 12-lead ECGs were recorded in triplicate. Measurement of QT interval was performed automatically with subsequent manual onscreen over-reading using electronic callipers. Blood samples were taken for determination of levofloxacin and moxifloxacin concentrations. RESULTS Mean QTcI (QT interval corrected for heart rate using a correction factor that is applicable to each individual) was prolonged in subjects receiving moxifloxacin 400 mg compared with placebo. The largest time-matched difference in QTcI for moxifloxacin compared with placebo was observed to be 13.19 ms (95% confidence interval 11.21, 15.17) at 3.5 h post dose. Prolonged mean QTcI was also observed in subjects receiving levofloxacin 1000 mg and 1500 mg compared with placebo. The largest time-matched difference in QTcI compared with placebo was observed at 3.5 h post dose for both 1000 mg and 1500 mg of levofloxacin [mean (95%) 4.42 ms (2.44, 6.39) in 1000 mg and 7.44 ms (5.47, 9.42) in 1500 mg]. A small increase in heart rate was observed with levofloxacin during the course of the study. However, moxifloxacin showed a greater increase compared with levofloxacin. CONCLUSIONS Both levofloxacin and moxifloxacin can fulfil the criteria for a positive comparator. The ICH E14 guidelines recommend a threshold of around 5 ms for a positive QT/QTc study. The largest time-matched difference in QTc for levofloxacin suggests the potential for use in more rigorous QT/QTc studies. This study has demonstrated the utility of levofloxacin on the assay in measuring mean QTc changes around 5 ms. PMID:20406223

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.

Analysis of single ion channel data incorporating time-interval omission and sampling

PubMed Central

The, Yu-Kai; Timmer, Jens

2005-01-01

Hidden Markov models are widely used to describe single channel currents from patch-clamp experiments. The inevitable anti-aliasing filter limits the time resolution of the measurements and therefore the standard hidden Markov model is not adequate anymore. The notion of time-interval omission has been introduced where brief events are not detected. The developed, exact solutions to this problem do not take into account that the measured intervals are limited by the sampling time. In this case the dead-time that specifies the minimal detectable interval length is not defined unambiguously. We show that a wrong choice of the dead-time leads to considerably biased estimates and present the appropriate equations to describe sampled data. PMID:16849220

High intensity interval training in the heat enhances exercise-induced lipid peroxidation, but prevents protein oxidation in physically active men

PubMed Central

Souza-Silva, Ana Angélica; Moreira, Eduardo; de Melo-Marins, Denise; Schöler, Cinthia M.; de Bittencourt, Paulo Ivo Homem; Laitano, Orlando

2016-01-01

ABSTRACT Aim. The purpose of this study was to determine the response of circulating markers of lipid and protein oxidation following an incremental test to exhaustion before and after 4 weeks of high-intensity interval training performed in the heat. Methods. To address this question, 16 physically active men (age = 23 ± 2 years; body mass = 73 ± 12 kg; height = 173 ± 6 cm; % body fat = 12.5 ± 6 %; body mass index = 24 ± 4 kg/m2) were allocated into 2 groups: control group (n = 8) performing high-intensity interval training at 22°C, 55% relative humidity and heat group (n = 8) training under 35°C, 55% relative humidity. Both groups performed high-intensity interval training 3 times per week for 4 consecutive weeks, accumulating a total of 12 training sessions. Before and after the completion of 4 weeks of high-intensity interval training, participants performed an incremental cycling test until exhaustion under temperate environment (22°C, 55% relative humidity) where blood samples were collected after the test for determination of exercise-induced changes in oxidative damage biomarkers (thiobarbituric acid reactive species and protein carbonyls). Results. When high-intensity interval training was performed under control conditions, there was an increase in protein carbonyls (p < 0.05) following the incremental test to exhaustion with no changes in thiobarbituric acid reactive species. Conversely, high-intensity interval training performed in high environmental temperature enhanced the incremental exercise-induced increases in thiobarbituric acid reactive species (p < 0.05) with no changes in protein carbonyls. Conclusion. In conclusion, 4 weeks of high-intensity interval training performed in the heat enhances exercise-induced lipid peroxidation, but prevents protein oxidation following a maximal incremental exercise in healthy active men. PMID:27227083

Digital time delay

DOEpatents

Martin, A.D.

1986-05-09

Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay provides a first output signal at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits latch the high resolution data to form a first synchronizing data set. A selected time interval has been preset to internal counters and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses count down the counters to generate an internal pulse delayed by an internal which is functionally related to the preset time interval. A second LCD corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD to generate a second set of synchronizing data which is complementary with the first set of synchronizing data for presentation to logic circuits. The logic circuits further delay the internal output signal with the internal pulses. The final delayed output signal thereafter enables the output pulse generator to produce the desired output pulse at the preset time delay interval following input of the trigger pulse.

Changes in Choice Reaction Time During and After 8 Days Exhaustive Cycling Are Not Related to Changes in Physical Performance.

PubMed

Ten Haaf, Twan; van Staveren, Selma; Iannetta, Danilo; Roelands, Bart; Meeusen, Romain; Piacentini, Maria F; Foster, Carl; Koenderman, Leo; Daanen, Hein A M; de Koning, Jos J

2018-04-01

Reaction time has been proposed as a training monitoring tool, but to date, results are equivocal. Therefore, it was investigated whether reaction time can be used as a monitoring tool to establish overreaching. The study included 30 subjects (11 females and 19 males, age: 40.8 [10.8] years, VO 2max : 51.8 [6.3] mL/kg/min) who participated in an 8-day cycling event. The external exercise load increased approximately 900% compared with the preparation period. Performance was measured before and after the event using a maximal incremental cycling test. Subjects with decreased performance after the event were classified as functionally overreached (FOR) and others as acutely fatigued (AF). A choice reaction time test was performed 2 weeks before (pre), 1 week after (post), and 5 weeks after (follow-up), as well as at the start and end of the event. A total of 14 subjects were classified as AF and 14 as FOR (2 subjects were excluded). During the event, reaction time at the end was 68 ms (95% confidence interval, 46-89) faster than at the start. Reaction time post event was 41 ms (95% confidence interval, 12-71) faster than pre event and follow-up was 55 ms faster (95% confidence interval, 26-83). The time by class interaction was not significant during (P = .26) and after (P = .43) the event. Correlations between physical performance and reaction time were not significant (all Ps > .30). No differences in choice reaction time between AF and FOR subjects were observed. It is suggested that choice reaction time is not valid for early detection of overreaching in the field.

High-intensity interval training improves VO2peak, maximal lactate accumulation, time trial and competition performance in 9–11-year-old swimmers

PubMed Central

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

2010-01-01

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 (T100 m and T2,000 m), VO2peak and rate of maximal lactate accumulation (Lacmax). 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 T2,000 m (P = 0.04; effect size = 0.21) performance increased following HIIT. No changes were found in T100 m (P = 0.20). Lacmax increased following HIIT (P < 0.01; effect size = 0.43) and decreased after HVT (P < 0.01; effect size = 0.51). VO2peak increased following both interventions (P < 0.05; effect sizes = 0.46–0.57). The increases in competition performance, T2,000 m, Lacmax and VO2peak following HIIT were achieved in significantly less training time (~2 h/week). PMID:20683609

Monitoring viability of seeds in gene banks: developing software tools to increase efficiency

USDA-ARS?s Scientific Manuscript database

Monitoring the decline of seed viability is essential for effective long term seed storage in ex situ collections. Recent FAO Genebank Standards recommend monitoring intervals at one-third the time predicted for viability to fall to 85% of initial viability. This poster outlines the development of ...

Measurement of transpiration in Pinus taeda L. and Liquidambar styraciflua L. in an environmental chamber using tritiated water

NASA Technical Reports Server (NTRS)

Levy, G. F.; Sonenshine, D. E.; Czoch, J. K.

1976-01-01

Transpiration rates of loblolly pine (Pinus taeda L.) and sweetgum (Liquidambar styraciflua L.) were measured at two different atmospheric water vapor pressure deficits (V.P.D.) in a controlled environment growth chamber using tritiated water as a tracer. The trees were maintained in a sealed plant bed containing a hydroponic nutrient solution into which labeled water (spike) was introduced. Samples of leaves, chamber air, spiked nutrient solution and control water were assayed for ratio-activity using liquid scintillation techniques to determine transpiration rates. The transpiration rate of sweetgum in ml./hr./gm. (4.95) was found to be 5 times greater than that of loblolly pine (1.03) at 1.84 V.P.D. and 8 times greater at 6.74 V.P.D. (15.99 for sweetgum vs. 2.19 for pine). Transpiration (based on measurements of leaf radioactivity) in both species rose with increasing deficit; however sweetgum increased its output by 3 times while pine only doubled its rate. Cyclical changes in transpiration rates were noted in both species; the sweetgum cycle required a 6 hour interval whereas the pine cycle required a 9 hour interval.

Effects of capacity limits, memory loss, and sound type in change deafness.

PubMed

Gregg, Melissa K; Irsik, Vanessa C; Snyder, Joel S

2017-11-01

Change deafness, the inability to notice changes to auditory scenes, has the potential to provide insights about sound perception in busy situations typical of everyday life. We determined the extent to which change deafness to sounds is due to the capacity of processing multiple sounds and the loss of memory for sounds over time. We also determined whether these processing limitations work differently for varying types of sounds within a scene. Auditory scenes composed of naturalistic sounds, spectrally dynamic unrecognizable sounds, tones, and noise rhythms were presented in a change-detection task. On each trial, two scenes were presented that were same or different. We manipulated the number of sounds within each scene to measure memory capacity and the silent interval between scenes to measure memory loss. For all sounds, change detection was worse as scene size increased, demonstrating the importance of capacity limits. Change detection to the natural sounds did not deteriorate much as the interval between scenes increased up to 2,000 ms, but it did deteriorate substantially with longer intervals. For artificial sounds, in contrast, change-detection performance suffered even for very short intervals. The results suggest that change detection is generally limited by capacity, regardless of sound type, but that auditory memory is more enduring for sounds with naturalistic acoustic structures.

Evaluation of the electromechanical properties of the cardiovascular system after prolonged weightlessness

NASA Technical Reports Server (NTRS)

Bergman, S. A., Jr.; Johnson, R. L.; Hoffler, G. W.

1977-01-01

Devices and techniques for measuring and analyzing systolic time intervals and quantitative phonocardiograms were initiated during Apollo 17. The data show that the systolic time interval from Apollo 17 crewmen remained elevated longer postflight than the response criteria of heart rate, blood pressure, and percent change in leg volume all of which had returned to preflight levels by the second day postflight. Although the systolic time interval values were only slightly outside the preflight fiducial limits, this finding suggested that: the analysis of systolic time intervals may help to identify the mechanisms of postflight orthostatic intolerance by virtue of measuring ventricular function more directly and, the noninvasive technique may prove useful in determining the extent and duration of cardiovascular instability after long duration space flight. The systolic time intervals obtained on the Apollo 17 crewmen during lower body negative pressure were similar to those noted in patients with significant heart disease.

Mumps vaccine performance among university students during a mumps outbreak.

PubMed

Cortese, Margaret M; Jordan, Hannah T; Curns, Aaron T; Quinlan, Patricia A; Ens, Kim A; Denning, Patricia M; Dayan, Gustavo H

2008-04-15

The largest reported mumps outbreak at a US college in 19 years occurred in 2006 at a Kansas university with a 2-dose measles-mumps-rubella (MMR) vaccination policy. We assessed vaccine performance and mumps risk factors, including the possibility of waning vaccine protection. Case students were compared with a cohort of the university's approximately 19,000 undergraduates. The secondary attack rate for clinical mumps was determined among roommates exposed to case students. Time from receipt of the second dose of MMR vaccine was compared between case students and roommates without mumps. Coverage with > or =2 dose of MMR vaccine was > or =95% among 140 undergraduate case students and 444 cohort students. The secondary attack rate for clinical mumps among roommates who had received 2 doses of vaccine ranged from 2.2% to 7.7%, depending on the case definition. Compared with roommates without mumps, case students were more likely (odds ratio, 2.46; 95% confidence interval, 1.25-4.82) to have received their second dose of MMR vaccine > or =10 years earlier. The odds of being a case student increased with each 1-year increase in time from receipt of the second dose of MMR vaccine (odds ratio, 1.36; 95% confidence interval, 1.10-1.68) among case students and roommates aged 18-19 years but not among those aged > or =20 years. Students aged 18-19 years had a higher risk of mumps (risk ratio, 3.14; 95% confidence interval, 1.60-6.16), compared with students aged > or =22 years; women living in dormitories had increased risk of mumps (risk ratio, 1.95; 95% confidence interval, 1.01-3.76), compared with men not living in dormitories. High 2-dose MMR coverage protected many students from developing mumps but was not sufficient to prevent the mumps outbreak. Vaccine-induced protection may wane. Similar US settings where large numbers of young adults from wild-type naive cohorts live closely together may be at particular risk for mumps outbreaks.

TOT measurement implemented in FPGA TDC

NASA Astrophysics Data System (ADS)

Fan, Huan-Huan; Cao, Ping; Liu, Shu-Bin; An, Qi

2015-11-01

Time measurement plays a crucial role for the purpose of particle identification in high energy physics experiments. With increasingly demanding physics goals and the development of electronics, modern time measurement systems need to meet the requirement of excellent resolution specification as well as high integrity. Based on Field Programmable Gate Arrays (FPGAs), FPGA time-to-digital converters (TDCs) have become one of the most mature and prominent time measurement methods in recent years. For correcting the time-walk effect caused by leading timing, a time-over-threshold (TOT) measurement should be added to the FPGA TDC. TOT can be obtained by measuring the interval between the signal leading and trailing edges. Unfortunately, a traditional TDC can recognize only one kind of signal edge, the leading or the trailing. Generally, to measure the interval, two TDC channels need to be used at the same time, one for leading, the other for trailing. However, this method unavoidably increases the amount of FPGA resources used and reduces the TDC's integrity. This paper presents one method of TOT measurement implemented in a Xilinx Virtex-5 FPGA. In this method, TOT measurement can be achieved using only one TDC input channel. The consumed resources and time resolution can both be guaranteed. Testing shows that this TDC can achieve resolution better than 15ps for leading edge measurement and 37 ps for TOT measurement. Furthermore, the TDC measurement dead time is about two clock cycles, which makes it good for applications with higher physics event rates. Supported by National Natural Science Foundation of China (11079003, 10979003)

Effects of Temporal Features and Order on the Apparent duration of a Visual Stimulus

PubMed Central

Bruno, Aurelio; Ayhan, Inci; Johnston, Alan

2012-01-01

The apparent duration of a visual stimulus has been shown to be influenced by its speed. For low speeds, apparent duration increases linearly with stimulus speed. This effect has been ascribed to the number of changes that occur within a visual interval. Accordingly, a higher number of changes should produce an increase in apparent duration. In order to test this prediction, we asked subjects to compare the relative duration of a 10-Hz drifting comparison stimulus with a standard stimulus that contained a different number of changes in different conditions. The standard could be static, drifting at 10 Hz, or mixed (a combination of variable duration static and drifting intervals). In this last condition the number of changes was intermediate between the static and the continuously drifting stimulus. For all standard durations, the mixed stimulus looked significantly compressed (∼20% reduction) relative to the drifting stimulus. However, no difference emerged between the static (that contained no changes) and the mixed stimuli (which contained an intermediate number of changes). We also observed that when the standard was displayed first, it appeared compressed relative to when it was displayed second with a magnitude that depended on standard duration. These results are at odds with a model of time perception that simply reflects the number of temporal features within an interval in determining the perceived passing of time. PMID:22461778

Periodic venting of MABR lumen allows high removal rates and high gas-transfer efficiencies.

