Market-based control strategy for long-span structures considering the multi-time delay issue

NASA Astrophysics Data System (ADS)

Li, Hongnan; Song, Jianzhu; Li, Gang

2017-01-01

To solve the different time delays that exist in the control device installed on spatial structures, in this study, discrete analysis using a 2 N precise algorithm was selected to solve the multi-time-delay issue for long-span structures based on the market-based control (MBC) method. The concept of interval mixed energy was introduced from computational structural mechanics and optimal control research areas, and it translates the design of the MBC multi-time-delay controller into a solution for the segment matrix. This approach transforms the serial algorithm in time to parallel computing in space, greatly improving the solving efficiency and numerical stability. The designed controller is able to consider the issue of time delay with a linear controlling force combination and is especially effective for large time-delay conditions. A numerical example of a long-span structure was selected to demonstrate the effectiveness of the presented controller, and the time delay was found to have a significant impact on the results.

Effects of time delay and pitch control sensitivity in the flared landing

NASA Technical Reports Server (NTRS)

Berthe, C. J.; Chalk, C. R.; Wingarten, N. C.; Grantham, W.

1986-01-01

Between December 1985 and January 1986, a flared landing program was conducted, using the USAF Total In-Flight simulator airplane, to examine time delay effects in a formal manner. Results show that as pitch sensitivity is increased, tolerance to time delay decreases. With the proper selection of pitch sensitivity, Level I performance was maintained with time delays ranging from 150 milliseconds to greater than 300 milliseconds. With higher sensitivity, configurations with Level I performance at 150 milliseconds degraded to level 2 at 200 milliseconds. When metrics of time delay and pitch sensitivity effects are applied to enhance previously developed predictive criteria, the result is an improved prediction technique which accounts for significant closed loop items.

Delay From First Medical Contact to Primary PCI and All‐Cause Mortality: A Nationwide Study of Patients With ST‐Elevation Myocardial Infarction

PubMed Central

Koul, Sasha; Andell, Pontus; Martinsson, Andreas; Gustav Smith, J.; van der Pals, Jesper; Scherstén, Fredrik; Jernberg, Tomas; Lagerqvist, Bo; Erlinge, David

2014-01-01

Background Early reperfusion in the setting of an ST‐elevation myocardial infarction (STEMI) is of utmost importance. However, the effects of early versus late reperfusion in this patient group undergoing primary percutaneous coronary intervention (PCI) have so far been inconsistent in previous studies. The purpose of this study was to evaluate in a nationwide cohort the effects of delay from first medical contact to PCI (first medical contact [FMC]‐to‐PCI) and secondarily delay from symptom‐to‐PCI on clinical outcomes. Methods and Results Using the national Swedish Coronary Angiography and Angioplasty Register (SCAAR) registry, STEMI patients undergoing primary PCI between the years 2003 and 2008 were screened for. A total of 13 790 patients were included in the FMC‐to‐PCI analysis and 11 489 patients were included in the symptom‐to‐PCI analyses. Unadjusted as well as multivariable analyses showed an overall significant association between increasing FMC‐to‐PCI delay and 1‐year mortality. A statistically significant increase in mortality was noted at FMC‐to‐PCI delays exceeding 1 hour in an incremental fashion. FMC‐to‐PCI delays in excess of 1 hour were also significantly associated with an increase in severe left ventricular dysfunction at discharge. An overall significant association between increasing symptom‐to‐PCI delays and 1‐year mortality was noted. However, when stratified into time delay cohorts, no symptom‐to‐PCI delay except for the highest time delay showed a statistically significant association with increased mortality. Conclusions Delays in FMC‐to‐PCI were strongly associated with increased mortality already at delays of more than 1 hour, possibly through an increase in severe heart failure. A goal of FMC‐to‐PCI of less than 1 hour might save patient lives. PMID:24595190

Effects of delayed polymerization time and bracket manipulation on orthodontic resin modified glass ionomer adhesive

NASA Astrophysics Data System (ADS)

Gilbert, Danielle Wiggins

This study examined the effect of varying delayed polymerization times in combination with bracket manipulation on shear bond strength (SBS), degree of conversion (DC), and adhesive remnant index (ARI) score when using a resin modified glass ionomer (RMGI) adhesive. Specimens were divided into three groups of clinically relevant delay times (0.5, 2, and 4-min) to simulate the delay that frequently occurs between bracket placement and manipulation and subsequent light curing. Based on an analysis of variance (alpha=.05), the SBS was not significantly different between the three groups. While one of the goals of this study was to be the first study to quantify DC of RMGI using Raman microspectroscopy, several challenges, including weak peak signal with and without fluorescence, were encountered and as a result, DC could not be determined. A significant difference (p<0.05) in ARI score was detected between the 0.5-min and 4.0-min delay groups with more adhesive remaining on the bracket with increasing delay time. A Spearman correlation between SBS and ARI indicated no positive association between SBS and ARI measures across delay times. The results of this study suggest that clinically relevant delay times of 0.5, 2, and 4-min do not negatively impact the SBS of a RMGI adhesive. However, with increasing delay time, the results suggest that more adhesive might remain on the bracket during debonding. With more adhesive remaining on the bracket, this could be beneficial in that less adhesive needs to be removed from enamel by grinding at the time of bracket removal when orthodontic treatment is completed.

Control of amplitude chimeras by time delay in oscillator networks

NASA Astrophysics Data System (ADS)

Gjurchinovski, Aleksandar; Schöll, Eckehard; Zakharova, Anna

2017-04-01

We investigate the influence of time-delayed coupling in a ring network of nonlocally coupled Stuart-Landau oscillators upon chimera states, i.e., space-time patterns with coexisting partially coherent and partially incoherent domains. We focus on amplitude chimeras, which exhibit incoherent behavior with respect to the amplitude rather than the phase and are transient patterns, and we show that their lifetime can be significantly enhanced by coupling delay. To characterize their transition to phase-lag synchronization (coherent traveling waves) and other coherent structures, we generalize the Kuramoto order parameter. Contrasting the results for instantaneous coupling with those for constant coupling delay, for time-varying delay, and for distributed-delay coupling, we demonstrate that the lifetime of amplitude chimera states and related partially incoherent states can be controlled, i.e., deliberately reduced or increased, depending upon the type of coupling delay.

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

NASA Technical Reports Server (NTRS)

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

1975-01-01

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

Incorporating time-delays in S-System model for reverse engineering genetic networks.

PubMed

Chowdhury, Ahsan Raja; Chetty, Madhu; Vinh, Nguyen Xuan

2013-06-18

In any gene regulatory network (GRN), the complex interactions occurring amongst transcription factors and target genes can be either instantaneous or time-delayed. However, many existing modeling approaches currently applied for inferring GRNs are unable to represent both these interactions simultaneously. As a result, all these approaches cannot detect important interactions of the other type. S-System model, a differential equation based approach which has been increasingly applied for modeling GRNs, also suffers from this limitation. In fact, all S-System based existing modeling approaches have been designed to capture only instantaneous interactions, and are unable to infer time-delayed interactions. In this paper, we propose a novel Time-Delayed S-System (TDSS) model which uses a set of delay differential equations to represent the system dynamics. The ability to incorporate time-delay parameters in the proposed S-System model enables simultaneous modeling of both instantaneous and time-delayed interactions. Furthermore, the delay parameters are not limited to just positive integer values (corresponding to time stamps in the data), but can also take fractional values. Moreover, we also propose a new criterion for model evaluation exploiting the sparse and scale-free nature of GRNs to effectively narrow down the search space, which not only reduces the computation time significantly but also improves model accuracy. The evaluation criterion systematically adapts the max-min in-degrees and also systematically balances the effect of network accuracy and complexity during optimization. The four well-known performance measures applied to the experimental studies on synthetic networks with various time-delayed regulations clearly demonstrate that the proposed method can capture both instantaneous and delayed interactions correctly with high precision. The experiments carried out on two well-known real-life networks, namely IRMA and SOS DNA repair network in Escherichia coli show a significant improvement compared with other state-of-the-art approaches for GRN modeling.

Neonatal blood cultures: effect of delayed entry into the blood culture machine and bacterial concentration on the time to positive growth in a simulated model.

PubMed

Jardine, Luke Anthony; Sturgess, Barbara Ruth; Inglis, Garry Donald Trevor; Davies, Mark William

2009-04-01

To determine if: time from blood culture inoculation to positive growth (total time to positive) and time from blood culture machine entry to positive growth (machine time to positive) is altered by delayed entry into the automated blood culture machine, and if the total time to positive differs by the concentration of organisms inoculated into blood culture bottles. Staphylococcus epidermidis, Escherichia coli and group B beta-haemolytic streptococci were chosen as clinically significant representative organisms. Two concentrations (> or =10 colony-forming units per millilitre and <1 colony-forming units per millilitre) were inoculated into PEDS BacT/Alert blood culture bottles and randomly allocated to one of three delayed automated blood culture machine entry times (30 min/8.5 h/15.5 h). For all organisms at all concentrations, except the Staphylococcus epidermidis, the machine time to positive was significantly decreased by delayed entry. For all organisms at all concentrations, the mean total time to positive significantly increased with increasing delayed entry into the blood culture machine. Higher concentrations of group B beta-haemolytic streptococci and Escherichia coli grew significantly faster than lower concentrations. Bacterial growth in inoculated bottles, stored at room temperature, continues although at a slower rate than in those blood culture bottles immediately entered into the machine. If a blood culture specimen has been stored at room temperature for greater than 15.5 h, the currently allowed safety margin of 36 h (before declaring a result negative) may be insufficient.

Risk Factors and Relationship Between Intestinal Parasites and the Growth Retardation and Psychomotor Development Delays of Children in Şanlıurfa, Turkey.

PubMed

Yentur Doni, Nebiye; Yildiz Zeyrek, Fadile; Simsek, Zeynep; Gurses, Gulcan; Sahin, İbrahim

2015-12-01

The objective of this study was to determine the risk factors for and relationship among parasitic infections, growth retardation, and psychomotor developmental delays in children aged 6 years and below. This case-control study was performed in Şanlıurfa in southeastern Turkey between October and December 2007. Data were collected using a structured questionnaire, anthropometry, Ankara Development Screening Inventory, and laboratory analysis of stool specimens. The most common parasite was Giardia intestinalis (42.53%) followed by Enterobius vermicularis (27.58%), Ascaris lumbricoides (18.39%), Hymenolepis nana (5.75%), Trichuris trichiura (3.45%), Escherichia coli (1.15%), and Blastocystis spp. (1.15%). Fifty-eight percent of all children were infected with intestinal parasites; 55.2% had only one parasite, whereas 44.8% had multiple parasites. The children infected with G. intestinalis and other intestinal parasites had significantly higher levels of growth retardation and psychomotor development delay than non-infected children. Children with parasitic infections had growth delay up to 2.9 times, general development delay up to 1.9 times, language-cognitive development delay up to 2.2 times, and fine motor development delay up to 2.9 times higher than children without any parasitic infections. However, no significant relationship among intestinal parasites, gross motor development, social-self skills, and development delay was identified. The education level of parents, poor economic situation, number of households, not washing hands, playing with soil, family history of parasitic infection were the significant risk factors for intestinal parasites. Our study indicates that the presence of either malnutrition or intestinal parasites may put a child in a high-risk group for developmental delays and growth retardation. Therefore, public health interventions can embrace nationwide deworming in children.

Evaluating blood-brain barrier permeability in delayed cerebral infarction after aneurysmal subarachnoid hemorrhage.

PubMed

Ivanidze, J; Kesavabhotla, K; Kallas, O N; Mir, D; Baradaran, H; Gupta, A; Segal, A Z; Claassen, J; Sanelli, P C

2015-05-01

Patients with SAH are at increased risk of delayed infarction. Early detection and treatment of delayed infarction remain challenging. We assessed blood-brain barrier permeability, measured as permeability surface area product, by using CTP in patients with SAH with delayed infarction. We performed a retrospective study of patients with SAH with delayed infarction on follow-up NCCT. CTP was performed before the development of delayed infarction. CTP data were postprocessed into permeability surface area product, CBF, and MTT maps. Coregistration was performed to align the infarcted region on the follow-up NCCT with the corresponding location on the CTP maps obtained before infarction. Permeability surface area product, CBF, and MTT values were then obtained in the location of the subsequent infarction. The contralateral noninfarcted region was compared with the affected side in each patient. Wilcoxon signed rank tests were performed to determine statistical significance. Clinical data were collected at the time of CTP and at the time of follow-up NCCT. Twenty-one patients with SAH were included in the study. There was a statistically significant increase in permeability surface area product in the regions of subsequent infarction compared with the contralateral control regions (P < .0001). However, CBF and MTT values were not significantly different in these 2 regions. Subsequent follow-up NCCT demonstrated new delayed infarction in all 21 patients, at which time 38% of patients had new focal neurologic deficits. Our study reveals a statistically significant increase in permeability surface area product preceding delayed infarction in patients with SAH. Further investigation of early permeability changes in SAH may provide new insights into the prediction of delayed infarction. © 2015 by American Journal of Neuroradiology.