PubMed

Perez-Calleja, P; Aybar, M; Picioreanu, C; Esteban-Garcia, A L; Martin, K J; Nerenberg, R

2017-09-15

The membrane-aerated biofilm reactor (MABR) is a novel treatment technology that employs gas-supplying membranes to deliver oxygen directly to a biofilm growing on the membrane surface. When operated with closed-end membranes, the MABR provides 100-percent oxygen transfer efficiencies (OTE), resulting in significant energy savings. However, closed-end MABRs are more sensitive to back-diffusion of inert gases, such as nitrogen. Back-diffusion reduces the average oxygen transfer rates (OTR), consequently decreasing the average contaminant removal fluxes (J). We hypothesized that venting the membrane lumen periodically would increase the OTR and J. Using an experimental flow cell and mathematical modeling, we showed that back-diffusion gas profiles developed over relatively long timescales. Thus, very short ventings could re-establish uniform gas profiles for relatively long time periods. Using modeling, we systematically explored the effect of the venting interval (time between ventings). At moderate venting intervals, opening the membrane for 20 s every 30 min, the venting significantly increased the average OTR and J without substantially impacting the OTEs. When the interval was short enough, in this case shorter than 20 min, the OTR was actually higher than for continuous open-end operation. Our results show that periodic venting is a promising strategy to combine the advantages of open-end and closed end operation, maximizing both the OTR and OTE. Copyright © 2017 Elsevier Ltd. All rights reserved.

A semi-automated method for rapid detection of ripple events on interictal voltage discharges in the scalp electroencephalogram.

PubMed

Chu, Catherine J; Chan, Arthur; Song, Dan; Staley, Kevin J; Stufflebeam, Steven M; Kramer, Mark A

2017-02-01

High frequency oscillations are emerging as a clinically important indicator of epileptic networks. However, manual detection of these high frequency oscillations is difficult, time consuming, and subjective, especially in the scalp EEG, thus hindering further clinical exploration and application. Semi-automated detection methods augment manual detection by reducing inspection to a subset of time intervals. We propose a new method to detect high frequency oscillations that co-occur with interictal epileptiform discharges. The new method proceeds in two steps. The first step identifies candidate time intervals during which high frequency activity is increased. The second step computes a set of seven features for each candidate interval. These features require that the candidate event contain a high frequency oscillation approximately sinusoidal in shape, with at least three cycles, that co-occurs with a large amplitude discharge. Candidate events that satisfy these features are stored for validation through visual analysis. We evaluate the detector performance in simulation and on ten examples of scalp EEG data, and show that the proposed method successfully detects spike-ripple events, with high positive predictive value, low false positive rate, and high intra-rater reliability. The proposed method is less sensitive than the existing method of visual inspection, but much faster and much more reliable. Accurate and rapid detection of high frequency activity increases the clinical viability of this rhythmic biomarker of epilepsy. The proposed spike-ripple detector rapidly identifies candidate spike-ripple events, thus making clinical analysis of prolonged, multielectrode scalp EEG recordings tractable. Copyright © 2016 Elsevier B.V. All rights reserved.

A semi-automated method for rapid detection of ripple events on interictal voltage discharges in the scalp electroencephalogram

PubMed Central

Chu, Catherine. J.; Chan, Arthur; Song, Dan; Staley, Kevin J.; Stufflebeam, Steven M.; Kramer, Mark A.

2017-01-01

Summary Background High frequency oscillations are emerging as a clinically important indicator of epileptic networks. However, manual detection of these high frequency oscillations is difficult, time consuming, and subjective, especially in the scalp EEG, thus hindering further clinical exploration and application. Semi-automated detection methods augment manual detection by reducing inspection to a subset of time intervals. We propose a new method to detect high frequency oscillations that co-occur with interictal epileptiform discharges. New Method The new method proceeds in two steps. The first step identifies candidate time intervals during which high frequency activity is increased. The second step computes a set of seven features for each candidate interval. These features require that the candidate event contain a high frequency oscillation approximately sinusoidal in shape, with at least three cycles, that co-occurs with a large amplitude discharge. Candidate events that satisfy these features are stored for validation through visual analysis. Results We evaluate the detector performance in simulation and on ten examples of scalp EEG data, and show that the proposed method successfully detects spike-ripple events, with high positive predictive value, low false positive rate, and high intra-rater reliability. Comparison with Existing Method The proposed method is less sensitive than the existing method of visual inspection, but much faster and much more reliable. Conclusions Accurate and rapid detection of high frequency activity increases the clinical viability of this rhythmic biomarker of epilepsy. The proposed spike-ripple detector rapidly identifies candidate spike-ripple events, thus making clinical analysis of prolonged, multielectrode scalp EEG recordings tractable. PMID:27988323

Seismic hazard assessment over time: Modelling earthquakes in Taiwan

NASA Astrophysics Data System (ADS)

Chan, Chung-Han; Wang, Yu; Wang, Yu-Ju; Lee, Ya-Ting

2017-04-01

To assess the seismic hazard with temporal change in Taiwan, we develop a new approach, combining both the Brownian Passage Time (BPT) model and the Coulomb stress change, and implement the seismogenic source parameters by the Taiwan Earthquake Model (TEM). The BPT model was adopted to describe the rupture recurrence intervals of the specific fault sources, together with the time elapsed since the last fault-rupture to derive their long-term rupture probability. We also evaluate the short-term seismicity rate change based on the static Coulomb stress interaction between seismogenic sources. By considering above time-dependent factors, our new combined model suggests an increased long-term seismic hazard in the vicinity of active faults along the western Coastal Plain and the Longitudinal Valley, where active faults have short recurrence intervals and long elapsed time since their last ruptures, and/or short-term elevated hazard levels right after the occurrence of large earthquakes due to the stress triggering effect. The stress enhanced by the February 6th, 2016, Meinong ML 6.6 earthquake also significantly increased rupture probabilities of several neighbouring seismogenic sources in Southwestern Taiwan and raised hazard level in the near future. Our approach draws on the advantage of incorporating long- and short-term models, to provide time-dependent earthquake probability constraints. Our time-dependent model considers more detailed information than any other published models. It thus offers decision-makers and public officials an adequate basis for rapid evaluations of and response to future emergency scenarios such as victim relocation and sheltering.

Loop electrosurgical excision procedure and the risk for preterm delivery.

PubMed

Heinonen, Annu; Gissler, Mika; Riska, Annika; Paavonen, Jorma; Tapper, Anna-Maija; Jakobsson, Maija

2013-05-01

To estimate whether the severity of cervical intraepithelial neoplasia (CIN) and the loop electrosurgical excision procedure (LEEP) increase the risk for preterm delivery, and to evaluate the role of repeat LEEP and time interval since LEEP. This was a retrospective register-based study from Finland from 1997 to 2009. We linked Hospital Discharge Register and Finnish Medical Birth Register data. Case group women consisted of 20,011 women who underwent LEEP during the study period and their subsequent singleton deliveries in 1998-2009. Control population included women from the Medical Birth Register with no LEEP (n=430,975). The main outcome measure was preterm delivery before 37 weeks of gestation. The risk for preterm delivery increased after LEEP. Women with previous LEEP had 547 (7.2%) preterm deliveries, whereas the control population had 30,151 (4.6%) preterm deliveries (odds ratio [OR] 1.61, confidence interval [CI] 1.47-1.75, number needed to harm 38.5). The overall preterm delivery rate in the study period was 4.6% for singleton deliveries. Repeat LEEP was associated with an almost threefold risk for preterm delivery (OR 2.80, CI 2.28-3.44). The severity of CIN did not increase the risk for preterm delivery. However, with LEEP for carcinoma in situ or microinvasive cancer, the risk for preterm delivery was higher (OR 2.55, CI 1.68-3.87). The increased risk also was associated with non-CIN lesions (OR 2.04, CI 1.46-2.87). Similarly, the risk was increased after diagnostic LEEP (OR 1.39, 95% CI 1.16-1.67). Time interval since LEEP was not associated with preterm delivery. Adjusting for maternal age, parity, socioeconomic or marital status, urbanism, and previous preterm deliveries did not change the results. The risk for preterm delivery was increased after LEEP regardless of the histopathologic diagnosis. The risk was highest after repeat LEEP, which should be avoided, especially among women of reproductive age. II.

Relationship between age and elite marathon race time in world single age records from 5 to 93 years

PubMed Central

2014-01-01

Background The aims of the study were (i) to investigate the relationship between elite marathon race times and age in 1-year intervals by using the world single age records in marathon running from 5 to 93 years and (ii) to evaluate the sex difference in elite marathon running performance with advancing age. Methods World single age records in marathon running in 1-year intervals for women and men were analysed regarding changes across age for both men and women using linear and non-linear regression analyses for each age for women and men. Results The relationship between elite marathon race time and age was non-linear (i.e. polynomial regression 4th degree) for women and men. The curve was U-shaped where performance improved from 5 to ~20 years. From 5 years to ~15 years, boys and girls performed very similar. Between ~20 and ~35 years, performance was quite linear, but started to decrease at the age of ~35 years in a curvilinear manner with increasing age in both women and men. The sex difference increased non-linearly (i.e. polynomial regression 7th degree) from 5 to ~20 years, remained unchanged at ~20 min from ~20 to ~50 years and increased thereafter. The sex difference was lowest (7.5%, 10.5 min) at the age of 49 years. Conclusion Elite marathon race times improved from 5 to ~20 years, remained linear between ~20 and ~35 years, and started to increase at the age of ~35 years in a curvilinear manner with increasing age in both women and men. The sex difference in elite marathon race time increased non-linearly and was lowest at the age of ~49 years. PMID:25120915

Eliminating the Lost Time Interval of Law Enforcement to Active Shooter Events in Schools

DTIC Science & Technology

2015-09-01

Bureau of Justice Assistance BJS Bureau of Justice Statistics BPD Blacksburg Police Department CPR cardiopulmonary resuscitation CSP...Big Brother and Big Sisters,11 and the Strengthening Families program.12 The Bureau of Justice Statistics (BJS) released the Indicators of School...result in school transfers or discipline were found to increase delinquency , dropout rate, and increased violence.44 Profiling students in an attempt

An Intervention to Reduce the Time Interval Between Hospital Entry and Emergency Coronary Angiography in Patients with ST-Elevation Myocardial Infarction.

PubMed

Karkabi, Basheer; Jaffe, Ronen; Halon, David A; Merdler, Amnon; Khader, Nader; Rubinshtein, Ronen; Goldstein, Jacob; Zafrir, Barak; Zissman, Keren; Ben-Dov, Nissan; Gabrielly, Michael; Fuks, Alex; Shiran, Avinoam; Adawi, Salim; Hellman, Yaron; Shahla, Johny; Halabi, Salim; Flugelman, Moshe Y; Cohen, Shai; Bergman, Irina; Kassem, Sameer; Shapira, Chen

2017-09-01

Outcomes of patients with acute ST-elevation myocardial infarction (STEMI) are strongly correlated to the time interval from hospital entry to primary percutaneous coronary intervention (PPCI). Current guidelines recommend a door to balloon time of < 90 minutes. To reduce the time from hospital admission to PPCI and to increase the proportion of patients treated within 90 minutes. In March 2013 the authors launched a seven-component intervention program:  Direct patient evacuation by out-of-hospital emergency medical services to the coronary intensive care unit or catheterization laboratory Education program for the emergency department staff Dissemination of information regarding the urgency of the PPCI decision Activation of the catheterization team by a single phone call Reimbursement for transportation costs to on-call staff who use their own cars Improvement in the quality of medical records Investigation of failed cases and feedback. During the 14 months prior to the intervention, initiation of catheterization occurred within 90 minutes of hospital arrival in 88/133 patients(65%); during the 18 months following the start of the intervention, the rate was 181/200 (90%) (P < 0.01). The respective mean/median times to treatment were 126/67 minutes and 52/47 minutes (P < 0.01). Intervention also resulted in shortening of the time interval from hospital entry to PPCI on nights and weekends. Following implementation of a comprehensive intervention, the time from hospital admission to PPCI of STEMI patients shortened significantly, as did the proportion of patients treated within 90 minutes of hospital arrival.

Compression based entropy estimation of heart rate variability on multiple time scales.

PubMed

Baumert, Mathias; Voss, Andreas; Javorka, Michal

2013-01-01

Heart rate fluctuates beat by beat in a complex manner. The aim of this study was to develop a framework for entropy assessment of heart rate fluctuations on multiple time scales. We employed the Lempel-Ziv algorithm for lossless data compression to investigate the compressibility of RR interval time series on different time scales, using a coarse-graining procedure. We estimated the entropy of RR interval time series of 20 young and 20 old subjects and also investigated the compressibility of randomly shuffled surrogate RR time series. The original RR time series displayed significantly smaller compression entropy values than randomized RR interval data. The RR interval time series of older subjects showed significantly different entropy characteristics over multiple time scales than those of younger subjects. In conclusion, data compression may be useful approach for multiscale entropy assessment of heart rate variability.

Spatial-temporal analysis of the of the risk of Rift Valley Fever in Kenya

NASA Astrophysics Data System (ADS)

Bett, B.; Omolo, A.; Hansen, F.; Notenbaert, A.; Kemp, S.

2012-04-01

Historical data on Rift Valley Fever (RVF) outbreaks in Kenya covering the period 1951 - 2010 were analyzed using a logistic regression model to identify factors associated with RVF occurrence. The analysis used a division, an administrative unit below a district, as the unit of analysis. The infection status of each division was defined on a monthly time scale and used as a dependent variable. Predictors investigated include: monthly precipitation (minimum, maximum and total), normalized difference vegetation index, altitude, agro-ecological zone, presence of game, livestock and human population densities, the number of times a division has had an outbreak before and time interval in months between successive outbreaks (used as a proxy for immunity). Both univariable and multivariable analyses were conducted. The models used incorporated an auto-regressive correlation matrix to account for clustering of observations in time, while dummy variables were fitted in the multivariable model to account for spatial relatedness/topology between divisions. This last procedure was followed because it is expected that the risk of RVF occurring in a given division increases when its immediate neighbor gets infected. Functional relationships between the continuous and the outcome variables were assessed to ensure that the linearity assumption was met. Deviance and leverage residuals were also generated from the final model and used for evaluating the goodness of fit of the model. Descriptive analyzes indicate that a total of 91 divisions in 42 districts (of the original 69 districts in place by 1999) reported RVF outbreaks at least once over the period. The mean interval between outbreaks was determined to be about 43 months. Factors that were positively associated with RVF occurrence include increased precipitation, high outbreak interval and the number of times a division has been infected or reported an outbreak. The model will be validated and used for developing an RVF forecasting system. This forecasting system can then be used with the existing regional RVF prediction tools such as EMPRES-i to downscale RVF risk predictions to country-specific scales and subsequently link them with decision support systems. The ultimate aim is to increase the capacity of the national institutions to formulate appropriate RVF mitigation measures.

Evaluation of the Finis Swimsense® and the Garmin Swim™ activity monitors for swimming performance and stroke kinematics analysis

PubMed Central

Mooney, Robert; Corley, Gavin; Godfrey, Alan; Osborough, Conor; ÓLaighin, Gearóid

2017-01-01

Aims The study aims were to evaluate the validity of two commercially available swimming activity monitors for quantifying temporal and kinematic swimming variables. Methods Ten national level swimmers (5 male, 5 female; 15.3±1.3years; 164.8±12.9cm; 62.4±11.1kg; 425±66 FINA points) completed a set protocol comprising 1,500m of swimming involving all four competitive swimming strokes. Swimmers wore the Finis Swimsense and the Garmin Swim activity monitors throughout. The devices automatically identified stroke type, swim distance, lap time, stroke count, stroke rate, stroke length and average speed. Video recordings were also obtained and used as a criterion measure to evaluate performance. Results A significant positive correlation was found between the monitors and video for the identification of each of the four swim strokes (Garmin: X2 (3) = 31.292, p<0.05; Finis:X2 (3) = 33.004, p<0.05). No significant differences were found for swim distance measurements. Swimming laps performed in the middle of a swimming interval showed no significant difference from the criterion (Garmin: bias -0.065, 95% confidence intervals -3.828–6.920; Finis bias -0.02, 95% confidence intervals -3.095–3.142). However laps performed at the beginning and end of an interval were not as accurately timed. Additionally, a statistical difference was found for stroke count measurements in all but two occasions (p<0.05). These differences affect the accuracy of stroke rate, stroke length and average speed scores reported by the monitors, as all of these are derived from lap times and stroke counts. Conclusions Both monitors were found to operate with a relatively similar performance level and appear suited for recreational use. However, issues with feature detection accuracy may be related to individual variances in stroke technique. It is reasonable to expect that this level of error would increase when the devices are used by recreational swimmers rather than elite swimmers. Further development to improve accuracy of feature detection algorithms, specifically for lap time and stroke count, would also increase their suitability within competitive settings. PMID:28178301

Effects of 4-Week Training Intervention with Unknown Loads on Power Output Performance and Throwing Velocity in Junior Team Handball Players

PubMed Central

Sabido, Rafael; Hernández-Davó, Jose Luis; Botella, Javier; Moya, Manuel

2016-01-01

Purpose To compare the effect of 4-week unknown vs known loads strength training intervention on power output performance and throwing velocity in junior team handball players. Methods Twenty-eight junior team-handball players (17.2 ± 0.6 years, 1.79 ± 0.07 m, 75.6 ± 9.4 kg)were divided into two groups (unknown loads: UL; known loads: KL). Both groups performed two sessions weekly consisting of four sets of six repetitions of the bench press throw exercise, using the 30%, 50% and 70% of subjects’ individual 1 repetition maximum (1RM). In each set, two repetitions with each load were performed, but the order of the loads was randomised. In the KL group, researchers told the subjects the load to mobilise prior each repetition, while in the UL group, researchers did not provide any information. Maximal dynamic strength (1RM bench press), power output (with 30, 50 and 70% of 1RM) and throwing velocity (7 m standing throw and 9 m jumping throw) were assessed pre- and post-training intervention. Results Both UL and KL group improved similarly their 1RM bench press as well as mean and peak power with all loads. There were significant improvements in power developed in all the early time intervals measured (150 ms) with the three loads (30, 50, 70% 1RM) in the UL group, while KL only improved with 30% 1RM (all the time intervals) and with 70% 1RM (at certain time intervals). Only the UL group improved throwing velocity in both standing (4.7%) and jumping (5.3%) throw (p > 0.05). Conclusions The use of unknown loads has led to greater gains in power output in the early time intervals as well as to increases in throwing velocity compared with known loads. Therefore unknown loads are of significant practical use to increase both strength and in-field performance in a short period of training. PMID:27310598

Evaluation of the Finis Swimsense® and the Garmin Swim™ activity monitors for swimming performance and stroke kinematics analysis.

PubMed

Mooney, Robert; Quinlan, Leo R; Corley, Gavin; Godfrey, Alan; Osborough, Conor; ÓLaighin, Gearóid

2017-01-01

The study aims were to evaluate the validity of two commercially available swimming activity monitors for quantifying temporal and kinematic swimming variables. Ten national level swimmers (5 male, 5 female; 15.3±1.3years; 164.8±12.9cm; 62.4±11.1kg; 425±66 FINA points) completed a set protocol comprising 1,500m of swimming involving all four competitive swimming strokes. Swimmers wore the Finis Swimsense and the Garmin Swim activity monitors throughout. The devices automatically identified stroke type, swim distance, lap time, stroke count, stroke rate, stroke length and average speed. Video recordings were also obtained and used as a criterion measure to evaluate performance. A significant positive correlation was found between the monitors and video for the identification of each of the four swim strokes (Garmin: X2 (3) = 31.292, p<0.05; Finis:X2 (3) = 33.004, p<0.05). No significant differences were found for swim distance measurements. Swimming laps performed in the middle of a swimming interval showed no significant difference from the criterion (Garmin: bias -0.065, 95% confidence intervals -3.828-6.920; Finis bias -0.02, 95% confidence intervals -3.095-3.142). However laps performed at the beginning and end of an interval were not as accurately timed. Additionally, a statistical difference was found for stroke count measurements in all but two occasions (p<0.05). These differences affect the accuracy of stroke rate, stroke length and average speed scores reported by the monitors, as all of these are derived from lap times and stroke counts. Both monitors were found to operate with a relatively similar performance level and appear suited for recreational use. However, issues with feature detection accuracy may be related to individual variances in stroke technique. It is reasonable to expect that this level of error would increase when the devices are used by recreational swimmers rather than elite swimmers. Further development to improve accuracy of feature detection algorithms, specifically for lap time and stroke count, would also increase their suitability within competitive settings.

Ca2+ cycling between sarcoplasmic reticulum and mitochondria in rabbit cardiac myocytes.

PubMed Central

Bassani, J W; Bassani, R A; Bers, D M

1993-01-01

1. Shortening and intracellular Ca2+ (Ca2+i) transients were measured in isolated rabbit ventricular myocytes during paired contractures induced by rapid application of 10 mM caffeine. 2. Caffeine-induced contractures relax despite maintained presence of caffeine. In control solution, a second phasic caffeine contracture failed to appear, unless the sarcoplasmic reticulum (SR) was refilled by a series of electrically stimulated twitches during the interval between caffeine exposures. 3. The relaxation of caffeine-induced contractures in 0 Na(+)-0 Ca2+ solution has previously been shown to rely on mitochondrial Ca2+ uptake and sarcolemmal Ca2(+)-ATPase. Thus, a second caffeine contracture (T2) while still in 0 Na(+)-0 Ca2+ was greatly reduced compared to the first one (T1). However, the amplitude of T2 increased exponentially with the time interval, attaining a maximum of approximately 50% of T1 for an interval of 180-300 s, with a time constant (tau) of 41.2 s. Similar results were found for Ca2+i transients (tau = 45 s). 4. Inhibition of the mitochondrial Ca2+ uptake by the oxidative phosphorylation uncoupler, FCCP during T1 dramatically depressed T2. On the other hand, inhibition of the sarcolemmal Ca2(+)-ATPase (by increasing extracellular Ca2+ concentration, [Ca2+]o) resulted in increase of T2. Spermine inclusion during T1 also increased T2, possibly by an increase of mitochondrial Ca2+ uptake. 5. We conclude that Ca2+ taken up by mitochondria during the decline of T1 moves back to the SR after caffeine is removed, with a tau approximately 40 s. 6. Partial intracellular Na+ depletion by prolonged (3 min) perfusion with 0 Na(+)-0 Ca2+ solution before T1 (a) accelerated relaxation and [Ca2+]i decline during T1, and (b) slowed, but did not abolish, the recovery of T2 as the interval was increased. This effect was particularly pronounced when choline was used instead of Li+ as the Na+ substitute. 7. We further conclude that the mitochondrial Na(+)-Ca2+ antiporter influences the rate of net Ca2+ uptake by mitochondria and is also important in Ca2+ efflux from mitochondria during rest. PMID:8387590

Ca2+ cycling between sarcoplasmic reticulum and mitochondria in rabbit cardiac myocytes.

PubMed

Bassani, J W; Bassani, R A; Bers, D M

1993-01-01

1. Shortening and intracellular Ca2+ (Ca2+i) transients were measured in isolated rabbit ventricular myocytes during paired contractures induced by rapid application of 10 mM caffeine. 2. Caffeine-induced contractures relax despite maintained presence of caffeine. In control solution, a second phasic caffeine contracture failed to appear, unless the sarcoplasmic reticulum (SR) was refilled by a series of electrically stimulated twitches during the interval between caffeine exposures. 3. The relaxation of caffeine-induced contractures in 0 Na(+)-0 Ca2+ solution has previously been shown to rely on mitochondrial Ca2+ uptake and sarcolemmal Ca2(+)-ATPase. Thus, a second caffeine contracture (T2) while still in 0 Na(+)-0 Ca2+ was greatly reduced compared to the first one (T1). However, the amplitude of T2 increased exponentially with the time interval, attaining a maximum of approximately 50% of T1 for an interval of 180-300 s, with a time constant (tau) of 41.2 s. Similar results were found for Ca2+i transients (tau = 45 s). 4. Inhibition of the mitochondrial Ca2+ uptake by the oxidative phosphorylation uncoupler, FCCP during T1 dramatically depressed T2. On the other hand, inhibition of the sarcolemmal Ca2(+)-ATPase (by increasing extracellular Ca2+ concentration, [Ca2+]o) resulted in increase of T2. Spermine inclusion during T1 also increased T2, possibly by an increase of mitochondrial Ca2+ uptake. 5. We conclude that Ca2+ taken up by mitochondria during the decline of T1 moves back to the SR after caffeine is removed, with a tau approximately 40 s. 6. Partial intracellular Na+ depletion by prolonged (3 min) perfusion with 0 Na(+)-0 Ca2+ solution before T1 (a) accelerated relaxation and [Ca2+]i decline during T1, and (b) slowed, but did not abolish, the recovery of T2 as the interval was increased. This effect was particularly pronounced when choline was used instead of Li+ as the Na+ substitute. 7. We further conclude that the mitochondrial Na(+)-Ca2+ antiporter influences the rate of net Ca2+ uptake by mitochondria and is also important in Ca2+ efflux from mitochondria during rest.

Are Earthquake Clusters/Supercycles Real or Random?

NASA Astrophysics Data System (ADS)

Salditch, L.; Brooks, E. M.; Stein, S.; Spencer, B. D.

2016-12-01

Long records of earthquakes at plate boundaries such as the San Andreas or Cascadia often show that large earthquakes occur in temporal clusters, also termed supercycles, separated by less active intervals. These are intriguing because the boundary is presumably being loaded by steady plate motion. If so, earthquakes resulting from seismic cycles - in which their probability is small shortly after the past one, and then increases with time - should occur quasi-periodically rather than be more frequent in some intervals than others. We are exploring this issue with two approaches. One is to assess whether the clusters result purely by chance from a time-independent process that has no "memory." Thus a future earthquake is equally likely immediately after the past one and much later, so earthquakes can cluster in time. We analyze the agreement between such a model and inter-event times for Parkfield, Pallet Creek, and other records. A useful tool is transformation by the inverse cumulative distribution function, so the inter-event times have a uniform distribution when the memorylessness property holds. The second is via a time-variable model in which earthquake probability increases with time between earthquakes and decreases after an earthquake. The probability of an event increases with time until one happens, after which it decreases, but not to zero. Hence after a long period of quiescence, the probability of an earthquake can remain higher than the long-term average for several cycles. Thus the probability of another earthquake is path dependent, i.e. depends on the prior earthquake history over multiple cycles. Time histories resulting from simulations give clusters with properties similar to those observed. The sequences of earthquakes result from both the model parameters and chance, so two runs with the same parameters look different. The model parameters control the average time between events and the variation of the actual times around this average, so models can be strongly or weakly time-dependent.

Effect of bolus volume and viscosity on pharyngeal automated impedance manometry variables derived for broad Dysphagia patients.