Delays during the administration of acetylcysteine for the treatment of paracetamol overdose

PubMed Central

Bailey, George P.; Najafi, Javad; Elamin, Muhammad E. M. O.; Waring, W. Stephen; Thomas, Simon H. L.; Archer, John R. H.; Wood, David M.

2016-01-01

Background The licensed intravenous acetylcysteine regimen for treating paracetamol overdose in most countries uses three separate infusions over 21 h. This complex regimen, requiring different infusion concentrations and rates, has been associated with administration errors. The aim of the present study was to assess the extent of administration delays occurring during this acetylcysteine regimen. Method A 6‐month retrospective observational study was conducted at three English teaching hospitals with clinical toxicology services from October 2014. Patients aged 16 years and over, treated with intravenous acetylcysteine for paracetamol overdose, were included. The start times for infusions were recorded and the delays compared with the prescribed infusion times were calculated. Anaphylactoid reactions, intravenous cannula problems, overdose intent and smoking status were recorded to assess their contribution to delays. Results From 263 cases identified, 198 met the study inclusion criteria. The median time between the start of infusions 1 and 3 was delayed from the intended 5 h by a median (interquartile range) of 90 (50–163) min, with 135 (68%) cases delayed by more than 1 h. Significantly longer delays were observed in patients with anaphylactoid reactions [median delay 267 (217–413) min, n = 8] and accidental/supratherapeutic overdose [median delay 170 (95–260) min, n = 29]. There were no significant differences between smokers and nonsmokers, or for patients with intravenous cannula problems. Conclusion Long delays were identified during the three‐infusion acetylcysteine regimen for the treatment of paracetamol overdose. These were of clinical significance and could lead to periods of subtherapeutic plasma acetylcysteine concentrations and potentially avoidable hepatotoxicity, as well as delaying hospital discharge. PMID:27412926

Delays during the administration of acetylcysteine for the treatment of paracetamol overdose.

PubMed

Bailey, George P; Najafi, Javad; Elamin, Muhammad E M O; Waring, W Stephen; Thomas, Simon H L; Archer, John R H; Wood, David M; Dargan, Paul I

2016-11-01

The licensed intravenous acetylcysteine regimen for treating paracetamol overdose in most countries uses three separate infusions over 21 h. This complex regimen, requiring different infusion concentrations and rates, has been associated with administration errors. The aim of the present study was to assess the extent of administration delays occurring during this acetylcysteine regimen. A 6-month retrospective observational study was conducted at three English teaching hospitals with clinical toxicology services from October 2014. Patients aged 16 years and over, treated with intravenous acetylcysteine for paracetamol overdose, were included. The start times for infusions were recorded and the delays compared with the prescribed infusion times were calculated. Anaphylactoid reactions, intravenous cannula problems, overdose intent and smoking status were recorded to assess their contribution to delays. From 263 cases identified, 198 met the study inclusion criteria. The median time between the start of infusions 1 and 3 was delayed from the intended 5 h by a median (interquartile range) of 90 (50-163) min, with 135 (68%) cases delayed by more than 1 h. Significantly longer delays were observed in patients with anaphylactoid reactions [median delay 267 (217-413) min, n = 8] and accidental/supratherapeutic overdose [median delay 170 (95-260) min, n = 29]. There were no significant differences between smokers and nonsmokers, or for patients with intravenous cannula problems. Long delays were identified during the three-infusion acetylcysteine regimen for the treatment of paracetamol overdose. These were of clinical significance and could lead to periods of subtherapeutic plasma acetylcysteine concentrations and potentially avoidable hepatotoxicity, as well as delaying hospital discharge. © 2016 The British Pharmacological Society.

Factors associated with delay in trauma team activation and impact on patient outcomes.

PubMed

Connolly, Rory; Woo, Michael Y; Lampron, Jacinthe; Perry, Jeffrey J

2017-09-05

Trauma code activation is initiated by emergency physicians using physiological and anatomical criteria, mechanism of injury, and patient demographic factors. Our objective was to identify factors associated with delayed trauma team activation. We assessed consecutive cases from a regional trauma database from January 2008 to March 2014. We defined a delay in trauma code activation as a time greater than 30 minutes from the time of arrival. We conducted univariate analysis for factors potentially influencing trauma team activation, and we subsequently used multiple logistic regression analysis models for delayed activation in relation to mortality, length of stay, and time to operative management. Patients totalling 846 were included for our analysis; 4.1% (35/846) of trauma codes were activated after 30 minutes. Mean age was 40.8 years in the early group versus 49.2 in the delayed group (p=0.01). Patients were over age 70 years in 7.6% in the early activation group versus 17.1% in the delayed group (p=0.04). There was no significant difference in sex, type of injury, injury severity, or time from injury between the two groups. There was no significant difference in mortality, median length of stay, or median time to operative management. Delayed activation is linked with increasing age with no clear link to increased mortality. Given the severe injuries in the delayed cohort that required activation of the trauma team, further emphasis on the older trauma patient and interventions to recognize this vulnerable population should be made.

Hindrance of conservation biology by delays in the submission of manuscripts.

PubMed

O'Donnell, Ryan P; Supp, Sarah R; Cobbold, Stephanie M

2010-04-01

Timely dissemination of scientific findings depends not only on rapid publication of submitted manuscripts, a topic which has received much discussion, but also on rapid submission of research after the research is completed. We measured submission delay (time from the last date of data collection to the submission of a manuscript) for every paper from 14 journals in 2007 and compared these submission delays among four fields of biology (conservation, taxonomy, behavior, and evolution). Manuscripts published in leading journals in the field of conservation biology have the longest delays in publication of accepted manuscripts and the longest intervals between completion of research and submission of the manuscript. Delay in manuscript submission accounts for more than half of the total time from last date of data collection to publication. Across fields, the number of authors was significantly negatively correlated with submission delay, but conservation journals had the second highest number of authors and the greatest submission delay, so submission of conservation manuscripts was not hindered by a shortage of collaboration relative to other fields. Rejection rates were greater in conservation journals than in behavior and evolution, but rejection times were faster; thus, there were no obvious net differences among fields in the time papers spent waiting to be rejected. Publication delay has been reduced significantly in the last 7 years, but was still greater in conservation journals than in any of the other three fields we studied. Thus, the urgent field of conservation biology is hindered in both preparation and publication of manuscripts.

Delayed Face Recognition in Children and Adolescents with Autism Spectrum Disorders

PubMed Central

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

2012-01-01

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

Single-shot transient absorption spectroscopy with a 45  ps pump-probe time delay range.

PubMed

Wilson, Kelly S; Wong, Cathy Y

2018-02-01

We report a single-shot transient absorption apparatus that successfully uses a tilted pump pulse to spatially encode a 45 ps pump-probe time delay. The time delay range is significantly improved over other reported instruments by using a spatial light modulator to flatten the intensity of the excitation field at the sample position. The full time delay range of the instrument is demonstrated by measuring a long-lived dye. A signal-to-noise ratio of >35 is attained in 8 s. This advance will enable the measurement of excited state dynamics of systems that are not at structural equilibrium.

Immediate versus delayed self-reporting of symptoms and side effects during chemotherapy: does timing matter?

PubMed

Coolbrandt, Annemarie; Van den Heede, Koen; Vanhove, Ellen; De Bom, Ann; Milisen, Koen; Wildiers, Hans

2011-04-01

The aim of this study was to examine how patients recall symptoms at a delayed self-report. Accurate insight into toxicity symptoms during chemotherapy is essential so that nurses and doctors can assess therapeutic tolerance and adjust supportive care accordingly. A non-experimental, longitudinal design was employed. Using the Therapy-Related Symptoms Checklist (TRSC), respondents (n = 142) reported their initial symptoms during the first 7 days of the chemotherapy cycle at two different times: (1) each day of the first seven days after the chemotherapy administration (immediate self-report), and (2) at their next hospital visit for chemotherapy (delayed self-report). We compared the number and severity of symptoms and side effects reported in the immediate and delayed self-reports. Respondents reported significantly fewer symptoms and fewer severe symptoms in the delayed self-report. For 22 out of 25 symptoms the delayed-reported grade was significantly lower than the immediate-reported maximum grade. Compared to the immediate-reported median grade, significant differences occurred in only 10 out of the 25 symptoms. In all cases, except fatigue, the delayed-reported grade was significantly higher than the immediate-reported median grade. This study indicates that delayed self-report of chemotherapy side effects is not an appropriate measure of actual symptoms and side effects experienced by patients. Delayed self-report gives a weaker insight into actual symptom burden. Fatigue is at particular risk to be minimized at the delayed self-report. Therefore it is recommended to assess chemotherapy-related symptoms and side effects by means of immediate self-report. Copyright © 2010 Elsevier Ltd. All rights reserved.

Comparison of metoprolol succinate versus carvedilol in time to cardiovascular admission in a Veterans Affairs healthcare system: An observational study.

PubMed

Church, Kara M; Henalt, Robert; Baker, Errol; Smith, Gary L; Brennan, Michael T; Joseph, Jacob

2015-12-01

To determine if metoprolol succinate or carvedilol is more effective in delaying the time to first cardiovascular disease hospital admission in systolic heart failure patients. As a secondary objective, to determine the most effective dose of each agent in delaying first cardiovascular disease hospital admission, including but not limited to heart failure exacerbation, myocardial infarction, ischemic heart disease, cardiac arrhythmias, or death. This study was a retrospective chart review of 272 veterans at the VA Boston Healthcare System newly started on metoprolol succinate (n = 157) or carvedilol (n = 115) between January 2000 and December 2008. After an 8-week study medication titration period, subjects were subcategorized into low-, medium-, and high-dose ranging groups and followed until the first cardiovascular disease hospitalization, death, or 365 days. The main outcome measure was time to first cardiovascular hospitalization or death. The mean age (69.9 years vs. 67.9 years) and ejection fraction (26% vs. 25%) were comparable between study arms at baseline. Mean time to first cardiovascular disease hospitalization was significantly different (p = 0.001) between study groups with 330.6 days with in metoprolol succinate group vs. 282.6 days in the carvedilol groups. High-dose carvedilol significantly delayed time to first hospitalization in comparison to medium or low carvedilol doses (p = 0.015, p = 0.005). Low- and high-dose metoprolol succinate were not significantly different (p = 0.509) in time to first event, and both dosing groups fared better compared to medium dose metoprolol succinate (p = 0.046). In this veteran patient population in need of additional heart failure treatments, metoprolol succinate use resulted in a delayed time to first cardiovascular disease hospitalization or death compared to carvedilol. Both low and high doses of metoprolol succinate showed a significant delay of time to first cardiovascular hospitalization compared to medium doses of metoprolol succinate. Higher doses of carvedilol showed a significant delay of time to cardiovascular hospitalization than lower carvedilol doses. Copyright © 2015 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

Microlensing makes lensed quasar time delays significantly time variable

NASA Astrophysics Data System (ADS)

Tie, S. S.; Kochanek, C. S.

2018-01-01

The time delays of gravitationally lensed quasars are generally believed to be unique numbers whose measurement is limited only by the quality of the light curves and the models for the contaminating contribution of gravitational microlensing to the light curves. This belief is incorrect - gravitational microlensing also produces changes in the actual time delays on the ∼day(s) light-crossing time-scale of the emission region. This is due to a combination of the inclination of the disc relative to the line of sight and the differential magnification of the temperature fluctuations producing the variability. We demonstrate this both mathematically and with direct calculations using microlensing magnification patterns. Measuring these delay fluctuations can provide a physical scale for microlensing observations, removing the need for priors on either the microlens masses or the component velocities. That time delays in lensed quasars are themselves time variable likely explains why repeated delay measurements of individual lensed quasars appear to vary by more than their estimated uncertainties. This effect is also a new important systematic problem for attempts to use time delays in lensed quasars for cosmology or to detect substructures (satellites) in lens galaxies.

Transfer effects of manipulating temporal constraints on learning a two-choice reaction time task with low stimulus-response compatibility.