PubMed

Omari, Taher I; Dejaeger, Eddy; Tack, Jan; Van Beckevoort, Dirk; Rommel, Nathalie

2013-06-01

Automated impedance manometry (AIM) analysis measures swallow variables defining bolus timing, pressure, contractile vigour, and bolus presence, which are combined to derive a swallow risk index (SRI) correlating with aspiration. In a heterogeneous cohort of dysphagia patients, we assessed the impact of bolus volume and viscosity on AIM variables. We studied 40 patients (average age = 46 years). Swallowing of boluses was recorded with manometry, impedance, and videofluoroscopy. AIMplot software was used to derive functional variables: peak pressure (PeakP), pressure at nadir impedance (PNadImp), time from nadir impedance to peak pressure (TNadImp-PeakP), the interval of impedance drop in the distal pharynx (flow interval, FI), upper oesophageal sphincter (UES) relaxation interval (UES RI), nadir UES pressure (Nad UESP), UES intrabolus pressure (UES IBP), and UES resistance. The SRI was derived using the formula SRI = (FI * PNadImp)/(PeakP * (TNadImp-PeakP + 1)) * 100. A total of 173 liquid, 44 semisolid, and 33 solid boluses were analysed. The SRI was elevated in relation to aspiration. PeakP increased with volume. SRI was not significantly altered by bolus volume. PNadImp, UES IBP, and UES resistance increased with viscosity. SRI was lower with increased viscosity. In patients with dysphagia, the SRI is elevated in relation to aspiration, reduced by bolus viscosity, and not affected by bolus volume. These data provide evidence that pharyngeal AIM analysis may have clinical utility for assessing deglutitive aspiration risk to liquid boluses.

Achilles tendinosis – a morphometrical study in a rat model

PubMed Central

Silva, Rafael Duarte; Glazebrook, Mark Anthony; Campos, Vinicius Castro; Vasconcelos, Anilton Cesar

2011-01-01

This study addresses the morphopathogenesis of Achilles tendinosis, using a rat model and presenting quantitative analysis of time-dependent histological changes. Thirty Wistar rats were used, randomly split in experimental and control groups. Animals of the experimental group were submitted to a treadmill running scheme. Five animals of each group were euthanized at four, eight and sixteen weeks. Achilles tendons were collected and processed routinely for histopath sections. Slides were stained by Hematoxylin-Eosin, Picrosirius Red, Alcian Blue, AgNOR, TUNEL and evaluated morphometrically. Cellular density decreased slightly along the time and was higher in the experimental group than in controls at fourth, eighth and sixteenth weeks. Fiber microtearing, percentual of reticular fibers and glycosaminoglycans content increased along the time and were higher in experimental group than in controls at all-time intervals. AgNOR labeling here interpreted as a marker of transcription activity was higher in the experimental groups than in controls at all-time intervals. Apoptotic cells were more frequent and diffusely distributed in tendinosis samples than in control groups. These results suggest that as mechanical overload is becoming chronic, cellular turnover and matrix deposition increases leading to tendinosis. The combination of staining techniques and morphometry used here to describe the evolution of lesions occurring in a rat model system has proved to be suited for the study of induced Achilles tendinosis. PMID:22076169

Longitudinal study on patent citations to academic research articles in nanotechnology (1976-2004)

NASA Astrophysics Data System (ADS)

Hu, Daning; Chen, Hsinchun; Huang, Zan; Roco, Mihail C.

2007-08-01

Academic nanoscale science and engineering (NSE) research provides a foundation for nanotechnology innovation reflected in patents. About 60% or about 50,000 of the NSE-related patents identified by "full-text" keyword searching between 1976 and 2004 at the United States Patent and Trademark Office (USPTO) have an average of approximately 18 academic citations. The most cited academic journals, individual researchers, and research articles have been evaluated as sources of technology innovation in the NSE area over the 28-year period. Each of the most influential articles was cited about 90 times on the average, while the most influential author was cited more than 700 times by the NSE-related patents. Thirteen mainstream journals accounted for about 20% of all citations. Science, Nature and Proceedings of the National Academy of Sciences (PNAS) have consistently been the top three most cited journals, with each article being cited three times on average. There is another kind of influential journals, represented by Biosystems and Origin of Life, which have very few articles cited but with exceptionally high frequencies. The number of academic citations per year from ten most cited journals has increased by over 17 times in the interval (1990-1999) as compared to (1976-1989), and again over 3 times in the interval (2000-2004) as compared to (1990-1999). This is an indication of increased used of academic knowledge creation in the NSE-related patents.

In vivo gamma-rays induced initial DNA damage and the effect of famotidine in mouse leukocytes as assayed by the alkaline comet assay.

PubMed

Mozdarani, Hossein; Nasirian, Borzo; Haeri, S Abolghasem

2007-03-01

Ionizing radiation induces a variety of lesions in DNA, each of which can be used as a bio-indicator for biological dosimetry or the study of the radioprotective effects of substances. To assess gamma ray-induced DNA damage in vivo in mouse leukocytes at various doses and the effect of famotidine, blood was collected from Balb/c male mice after irradiation with 4 Gy gamma-rays at different time intervals post-irradiation. To assess the response, mice were irradiated with doses of gamma-rays at 1 to 4 Grays. Famotidine was injected intra-peritoneally (i.p) at a dose of 5 mg/kg at various time intervals before irradiation. Four slides were prepared from each sample and alkaline comet assay was performed using standard protocols. Results obtained show that radiation significantly increases DNA damage in leukocytes in a dose dependent manner (p < 0.01) when using appropriate sampling time after irradiation, because increasing sampling time after irradiation resulted in a time dependent disappearance of DNA damage. Treatment with only 5 mg/kg famotidine before 4 Gy irradiation led to almost 50% reduction in DNA damage when compared with those animals which received radiation alone. The radioprotective capability of famotidine might be attributed to radical scavenging properties and an anti-oxidation mechanism.

Antihypertensive treatment prolongs tissue plasminogen activator door-to-treatment time: secondary analysis of the INSTINCT trial.

PubMed

Skolarus, Lesli E; Scott, Phillip A; Burke, James F; Adelman, Eric E; Frederiksen, Shirley M; Kade, Allison M; Kalbfleisch, Jack D; Ford, Andria L; Meurer, William J

2012-12-01

Identifying modifiable tissue plasminogen activator treatment delays may improve stroke outcomes. We hypothesized that prethrombolytic antihypertensive treatment (AHT) may prolong door-to-treatment time (DTT). We performed an analysis of consecutive tissue plasminogen activator-treated patients at 24 randomly selected community hospitals in the Increasing Stroke Treatment through Interventional Behavior Change Tactics (INSTINCT) trial between 2007 and 2010. DTT among stroke patients who received prethrombolytic AHT were compared with those who did not receive prethrombolytic AHT. We then calculated a propensity score for the probability of receiving prethrombolytic AHT using logistic regression with demographics, stroke risk factors, home medications, stroke severity (National Institutes of Health Stroke Scale), onset-to-door time, admission glucose, pretreatment blood pressure, emergency medical service transport, and location at time of stroke as independent variables. A paired t test was performed to compare the DTT between the propensity-matched groups. Of 534 tissue plasminogen activator-treated stroke patients analyzed, 95 received prethrombolytic AHT. In the unmatched cohort, patients who received prethrombolytic AHT had a longer DTT (mean increase, 9 minutes; 95% confidence interval, 2-16 minutes) than patients who did not. After propensity matching, patients who received prethrombolytic AHT had a longer DTT (mean increase, 10.4 minutes; 95% confidence interval, 1.9-18.8) than patients who did not receive prethrombolytic AHT. Prethrombolytic AHT is associated with modest delays in DTT. This represents a potential target for quality-improvement initiatives. Further research evaluating optimum prethrombolytic hypertension management is warranted.

Relationship between cutoff frequency and accuracy in time-interval photon statistics applied to oscillating signals

NASA Astrophysics Data System (ADS)

Rebolledo, M. A.; Martinez-Betorz, J. A.

1989-04-01

In this paper the accuracy in the determination of the period of an oscillating signal, when obtained from the photon statistics time-interval probability, is studied as a function of the precision (the inverse of the cutoff frequency of the photon counting system) with which time intervals are measured. The results are obtained by means of an experiment with a square-wave signal, where the Fourier or square-wave transforms of the time-interval probability are measured. It is found that for values of the frequency of the signal near the cutoff frequency the errors in the period are small.

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.

Sprint interval and endurance training are equally effective in increasing muscle microvascular density and eNOS content in sedentary males

PubMed Central

Cocks, Matthew; Shaw, Christopher S; Shepherd, Sam O; Fisher, James P; Ranasinghe, Aaron M; Barker, Thomas A; Tipton, Kevin D; Wagenmakers, Anton J M

2013-01-01

Sprint interval training (SIT) has been proposed as a time efficient alternative to endurance training (ET) for increasing skeletal muscle oxidative capacity and improving certain cardiovascular functions. In this study we sought to make the first comparisons of the structural and endothelial enzymatic changes in skeletal muscle microvessels in response to ET and SIT. Sixteen young sedentary males (age 21 ± SEM 0.7 years, BMI 23.8 ± SEM 0.7 kg m−2) were randomly assigned to 6 weeks of ET (40–60 min cycling at ∼65%, 5 times per week) or SIT (4–6 Wingate tests, 3 times per week). Muscle biopsies were taken from the m. vastus lateralis before and following 60 min cycling at 65% to measure muscle microvascular endothelial eNOS content, eNOS serine1177 phosphorylation, NOX2 content and capillarisation using quantitative immunofluorescence microscopy. Whole body insulin sensitivity, arterial stiffness and blood pressure were also assessed. ET and SIT increased skeletal muscle microvascular eNOS content (ET 14%; P < 0.05, SIT 36%; P < 0.05), with a significantly greater increase observed following SIT (P < 0.05). Sixty minutes of moderate intensity exercise increased eNOS ser1177 phosphorylation in all instances (P < 0.05), but basal and post-exercise eNOS ser1177 phosphorylation was lower following both training modes. All microscopy measures of skeletal muscle capillarisation (P < 0.05) were increased with SIT or ET, while neither endothelial nor sarcolemmal NOX2 was changed. Both training modes reduced aortic stiffness and increased whole body insulin sensitivity (P < 0.05). In conclusion, in sedentary males SIT and ET are effective in improving muscle microvascular density and eNOS protein content. PMID:22946099

Methods for estimating confidence intervals in interrupted time series analyses of health interventions.

PubMed

Zhang, Fang; Wagner, Anita K; Soumerai, Stephen B; Ross-Degnan, Dennis

2009-02-01

Interrupted time series (ITS) is a strong quasi-experimental research design, which is increasingly applied to estimate the effects of health services and policy interventions. We describe and illustrate two methods for estimating confidence intervals (CIs) around absolute and relative changes in outcomes calculated from segmented regression parameter estimates. We used multivariate delta and bootstrapping methods (BMs) to construct CIs around relative changes in level and trend, and around absolute changes in outcome based on segmented linear regression analyses of time series data corrected for autocorrelated errors. Using previously published time series data, we estimated CIs around the effect of prescription alerts for interacting medications with warfarin on the rate of prescriptions per 10,000 warfarin users per month. Both the multivariate delta method (MDM) and the BM produced similar results. BM is preferred for calculating CIs of relative changes in outcomes of time series studies, because it does not require large sample sizes when parameter estimates are obtained correctly from the model. Caution is needed when sample size is small.

Comparison of the relation between timing and force control during finger-tapping sequences by pianists and non pianists.

PubMed

Inui, N; Ichihara, T

2001-10-01

To examine the relation between timing and force control during finger taping sequences by both pianists and nonpianists, participants tapped a force plate connected to strain gauges. A series of finger tapping tasks consisted of 16 combinations of pace (intertap interval: 180, 200, 400, or 800 ms) and peak force (50, 100, 200, or 400 g). Analysis showed that, although movement timing was independent of force control under low or medium pace conditions, there were strong interactions between the 2 parameters under high pace conditions. The results indicate that participants adapted the movement by switching from separately controlling these parameters in the slow and moderate movement to coupling them in the fast movement. While variations in the intertap interval affected force production by nonpianists, they had little effect for pianists. The ratios of time-to-peak force to press duration increased linearly in pianists but varied irregularly in nonpianists, as the required force decreased. Thus, pianists regulate peak force by timing control of peak force to press duration, suggesting that training affects the relationship between the 2 parameters.

Participation of ethylene in gravitropism

NASA Technical Reports Server (NTRS)

Harrison, M.; Pickard, B. G.

1984-01-01

In shoots of many plants, of which tomato (Lycopersicon esculentum Mill.) is an example, ethylene production is substantially increased during gravitropism. As a first step toward elucidating the role of ethylene in gravitropism, detailed time courses of ethylene production in isolated hypocotyl segments and whole plants were measured for gravistimulated and upright tomato seedlings. In the first experiment, seedlings were set upright or laid horizontal and then, at 15 min intervals, sets of hypocotyls were excised and sealed into gas tight vials. A steady long term rise in ethylene production begins after 15 min gravistimulation. It is possible that this increase is a consequence of the accumulation of indoleacetic acid (IAA) in the lower tissue of the hypocotyle. In a second kind of experiment, whole seedlings were enclosed in sealed chambers and air samples were withdrawn at 5 min intervals. Stimulated seedlings produced more ethylene than controls during the first 5 min interval, but not appreciably more during the second. This suggests the possibility that the ethylene production induced during the first 5 min occurs immediately rather than after a lag, and thus much too soon to be controlled by redistribution of IAA.

Does major depression result in lasting personality change?

PubMed

Shea, M T; Leon, A C; Mueller, T I; Solomon, D A; Warshaw, M G; Keller, M B

1996-11-01

Individuals with a history of depression are characterized by high levels of certain personality traits, particularly neuroticism, introversion, and interpersonal dependency. The authors examined the "scar hypothesis," i.e., the possibility that episodes of major depression result in lasting personality changes that persist beyond recovery from the depression. A large sample of first-degree relatives, spouses, and comparison subjects ascertained in connection with the proband sample from the National Institute of Mental Health Collaborative Program on the Psychobiology of Depression were assessed at two points in time separated by an interval of 6 years. Subjects with a prospectively observed first episode of major depression during the interval were compared with subjects remaining well in terms of change from time 1 to time 2 in self-reported personality traits. All subjects studied were well (had no mental disorders) at the time of both assessments. There was no evidence of negative change from premorbid to postmorbid assessment in any of the personality traits for subjects with a prospectively observed first episode of major depression during the interval. The results suggested a possible association of number and length of episodes with increased levels of emotional reliance and introversion, respectively. The findings suggest that self-reported personality traits do not change after a typical episode of major depression. Future studies are needed to determine whether such change occurs following more severe, chronic, or recurrent episodes of depression.

Health Insurance Trajectories and Long-Term Survival After Heart Transplantation.

PubMed

Tumin, Dmitry; Foraker, Randi E; Smith, Sakima; Tobias, Joseph D; Hayes, Don

2016-09-01

Health insurance status at heart transplantation influences recipient survival, but implications of change in insurance for long-term outcomes are unclear. Adults aged 18 to 64 receiving first-time orthotopic heart transplants between July 2006 and December 2013 were identified in the United Network for Organ Sharing registry. Patients surviving >1 year were categorized according to trajectory of insurance status (private compared with public) at wait listing, transplantation, and 1-year follow-up. The most common insurance trajectories were continuous private coverage (44%), continuous public coverage (27%), and transition from private to public coverage (11%). Among patients who survived to 1 year (n=9088), continuous public insurance (hazard ratio =1.36; 95% confidence interval 1.19, 1.56; P<0.001) and transition from private to public insurance (hazard ratio =1.25; 95% confidence interval 1.04, 1.50; P=0.017) were associated with increased mortality hazard relative to continuous private insurance. Supplementary analyses of 11 247 patients included all durations of post-transplant survival and examined post-transplant private-to-public and public-to-private transitions as time-varying covariates. In these analyses, transition from private to public insurance was associated with increased mortality hazard (hazard ratio =1.25; 95% confidence interval 1.07, 1.47; P=0.005), whereas transition from public to private insurance was associated with lower mortality hazard (hazard ratio =0.78; 95% confidence interval 0.62, 0.97; P=0.024). Transition from private to public insurance after heart transplantation is associated with worse long-term outcomes, compounding disparities in post-transplant survival attributed to insurance status at transplantation. By contrast, post-transplant gain of private insurance among patients receiving publicly funded heart transplants was associated with improved outcomes. © 2016 American Heart Association, Inc.

Echolocating Big Brown Bats, Eptesicus fuscus, Modulate Pulse Intervals to Overcome Range Ambiguity in Cluttered Surroundings

PubMed Central

Wheeler, Alyssa R.; Fulton, Kara A.; Gaudette, Jason E.; Simmons, Ryan A.; Matsuo, Ikuo; Simmons, James A.

2016-01-01

Big brown bats (Eptesicus fuscus) emit trains of brief, wideband frequency-modulated (FM) echolocation sounds and use echoes of these sounds to orient, find insects, and guide flight through vegetation. They are observed to emit sounds that alternate between short and long inter-pulse intervals (IPIs), forming sonar sound groups. The occurrence of these strobe groups has been linked to flight in cluttered acoustic environments, but how exactly bats use sonar sound groups to orient and navigate is still a mystery. Here, the production of sound groups during clutter navigation was examined. Controlled flight experiments were conducted where the proximity of the nearest obstacles was systematically decreased while the extended scene was kept constant. Four bats flew along a corridor of varying widths (100, 70, and 40 cm) bounded by rows of vertically hanging plastic chains while in-flight echolocation calls were recorded. Bats shortened their IPIs for more rapid spatial sampling and also grouped their sounds more tightly when flying in narrower corridors. Bats emitted echolocation calls with progressively shorter IPIs over the course of a flight, and began their flights by emitting shorter starting IPI calls when clutter was denser. The percentage of sound groups containing 3 or more calls increased with increasing clutter proximity. Moreover, IPI sequences having internal structure become more pronounced when corridor width narrows. A novel metric for analyzing the temporal organization of sound sequences was developed, and the results indicate that the time interval between echolocation calls depends heavily on the preceding time interval. The occurrence of specific IPI patterns were dependent upon clutter, which suggests that sonar sound grouping may be an adaptive strategy for coping with pulse-echo ambiguity in cluttered surroundings. PMID:27445723

High-intensity cycle interval training improves cycling and running performance in triathletes.

PubMed

Etxebarria, Naroa; Anson, Judith M; Pyne, David B; Ferguson, Richard A

2014-01-01

Effective cycle training for triathlon is a challenge for coaches. We compared the effects of two variants of cycle high-intensity interval training (HIT) on triathlon-specific cycling and running. Fourteen moderately-trained male triathletes ([Formula: see text]O2peak 58.7 ± 8.1 mL kg(-1) min(-1); mean ± SD) completed on separate occasions a maximal incremental test ([Formula: see text]O2peak and maximal aerobic power), 16 × 20 s cycle sprints and a 1-h triathlon-specific cycle followed immediately by a 5 km run time trial. Participants were then pair-matched and assigned randomly to either a long high-intensity interval training (LONG) (6-8 × 5 min efforts) or short high-intensity interval training (SHORT) (9-11 × 10, 20 and 40 s efforts) HIT cycle training intervention. Six training sessions were completed over 3 weeks before participants repeated the baseline testing. Both groups had an ∼7% increase in [Formula: see text]O2peak (SHORT 7.3%, ±4.6%; mean, ±90% confidence limits; LONG 7.5%, ±1.7%). There was a moderate improvement in mean power for both the SHORT (10.3%, ±4.4%) and LONG (10.7%, ±6.8%) groups during the last eight 20-s sprints. There was a small to moderate decrease in heart rate, blood lactate and perceived exertion in both groups during the 1-h triathlon-specific cycling but only the LONG group had a substantial decrease in the subsequent 5-km run time (64, ±59 s). Moderately-trained triathletes should use both short and long high-intensity intervals to improve cycling physiology and performance. Longer 5-min intervals on the bike are more likely to benefit 5 km running performance.

[III Catalan registry of ST elevation acute myocardial infarction. Comparison with former Catalan registries I and II from Catalonia, Spain].

PubMed

Figueras, Jaume; Heras, Magda; Baigorri, Francisco; Elosua, Roberto; Ferreira, Ignacio; Santaló, Miquel

2009-11-14

To analyze the use of reperfusion therapy in patients with ST elevation myocardial infarction (STEMI) in Catalonia in a registry performed in 2006 (IAM CAT III) and its comparison with 2 previous registries Frequency of reperfusion therapy and time intervals between symptom onset - reperfusion therapy were the principal variables investigated. The IAM CAT I (June-December 2000) included 1,450 patients, the IAM CAT II (October 2002-April 2003) 1,386, and the IAM CAT III (October-December 2006) 367. The proportion of patients treated with reperfusion increased progressively (72%, 79% and 81%) as the use of primary angioplasty (5%, 10% and 33%). In the III registry the transfer system most frequently used was the SEM/061 (17%, 32% and 47%, respectively) but the time interval symptom onset-first contact with the medical system did not improve (II, 90 vs III, 105 min), the interval symptom onset-thrombolytic therapy did hardly change (178, 165 and 177 min) and the interval hospital arrival-trombolysis (needle-door) tended to improve (59, 42 and 42 min). Thirty day mortality in STEMI patients declined progressively through the 3 registries (12.1, 10.6 and 7.4%, p=0.012). The proportion of STEMI patients treated with reperfusion has improved but the interval to its application has not been shortened. To improve the latter it is mandatory an earlier contact with the medical system, a shortening of the intervals door-needle and door-balloon through better coordination between the 061, the sanitary personnel and the hospital administration, and to consider the subject as a real sanitary priority.

Stream structure at low flow: biogeochemical patterns in intermittent streams over space and time

NASA Astrophysics Data System (ADS)

MacNeille, R. B.; Lohse, K. A.; Godsey, S.; McCorkle, E. P.; Parsons, S.; Baxter, C.

2017-12-01

Climate change in the western United States is projected to lead to earlier snowmelt, increasing fire risk and potentially transitioning perennial streams to intermittent ones. Differences between perennial and intermittent streams, especially the temporal and spatial patterns of carbon and nutrient dynamics during periods of drying, are understudied. We examined spatial and temporal patterns in surface water biogeochemistry during a dry (2016) and a wet (2017) water year in southwest Idaho. We hypothesized that as streams dry, carbon concentrations would increase due to evapoconcentration and/or increased in-stream production, and that the heterogeneity of constituents within each stream would increase. We expected these patterns to differ in a high water year compared to a low water year due to algae scour. Finally, we expected that the spatial heterogeneity of biogeochemistry would decrease with time following fire. To test these hypotheses, in 2016 we collected surface water samples at 50 meter intervals from two intermittent headwater streams over 2,500 meter reaches in April, May, and June. One stream is burned and one remains unburned. In 2017, we collected surface water at the 50, 25 and 10 meter intervals from each stream once during low flow. 2016 results showed average concentrations of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) increased 3-fold from April to June in the burned site compared to the unburned site. Interestingly, average concentrations of total nitrogen (TN) dropped substantially for the burned site over these three months, but only decreased slightly for the unburned site over the same time period. Between wet and dry water years, we observed a decrease in the spatial heterogeneity as measured by the standard deviation (SD) in conductivity at 50 meter intervals; the burned stream had a SD of 23.08 in 2016 and 11.40 in 2017 whereas the unburned stream had similar SDs. We conclude that the burned stream experienced more inter and intra-annual surface water change in chemistry patterns than did the unburned stream.

Choice in the repeated-gambles experiment.

PubMed

Silberberg, A; Murray, P; Christensen, J; Asano, T

1988-09-01

Humans chose 10 times between two roulette wheels projected on a monitor. During the first trial, the left wheel provided a hypothetical $100 with p = .94, and the right wheel provided $250 with p = .39. A titration procedure adjusted the probability of a $250 win across trials to permit estimation of an indifference point between alternatives. In Experiment 1, intertrial-interval duration (25 vs. 90 s) and whether sessions began with an intertrial interval or a trial were varied in a 2 x 2 design in this risky-choice procedure. Risk aversion (preference for the $100 wheel) increased with intertrial interval but was unaffected by whether sessions began with a trial or an intertrial interval. In Experiment 2, all sessions began with a trial, and subjects were informed that the experiment ended after 10 trials. Intertrial-interval duration had no effect on choice. In Experiment 3, intertrial-interval duration and whether subjects were given $10 or $10,000 before beginning were varied among four groups in a 2 x 2 design. In all other ways, the procedure was unchanged from Experiment 2. Intertrial interval had no effect on choice, but the $10,000 groups showed less risk aversion than the $10 groups. These results can be explained more readily in terms of Kahneman and Tversky's (1984) notion of "framing of the prospect" than in terms of Rachlin, Logue, Gibbon, and Frankel's (1986) behavioral account of risky choice.

Challenges in risk estimation using routinely collected clinical data: The example of estimating cervical cancer risks from electronic health-records.

PubMed

Landy, Rebecca; Cheung, Li C; Schiffman, Mark; Gage, Julia C; Hyun, Noorie; Wentzensen, Nicolas; Kinney, Walter K; Castle, Philip E; Fetterman, Barbara; Poitras, Nancy E; Lorey, Thomas; Sasieni, Peter D; Katki, Hormuzd A

2018-06-01

Electronic health-records (EHR) are increasingly used by epidemiologists studying disease following surveillance testing to provide evidence for screening intervals and referral guidelines. Although cost-effective, undiagnosed prevalent disease and interval censoring (in which asymptomatic disease is only observed at the time of testing) raise substantial analytic issues when estimating risk that cannot be addressed using Kaplan-Meier methods. Based on our experience analysing EHR from cervical cancer screening, we previously proposed the logistic-Weibull model to address these issues. Here we demonstrate how the choice of statistical method can impact risk estimates. We use observed data on 41,067 women in the cervical cancer screening program at Kaiser Permanente Northern California, 2003-2013, as well as simulations to evaluate the ability of different methods (Kaplan-Meier, Turnbull, Weibull and logistic-Weibull) to accurately estimate risk within a screening program. Cumulative risk estimates from the statistical methods varied considerably, with the largest differences occurring for prevalent disease risk when baseline disease ascertainment was random but incomplete. Kaplan-Meier underestimated risk at earlier times and overestimated risk at later times in the presence of interval censoring or undiagnosed prevalent disease. Turnbull performed well, though was inefficient and not smooth. The logistic-Weibull model performed well, except when event times didn't follow a Weibull distribution. We have demonstrated that methods for right-censored data, such as Kaplan-Meier, result in biased estimates of disease risks when applied to interval-censored data, such as screening programs using EHR data. The logistic-Weibull model is attractive, but the model fit must be checked against Turnbull non-parametric risk estimates. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Changes in corticospinal excitability and the direction of evoked movements during motor preparation: A TMS study

PubMed Central

van Elswijk, Gijs; Schot, Willemijn D; Stegeman, Dick F; Overeem, Sebastiaan

2008-01-01

Background Preparation of the direction of a forthcoming movement has a particularly strong influence on both reaction times and neuronal activity in the primate motor cortex. Here, we aimed to find direct neurophysiologic evidence for the preparation of movement direction in humans. We used single-pulse transcranial magnetic stimulation (TMS) to evoke isolated thumb-movements, of which the direction can be modulated experimentally, for example by training or by motor tasks. Sixteen healthy subjects performed brisk concentric voluntary thumb movements during a reaction time task in which the required movement direction was precued. We assessed whether preparation for the thumb movement lead to changes in the direction of TMS-evoked movements and to changes in amplitudes of motor-evoked potentials (MEPs) from the hand muscles. Results When the required movement direction was precued early in the preparatory interval, reaction times were 50 ms faster than when precued at the end of the preparatory interval. Over time, the direction of the TMS-evoked thumb movements became increasingly variable, but it did not turn towards the precued direction. MEPs from the thumb muscle (agonist) were differentially modulated by the direction of the precue, but only in the late phase of the preparatory interval and thereafter. MEPs from the index finger muscle did not depend on the precued direction and progressively decreased during the preparatory interval. Conclusion Our data show that the human corticospinal movement representation undergoes progressive changes during motor preparation. These changes are accompanied by inhibitory changes in corticospinal excitability, which are muscle specific and depend on the prepared movement direction. This inhibition might indicate a corticospinal braking mechanism that counteracts any preparatory motor activation. PMID:18559096

Beta-band oscillations during passive listening to metronome sounds reflect improved timing representation after short-term musical training in healthy older adults.