PubMed

Chen, David D; Pei, Laura; Chan, John S Y; Yan, Jin H

2012-10-01

Recent research using deliberate amplification of spatial errors to increase motor learning leads to the question of whether amplifying temporal errors may also facilitate learning. We investigated transfer effects caused by manipulating temporal constraints on learning a two-choice reaction time (CRT) task with varying degrees of stimulus-response compatibility. Thirty-four participants were randomly assigned to one of the three groups and completed 120 trials during acquisition. For every fourth trial, one group was instructed to decrease CRT by 50 msec. relative to the previous trial and a second group was instructed to increase CRT by 50 msec. The third group (the control) was told not to change their responses. After a 5-min. break, participants completed a 40-trial no-feedback transfer test. A 40-trial delayed transfer test was administered 24 hours later. During acquisition, the Decreased Reaction Time group responded faster than the two other groups, but this group also made more errors than the other two groups. In the 5-min. delayed test (immediate transfer), the Decreased Reaction Time group had faster reaction times than the other two groups, while for the 24-hr. delayed test (delayed transfer), both the Decreased Reaction Time group and Increased Reaction Time group had significantly faster reaction times than the control. For delayed transfer, both Decreased and Increased Reaction Time groups reacted significantly faster than the control group. Analyses of error scores in the transfer tests indicated revealed no significant group differences. Results were discussed with regard to the notion of practice variability and goal-setting benefits.

The phantom robot - Predictive displays for teleoperation with time delay

NASA Technical Reports Server (NTRS)

Bejczy, Antal K.; Kim, Won S.; Venema, Steven C.

1990-01-01

An enhanced teleoperation technique for time-delayed bilateral teleoperator control is discussed. The control technique selected for time delay is based on the use of a high-fidelity graphics phantom robot that is being controlled in real time (without time delay) against the static task image. Thus, the motion of the phantom robot image on the monitor predicts the motion of the real robot. The real robot's motion will follow the phantom robot's motion on the monitor with the communication time delay implied in the task. Real-time high-fidelity graphics simulation of a PUMA arm is generated and overlaid on the actual camera view of the arm. A simple camera calibration technique is used for calibrated graphics overlay. A preliminary experiment is performed with the predictive display by using a very simple tapping task. The results with this simple task indicate that predictive display enhances the human operator's telemanipulation task performance significantly during free motion when there is a long time delay. It appears, however, that either two-view or stereoscopic predictive displays are necessary for general three-dimensional tasks.

Factors influencing diagnosis delay of advanced breast cancer in Moroccan women.

PubMed

Maghous, A; Rais, F; Ahid, S; Benhmidou, N; Bellahamou, K; Loughlimi, H; Marnouche, E; Elmajjaoui, S; Elkacemi, H; Kebdani, T; Benjaafar, N

2016-06-07

Delay in the diagnosis of breast cancer in symptomatic women of 3 months or more is associated with advanced stage and low survival. We conducted this study to learn more about the extent and reasons behind diagnosis delay of advanced breast cancer in Moroccan women. A group of patients with advanced breast cancer were interviewed at the National Institute of Oncology in Rabat during the period from February to December 2014. Diagnosis delay was devised into patient delay and system delay. Patient delay was defined as time from first symptoms until first medical consultation. System delay was defined as time from first presentation to a health care provider until definite diagnosis or treatment. Prospective information and clinical data were collected on a form during an interview with each patient and from medical records. In all, 137 patients were interviewed. The mean age of women was 48.3 ± 10.4 years. The median of consultation time was 6[4,12] months and the median of diagnosis time was 1[1,3] months. Diagnosis delay was associated to a personal reason in 96 (70.1 %) patients and to a medical reason in 19 (13.9 %) patients. A number of factors predicted diagnosis delay: symptoms were not considered serious in 66 (55.9 %) patients; traditional therapy was applied in 15 (12.7 %) patients and fear of cancer diagnosis and/or treatment in 14 (11.9 %) patients. A use of traditional methods was significantly associated with rural residence and far away from basic health center (p = 0.000). Paradoxically, a family history of breast cancer was significantly higher in who report a fear of cancer diagnosis and/or treatment to diagnosis delay (p < 0.001). Also, a significantly higher risk of more than 6 months delay was found among rural women (P = 0.035) and women who live far away from specialized care center (P = 0.001). Diagnosis delay is very serious problem in Morocco. Diagnosis delay was associated with complex interactions between several factors and with advanced stages. There is a need for improving breast cancer information in our populations and training of general practitioners to reduce advanced breast cancer by promoting early detection.

Survival outcome of early versus delayed bevacizumab treatment in patients with recurrent glioblastoma

PubMed Central

Hamza, Mohamed A.; Mandel, Jacob J.; Conrad, Charles A.; Gilbert, Mark R.; Yung, W. K. Alfred; Puduvalli, Vinay K.; DeGroot, John F.

2015-01-01

Bevacizumab (BEV) is widely used for treatment of patients with recurrent glioblastoma. It is not known if there are differences in outcome between early versus delayed BEV treatment of recurrent glioblastoma. We examined the relationship between the time of starting BEV treatment and outcomes in patients with recurrent glioblastoma. In this retrospective chart review, we identified patients with recurrent glioblastoma diagnosed between 2005 and 2011 who were treated with BEV alone or BEV-containing regimens. Data was analyzed to determine overall survival (OS) from time of diagnosis and progression free survival (PFS) from time of starting BEV. A total of 298 patients were identified, 112 patients received early BEV, 133 patients received delayed BEV, and 53 patients were excluded because they either progressed within 3 months of radiation or received BEV at the time of diagnosis. There was no significant difference in PFS between patients that received early BEV and those that received delayed BEV (5.2 vs. 4.3 months, p = 0.2). Patients treated with delayed BEV had longer OS when compared to those treated with early BEV (25.9 vs. 20.8 months, p = 0.005). In patients with recurrent glioblastoma, there was no significant difference in PFS from the time of starting BEV between early and delayed BEV. Although patients treated with delayed BEV seemed to have longer OS, a conclusion regarding OS outcome requires further prospective trials. These results may indicate that delaying treatment with BEV is not detrimental for survival of patients with recurrent glioblastoma. PMID:24803001

Effect of metrology time delay on overlay APC

NASA Astrophysics Data System (ADS)

Carlson, Alan; DiBiase, Debra

2002-07-01

The run-to-run control strategy of lithography APC is primarily composed of a feedback loop as shown in the diagram below. It is known that the insertion of a time delay in a feedback loop can cause degradation in control performance and could even cause a stable system to become unstable, if the time delay becomes sufficiently large. Many proponents of integrated metrology methods have cited the damage caused by metrology time delays as the primary justification for moving from a stand-alone to integrated metrology. While there is little dispute over the qualitative form of this argument, there has been very light published about the quantitative effects under real fab conditions - precisely how much control is lost due to these time delays. Another issue regarding time delays is that the length of these delays is not typically fixed - they vary from lot to lot and in some cases this variance can be large - from one hour on the short side to over 32 hours on the long side. Concern has been expressed that the variability in metrology time delays can cause undesirable dynamics in feedback loops that make it difficult to optimize feedback filters and gains and at worst could drive a system unstable. By using data from numerous fabs, spanning many sizes and styles of operation, we have conducted a quantitative study of the time delay effect on overlay run- to-run control. Our analysis resulted in the following conclusions: (1) There is a significant and material relationship between metrology time delay and overlay control under a variety of real world production conditions. (2) The run-to-run controller can be configured to minimize sensitivity to time delay variations. (3) The value of moving to integrated metrology can be quantified.

Measurement of oxidative metabolism of the working human muscles by near-infrared spectroscopy

NASA Astrophysics Data System (ADS)

Yücetaş, Akin; Şayli, Ömer; Karahan, Mustafa; Akin, Ata

2006-02-01

Monitoring the oxygenation of skeletal muscle tissues during rest to work transient provides valuable information about the performance of a particular tissue in adapting to aerobic glycolysis. In this paper we analyze the temporal relation of O II consumption with deoxy-hemoglobin (Hb) signals measured by functional Near Infrared Spectroscopy (fNIRS) technique during moderate isotonic forearm finger joint flexion exercise under ischemic conditions and model it with a mono exponential equation with delay. The time constants of fitting equation are questioned under two different work loads and among subjects differing in gender. Ten (6 men and 4 women) subjects performed isotonic forearm finger joint flexion exercise with two different loads. It is shown that under the same load, men and women subjects generate similar time constants and time delays. However, apparent change in time constants and time delays were observed when exercise was performed under different loads. When t-test is applied to compare the outputs for time constants between 0.41202 Watts and 0.90252 Watts, P value of 9.3445x10 -4 < 0.05 is observed which implies that the differences between the time constants are statistically significant. When the same procedure is applied for the time delay comparison, P value of 0.027<0.05 is observed which implies that also the differences between the time delays are statistically significant.

Later school start time is associated with improved sleep and daytime functioning in adolescents.

PubMed

Boergers, Julie; Gable, Christopher J; Owens, Judith A

2014-01-01

Chronic insufficient sleep is a growing concern among adolescents and is associated with a host of adverse health consequences. Early school start times may be an environmental contributor to this problem. The purpose of this study was to examine the impact of a delay in school start time on sleep patterns, sleepiness, mood, and health-related outcomes. Boarding students (n = 197, mean age = 15.6 yr) attending an independent high school completed the School Sleep Habits Survey before and after the school start time was experimentally delayed from 8:00 a.m. to 8:25 a.m. The delay in school start time was associated with a significant (29 min) increase in sleep duration on school nights. The percentage of students receiving 8 or more hours of sleep on a school night increased to more than double, from 18% to 44%. Students in 9th and 10th grade and those with lower baseline sleep amounts were more likely to report improvements in sleep duration after the schedule change. Daytime sleepiness, depressed mood, and caffeine use were all significantly reduced after the delay in school start time. Sleep duration reverted to baseline levels when the original (earlier) school start time was reinstituted. A modest (25 min) delay in school start time was associated with significant improvements in sleep duration, daytime sleepiness, mood, and caffeine use. These findings have important implications for public policy and add to research suggesting the health benefits of modifying school schedules to more closely align with adolescents' circadian rhythms and sleep needs.

Delayed clamping of the umbilical cord after delivery and implications for public cord blood banking.

PubMed

Allan, David S; Scrivens, Nicholas; Lawless, Tiffany; Mostert, Karen; Oppenheimer, Lawrence; Walker, Mark; Petraszko, Tanya; Elmoazzen, Heidi

2016-03-01

Public banking of umbilical cord blood units (CBUs) containing higher numbers of cells ensures timely engraftment after transplantation for increasing numbers of patients. Delayed clamping of the umbilical cord after birth may benefit some infants by preventing iron deficiency. Implications of delayed cord clamping for public cord blood banking remains unclear. CBUs collected by Canadian Blood Services at one collection site between November 1, 2014, and March 17, 2015, were analyzed. The delay in cord clamping after birth was timed and classified as "no delay," 20 to 60 seconds, more than 60 seconds, or more than 120 seconds. Of 367 collections, 100 reported no delay in clamping while clamping was delayed by 20 to 60 seconds (n = 69), more than 60 seconds (n = 98), or more than 120 seconds (n = 100) in the remaining cases. The mean volume and total nucleated cells (TNCs) in units with no delay in clamping were significantly greater than mean volumes for all categories of delayed clamping (Tukey's test, p < 0.05 for each comparison). The proportion of units with more than 1.5 × 10(9) TNCs was significantly reduced when clamping was delayed (p = 5.5 × 10(-8) ). The difference was most marked for cords that were clamped more than 120 seconds after delivery (6.2% compared with 39%). Delayed cord clamping greatly diminishes the volume and TNC count of units collected for a public cord blood bank. Creating an inventory of CBUs with high TNC content may take more time than expected. © 2015 AABB.

Sources of Delay in the Acute Limb Ischemia Patient Pathway.