PubMed

Fujioka, Takako; Ross, Bernhard

2017-10-01

Sub-second time intervals in musical rhythms provide predictive cues about future events to performers and listeners through an internalized representation of timing. While the acuity of automatic, sub-second timing as well as cognitively controlled, supra-second timing declines with ageing, musical experts are less affected. This study investigated the influence of piano training on temporal processing abilities in older adults using behavioural and neuronal correlates. We hypothesized that neuroplastic changes in beta networks, caused by training in sensorimotor coordination with timing processing, can be assessed even in the absence of movement. Behavioural performance of internal timing stability was assessed with synchronization-continuation finger-tapping paradigms. Magnetoencephalography (MEG) was recorded from older adults before and after one month of one-on-one training. For neural measures of automatic timing processing, we focused on beta oscillations (13-30 Hz) during passive listening to metronome beats. Periodic beta-band modulations in older adults before training were similar to previous findings in young listeners at a beat interval of 800 ms. After training, behavioural performance for continuation tapping was improved and accompanied by an increased range of beat-induced beta modulation, compared to participants who did not receive training. Beta changes were observed in the caudate, auditory, sensorimotor and premotor cortices, parietal lobe, cerebellum and medial prefrontal cortex, suggesting that increased resources are involved in timing processing and goal-oriented monitoring as well as reward-based sensorimotor learning. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

The influence of prior experience and expected timing on vibrotactile discrimination

PubMed Central

Karim, Muhsin; Harris, Justin A.; Langdon, Angela; Breakspear, Michael

2013-01-01

Vibrotactile discrimination tasks involve perceptual judgements on stimulus pairs separated by a brief interstimulus interval (ISI). Despite their apparent simplicity, decision making during these tasks is biased by prior experience in a manner that is not well understood. A striking example is when participants perform well on trials where the first stimulus is closer to the mean of the stimulus-set than the second stimulus, and perform comparatively poorly when the first stimulus is further from the stimulus mean. This “time-order effect” suggests that participants implicitly encode the mean of the stimulus-set and use this internal standard to bias decisions on any given trial. For relatively short ISIs, the magnitude of the time-order effect typically increases with the distance of the first stimulus from the global mean. Working from the premise that the time-order effect reflects the loss of precision in working memory representations, we predicted that the influence of the time-order effect, and this superimposed “distance” effect, would monotonically increase for trials with longer ISIs. However, by varying the ISI across four intervals (300, 600, 1200, and 2400 ms) we instead found a complex, non-linear dependence of the time-order effect on both the ISI and the distance, with the time-order effect being paradoxically stronger at short ISIs. We also found that this relationship depended strongly on participants' prior experience of the ISI (from previous task titration). The time-order effect not only depends on participants' expectations concerning the distribution of stimuli, but also on the expected timing of the trials. PMID:24399927

High resolution digital delay timer

DOEpatents

Martin, Albert D.

1988-01-01

Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay (20) provides a first output signal (24) at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits (26, 28) latch the high resolution data (24) to form a first synchronizing data set (60). A selected time interval has been preset to internal counters (142, 146, 154) and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses (32, 34) count down the counters to generate an internal pulse delayed by an interval which is functionally related to the preset time interval. A second LCD (184) corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD (74) to generate a second set of synchronizing data (76) which is complementary with the first set of synchronizing data (60) for presentation to logic circuits (64). The logic circuits (64) further delay the internal output signal (72) to obtain a proper phase relationship of an output signal (80) with the internal pulses (32, 34). The final delayed output signal (80) thereafter enables the output pulse generator (82) to produce the desired output pulse (84) at the preset time delay interval following input of the trigger pulse (10, 12).

No Clear Association between Impaired Short-Term or Working Memory Storage and Time Reproduction Capacity in Adult ADHD Patients.

PubMed

Mette, Christian; Grabemann, Marco; Zimmermann, Marco; Strunz, Laura; Scherbaum, Norbert; Wiltfang, Jens; Kis, Bernhard

2015-01-01

Altered time reproduction is exhibited by patients with adult attention deficit hyperactivity disorder (ADHD). It remains unclear whether memory capacity influences the ability of adults with ADHD to reproduce time intervals. We conducted a behavioral study on 30 ADHD patients who were medicated with methylphenidate, 29 unmedicated adult ADHD patients and 32 healthy controls (HCs). We assessed time reproduction using six time intervals (1 s, 4 s, 6 s, 10 s, 24 s and 60 s) and assessed memory performance using the Wechsler memory scale. The patients with ADHD exhibited lower memory performance scores than the HCs. No significant differences in the raw scores for any of the time intervals (p > .05), with the exception of the variability at the short time intervals (1 s, 4 s and 6 s) (p < .01), were found between the groups. The overall analyses failed to reveal any significant correlations between time reproduction at any of the time intervals examined in the time reproduction task and working memory performance (p > .05). We detected no findings indicating that working memory might influence time reproduction in adult patients with ADHD. Therefore, further studies concerning time reproduction and memory capacity among adult patients with ADHD must be performed to verify and replicate the present findings.

Prediction of future asset prices

NASA Astrophysics Data System (ADS)

Seong, Ng Yew; Hin, Pooi Ah; Ching, Soo Huei

2014-12-01

This paper attempts to incorporate trading volumes as an additional predictor for predicting asset prices. Denoting r(t) as the vector consisting of the time-t values of the trading volume and price of a given asset, we model the time-(t+1) asset price to be dependent on the present and l-1 past values r(t), r(t-1), ....., r(t-1+1) via a conditional distribution which is derived from a (2l+1)-dimensional power-normal distribution. A prediction interval based on the 100(α/2)% and 100(1-α/2)% points of the conditional distribution is then obtained. By examining the average lengths of the prediction intervals found by using the composite indices of the Malaysia stock market for the period 2008 to 2013, we found that the value 2 appears to be a good choice for l. With the omission of the trading volume in the vector r(t), the corresponding prediction interval exhibits a slightly longer average length, showing that it might be desirable to keep trading volume as a predictor. From the above conditional distribution, the probability that the time-(t+1) asset price will be larger than the time-t asset price is next computed. When the probability differs from 0 (or 1) by less than 0.03, the observed time-(t+1) increase in price tends to be negative (or positive). Thus the above probability has a good potential of being used as a market indicator in technical analysis.

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.

Evaluating the risk of decompression sickness for a yo-yo dive using a rat model.

PubMed

Ofir, Dror; Yanir, Yoav; Abramovich, Amir; Bar, Ronen; Arieli, Yehuda

2016-01-01

The frequent ascents made during yo-yo diving may contribute to gas bubble clearance but paradoxically may also increase the risk of central nervous system decompression illness (DCI). We evaluated the risk of DCI due to yo-yo dives with very short surface intervals, using a controlled animal model. Dives were conducted on air to a depth of 90 meters (10 atmospheres absolute) for 32 minutes of bottom time, at a descent/ascent rate of 10 meters/ minute. Sprague-Dawley rats weighing ~ 300 grams were divided randomly into three groups. Group A performed a square dive protocol without any surface intervals, Group B conducted a protocol that included two surface intervals during the dive, and Group C performed a protocol with three surface intervals. Ascent/descent rate for surface intervals, each lasting one minute, was also 10 meters/minute. Manifestations of DCI were observed in 13 of 16 animals in Group A (81.3%), six of 12 in Group B (58.3%), and two of 12 in Group C (16.7%). Mortality rates were similar in all groups. Surface intervals during dives breathing air significantly reduced DCI risk in the rat. Further studies are required using a larger animal model to reinforce the results of the present investigation.

Palaeoclimate records 60-8 ka in the Austrian and Swiss Alps and their forelands

NASA Astrophysics Data System (ADS)

Heiri, Oliver; Koinig, Karin A.; Spötl, Christoph; Barrett, Sam; Brauer, Achim; Drescher-Schneider, Ruth; Gaar, Dorian; Ivy-Ochs, Susan; Kerschner, Hanns; Luetscher, Marc; Moran, Andrew; Nicolussi, Kurt; Preusser, Frank; Schmidt, Roland; Schoeneich, Philippe; Schwörer, Christoph; Sprafke, Tobias; Terhorst, Birgit; Tinner, Willy

2014-12-01

The European Alps and their forelands provide a range of different archives and climate proxies for developing climate records in the time interval 60-8 thousand years (ka) ago. We review quantitative and semi-quantitative approaches for reconstructing climatic variables in the Austrian and Swiss sector of the Alpine region within this time interval. Available quantitative to semi-quantitative climate records in this region are mainly based on fossil assemblages of biota such as chironomids, cladocerans, coleopterans, diatoms and pollen preserved in lake sediments and peat, the analysis of oxygen isotopes in speleothems and lake sediment records, the reconstruction of past variations in treeline altitude, the reconstruction of past equilibrium line altitude and extent of glaciers based on geomorphological evidence, and the interpretation of past soil formation processes, dust deposition and permafrost as apparent in loess-palaeosol sequences. Palaeoclimate reconstructions in the Alpine region are affected by dating uncertainties increasing with age, the fragmentary nature of most of the available records, which typically only incorporate a fraction of the time interval of interest, and the limited replication of records within and between regions. Furthermore, there have been few attempts to cross-validate different approaches across this time interval to confirm reconstructed patterns of climatic change by several independent lines of evidence. Based on our review we identify a number of developments that would provide major advances for palaeoclimate reconstruction for the period 60-8 ka in the Alps and their forelands. These include (1) the compilation of individual, fragmentary records to longer and continuous reconstructions, (2) replication of climate records and the development of regional reconstructions for different parts of the Alps, (3) the cross-validation of different proxy-types and approaches, and (4) the reconstruction of past variations in climate gradients across the Alps and their forelands. Furthermore, the development of downscaled climate model runs for the Alpine region 60-8 ka, and of forward modelling approaches for climate proxies would expand the opportunities for quantitative assessments of climatic conditions in Europe within this time-interval.

Eliciting interval beliefs: An experimental study

PubMed Central

Peeters, Ronald; Wolk, Leonard

2017-01-01

In this paper we study the interval scoring rule as a mechanism to elicit subjective beliefs under varying degrees of uncertainty. In our experiment, subjects forecast the termination time of a time series to be generated from a given but unknown stochastic process. Subjects gradually learn more about the underlying process over time and hence the true distribution over termination times. We conduct two treatments, one with a high and one with a low volatility process. We find that elicited intervals are better when subjects are facing a low volatility process. In this treatment, participants learn to position their intervals almost optimally over the course of the experiment. This is in contrast with the high volatility treatment, where subjects, over the course of the experiment, learn to optimize the location of their intervals but fail to provide the optimal length. PMID:28380020

Filling the blanks in temporal intervals: the type of filling influences perceived duration and discrimination performance

PubMed Central

Horr, Ninja K.; Di Luca, Massimiliano

2015-01-01

In this work we investigate how judgments of perceived duration are influenced by the properties of the signals that define the intervals. Participants compared two auditory intervals that could be any combination of the following four types: intervals filled with continuous tones (filled intervals), intervals filled with regularly-timed short tones (isochronous intervals), intervals filled with irregularly-timed short tones (anisochronous intervals), and intervals demarcated by two short tones (empty intervals). Results indicate that the type of intervals to be compared affects discrimination performance and induces distortions in perceived duration. In particular, we find that duration judgments are most precise when comparing two isochronous and two continuous intervals, while the comparison of two anisochronous intervals leads to the worst performance. Moreover, we determined that the magnitude of the distortions in perceived duration (an effect akin to the filled duration illusion) is higher for tone sequences (no matter whether isochronous or anisochronous) than for continuous tones. Further analysis of how duration distortions depend on the type of filling suggests that distortions are not only due to the perceived duration of the two individual intervals, but they may also be due to the comparison of two different filling types. PMID:25717310

Possible helio-geomagnetic activity influence on cardiological cases

NASA Astrophysics Data System (ADS)

Katsavrias, Christos

Eruptive solar events as flares and coronal mass ejections (CMEs) occur during solar activ-ity periods. Energetic particles, fast solar wind plasma and electromagnetic radiation pass through interplanetary space, arrive on Earth's ionosphere-magnetosphere and produce various disturbances. It is well known the negative influence of geomagnetic substorms on the human technological applications on geospace. During the last 25 years, many studies concerning the possible influence on the human health are published. Increase of the Acute Coronary Syn-dromes and disorders of the Cardiac Rhythm, increase of accidents as well as neurological and psychological disorders (e.g. increase of suicides) during or near to the geomagnetic storms time interval are reported. In this study, we research the problem in Greece, focusing on patients with Acute Myocardial Infraction, hospitalized in the 2nd Cardiological Department of the General Hospital of Nikaea (Piraeus City), for the time interval 1997-2007 (23rd solar cycle) and also to the arrival of emergency cardiological cases to Emergency Department of two greek hospitals, the General Hospital of Lamia City and the General Hospital of Veria City during the selected months, with or without helio-geomagnetic activity, of the 23rd solar cycle. Increase of cases is recorded during the periods with increase helio-geomagnetic activity. The necessity of continuing the research for a longer period and with a bigger sample is high; so as to exact more secure conclusions.

Spatial variability in the trends in extreme storm surges and weekly-scale high water levels in the eastern Baltic Sea

NASA Astrophysics Data System (ADS)

Soomere, Tarmo; Pindsoo, Katri

2016-03-01

We address the possibilities of a separation of the overall increasing trend in maximum water levels of semi-enclosed water bodies into associated trends in the heights of local storm surges and basin-scale components of the water level based on recorded and modelled local water level time series. The test area is the Baltic Sea. Sequences of strong storms may substantially increase its water volume and raise the average sea level by almost 1 m for a few weeks. Such events are singled out from the water level time series using a weekly-scale average. The trends in the annual maxima of the weekly average have an almost constant value along the entire eastern Baltic Sea coast for averaging intervals longer than 4 days. Their slopes are ~4 cm/decade for 8-day running average and decrease with an increase of the averaging interval. The trends for maxima of local storm surge heights represent almost the entire spatial variability in the water level maxima. Their slopes vary from almost zero for the open Baltic Proper coast up to 5-7 cm/decade in the eastern Gulf of Finland and Gulf of Riga. This pattern suggests that an increase in wind speed in strong storms is unlikely in this area but storm duration may have increased and wind direction may have rotated.

How Fast Do Objects Fall in Visual Memory? Uncovering the Temporal and Spatial Features of Representational Gravity

PubMed Central

De Sá Teixeira, Nuno

2016-01-01

Visual memory for the spatial location where a moving target vanishes has been found to be systematically displaced downward in the direction of gravity. Moreover, it was recently reported that the magnitude of the downward error increases steadily with increasing retention intervals imposed after object’s offset and before observers are allowed to perform the spatial localization task, in a pattern where the remembered vanishing location drifts downward as if following a falling trajectory. This outcome was taken to reflect the dynamics of a representational model of earth’s gravity. The present study aims to establish the spatial and temporal features of this downward drift by taking into account the dynamics of the motor response. The obtained results show that the memory for the last location of the target drifts downward with time, thus replicating previous results. Moreover, the time taken for completion of the behavioural localization movements seems to add to the imposed retention intervals in determining the temporal frame during which the visual memory is updated. Overall, it is reported that the representation of spatial location drifts downward by about 3 pixels for each two-fold increase of time until response. The outcomes are discussed in relation to a predictive internal model of gravity which outputs an on-line spatial update of remembered objects’ location. PMID:26910260

Cyclic fatigue of endodontic nickel titanium rotary instruments: static and dynamic tests.

PubMed

Li, Uei-Ming; Lee, Bor-Shiunn; Shih, Chin-Tsai; Lan, Wan-Hong; Lin, Chun-Pin

2002-06-01

Endodontic instruments upon rotation are subjected to both tensile and compressive stress in curved canals. This stress is localized at the point of curvature. The purpose of this study was to evaluate the cyclic fatigue of 0.04 ProFile nickel titanium rotary instruments operating at different rotational speeds and varied distances of pecking motion in metal blocks that simulated curved canals. A total of 150 ProFile instruments were made to rotate freely in sloped metal blocks at speeds of 200, 300, or 400 rpm by a contra-angle handpiece mounted on an Instron machine. The electric motor and Instron machine were activated until the instruments were broken in two different modes, static and dynamic pecking-motion. The fractured surfaces of separated instruments were examined under a scanning electron microscope. All data obtained were analyzed by a stepwise multiple regression method using a 95% confidence interval. The results demonstrated that the time to failure significantly decreased as the angles of curvature or the rotational speeds increased. However, as pecking distances increased, the time to failure increased. This is because a longer pecking distance gives the instrument a longer time interval before it once again passes through the highest stress area. Microscopic evaluation indicated that ductile fracture was the major cyclic failure mode. To prevent breakage of a NiTi rotary instrument, appropriate rotational speeds and continuous pecking motion in the root canals are recommended.

How Fast Do Objects Fall in Visual Memory? Uncovering the Temporal and Spatial Features of Representational Gravity.

PubMed

De Sá Teixeira, Nuno

2016-01-01

Visual memory for the spatial location where a moving target vanishes has been found to be systematically displaced downward in the direction of gravity. Moreover, it was recently reported that the magnitude of the downward error increases steadily with increasing retention intervals imposed after object's offset and before observers are allowed to perform the spatial localization task, in a pattern where the remembered vanishing location drifts downward as if following a falling trajectory. This outcome was taken to reflect the dynamics of a representational model of earth's gravity. The present study aims to establish the spatial and temporal features of this downward drift by taking into account the dynamics of the motor response. The obtained results show that the memory for the last location of the target drifts downward with time, thus replicating previous results. Moreover, the time taken for completion of the behavioural localization movements seems to add to the imposed retention intervals in determining the temporal frame during which the visual memory is updated. Overall, it is reported that the representation of spatial location drifts downward by about 3 pixels for each two-fold increase of time until response. The outcomes are discussed in relation to a predictive internal model of gravity which outputs an on-line spatial update of remembered objects' location.

Use of precision time and time interval (PTTI)

NASA Technical Reports Server (NTRS)

Taylor, J. D.

1974-01-01

A review of range time synchronization methods are discussed as an important aspect of range operations. The overall capabilities of various missile ranges to determine precise time of day by synchronizing to available references and applying this time point to instrumentation for time interval measurements are described.

[Comparative effects of nebivolol and valsartan on atrial electromechanical coupling in newly diagnosed stage 1 hypertensive patients].

PubMed

Altun, Burak; Acar, Gürkan; Akçay, Ahmet; Sökmen, Abdullah; Kaya, Hakan; Köroğlu, Sedat

2011-10-01

Hypertension is an important cardiovascular risk factor for the development of atrial fibrillation (AF). Increased atrial electromechanical coupling time interval measured by tissue Doppler is accepted as an important factor for prediction of AF development in hypertensive patients. The aim of this study was to compare the effects of valsartan, an angiotensin receptor blocker, and nebivolol, a beta-blocker, on atrial electromechanical coupling in newly diagnosed stage 1 hypertensive patients. The study included 60 newly diagnosed stage 1 hypertensive patients with no other systemic disease. The patients were randomized to receive nebivolol 5 mg (30 patients; 21 women, 9 men; mean age 48.4 ± 11.4 years) and valsartan 160 mg (30 patients; 21 women, 9 men; mean age 49.8 ± 11.3 years). All the patients underwent tissue Doppler echocardiographic examination before and three months after treatment to compare the effects of the two drugs on atrial electromechanical coupling. Baseline blood pressures, electrocardiographic and echocardiographic findings, and atrial electromechanical coupling were similar in both groups (p>0.05). Both drugs significantly reduced blood pressure after treatment, with similar efficacy (p>0.05). Atrial electromechanical coupling time intervals showed significant decreases in both groups. Prolonged interatrial electromechanical time intervals in hypertensives are improved with antihypertensive treatment.

Heart Rate Dynamics and their Relation with the Cyclic Alternating Pattern of Sleep in Normal Subjects and NFLE Patients

NASA Astrophysics Data System (ADS)

González, Jose S.; Dorantes, Guadalupe; Alba, Alfonso; Méndez, Martin O.; Camacho, Sergio; Luna-Rivera, Martin; Parrino, Liborio; Riccardi, Silvia; Terzano, Mario G.; Milioli, Giulia

The aim of this work is to study the behavior of the autonomic system through variations in the heart rate (HR) during the Cyclic Alternating Pattern (CAP) which is formed by A-phases. The analysis was carried out in 10 healthy subjects and 10 patients with Nocturnal Front Lobe Epilepsy (NFLE) that underwent one whole night of polysomnographic recordings. In order to assess the relation of A-phases with the cardiovascular system, two time domain features were computed: the amplitude reduction and time delay of the minimum of the R-R intervals with respect to A-phases onset. In addition, the same process was performed over randomly chosen R-R interval segments during the NREM sleep for baseline comparisons. A non-parametric bootstrap procedure was used to test differences of the kurtosis values of two populations. The results suggest that the onset of the A-phases is correlated with a significant increase of the HR that peaks at around 4s after the A-phase onset, independently of the A-phase subtype and sleep time for both healthy subjects and NFLE patients. Furthermore, the behavior of the reduction in the R-R intervals during the A-phases was significantly different for NFLE patients with respect to control subjects.

Pulse Transit Time Based Continuous Cuffless Blood Pressure Estimation: A New Extension and A Comprehensive Evaluation.

PubMed

Ding, Xiaorong; Yan, Bryan P; Zhang, Yuan-Ting; Liu, Jing; Zhao, Ni; Tsang, Hon Ki

2017-09-14

Cuffless technique enables continuous blood pressure (BP) measurement in an unobtrusive manner, and thus has the potential to revolutionize the conventional cuff-based approaches. This study extends the pulse transit time (PTT) based cuffless BP measurement method by introducing a new indicator - the photoplethysmogram (PPG) intensity ratio (PIR). The performance of the models with PTT and PIR was comprehensively evaluated in comparison with six models that are based on sole PTT. The validation conducted on 33 subjects with and without hypertension, at rest and under various maneuvers with induced BP changes, and over an extended calibration interval, respectively. The results showed that, comparing to the PTT models, the proposed methods achieved better accuracy on each subject group at rest state and over 24 hours calibration interval. Although the BP estimation errors under dynamic maneuvers and over extended calibration interval were significantly increased for all methods, the proposed methods still outperformed the compared methods in the latter situation. These findings suggest that additional BP-related indicator other than PTT has added value for improving the accuracy of cuffless BP measurement. This study also offers insights into future research in cuffless BP measurement for tracking dynamic BP changes and over extended periods of time.

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

PubMed

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

2014-01-01

To investigate the use of time intervals in the treatment of fractured femurs as indicators of the quality of trauma systems. 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. 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. 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.

Preventive care and recall intervals. Targeting of services in child dental care in Norway.

PubMed

Wang, N J; Aspelund, G Ø

2010-03-01

Skewed caries distribution has made interesting the use of a high risk strategy in child dental services. The purpose of this study was to describe the preventive dental care given and the recall intervals used for children and adolescents in a low caries risk population, and to study how the time spent for preventive care and the length of intervals were associated with characteristics of the children and factors related to care delivery. Time spent for and type of preventive care, recall intervals, oral health and health behaviour of children and adolescents three to 18 years of age (n = 576) and the preventive services delivered were registered at routine dental examinations in the public dental services. The time used for preventive dental care was on average 22% of the total time used in a course of treatment (7.3 of 33.4 minutes). Less than 15% of the variation in time spent for prevention was explained by oral health, oral health behaviours and other characteristics of the children and the service delivery. The mean (SD) recall intervals were 15.4 (4.6) months and 55% of the children were given intervals equal to or longer than 18 months. Approximately 30% of the variation in the length of the recall intervals was explained by characteristics of the child and the service delivery. The time used for preventive dental care of children in a low risk population was standardized, while the recall intervals to a certain extent were individualized according to dental health and dental health behaviour.

Xenon does not increase heart rate-corrected cardiac QT interval in volunteers and in patients free of cardiovascular disease.

PubMed

Neukirchen, Martin; Schaefer, Maximilian S; Kern, Carolin; Brett, Sarah; Werdehausen, Robert; Rellecke, Philipp; Reyle-Hahn, Matthias; Kienbaum, Peter

2015-09-01

Impaired cardiac repolarization, indicated by prolonged QT interval, may cause critical ventricular arrhythmias. Many anesthetics increase the QT interval by blockade of rapidly acting potassium rectifier channels. Although xenon does not affect these channels in isolated cardiomyocytes, the authors hypothesized that xenon increases the QT interval by direct and/or indirect sympathomimetic effects. Thus, the authors tested the hypothesis that xenon alters the heart rate-corrected cardiac QT (QTc) interval in anesthetic concentrations. The effect of xenon on the QTc interval was evaluated in eight healthy volunteers and in 35 patients undergoing abdominal or trauma surgery. The QTc interval was recorded on subjects in awake state, after their denitrogenation, and during xenon monoanesthesia (FetXe > 0.65). In patients, the QTc interval was recorded while awake, after anesthesia induction with propofol and remifentanil, and during steady state of xenon/remifentanil anesthesia (FetXe > 0.65). The QTc interval was determined from three consecutive cardiac intervals on electrocardiogram printouts in a blinded manner and corrected with Bazett formula. In healthy volunteers, xenon did not alter the QTc interval (mean difference: +0.11 ms [95% CI, -22.4 to 22.7]). In patients, after anesthesia induction with propofol/remifentanil, no alteration of QTc interval was noted. After propofol was replaced with xenon, the QTc interval remained unaffected (417 ± 32 ms vs. awake: 414 ± 25 ms) with a mean difference of 4.4 ms (95% CI, -4.6 to 13.5). Xenon monoanesthesia in healthy volunteers and xenon/remifentanil anesthesia in patients without clinically relevant cardiovascular disease do not increase QTc interval.

Effects of High Intensity Interval Training and Strength Training on Metabolic, Cardiovascular and Hormonal Outcomes in Women with Polycystic Ovary Syndrome: A Pilot Study.

PubMed

Almenning, Ida; Rieber-Mohn, Astrid; Lundgren, Kari Margrethe; Shetelig Løvvik, Tone; Garnæs, Kirsti Krohn; Moholdt, Trine

2015-01-01

Polycystic ovary syndrome is a common endocrinopathy in reproductive-age women, and associates with insulin resistance. Exercise is advocated in this disorder, but little knowledge exists on the optimal exercise regimes. We assessed the effects of high intensity interval training and strength training on metabolic, cardiovascular, and hormonal outcomes in women with polycystic ovary syndrome. Three-arm parallel randomized controlled trial. Thirty-one women with polycystic ovary syndrome (age 27.2 ± 5.5 years; body mass index 26.7 ± 6.0 kg/m2) were randomly assigned to high intensity interval training, strength training, or a control group. The exercise groups exercised three times weekly for 10 weeks. The main outcome measure was change in homeostatic assessment of insulin resistance (HOMA-IR). HOMA-IR improved significantly only after high intensity interval training, by -0.83 (95% confidence interval [CI], -1.45, -0.20), equal to 17%, with between-group difference (p = 0.014). After high intensity interval training, high-density lipoprotein cholesterol increased by 0.2 (95% CI, 0.02, 0.5) mmol/L, with between group difference (p = 0.04). Endothelial function, measured as flow-mediated dilatation of the brachial artery, increased significantly after high intensity interval training, by 2.0 (95% CI, 0.1, 4.0) %, between-group difference (p = 0.08). Fat percentage decreased significantly after both exercise regimes, without changes in body weight. After strength training, anti-Müllarian hormone was significantly reduced, by -14.8 (95% CI, -21.2, -8.4) pmol/L, between-group difference (p = 0.04). There were no significant changes in high-sensitivity C-reactive protein, adiponectin or leptin in any group. High intensity interval training for ten weeks improved insulin resistance, without weight loss, in women with polycystic ovary syndrome. Body composition improved significantly after both strength training and high intensity interval training. This pilot study indicates that exercise training can improve the cardiometabolic profile in polycystic ovary syndrome in the absence of weight loss. ClinicalTrial.gov NCT01919281.

Five centuries of climate change in Australia: the view from underground

NASA Astrophysics Data System (ADS)

Pollack, Henry N.; Huang, Shaopeng; Smerdon, Jason E.

2006-10-01

Fifty-seven borehole temperature profiles from across Australia are analysed to reconstruct a ground surface temperature history for the past five centuries. The five-hundred-year reconstruction is characterised by a temperature increase of approximately 0.5 K, with most of the warming occurring in the 19th and 20th centuries. The 17th century was the coolest interval of the five-century reconstruction. Comparison of the geothermal reconstruction to the Australian annual surface air temperature time series in their period of overlap shows excellent agreement. The full geothermal reconstruction also agrees well with the low-frequency component of dendroclimatic reconstructions from Tasmania and New Zealand. The warming of Australia over the past five centuries is only about half that experienced by the continents of the Northern Hemisphere in the same time interval. Copyright

Ultra-low-frequency wave power in the magnetotail lobes. I - Relation to substorm onsets and the auroral electrojet index

NASA Technical Reports Server (NTRS)

Smith, R. A.; Goertz, C. K.; Harrold, B. G.; Goldstein, M. L.; Lepping, R. P.; Fitch, C. A.; Sands, M. R.