PubMed

Normahani, Pasha; Standfield, Nigel J; Jaffer, Usman

2017-01-01

Acute limb ischemia (ALI) continues to pose a significant challenge to clinicians and is associated with an unacceptably high rate of morbidity and mortality. Despite its time critical nature, little is known regarding the delays encountered during the patient pathway. The aim of this study was to identify sources of delay in the patient pathway at our institution. Sixty-seven cases of ALI of the lower extremities from 66 patients, who had presented to our center between May 2003 and April 2014, were identified for retrospective analysis. Data were retrieved from the patient records, discharge summaries and hospital laboratory, emergency department and radiology databases. Median time from onset of symptom to arrival at our institution was 11.35 hr (interquartile range [IQR] 6.27-72). Median cumulative time taken from arrival to vascular team review was 40 min (22.5-120), to imaging being performed was 4.75 hr (2.42-17.25), and to intervention being performed was 10.2 hr (4-31). There were significantly longer delays to presentation in those transferred from inpatient beds as compared with those transferred from the emergency department of other hospitals (66 hr [10.3-98] vs. 8 hr [5.6-14.9], P = 0.007). In total, 84.6% of patients underwent preoperative arterial imaging. Time taken from arrival to diagnostic arterial imaging was significantly longer in patients presenting out-of-ours (15 hr [6.5-20.75]) as compared with patients presenting in-hours (3.5 hr [2-6.5], P = 0.014) or during the weekend (2 hr [2-3], P = 0.022). Time from presentation to intervention was significantly shorter in patients presenting over the weekend (3.9 hr [2.6-5.1]) as compared with those presenting in-hours (14.2 hr [6.2-29], P = 0.006) and out-of-hours (16 hr [10-33], P = 0.021). Out-of-hours, a significant portion of the delay, was attributable to imaging (median time to imaging 15 hr). This study demonstrates the systematic nature of delays in the patient pathway from onset of symptoms to treatment. Several factors including time to patient presentation and time to imaging and delays in timely transfer to an appropriate facility contribute to this. Strategies need to be deployed to reduce time to revascularization. Copyright © 2016 Elsevier Inc. All rights reserved.

Time Delay of CGM Sensors

PubMed Central

Schmelzeisen-Redeker, Günther; Schoemaker, Michael; Kirchsteiger, Harald; Freckmann, Guido; Heinemann, Lutz; del Re, Luigi

2015-01-01

Background: Continuous glucose monitoring (CGM) is a powerful tool to support the optimization of glucose control of patients with diabetes. However, CGM systems measure glucose in interstitial fluid but not in blood. Rapid changes in one compartment are not accompanied by similar changes in the other, but follow with some delay. Such time delays hamper detection of, for example, hypoglycemic events. Our aim is to discuss the causes and extent of time delays and approaches to compensate for these. Methods: CGM data were obtained in a clinical study with 37 patients with a prototype glucose sensor. The study was divided into 5 phases over 2 years. In all, 8 patients participated in 2 phases separated by 8 months. A total number of 108 CGM data sets including raw signals were used for data analysis and were processed by statistical methods to obtain estimates of the time delay. Results: Overall mean (SD) time delay of the raw signals with respect to blood glucose was 9.5 (3.7) min, median was 9 min (interquartile range 4 min). Analysis of time delays observed in the same patients separated by 8 months suggests a patient dependent delay. No significant correlation was observed between delay and anamnestic or anthropometric data. The use of a prediction algorithm reduced the delay by 4 minutes on average. Conclusions: Prediction algorithms should be used to provide real-time CGM readings more consistent with simultaneous measurements by SMBG. Patient specificity may play an important role in improving prediction quality. PMID:26243773

Effect of delayed polymerization time and bracket manipulation on orthodontic bracket bonding

NASA Astrophysics Data System (ADS)

Ponikvar, Michael J.

This study examined the effect of bracket manipulation in combination with delayed polymerization times on orthodontic bracket shear bond strength and degree of resin composite conversion. Orthodontics brackets were bonded to extracted third molars in a simulated oral environment after a set period of delayed polymerization time and bracket manipulation. After curing the bracket adhesive, each bracket underwent shear bond strength testing followed by micro-Raman spectroscopy analysis to measure the degree of conversion of the resin composite. Results demonstrated the shear bond strength and the degree of conversion of ceramic brackets did not vary over time. However, with stainless steel brackets there was a significant effect (p ≤ 0.05) of delay time on shear bond strength between the 0.5 min and 10 min bracket groups. In addition, stainless steel brackets showed significant differences related to degree of conversion over time between the 0.5 min and 5 min groups, in addition to the 0.5 min and 10 min groups. This investigation suggests that delaying bracket adhesive polymerization up to a period of 10 min then adjusting the orthodontic bracket may increase both shear bond strength and degree of conversion of stainless steel brackets while having no effect on ceramic brackets.

Improving on-time surgical starts: the impact of implementing pre-OR timeouts and performance pay.

PubMed

Martin, Luke; Langell, John

2017-11-01

Operating room (OR) time is expensive. Underutilized OR time negatively impacts efficiency and is an unnecessary cost for hospitals. The purpose of this study was to evaluate the impact of a pre-OR timeout and performance pay incentive on the frequency of on-time, first surgical starts. At a single Veterans Affairs Medical Center, we implemented a pre-OR timeout in the form of a safety-briefing checklist and a modest performance pay incentive for on-time starts (>90% compliance) for attending surgeons. Data were collected on all first-start cases beginning before implementation in 2008 and continued through 2015. Each year, an average of 960 first starts occurred across nine surgical divisions. Before implementation of either the timeout or pay incentive, only 15% of cases started on time, and by 2015, greater than 72% were on time (P < 0.001). Over the study period, there were significant improvements in on-time starts (P = 0.01), of delays <15 min (P = 0.01), and of delays 16 to 30 min (P = 0.04). The trends for delays of 31 to 60 min or >60 min were not significant (P = 0.31; P = 0.81). Assuming a loss of 7 min per case for delays <15 min and 20 min per case for delays of 16 to 30 min, the total OR time saved from implementing these measures was 37,556 min. At an estimated cost of $20/min, gross savings from this project were $751,120. Implementation of a pre-OR timeout and performance pay for on-time starts significantly improves OR utilization and reduces unnecessary costs. Published by Elsevier Inc.

Cognitive performance in adolescents with Delayed Sleep-Wake Phase Disorder: Treatment effects and a comparison with good sleepers.

PubMed

Richardson, C; Micic, G; Cain, N; Bartel, K; Maddock, B; Gradisar, M

2018-06-01

The present study aimed to investigate whether Australian adolescents with Delayed Sleep-Wake Phase Disorder have impaired cognitive performance and whether chronobiological treatment for Delayed Sleep-Wake Phase Disorder improves adolescents' sleep, daytime functioning and cognitive performance. Adolescents with Delayed Sleep-Wake Phase Disorder (mean = 15.68 ± 2.1 y, 62% f) reported significantly later sleep timing (d = 1.03-1.45), less total sleep time (d = 0.82) and greater daytime sleepiness (d = 2.66), fatigue (d = 0.63) and impairment (d = 2.41), compared to good sleeping adolescents (mean = 15.9 ± 2.4 y, 75% f). However, there were no significant between-group differences (all p > 0.05) in performance on the Operation Span (ηp 2  = 0.043), Digit Span (forwards: ηp 2  = 0.002, backwards: ηp 2  = 0.003), Letter Number Sequencing (ηp 2  < 0.001) (working memory) and Digit-Symbol Substitution Tasks (ηp 2  = 0.010) (processing speed). Adolescents with Delayed Sleep-Wake Phase Disorder went on to receive 3 weeks of light therapy. At 3 months post-treatment, adolescents with Delayed Sleep-Wake Phase Disorder reported significantly advanced sleep timing (d = 0.56-0.65), greater total sleep time (d = 0.52) and improved daytime sleepiness (d = 1.33), fatigue (d = 0.84) and impairment (d = 0.78). Performance on the Operation Span (d = 0.46), Letter Number Sequencing (d = 0.45) and Digit-Symbol Substitution tasks (d = 0.57) also significantly improved. Copyright © 2018. Published by Elsevier Ltd.

A prospective comparison of times to presentation and treatment of regional and remote head and neck patients in North Queensland, Australia.

PubMed

Tan, J Y-A; Otty, Z A; Vangaveti, V N; Buttner, P; Varma, S C; Joshi, A J; Kelly, J; Collins, M; Sabesan, S S

2016-08-01

This study aims to examine differences between outer regional (OR) and remote/very remote (RVR) patients in northern Queensland, Australia in the times taken to receive various aspects of head and neck cancer management. Our study prospectively recruited head and neck cancer patients presenting to three North Queensland regional hospitals from January 2009 to January 2011. Data on demographic and cancer-specific details, comorbidities and timing of presentation to various services, were collected using a self-administered questionnaire that included two questions in relation to possible reason for delays to health services. Multivariate linear regression analyses were conducted to assess the effects of various demographic characteristics on time delays. Survival and disease recurrence data were analysed in 2014. One hundred and fifty-eight patients participated. RVR patients had significantly longer median times between diagnosis and first treatment compared with OR patients (P = 0.015). Indigenous patients had significant delays from diagnosis to first treatment (P = 0.013) and visit to first specialist and treatment (P = 0.031) compared to non-Indigenous patients. Longer median times between symptoms and first treatment was associated with low income (P = 0.03) and lower education level (P = 0.04). Disease recurrence was higher for RVR patients compared with OR patients (P = 0.04), without significant differences in overall survival. Possible reasons for delays included patient and professional factors. Significant delays in various aspects of head and neck cancer management were associated with remoteness, Indigenous and socioeconomic status. While patient and professional factors could be addressed at local levels, sustainable improvement in outcomes requires a state and national level approach. © 2016 Royal Australasian College of Physicians.

Factors associated with delayed diagnosis of mood and/or anxiety disorders

PubMed Central

Ricky, Cheung; Siobhan, O’Donnell; Nawaf, Madi; Elliot M., Goldner

2017-01-01

Abstract Introduction: This study examined the association between time to diagnosis and sociodemographic and clinical characteristics as well as time to diagnosis and physical and mental health status, among Canadian adults with a self-reported mood and/or anxiety disorder diagnosis. Methods: We used data from the 2014 Survey on Living with Chronic Diseases in Canada—Mood and Anxiety Disorders Component. The study sample (n=3212) was divided into three time to diagnosis subgroups: long (> 5 years), moderate (1–5 years) and short (< 1 year). We performed descriptive and multinomial multivariate logistic regression analyses. Estimates were weighted to represent the Canadian adult household population living in the 10 provinces with diagnosed mood and/or anxiety disorders. Results: The majority (61.6%) of Canadians with a mood and/or anxiety disorder diagnosis reported having received their diagnosis more than one year after symptom onset (30.0% reported a moderate delay and 31.6% a long delay). Upon controlling for individual characteristics, we found significant associations between a moderate delay and having no or few physical comorbidities; a long delay and older age; and both moderate and long delays and early age of symptom onset. In addition, a long delay was significantly associated with “poor” or “fair” perceived mental health and the greatest number of activity limitations. Conclusion: These findings affirm that a long delay in diagnosis is associated with negative health outcomes among Canadian adults with mood and/or anxiety disorders. Time to diagnosis is particularly suboptimal among older adults and people with early symptom onset. Tailored strategies to facilitate an early diagnosis for those at greatest risk of a delayed diagnosis, especially for those with early symptom onset, are needed. PMID:28493658

Slow-onset and fast-onset symptom presentations in acute coronary syndrome (ACS): new perspectives on prehospital delay in patients with ACS.

PubMed

O'Donnell, Sharon; McKee, Gabrielle; Mooney, Mary; O'Brien, Frances; Moser, Debra K

2014-04-01

Patient decision delay is the main reason why many patients fail to receive timely medical intervention for symptoms of acute coronary syndrome (ACS). This study examines the validity of slow-onset and fast-onset ACS presentations and their influence on ACS prehospital delay times. A fast-onset ACS presentation is characterized by sudden, continuous, and severe chest pain, and slow-onset ACS pertains to all other ACS presentations. Baseline data pertaining to medical profiles, prehospital delay times, and ACS symptoms were recorded for all ACS patients who participated in a large multisite randomized control trial (RCT) in Dublin, Ireland. Patients were interviewed 2-4 days after their ACS event, and data were gathered using the ACS Response to Symptom Index. Only baseline data from the RCT, N = 893 patients, were analyzed. A total of 65% (n = 577) of patients experienced slow-onset ACS presentation, whereas 35% (n = 316) experienced fast-onset ACS. Patients who experienced slow-onset ACS were significantly more likely to have longer prehospital delays than patients with fast-onset ACS (3.5 h vs. 2.0 h, respectively, t = -5.63, df 890, p < 0.001). A multivariate analysis of delay revealed that, in the presence of other known delay factors, the only independent predictors of delay were slow-onset and fast-onset ACS (β = -.096, p < 0.002) and other factors associated with patient behavior. Slow-onset ACS and fast-onset ACS presentations are associated with distinct behavioral patterns that significantly influence prehospital time frames. As such, slow-onset ACS and fast-onset ACS are legitimate ACS presentation phenomena that should be seriously considered when examining the factors associated with prehospital delay. Copyright © 2014 Elsevier Inc. All rights reserved.