1990-01-01

Time-series observations of the magnetotail-lobe magnetic field have been Fourier analyzed to compute the frequency-weighted energy density Pfz in the range 1-30 mHz. Pfz is generally observed in the range 0.0001-0.01 gamma-squared Hz with a mean value of 0.0012 during substorm growth phases and 0.001 in the comparison intervals. No strong correlation of Pfz is found with the auroral electrojet index in either set of intervals, but during substorm growth phases Pfz may vary by an order of magnitude over time scales of 30 min, with a tendency for higher power levels to occur later in the growth phase. Increases in Pfz precede by about 10 min localized expansive phase activity observed in individual magnetograms.

Bimanual coordination of bowing and fingering in violinists--effects of position changes and string changes.

PubMed

Kazennikov, Oleg; Wiesendanger, Mario

2009-07-01

Music performance is based on demanding motor control with much practice from young age onward. We have chosen to investigate basic bimanual movements played by violin amateurs and professionals. We posed the question whether position and string changes, two frequent mechanisms, may influence the time interval bowing (right)-fingering (left) coordination. The objective was to measure bimanual coordination, i.e., with or without position changes and string changes. The tendency was that the bimanual coordination was statistically only slightly increased or even unchanged but not perceptible. We conclude that the coordination index is limited up to 100 ms intervals, without any erroneous perception. Although the mentioned position changes and string changes are movements with their timing, they are executed in parallel rather than in series with the bow-fingering coordination.

A photoelectric amplifier as a dye detector

USGS Publications Warehouse

Ebel, Wesley J.

1962-01-01

A dye detector, based on a modified photoelectric amplifier, has been planned, built, and tested. It was designed to record automatically the time of arrival of fluorescein dye at predetermined points in a stream system. Laboratory tests and stream trials proved the instrument to be efficient. Small changes in color can be detected in turbid or clear water. The unit has been used successfully for timing intervals of more than 17 hours; significant savings of time and manpower have resulted. Replacement of the clock, included in the original device, with a recording milliammeter increases the efficiency of the unit by contin,!ously recording changes in turbidity. The addition of this component would increase the cost from $75 to approximately $105.

Predicting the time of conversion to MCI in the elderly: role of verbal expression and learning.

PubMed

Oulhaj, Abderrahim; Wilcock, Gordon K; Smith, A David; de Jager, Celeste A

2009-11-03

Increasing awareness that minimal or mild cognitive impairment (MCI) in the elderly may be a precursor of dementia has led to an increase in the number of people attending memory clinics. We aimed to develop a way of predicting the period of time before cognitive impairment occurs in community-dwelling elderly. The method is illustrated by the use of simple tests of different cognitive domains. A cohort of 241 normal elderly volunteers was followed for up to 20 years with regular assessments of cognitive abilities using the Cambridge Cognitive Examination (CAMCOG); 91 participants developed MCI. We used interval-censored survival analysis statistical methods to model which baseline cognitive tests best predicted the time to convert to MCI. Out of several baseline variables, only age and CAMCOG subscores for expression and learning/memory were predictors of the time to conversion. The time to conversion was 14% shorter for each 5 years of age, 17% shorter for each point lower in the expression score, and 15% shorter for each point lower in the learning score. We present in tabular form the probability of converting to MCI over intervals between 2 and 10 years for different combinations of expression and learning scores. In apparently normal elderly people, subtle measurable cognitive deficits that occur within the normal range on standard testing protocols reliably predict the time to clinically relevant cognitive impairment long before clinical symptoms are reported.

Trends and racial and ethnic disparities in the prevalence of pregestational type 1 and type 2 diabetes in Northern California: 1996-2014.

PubMed

Peng, Tiffany Y; Ehrlich, Samantha F; Crites, Yvonne; Kitzmiller, John L; Kuzniewicz, Michael W; Hedderson, Monique M; Ferrara, Assiamira

2017-02-01

Despite concern for adverse perinatal outcomes in women with diabetes mellitus before pregnancy, recent data on the prevalence of pregestational type 1 and type 2 diabetes mellitus in the United States are lacking. The purpose of this study was to estimate changes in the prevalence of overall pregestational diabetes mellitus (all types) and pregestational type 1 and type 2 diabetes mellitus and to estimate whether changes varied by race-ethnicity from 1996-2014. We conducted a cohort study among 655,428 pregnancies at a Northern California integrated health delivery system from 1996-2014. Logistic regression analyses provided estimates of prevalence and trends. The age-adjusted prevalence (per 100 deliveries) of overall pregestational diabetes mellitus increased from 1996-1999 to 2012-2014 (from 0.58 [95% confidence interval, 0.54-0.63] to 1.06 [95% confidence interval, 1.00-1.12]; P trend <.0001). Significant increases occurred in all racial-ethnic groups; the largest relative increase was among Hispanic women (121.8% [95% confidence interval, 84.4-166.7]); the smallest relative increase was among non-Hispanic white women (49.6% [95% confidence interval, 27.5-75.4]). The age-adjusted prevalence of pregestational type 1 and type 2 diabetes mellitus increased from 0.14 (95% confidence interval, 0.12-0.16) to 0.23 (95% confidence interval, 0.21-0.27; P trend <.0001) and from 0.42 (95% confidence interval, 0.38-0.46) to 0.78 (95% confidence interval, 0.73-0.83; P trend <.0001), respectively. The greatest relative increase in the prevalence of type 1 diabetes mellitus was in non-Hispanic white women (118.4% [95% confidence interval, 70.0-180.5]), who had the lowest increases in the prevalence of type 2 diabetes mellitus (13.6% [95% confidence interval, -8.0 to 40.1]). The greatest relative increase in the prevalence of type 2 diabetes mellitus was in Hispanic women (125.2% [95% confidence interval, 84.8-174.4]), followed by African American women (102.0% [95% confidence interval, 38.3-194.3]) and Asian women (93.3% [95% confidence interval, 48.9-150.9]). The prevalence of overall pregestational diabetes mellitus and pregestational type 1 and type 2 diabetes mellitus increased from 1996-1999 to 2012-2014 and racial-ethnic disparities were observed, possibly because of differing prevalence of maternal obesity. Targeted prevention efforts, preconception care, and disease management strategies are needed to reduce the burden of diabetes mellitus and its sequelae. Copyright © 2016 Elsevier Inc. All rights reserved.

Training contraceptive providers to offer intrauterine devices and implants in contraceptive care: a cluster randomized trial.

PubMed

Thompson, Kirsten M J; Rocca, Corinne H; Stern, Lisa; Morfesis, Johanna; Goodman, Suzan; Steinauer, Jody; Harper, Cynthia C

2018-06-01

US unintended pregnancy rates remain high, and contraceptive providers are not universally trained to offer intrauterine devices and implants to women who wish to use these methods. We sought to measure the impact of a provider training intervention on integration of intrauterine devices and implants into contraceptive care. We measured the impact of a continuing medical education-accredited provider training intervention on provider attitudes, knowledge, and practices in a cluster randomized trial in 40 US health centers from 2011 through 2013. Twenty clinics were randomly assigned to the intervention arm; 20 offered routine care. Clinic staff participated in baseline and 1-year surveys assessing intrauterine device and implant knowledge, attitudes, and practices. We used a difference-in-differences approach to compare changes that occurred in the intervention sites to changes in the control sites 1 year later. Prespecified outcome measures included: knowledge of patient eligibility for intrauterine devices and implants; attitudes about method safety; and counseling practices. We used multivariable regression with generalized estimating equations to account for clustering by clinic to examine intervention effects on provider outcomes 1 year later. Overall, we surveyed 576 clinic staff (314 intervention, 262 control) at baseline and/or 1-year follow-up. The change in proportion of providers who believed that the intrauterine device was safe was greater in intervention (60% at baseline to 76% at follow-up) than control sites (66% at both times) (adjusted odds ratio, 2.48; 95% confidence interval, 1.13-5.4). Likewise, for the implant, the proportion increased from 57-77% in intervention, compared to 61-65% in control sites (adjusted odds ratio, 2.57; 95% confidence interval, 1.44-4.59). The proportion of providers who believed they were experienced to counsel on intrauterine devices also increased in intervention (53-67%) and remained the same in control sites (60%) (adjusted odds ratio, 1.89; 95% confidence interval, 1.04-3.44), and for the implant increased more in intervention (41-62%) compared to control sites (48-50%) (adjusted odds ratio, 2.30; 95% confidence interval, 1.28-4.12). Knowledge scores of patient eligibility for intrauterine devices increased at intervention sites (from 0.77-0.86) 6% more over time compared to control sites (from 0.78-0.80) (adjusted coefficient, 0.058; 95% confidence interval, 0.003-0.113). Knowledge scores of eligibility for intrauterine device and implant use with common medical conditions increased 15% more in intervention (0.65-0.79) compared to control sites (0.67-0.66) (adjusted coefficient, 0.15; 95% confidence interval, 0.09-0.21). Routine discussion of intrauterine devices and implants by providers in intervention sites increased significantly, 71-87%, compared to in control sites, 76-82% (adjusted odds ratio, 1.97; 95% confidence interval, 1.02-3.80). Professional guidelines encourage intrauterine device and implant competency for all contraceptive care providers. Integrating these methods into routine care is important for access. This replicable training intervention translating evidence into care had a sustained impact on provider attitudes, knowledge, and counseling practices, demonstrating significant changes in clinical care a full year after the training intervention. Copyright © 2018 Elsevier Inc. All rights reserved.

Temporal Context in Concurrent Chains: I. Terminal-Link Duration

ERIC Educational Resources Information Center

Grace, Randolph C.

2004-01-01

Two experiments are reported in which the ratio of the average times spent in the terminal and initial links ("Tt/Ti") in concurrent chains was varied. In Experiment 1, pigeons responded in a three-component procedure in which terminal-link variable-interval schedules were in constant ratio, but their average duration increased across components…

[Plasma levels of interferon gamma and interleukin 10 in patients with lymphonodular toxoplasmosis].

PubMed

Bielec, D; Patorska-Mach, E; Semczuk, G; Toruń, E

1997-01-01

The concentrations of IFN gamma and IL 10 in plasma of sixteen patients with toxoplasmic lymphadenopathy were measured. These examinations were carried out two times in the interval of a month. We found increased level of IFN gamma and normal concentrations of IL 10 in both of these terms.

Techniques for Increasing the Efficiency of Automation Systems in School Library Media Centers.

ERIC Educational Resources Information Center

Caffarella, Edward P.

1996-01-01

Discusses methods of managing queues (waiting lines) to optimize the use of student computer stations in school library media centers and to make searches more efficient and effective. The three major factors in queue management are arrival interval of the patrons, service time, and number of stations. (Author/LRW)

The Joint Associations of Sedentary Time and Physical Activity With Mobility Disability in Older People: The NIH-AARP Diet and Health Study.

PubMed

DiPietro, Loretta; Jin, Yichen; Talegawkar, Sameera; Matthews, Charles E

2018-03-14

The purpose of this study was to determine the joint associations of sedentary time and physical activity with mobility disability in older age. We analyzed prospective data from 134,269 participants in the National Institutes of Health (NIH)-American Association of Retired Persons (NIH-AARP) Diet and Health Study between 1995-1996 and 2004-2005. Total sitting time (h/d), TV viewing time (h/d) and light- and moderate-to-vigorous-intensity physical activity (h/wk) were self-reported at baseline, and mobility disability at follow-up was defined as being "unable to walk" or having an "easy usual walking pace (<2 mph)." Multivariable logistic regression determined the independent and joint associations of sedentary time and total physical activity with the odds of disability. Among the most active participants (>7 h/wk), sitting <6 h/d was not related to excess disability at follow-up, and those in the most active group reporting the highest level of sitting time (≥7 h/d) still had a significantly lower odds (odds ratios = 1.11; 95% confidence interval = 1.02, 1.20) compared with those reporting the lowest level of sitting (<3 h/d) in the least active group (≤3 h/wk; odds ratios = 2.07; 95% confidence interval = 1.92, 2.23). Greater TV time was significantly related to increased disability within all levels of physical activity. Reduction of sedentary time, combined with increased physical activity may be necessary to maintain function in older age.

Antidepressant Use Is Associated With an Increased Risk of Developing Microbleeds.

PubMed

Akoudad, Saloua; Aarts, Nikkie; Noordam, Raymond; Ikram, M Arfan; Tiemeier, Henning; Hofman, Albert; Stricker, Bruno H; Vernooij, Meike W; Visser, Loes E

2016-01-01

Serotonin-specific antidepressants may increase the risk of adverse bleeding events. In a previous cross-sectional study, we did not observe an association between antidepressant use and presence of subclinical cerebral bleedings. In this study, we investigated longitudinally whether antidepressant use is associated with an increased risk of new subclinical cerebral microbleeds. In total, 2559 participants aged ≥45 years of the population-based Rotterdam Study, all without microbleeds at baseline, underwent baseline and repeat brain magnetic resonance imaging between 2005 and 2013 (mean time interval, 3.9 years; SD, 0.5) to determine the incidence of microbleeds. Antidepressant use (yes versus no) was assessed between baseline and follow-up scan. In additional analyses, antidepressants were classified as low, intermediate, or high affinity for the serotonin transporter, and alternatively as selective serotonin reuptake inhibitors or non-selective serotonin reuptake inhibitors. We used multivariable logistic regression models to investigate the association of antidepressants with incident microbleeds. Antidepressant use was associated with a higher cerebral microbleed incidence (odds ratio, 2.22; 95% confidence interval, 1.31-3.76) than nonuse. When stratified by affinity for the serotonin transporter, intermediate serotonin affinity antidepressant use was associated with an increased risk of developing microbleeds (odds ratio, 3.07; 95% confidence interval, 1.53-6.17). Finally, selective serotonin reuptake inhibitor and non-selective serotonin reuptake inhibitor use were both associated with increased microbleed incidence. Antidepressant use was associated with an increased risk of developing microbleeds. Our results may support findings from previous clinical studies about increased intracranial and extracranial bleeding risk in antidepressant users. © 2015 American Heart Association, Inc.

75 FR 80097 - Self-Regulatory Organizations; Notice of Filing and Immediate Effectiveness of Proposed Rule...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-21

... LLC Establishing Strike Price Intervals of $1 and Increasing Position and Exercise Limits With Respect... ``Index'') to (i) establish strike price intervals of $1.00 and (ii) increase the position and exercise... price intervals of $1.00 and (ii) increase the position and exercise limits applicable thereto. The...