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

PubMed

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

2017-10-01

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

Effects of instrumentation time on microleakage of resin-modified glass ionomer cements.

PubMed

Yap, Adrian U J; Yeo, Egwin J C; Yap, W Y; Ong, Debbie S B; Tan, Jane W S

2003-01-01

This study investigated the effect of instrumentation time on the microleakage of resin-modified glass ionomer cements (RMGICs). Class V cavities were prepared on buccal and lingual/ palatal surfaces of 64 freshly extracted non-carious premolars. The cavities on each tooth were restored with Fuji II LC (FT [GC]) and Photac-Fil Quick (PF [3M-ESPE]). The restored teeth were randomly divided into two groups of 32 teeth. Finishing/polishing was done immediately after light-polymerization in one group and was delayed for one week in the other group. The following finishing/polishing systems were evaluated: (a) Robot Carbides (RC); (b) SuperSnap (SS); (c) OneGloss (OG) and (d) CompoSite Polishers (CS). The sample size for each instrumentation time, material and finishing/polishing system combination was 8. Storage medium for both immediate and delayed instrumentation groups was distilled water at 37 degrees C during the hiatus period. The teeth were subsequently subjected to dye penetration testing (0.5% basic fushcin), sectioned and scored. Data were analyzed using Kruskal-Wallis and Mann-Whitney U tests at significance level 0.05. For PF, significant difference in enamel leakage was observed between immediate and delayed instrumentation with SS and CS. Significant differences in dentin leakage were also observed between the two instrumentation times for SS. For FT, significant differences in leakage between instrumentation times were observed only in dentin and with RC. Where significant differences in dye penetration scores existed, delayed finishing/polishing resulted in less microleakage.

Contemporary Determinants of Delayed Benchmark Timelines in Acute Myocardial Infarction in Men and Women.

PubMed

Alnsasra, Hilmi; Zahger, Doron; Geva, Diklah; Matetzky, Shlomi; Beigel, Roy; Iakobishvili, Zaza; Alcalai, Ronny; Atar, Shaul; Shimony, Avi

2017-11-15

Treatment delays in patients with acute myocardial infarction (AMI) are related to increased morbidity and mortality. Hence, identifying determinants of delay may help reduce time to treatment. Importantly, limited data suggest that there may be sex-related disparities in benchmark timelines. Although guidelines advocate the use of the first medical contact (FMC) rather than hospital admission as the moment from which delays to treatment should be monitored, the latter is still often used for quality purposes. We aimed to identify factors associated with treatment delays, with an emphasis on sex-related disparities. We reviewed data on 3,658 patients with AMI from 2 contemporary, consecutive multicenter surveys. Measured delays were FMC-to-electrocardiogram >10 minutes in ST-elevation MI (STEMI) and non-STEMI, FMC-to-primary percutaneous coronary intervention >90 minutes in STEMI, and invasive angiography >72 hours after admission in non-STEMI patients. Timely electrocardiogram was performed in 48% of patients with STEMI and in 39.8% of non-STEMI patients without significant sex-related differences. Independent determinants of delay included atypical chest pain (CP) and presentation during daytime. In patients with STEMI, 37.5% had primary percutaneous coronary intervention in less than 90 minutes without significant sex-related disparities. Independent determinants of delay included atypical CP, night presentation, and diabetes. In non-STEMI patients, independent determinants of delayed invasive approach were female sex, age >75 years, atypical CP, and renal failure. In conclusion, significant treatment delays in patients with AMI are still frequent in contemporary practice, highlighting the need for improvement and guidelines implementation. Predictors of delay identified in our study may facilitate targeting of interventions to improve adherence to guidelines. Copyright © 2017 Elsevier Inc. All rights reserved.

Determining delayed admission to intensive care unit for mechanically ventilated patients in the emergency department.

PubMed

Hung, Shih-Chiang; Kung, Chia-Te; Hung, Chih-Wei; Liu, Ber-Ming; Liu, Jien-Wei; Chew, Ghee; Chuang, Hung-Yi; Lee, Wen-Huei; Lee, Tzu-Chi

2014-08-23

The adverse effects of delayed admission to the intensive care unit (ICU) have been recognized in previous studies. However, the definitions of delayed admission varies across studies. This study proposed a model to define "delayed admission", and explored the effect of ICU-waiting time on patients' outcome. This retrospective cohort study included non-traumatic adult patients on mechanical ventilation in the emergency department (ED), from July 2009 to June 2010. The primary outcomes measures were 21-ventilator-day mortality and prolonged hospital stays (over 30 days). Models of Cox regression and logistic regression were used for multivariate analysis. The non-delayed ICU-waiting was defined as a period in which the time effect on mortality was not statistically significant in a Cox regression model. To identify a suitable cut-off point between "delayed" and "non-delayed", subsets from the overall data were made based on ICU-waiting time and the hazard ratio of ICU-waiting hour in each subset was iteratively calculated. The cut-off time was then used to evaluate the impact of delayed ICU admission on mortality and prolonged length of hospital stay. The final analysis included 1,242 patients. The time effect on mortality emerged after 4 hours, thus we deduced ICU-waiting time in ED > 4 hours as delayed. By logistic regression analysis, delayed ICU admission affected the outcomes of 21 ventilator-days mortality and prolonged hospital stay, with odds ratio of 1.41 (95% confidence interval, 1.05 to 1.89) and 1.56 (95% confidence interval, 1.07 to 2.27) respectively. For patients on mechanical ventilation at the ED, delayed ICU admission is associated with higher probability of mortality and additional resource expenditure. A benchmark waiting time of no more than 4 hours for ICU admission is recommended.

Impulsive effect on global exponential stability of BAM fuzzy cellular neural networks with time-varying delays

NASA Astrophysics Data System (ADS)

Li, Kelin

2010-02-01

In this article, a class of impulsive bidirectional associative memory (BAM) fuzzy cellular neural networks (FCNNs) with time-varying delays is formulated and investigated. By employing delay differential inequality and M-matrix theory, some sufficient conditions ensuring the existence, uniqueness and global exponential stability of equilibrium point for impulsive BAM FCNNs with time-varying delays are obtained. In particular, a precise estimate of the exponential convergence rate is also provided, which depends on system parameters and impulsive perturbation intention. It is believed that these results are significant and useful for the design and applications of BAM FCNNs. An example is given to show the effectiveness of the results obtained here.

Impact of delaying school start time on adolescent sleep, mood, and behavior.

PubMed

Owens, Judith A; Belon, Katherine; Moss, Patricia

2010-07-01

To examine the impact of a 30-minute delay in school start time on adolescents' sleep, mood, and behavior. Participants completed the online retrospective Sleep Habits Survey before and after a change in school start time. An independent high school in Rhode Island. Students (n = 201) in grades 9 through 12. Intervention Institution of a delay in school start time from 8 to 8:30 am. Sleep patterns and behavior, daytime sleepiness, mood, data from the Health Center, and absences/tardies. After the start time delay, mean school night sleep duration increased by 45 minutes, and average bedtime advanced by 18 minutes (95% confidence interval, 7-29 minutes [t(423) = 3.36; P < .001]); the percentage of students getting less than 7 hours of sleep decreased by 79.4%, and those reporting at least 8 hours of sleep increased from 16.4% to 54.7%. Students reported significantly more satisfaction with sleep and experienced improved motivation. Daytime sleepiness, fatigue, and depressed mood were all reduced. Most health-related variables, including Health Center visits for fatigue-related complaints, and class attendance also improved. A modest delay in school start time was associated with significant improvements in measures of adolescent alertness, mood, and health. The results of this study support the potential benefits of adjusting school schedules to adolescents' sleep needs, circadian rhythm, and developmental stage.

The Effects of Delaying Tracking in Secondary School: Evidence from the 1999 Education Reform in Poland

ERIC Educational Resources Information Center

Jakubowski, Maciej; Patrinos, Harry Anthony; Porta, Emilio Ernesto; Wisniewski, Jerzy

2016-01-01

Delaying tracking, extending students' exposure to a general academic education and increasing their time on task on basic competences (reading, mathematics) could improve academic outcomes. To test the hypothesis that delayed vocational streaming improves academic outcomes, this paper analyzes Poland's significant improvements in international…

High-speed switching of biphoton delays through electro-optic pump frequency modulation

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

Odele, Ogaga D.; Lukens, Joseph M.; Jaramillo-Villegas, Jose A.

The realization of high-speed tunable delay control has received significant attention in the scene of classical photonics. In quantum optics, however, such rapid delay control systems for entangled photons have remained undeveloped. Here for the first time, we demonstrate rapid (2.5 MHz) modulation of signal-idler arrival times through electro-optic pump frequency modulation. Our technique applies the quantum phenomenon of nonlocal dispersion cancellation along with pump frequency tuning to control the relative delay between photon pairs. Chirped fiber Bragg gratings are employed to provide large amounts of dispersion which result in biphoton delays exceeding 30 ns. This rapid delay modulation schememore » could be useful for on-demand single-photon distribution in addition to quantum versions of pulse position modulation.« less

High-speed switching of biphoton delays through electro-optic pump frequency modulation

DOE PAGES

Odele, Ogaga D.; Lukens, Joseph M.; Jaramillo-Villegas, Jose A.; ...

2016-12-08

The realization of high-speed tunable delay control has received significant attention in the scene of classical photonics. In quantum optics, however, such rapid delay control systems for entangled photons have remained undeveloped. Here for the first time, we demonstrate rapid (2.5 MHz) modulation of signal-idler arrival times through electro-optic pump frequency modulation. Our technique applies the quantum phenomenon of nonlocal dispersion cancellation along with pump frequency tuning to control the relative delay between photon pairs. Chirped fiber Bragg gratings are employed to provide large amounts of dispersion which result in biphoton delays exceeding 30 ns. This rapid delay modulation schememore » could be useful for on-demand single-photon distribution in addition to quantum versions of pulse position modulation.« less

An institutional study of time delays for symptomatic carotid endarterectomy.

PubMed

Charbonneau, Philippe; Bonaventure, Paule Lessard; Drudi, Laura M; Beaudoin, Nathalie; Blair, Jean-François; Elkouri, Stéphane

2016-12-01

The aim of this study was to assess time delays between first cerebrovascular symptoms and carotid endarterectomy (CEA) at a single center and to systematically evaluate causes of these delays. Consecutive adult patients who underwent CEAs between January 2010 and September 2011 at a single university-affiliated center (Centre Hospitalier de l'Université Montréal-Hôtel-Dieu Hospital, Montreal) were identified from a clinical database and operative records. Covariates of interest were extracted from electronic medical records. Timing and nature of the first cerebrovascular symptoms were also documented. The first medical contact and pathway of referral were also assessed. When possible, the ABCD 2 score (age, blood pressure, clinical features, duration of symptoms, and diabetes) was calculated to calculate further risk of stroke. The nonparametric Wilcoxon test was used to assess differences in time intervals between two variables. The Kruskal-Wallis test was used to assess differences in time intervals in comparing more than two variables. A multivariate linear regression analysis was performed using covariates that were determined to be statistically significant in our sensitivity analyses. The cohort consisted of 111 patients with documented symptomatic carotid stenosis undergoing surgical intervention. Thirty-nine percent of all patients were operated on within 2 weeks from the first cerebrovascular symptoms. The median time between the occurrence of the first neurologic symptom and the CEA procedure was 25 (interquartile range [IQR], 11-85) days. The patient-dependent delay, defined as the median delay between the first neurologic symptom and the first medical contact, was 1 (IQR, 0-14) day. The medical-dependent delay was defined as the time interval between the first medical contact and CEA. This included the delay between the first medical contact and the request for surgery consultation (median, 3 [IQR, 1-10] days). The multivariate regression model demonstrated that the emergency physician as referral source (P = .0002) was statistically significant for reducing CEA delay. Patients who were investigated as an outpatient (P = .02), first medical contact with a general practitioner (P = .0002), and hospital center I as referral center (P = .045) were also found to be statistically significant to extend CEA delay when the model was adjusted over all covariates. In this center, there was no correlation between ABCD 2 risk score and waiting time for surgery. The majority of our cohort falls short of the recommended 2-week interval to perform CEA. Factors contributing to reduced CEA delay were presentation to an emergency department, in-patient investigations, and a stroke center where a vascular surgeon is available. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Stick balancing with reflex delay in case of parametric forcing

NASA Astrophysics Data System (ADS)

Insperger, Tamas

2011-04-01

The effect of parametric forcing on a PD control of an inverted pendulum is analyzed in the presence of feedback delay. The stability of the time-periodic and time-delayed system is determined numerically using the first-order semi-discretization method in the 5-dimensional parameter space of the pendulum's length, the forcing frequency, the forcing amplitude, the proportional and the differential gains. It is shown that the critical length of the pendulum (that can just be balanced against the time-delay) can significantly be decreased by parametric forcing even if the maximum forcing acceleration is limited. The numerical analysis showed that the critical stick length about 30 cm corresponding to the unforced system with reflex delay 0.1 s can be decreased to 18 cm with keeping maximum acceleration below the gravitational acceleration.

Operating room efficiency improvement after implementation of a postoperative team assessment.

PubMed

Porta, Christopher R; Foster, Andrew; Causey, Marlin W; Cordier, Patricia; Ozbirn, Roger; Bolt, Stephen; Allison, Dennis; Rush, Robert

2013-03-01

Operating room time is highly resource intensive, and delays can be a source of lost revenue and surgeon frustration. Methods to decrease these delays are important not only for patient care, but to maximize operating room resource utilization. The purpose of this study was to determine the root cause of operating room delays in a standardized manner to help improve overall operating room efficiency. We performed a single-center prospective observational study analyzing operating room utilization and efficiency after implementing an executive-driven standardized postoperative team debriefing system from January 2010 to December 2010. A total of 11,342 procedures were performed over the 1-y study period (elective 86%, urgent 11%, and emergent 3%), with 1.3 million min of operating room time, 865,864 min of surgeon operative time (62.5%), and 162,958 min of anesthesia time (11.8%). Overall, the average operating room delay was 18 min and varied greatly based on the surgical specialty. The longest delays were due to need for radiology (40 min); other significant delays were due to supply issues (22.7 min), surgeon issues (18 min), nursing issues (14 min), and room turnover (14 min). Over the 1-y period, there was a decrease in mean delay duration, averaging a decrease in delay of 0.147 min/mo with an overall 9% decrease in the mean delay times. With regard to overall operating room utilization, there was a 39% decrease in overall un-utilized available OR time that was due to delays, improving efficiency by 2334 min (212 min/mo). During this study interval no sentinel events occurred in the operating room. A standardized postoperative debrief tracking system is highly beneficial in identifying and reducing overall operative delays and improving operating room utilization. Published by Elsevier Inc.

Evaluation of atrial electromechanical conduction delay in case of hemodynamically insignificant rheumatic heart disease: A tissue Doppler study.

PubMed

Cagdas, Metin; Velibey, Yalcin; Guvenc, Tolga Sinan; Gungor, Baris; Guzelburc, Ozge; Calik, Nazmi; Ugur, Murat; Tekkesin, Ahmet Ilker; Gurkan, Kadir; Eren, Mehmet

2015-01-01

Atrial electromechanical delay (AEMD) that reflects delayed conduction may show us the clinical reflection of pathological changes in the atria. The main objective of the present study is to investigate AEMD in patients who had previous rheumatic carditis but without hemodynamically significant valvular disease. A total of 40 patients, previously diagnosed as rheumatic carditis but without significant valvular stenosis/regurgitation and atrial enlargement; and 39 age- and-sex matched controls were enrolled for the present study. Parameters of AEMD (lateral mitral annulus electromechanical delay, septal mitral annulus electromechanical delay and lateral tricuspid annulus electromechanical delay) were measured with tissue Doppler echocardiography and left intra-atrial and inter-atrial conduction times were calculated accordingly. A 24h ambulatory Holter monitoring was used in both groups to detect atrial fibrillation episodes and quantify atrial extrasystoles. Parameters of AEMD, including left intra-atrial and inter-atrial conduction times of subjects in the study group were longer compared to the control group (23.7 ± 7.0 vs. 18.3 ± 6.2). Increased AEMD is observed in patients with previous rheumatic carditis and no significant valvular stenosis/regurgitation and atrial enlargement, which may partly explain the increased incidence of atrial fibrillation observed in these patients.

Computer laboratory notification system via short message service to reduce health care delays in management of tuberculosis in Taiwan.

PubMed

Chen, Tun-Chieh; Lin, Wei-Ru; Lu, Po-Liang; Lin, Chun-Yu; Lin, Shu-Hui; Lin, Chuen-Ju; Feng, Ming-Chu; Chiang, Horn-Che; Chen, Yen-Hsu; Huang, Ming-Shyan

2011-06-01

We investigated the impacts of introducing an expedited acid-fast bacilli (AFB) smear laboratory procedure and an automatic, real-time laboratory notification system by short message with mobile phones on delays in prompt isolation of patients with pulmonary tuberculosis (TB). We analyzed the data for all patients with active pulmonary tuberculosis at a hospital in Kaohsiung, Taiwan, a 1,600-bed medical center, during baseline (January 2004 to February 2005) and intervention (July 2005 to August 2006) phases. A total of 96 and 127 patients with AFB-positive TB was reported during the baseline and intervention phases, respectively. There were significant decreases in health care system delays (ie, laboratory delays: reception of sputum to reporting, P < .001; response delays: reporting to patient isolation, P = .045; and interval from admission to patient isolation, P < .001) during the intervention phase. Significantly fewer nurses were exposed to each patient with active pulmonary TB during the intervention phase (P = .039). Implementation of expedited AFB smear laboratory procedures and an automatic, real-time laboratory mobile notification system significantly decreased delays in the diagnosis and isolation of patients with active TB. Copyright © 2011 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Stability Criteria for Differential Equations with Variable Time Delays

ERIC Educational Resources Information Center

Schley, D.; Shail, R.; Gourley, S. A.

2002-01-01

Time delays are an important aspect of mathematical modelling, but often result in highly complicated equations which are difficult to treat analytically. In this paper it is shown how careful application of certain undergraduate tools such as the Method of Steps and the Principle of the Argument can yield significant results. Certain delay…

Sound System Engineering & Optimization: The effects of multiple arrivals on the intelligibility of reinforced speech

NASA Astrophysics Data System (ADS)

Ryan, Timothy James

The effects of multiple arrivals on the intelligibility of speech produced by live-sound reinforcement systems are examined. The intent is to determine if correlations exist between the manipulation of sound system optimization parameters and the subjective attribute speech intelligibility. Given the number, and wide range, of variables involved, this exploratory research project attempts to narrow the focus of further studies. Investigated variables are delay time between signals arriving from multiple elements of a loudspeaker array, array type and geometry and the two-way interactions of speech-to-noise ratio and array geometry with delay time. Intelligibility scores were obtained through subjective evaluation of binaural recordings, reproduced via headphone, using the Modified Rhyme Test. These word-score results are compared with objective measurements of Speech Transmission Index (STI). Results indicate that both variables, delay time and array geometry, have significant effects on intelligibility. Additionally, it is seen that all three of the possible two-way interactions have significant effects. Results further reveal that the STI measurement method overestimates the decrease in intelligibility due to short delay times between multiple arrivals.

Micromachined silicon acoustic delay line with improved structural stability and acoustic directivity for real-time photoacoustic tomography

NASA Astrophysics Data System (ADS)

Cho, Young; Kumar, Akhil; Xu, Song; Zou, Jun

2017-03-01

Recent studies have shown that micromachined silicon acoustic delay lines can provide a promising solution to achieve real-time photoacoustic tomography without the need for complex transducer arrays and data acquisition electronics. However, as its length increases to provide longer delay time, the delay line becomes more vulnerable to structural instability due to reduced mechanical stiffness. In addition, the small cross-section area of the delay line results in a large acoustic acceptance angle and therefore poor directivity. To address these two issues, this paper reports the design, fabrication, and testing of a new silicon acoustic delay line enhanced with 3D printed polymer micro linker structures. First, mechanical deformation of the silicon acoustic delay line (with and without linker structures) under gravity was simulated by using finite element method. Second, the acoustic crosstalk and acoustic attenuation caused by the polymer micro linker structures were evaluated with both numerical simulation and ultrasound transmission testing. The result shows that the use of the polymer micro linker structures significantly improves the structural stability of the silicon acoustic delay lines without creating additional acoustic attenuation and crosstalk. In addition, a new tapered design for the input terminal of the delay line was also investigate to improve its acoustic directivity by reducing the acoustic acceptance angle. These two improvements are expected to provide an effective solution to eliminate current limitations on the achievable acoustic delay time and out-of-plane imaging resolution of micromachined silicon acoustic delay line arrays.

Delay in reviewing test results prolongs hospital length of stay: a retrospective cohort study.

PubMed

Ong, Mei-Sing; Magrabi, Farah; Coiera, Enrico

2018-05-16

Failure in the timely follow-up of test results has been widely documented, contributing to delayed medical care. Yet, the impact of delay in reviewing test results on hospital length of stay (LOS) has not been studied. We examine the relationship between laboratory tests review time and hospital LOS. A retrospective cohort study of inpatients admitted to a metropolitan teaching hospital in Sydney, Australia, between 2011 and 2012 (n = 5804). Generalized linear models were developed to examine the relationship between hospital LOS and cumulative clinician read time (CRT), defined as the time taken by clinicians to review laboratory test results performed during an inpatient stay after they were reported in the computerized test reporting system. The models were adjusted for patients' age, sex, and disease severity (measured by the Charlson Comorbidity index), the number of test panels performed, the number of unreviewed tests pre-discharge, and the cumulative laboratory turnaround time (LTAT) of tests performed during an inpatient stay. Cumulative CRT is significantly associated with prolonged LOS, with each day of delay in reviewing test results increasing the likelihood of prolonged LOS by 13.2% (p < 0.0001). Restricting the analysis to tests with abnormal results strengthened the relationship between cumulative CRT and prolonged LOS, with each day of delay in reviewing test results increasing the likelihood of delayed discharge by 33.6% (p < 0.0001). Increasing age, disease severity and total number of tests were also significantly associated with prolonged LOS. Increasing number of unreviewed tests was negatively associated with prolonged LOS. Reducing unnecessary hospital LOS has become a critical health policy goal as healthcare costs escalate. Preventing delay in reviewing test results represents an important opportunity to address potentially avoidable hospital stays and unnecessary resource utilization.

Effect of delayed auditory feedback on normal speakers at two speech rates

NASA Astrophysics Data System (ADS)

Stuart, Andrew; Kalinowski, Joseph; Rastatter, Michael P.; Lynch, Kerry

2002-05-01

This study investigated the effect of short and long auditory feedback delays at two speech rates with normal speakers. Seventeen participants spoke under delayed auditory feedback (DAF) at 0, 25, 50, and 200 ms at normal and fast rates of speech. Significantly two to three times more dysfluencies were displayed at 200 ms (p<0.05) relative to no delay or the shorter delays. There were significantly more dysfluencies observed at the fast rate of speech (p=0.028). These findings implicate the peripheral feedback system(s) of fluent speakers for the disruptive effects of DAF on normal speech production at long auditory feedback delays. Considering the contrast in fluency/dysfluency exhibited between normal speakers and those who stutter at short and long delays, it appears that speech disruption of normal speakers under DAF is a poor analog of stuttering.

How does signal fade on photo-stimulable storage phosphor imaging plates when scanned with a delay and what is the effect on image quality?

PubMed

Ang, Dan B; Angelopoulos, Christos; Katz, Jerald O

2006-11-01

The goals of this in vitro study were to determine the effect of signal fading of DenOptix photo-stimulable storage phosphor imaging plates scanned with a delay and to determine the effect on the diagnostic quality of the image. In addition, we sought to correlate signal fading with image spatial resolution and average pixel intensity values. Forty-eight images were obtained of a test specimen apparatus and scanned at 6 delayed time intervals: immediately scanned, 1 hour, 8 hours, 24 hours, 72 hours, and 168 hours. Six general dentists using Vixwin2000 software performed a measuring task to determine the location of an endodontic file tip and root apex. One-way ANOVA with repeated measures was used to determine the effect of signal fading (delayed scan time) on diagnostic image quality and average pixel intensity value. There was no statistically significant difference in diagnostic image quality resulting from signal fading. No difference was observed in spatial resolution of the images. There was a statistically significant difference in the pixel intensity analysis of an 8-step aluminum wedge between immediate scanning and 24-hour delayed scan time. There was an effect of delayed scanning on the average pixel intensity value. However, there was no effect on image quality and raters' ability to perform a clinical identification task. Proprietary software of the DenOptix digital imaging system demonstrates an excellent ability to process a delayed scan time signal and create an image of diagnostic quality.

Delays before Diagnosis and Initiation of Treatment in Patients Presenting to Mental Health Services with Bipolar Disorder.

PubMed

Patel, Rashmi; Shetty, Hitesh; Jackson, Richard; Broadbent, Matthew; Stewart, Robert; Boydell, Jane; McGuire, Philip; Taylor, Matthew

2015-01-01

Bipolar disorder is a significant cause of morbidity and mortality. Although existing treatments are effective, there is often a substantial delay before diagnosis and treatment initiation. We sought to investigate factors associated with the delay before diagnosis of bipolar disorder and the onset of treatment in secondary mental healthcare. Retrospective cohort study using anonymised electronic mental health record data from the South London and Maudsley NHS Foundation Trust (SLaM) Biomedical Research Centre (BRC) Case Register on 1364 adults diagnosed with bipolar disorder between 2007 and 2012. The following predictor variables were analysed in a multivariable Cox regression analysis: age, gender, ethnicity, compulsory admission to hospital under the UK Mental Health Act, marital status and other diagnoses prior to bipolar disorder. The outcomes were time to recorded diagnosis from first presentation to specialist mental health services (the diagnostic delay), and time to the start of appropriate therapy (treatment delay). The median diagnostic delay was 62 days (interquartile range: 17-243) and median treatment delay was 31 days (4-122). Compulsory hospital admission was associated with a significant reduction in both diagnostic delay (hazard ratio 2.58, 95% CI 2.18-3.06) and treatment delay (4.40, 3.63-5.62). Prior diagnoses of other psychiatric disorders were associated with increased diagnostic delay, particularly alcohol (0.48, 0.33-0.41) and substance misuse disorders (0.44, 0.31-0.61). Prior diagnosis of schizophrenia and psychotic depression were associated with reduced treatment delay. Some individuals experience a significant delay in diagnosis and treatment of bipolar disorder after initiation of specialist mental healthcare, particularly those who have prior diagnoses of alcohol and substance misuse disorders. These findings highlight a need for further study on strategies to better identify underlying symptoms and offer appropriate treatment sooner in order to facilitate improved clinical outcomes, such as developing specialist early intervention services to identify and treat people with bipolar disorder.

The influence of chronic conditions and the environment on pubertal development. An example from medieval England.

PubMed

Lewis, M E; Shapland, F; Watts, R

2016-03-01

Adolescence is a unique period in human development encompassing sexual maturation (puberty) and the physical and psychological transition into adulthood. It is a crucial time for healthy development and any adverse environmental conditions, poor nutrition, or chronic infection can alter the timing of these physical changes; delaying menarche in girls or the age of peak height velocity in boys. This study explores the impact of chronic illness on the tempo of puberty in 607 adolescent skeletons from medieval England (AD 900-1550). A total of 135 (22.2%) adolescents showed some delay in their pubertal development, and this lag increased with age. Of those with a chronic condition, 40.0% (n=24/60) showed delay compared to only 20.3% (n=111/547) of the non-pathology group. This difference was statistically significant. A binary logistic regression model demonstrated a significant association between increasing delay in pubertal stage attainment with age in the pathology group. This is the first time that chronic conditions have been directly associated with a delay in maturation in the osteological record, using a new method to assess stages of puberty in skeletal remains. Copyright © 2015 Elsevier Inc. All rights reserved.

Effect of a comprehensive health education program on pre-hospital delay intentions in high-risk stroke population and caregivers.

PubMed

Yang, Li; Zhao, Qiuli; Zhu, Xuemei; Shen, Xiaoying; Zhu, Yulan; Yang, Liu; Gao, Wei; Li, Minghui

2017-08-01

Many factors influence pre-hospital delays in the event of stroke. This study aimed to develop and evaluate a comprehensive educational program for decreasing pre-hospital delays in high-risk stroke population. We enrolled 220 high-risk stroke population and caregivers from six urban communities in Harbin from May 2013 to May 2015, and randomly divided them into intervention and control groups. We implemented a comprehensive educational program (intervention group), comprising public lectures, instructional brochures, case videos, simulations, and role-playing from May 2013 to May 2015. We delivered conventional oral education in the control group. We compared stroke pre-hospital delay behavioral intention (SPDBI), pre-hospital stroke symptom coping test (PSSCT), and stroke pre-symptoms alert test (SPSAT) results between the groups before and 6, 12, and 18 months after health intervention. There were significant differences between before and after intervention (P < 0.01). SPDBI, PSSCT, and SPSAT scores were significantly different between the groups (P < 0.01). The interaction between time and intervention method was significant (P < 0.01). According to multivariate repeated measures analysis of variance, SPDBI, PSSCT, and SPSAT scores were significantly different at each time after intervention (P < 0.05). The comprehensive educational program was significantly effective in decreasing SPDBI, improving knowledge, enhancing stroke pre-symptoms alert, and reducing the possibility of pre-hospital delays.

Comparative effects of 60Co gamma-rays and neon and helium ions on cycle duration and division probability of EMT 6 cells. A time-lapse cinematography study.

PubMed

Collyn-d'Hooghe, M; Hemon, D; Gilet, R; Curtis, S B; Valleron, A J; Malaise, E P

1981-03-01

Exponentially growing cultures of EMT 6 cells were irradiated in vitro with neon ions, helium ions or 60Co gamma-rays. Time-lapse cinematography allowed the determination, for individual cells, of cycle duration, success of the mitotic division and the age of the cell at the moment of irradiation. Irradiation induced a significant mitotic delay increasing proportionally with the delivered dose. Using mitotic delay as an endpoint, the r.b.e. for neon ions with respect to 60Co gamma-rays was 3.3 +/- 0.2 while for helium ions it was 1.2 +/- 0.1. Mitotic delay was greatest in those cells that had progressed furthest in their cycle at the time of irradiation. No significant mitotic delay was observed in the post-irradiation generation. Division probability was significantly reduced by irradiation both in the irradiated and in the post-irradiated generation. The reduction in division probability obtained with 3 Gy of neon ions was similar to that obtained after irradiation with 6 Gy of helium ions or 60Co gamma-rays.

Impact of time delay on the dynamics of SEIR epidemic model using cellular automata

NASA Astrophysics Data System (ADS)

Sharma, Natasha; Gupta, Arvind Kumar

2017-04-01

The delay of an infectious disease is significant when aiming to predict its strength and spreading patterns. In this paper the SEIR ​(susceptible-exposed-infected-recovered) epidemic spread with time delay is analyzed through a two-dimensional cellular automata model. The time delay corresponding to the infectious span, predominantly, includes death during the latency period in due course of infection. The advancement of whole system is described by SEIR transition function complemented with crucial factors like inhomogeneous population distribution, birth and disease independent mortality. Moreover, to reflect more realistic population dynamics some stochastic parameters like population movement and connections at local level are also considered. The existence and stability of disease free equilibrium is investigated. Two prime behavioral patterns of disease dynamics is found depending on delay. The critical value of delay, beyond which there are notable variations in spread patterns, is computed. The influence of important parameters affecting the disease dynamics on basic reproduction number is also examined. The results obtained show that delay plays an affirmative role to control disease progression in an infected host.

New exponential synchronization criteria for time-varying delayed neural networks with discontinuous activations.

PubMed

Cai, Zuowei; Huang, Lihong; Zhang, Lingling

2015-05-01

This paper investigates the problem of exponential synchronization of time-varying delayed neural networks with discontinuous neuron activations. Under the extended Filippov differential inclusion framework, by designing discontinuous state-feedback controller and using some analytic techniques, new testable algebraic criteria are obtained to realize two different kinds of global exponential synchronization of the drive-response system. Moreover, we give the estimated rate of exponential synchronization which depends on the delays and system parameters. The obtained results extend some previous works on synchronization of delayed neural networks not only with continuous activations but also with discontinuous activations. Finally, numerical examples are provided to show the correctness of our analysis via computer simulations. Our method and theoretical results have a leading significance in the design of synchronized neural network circuits involving discontinuous factors and time-varying delays. Copyright © 2015 Elsevier Ltd. All rights reserved.

Premixed autoignition in compressible turbulence

NASA Astrophysics Data System (ADS)

Konduri, Aditya; Kolla, Hemanth; Krisman, Alexander; Chen, Jacqueline

2016-11-01

Prediction of chemical ignition delay in an autoignition process is critical in combustion systems like compression ignition engines and gas turbines. Often, ignition delay times measured in simple homogeneous experiments or homogeneous calculations are not representative of actual autoignition processes in complex turbulent flows. This is due the presence of turbulent mixing which results in fluctuations in thermodynamic properties as well as chemical composition. In the present study the effect of fluctuations of thermodynamic variables on the ignition delay is quantified with direct numerical simulations of compressible isotropic turbulence. A premixed syngas-air mixture is used to remove the effects of inhomogeneity in the chemical composition. Preliminary results show a significant spatial variation in the ignition delay time. We analyze the topology of autoignition kernels and identify the influence of extreme events resulting from compressibility and intermittency. The dependence of ignition delay time on Reynolds and turbulent Mach numbers is also quantified. Supported by Basic Energy Sciences, Dept of Energy, United States.

Delayed onset of lactogenesis among first-time mothers is related to maternal obesity and factors associated with ineffective breastfeeding.

PubMed

Nommsen-Rivers, Laurie A; Chantry, Caroline J; Peerson, Janet M; Cohen, Roberta J; Dewey, Kathryn G

2010-09-01

Delayed onset of lactogenesis (OL) is most common in primiparas and increases the risk of excess neonatal weight loss, formula supplementation, and early weaning. We examined variables associated with delayed OL among first-time mothers who delivered at term and initiated breastfeeding (n = 431). We conducted in-person interviews during pregnancy and at days 0, 3, and 7 postpartum and extracted obstetric and newborn information from medical records. We defined OL as delayed if it occurred after 72 h and used chi-square analysis to examine its association with potential risk factors across 6 dimensions: 1) prenatal characteristics, 2) maternal anthropometric characteristics, 3) labor and delivery experience, 4) newborn characteristics, 5) maternal postpartum factors, and 6) infant feeding variables. We examined independent associations by using multivariable logistic regression analysis. Median OL was 68.9 h postpartum; 44% of mothers experienced delayed OL. We observed significant bivariate associations between delayed OL and variables in all 6 dimensions (P < 0.05). In a multivariate model adjusted for prenatal feeding intentions, independent risk factors for delayed OL were maternal age > or =30 y, body mass index in the overweight or obese range, birth weight >3600 g, absence of nipple discomfort between 0-3 d postpartum, and infant failing to "breastfeed well" > or =2 times in the first 24 h. Postpartum edema was significant in an alternate model excluding body mass index (P < 0.05). The risk factors for delayed OL are multidimensional. Public health and obstetric and maternity care interventions are needed to address what has become an alarmingly common problem among primiparas.

Effect of longer health service provider delays on stage at diagnosis and mortality in symptomatic breast cancer.

PubMed

Murchie, P; Raja, E A; Lee, A J; Brewster, D H; Campbell, N C; Gray, N M; Ritchie, L D; Robertson, R; Samuel, L

2015-06-01

This study explored whether longer provider delays (between first presentation and treatment) were associated with later stage and poorer survival in women with symptomatic breast cancer. Data from 850 women with symptomatic breast cancer were linked with the Scottish Cancer Registry; Death Registry; and hospital discharge dataset. Logistic regression and Cox survival analyses with restricted cubic splines explored relationships between provider delays, stage and survival, with sequential adjustment for patient and tumour factors. Although confidence intervals were wide in both adjusted analyses, those with the shortest provider delays had more advanced breast cancer at diagnosis. Beyond approximately 20 weeks, the trend suggests longer delays are associated with more advanced stage, but is not statistically significant. Those with symptomatic breast cancer and the shortest presentation to treatment time (within 4 weeks) had the poorest survival. Longer time to treatment was not significantly associated with worsening mortality. Poor prognosis patients with breast cancer are being triaged for rapid treatment with limited effect on outcome. Prolonged time to treatment does not appear to be strongly associated with poorer outcomes for patients with breast cancer, but the power of this study to assess the effect of very long delays (>25 weeks) was limited. Efforts to reduce waiting times are important from a quality of life perspective, but tumour biology may often be a more important determinant of stage at diagnosis and survival outcome. Copyright © 2015 Elsevier Ltd. All rights reserved.

Improving brain-machine interface performance by decoding intended future movements

NASA Astrophysics Data System (ADS)

Willett, Francis R.; Suminski, Aaron J.; Fagg, Andrew H.; Hatsopoulos, Nicholas G.

2013-04-01

Objective. A brain-machine interface (BMI) records neural signals in real time from a subject's brain, interprets them as motor commands, and reroutes them to a device such as a robotic arm, so as to restore lost motor function. Our objective here is to improve BMI performance by minimizing the deleterious effects of delay in the BMI control loop. We mitigate the effects of delay by decoding the subject's intended movements a short time lead in the future. Approach. We use the decoded, intended future movements of the subject as the control signal that drives the movement of our BMI. This should allow the user's intended trajectory to be implemented more quickly by the BMI, reducing the amount of delay in the system. In our experiment, a monkey (Macaca mulatta) uses a future prediction BMI to control a simulated arm to hit targets on a screen. Main Results. Results from experiments with BMIs possessing different system delays (100, 200 and 300 ms) show that the monkey can make significantly straighter, faster and smoother movements when the decoder predicts the user's future intent. We also characterize how BMI performance changes as a function of delay, and explore offline how the accuracy of future prediction decoders varies at different time leads. Significance. This study is the first to characterize the effects of control delays in a BMI and to show that decoding the user's future intent can compensate for the negative effect of control delay on BMI performance.

A Space Affine Matching Approach to fMRI Time Series Analysis.

PubMed

Chen, Liang; Zhang, Weishi; Liu, Hongbo; Feng, Shigang; Chen, C L Philip; Wang, Huili

2016-07-01

For fMRI time series analysis, an important challenge is to overcome the potential delay between hemodynamic response signal and cognitive stimuli signal, namely the same frequency but different phase (SFDP) problem. In this paper, a novel space affine matching feature is presented by introducing the time domain and frequency domain features. The time domain feature is used to discern different stimuli, while the frequency domain feature to eliminate the delay. And then we propose a space affine matching (SAM) algorithm to match fMRI time series by our affine feature, in which a normal vector is estimated using gradient descent to explore the time series matching optimally. The experimental results illustrate that the SAM algorithm is insensitive to the delay between the hemodynamic response signal and the cognitive stimuli signal. Our approach significantly outperforms GLM method while there exists the delay. The approach can help us solve the SFDP problem in fMRI time series matching and thus of great promise to reveal brain dynamics.

Delays in clinical development of neurological drugs in Japan.

PubMed

Ikeda, Masayuki

2017-06-28

The delays in the approval and development of neurological drugs between Japan and other countries have been a major issue for patients with neurological diseases. The objective of this study was to analyze factors contributing to the delay in the launching of neurological drugs in Japan. We analyzed data from Japan and the US for the approval of 42 neurological drugs, all of which were approved earlier in the US than in Japan, and examined the potential factors that may cause the delay of their launch. Introductions of the 42 drugs in Japan occurred at a median of 87 months after introductions in the US. The mean review time of new drug applications for the 20 drugs introduced in Japan in January 2011 or later (15 months) was significantly shorter than that for the other 22 drugs introduced in Japan in December 2010 or earlier (24 months). The lag in the Japan's review time behind the US could not explain the approval delays. In the 31 of the 42 drugs, the application data package included overseas data. The mean review time of these 31 drugs (17 months) was significantly shorter than that of the other 11 drugs without overseas data (26 months). The mean approval lag behind the US of the 31 drugs (78 months) was also significantly shorter than that of the other 11 drugs (134 months). These results show that several important reforms in the Japanese drug development and approval system (e.g., inclusion of global clinical trial data) have reduced the delays in the clinical development of neurological drugs.

Gender and socio-cultural determinants of delay to diagnosis of TB in Bangladesh, India and Malawi.

PubMed

Gosoniu, G D; Ganapathy, S; Kemp, J; Auer, C; Somma, D; Karim, F; Weiss, M G

2008-07-01

Tuberculosis (TB) control programmes in Bangladesh, India and Malawi. To compare the interval from symptom onset to diagnosis of TB for men and women, and to assess socio-cultural and gender-related features of illness explaining diagnostic delay. Semi-structured Explanatory Model Interview Catalogue (EMIC) interviews were administered to 100 or more patients at each site, assessing categories of distress, perceived causes and help seeking. Based on time from initial symptoms to diagnosis of TB, patients were classified with problem delay (>90 days), timely diagnosis (< or =30 days) or moderate delay. EMIC interview data were analysed to explain problem delay. The median interval from symptom onset to diagnosis was longest in India and shortest in Malawi. With adjustment for confounding, female sex (Bangladesh), and status of married woman (India) and housewife (Malawi) were associated with problem delay. Prominent non-specific symptoms--chest pain (Bangladesh) and breathlessness (Malawi)--were also significant. Cough in India, widely associated with TB, was associated with timely diagnosis. Sanitation as a perceived cause linked to poor urban conditions was associated with delayed diagnosis in India. Specific prior help seeking with circuitous referral patterns was identified. The study identified gender- and illness-related features of diagnostic delay. Further research distinguishing patient and provider delay is needed.

Root cause analysis of laboratory turnaround times for patients in the emergency department.

PubMed

Fernandes, Christopher M B; Worster, Andrew; Hill, Stephen; McCallum, Catherine; Eva, Kevin

2004-03-01

Laboratory investigations are essential to patient care and are conducted routinely in emergency departments (EDs). This study reports the turnaround times at an academic, tertiary care ED, using root cause analysis to identify potential areas of improvement. Our objectives were to compare the laboratory turnaround times with established benchmarks and identify root causes for delays. Turnaround and process event times for a consecutive sample of hemoglobin and potassium measurements were recorded during an 8-day study period using synchronized time stamps. A log transformation (ln [minutes + 1]) was performed to normalize the time data, which were then compared with established benchmarks using one-sample t tests. The turnaround time for hemoglobin was significantly less than the established benchmark (n = 140, t = -5.69, p < 0.001) and that of potassium was significantly greater (n = 121, t = 12.65, p < 0.001). The hemolysis rate was 5.8%, with 0.017% of samples needing recollection. Causes of delays included order-processing time, a high proportion (43%) of tests performed on patients who had been admitted but were still in the ED waiting for a bed, and excessive laboratory process times for potassium. The turnaround time for hemoglobin (18 min) met the established benchmark, but that for potassium (49 min) did not. Root causes for delay were order-processing time, excessive queue and instrument times for potassium and volume of tests for admitted patients. Further study of these identified causes of delays is required to see whether laboratory TATs can be reduced.

Perceived Delay in Healthcare-seeking for Episodes of Serious Illness and Its Implications for Safe Motherhood Interventions in Rural Bangladesh

PubMed Central

Killewo, J.; Bashir, I.; Yunus, M.; Chakraborty, J.

2006-01-01

Delay in accessing emergency obstetric-care facilities during life-threatening obstetric complications is a significant determinant of high maternal mortality in developing countries. To examine the factors associated with delays in seeking care for episodes of serious illness and their possible implications for safe motherhood interventions in rural Bangladesh, a cross-sectional study was initiated in Matlab sub-district on the perceptions of household heads regarding delays in seeking care for episodes of serious illness among household members. Of 2,177 households in the study, 881 (40.5%) reported at least one household member who experienced an illness perceived to be serious enough to warrant care-seeking either from health facilities or from providers. Of these, 775 (88.0%) actually visited some providers for treatment, of whom 79.1% used transport. Overall, 69.3% perceived a delay in deciding to seek care, while 12.1% and 24.6% perceived a delay in accessing transport and in reaching the provider respectively. The median time required to make a decision to seek care was 72 minutes, while the same was 10 minutes to get transport and 80 minutes to reach a facility or a provider. Time to decide to seek care was shortest for pregnancy-related conditions and longest for illnesses classified as chronic, while time to reach a facility was longest for pregnancy-related illnesses and shortest for illnesses classified as acute. However, the perceived delay in seeking care did not differ significantly across socioeconomic levels or gender categories but differed significantly between those seeking care from informal providers compared to formal providers. Reasons for the delay included waiting time for results of informal treatment, inability to judge the graveness of disease, and lack of money. For pregnancy-related morbidities, 45% reported ‘inability to judge the graveness of the situation’ as a reason for delay in making decision. After controlling for possible confounders in multivariate analysis, type of illness and facility visited were the strongest determinants of delay in making decision to seek care. To reduce delays in making decision to seek care in rural Bangladesh, safe motherhood interventions should intensify behaviour change-communication efforts to educate communities to recognize pregnancy-danger signs for which a prompt action must be taken to save life. This strategy should be combined with efforts to train community-based skilled birth attendants, upgrading public facilities to provide emergency obstetric care, introduce voucher schemes to improve access by the poorest of the poor, and improve the quality of care at all levels. PMID:17591337

Early or delayed provision of an ankle-foot orthosis in patients with acute and subacute stroke: a randomized controlled trial.

PubMed

Nikamp, Corien Dm; Buurke, Jaap H; van der Palen, Job; Hermens, Hermie J; Rietman, Johan S

2017-06-01

(1) To study the effects of providing ankle-foot orthoses in subjects with (sub)acute stroke; and (2) to study whether the point in time at which an ankle-foot orthosis is provided post-stroke (early or delayed) influences these effects. Randomized controlled trial. Rehabilitation centre. Unilateral hemiparetic stroke subjects with indication for use of an ankle-foot orthosis and maximal six weeks post-stroke. Subjects were randomly assigned to: early provision (at inclusion; Week 1) or delayed provision (eight weeks later; Week 9). 10-metre walk test, 6-minute walk test, Timed Up and Go Test, stairs test, Functional Ambulation Categories, Berg Balance Scale, Rivermead Mobility Index and Barthel Index; assessed in Weeks 1, 3, 9 and 11. A total of 33 subjects were randomized (16 early, 17 delayed). Positive effects of ankle-foot orthoses were found two weeks after provision, both when provided early (significant effects on all outcomes) or delayed (Berg Balance Scale p = 0.011, Functional Ambulation Categories p = 0.008, 6-minute walk test p = 0.005, Timed Up and Go Test p = 0.028). Comparing effects after early and delayed provision showed that early provision resulted in increased levels of improvement on Berg Balance Scale (+5.1 points, p = 0.002), Barthel Index (+1.9 points, p = 0.002) and non-significant improvements on 10-metre walk test (+0.14 m/s, p = 0.093) and Timed Up and Go Test (-5.4 seconds, p = 0.087), compared with delayed provision. We found positive effects of providing ankle-foot orthoses in (sub)acute stroke subjects that had not used these orthoses before.

Methodology for Analysis, Modeling and Simulation of Airport Gate-waiting Delays

NASA Astrophysics Data System (ADS)

Wang, Jianfeng

This dissertation presents methodologies to estimate gate-waiting delays from historical data, to identify gate-waiting-delay functional causes in major U.S. airports, and to evaluate the impact of gate operation disruptions and mitigation strategies on gate-waiting delay. Airport gates are a resource of congestion in the air transportation system. When an arriving flight cannot pull into its gate, the delay it experiences is called gate-waiting delay. Some possible reasons for gate-waiting delay are: the gate is occupied, gate staff or equipment is unavailable, the weather prevents the use of the gate (e.g. lightning), or the airline has a preferred gate assignment. Gate-waiting delays potentially stay with the aircraft throughout the day (unless they are absorbed), adding costs to passengers and the airlines. As the volume of flights increases, ensuring that airport gates do not become a choke point of the system is critical. The first part of the dissertation presents a methodology for estimating gate-waiting delays based on historical, publicly available sources. Analysis of gate-waiting delays at major U.S. airports in the summer of 2007 identifies the following. (i) Gate-waiting delay is not a significant problem on majority of days; however, the worst delay days (e.g. 4% of the days at LGA) are extreme outliers. (ii) The Atlanta International Airport (ATL), the John F. Kennedy International Airport (JFK), the Dallas/Fort Worth International Airport (DFW) and the Philadelphia International Airport (PHL) experience the highest gate-waiting delays among major U.S. airports. (iii) There is a significant gate-waiting-delay difference between airlines due to a disproportional gate allocation. (iv) Gate-waiting delay is sensitive to time of a day and schedule peaks. According to basic principles of queueing theory, gate-waiting delay can be attributed to over-scheduling, higher-than-scheduled arrival rate, longer-than-scheduled gate-occupancy time, and reduced gate availability. Analysis of the worst days at six major airports in the summer of 2007 indicates that major gate-waiting delays are primarily due to operational disruptions---specifically, extended gate occupancy time, reduced gate availability and higher-than-scheduled arrival rate (usually due to arrival delay). Major gate-waiting delays are not a result of over-scheduling. The second part of this dissertation presents a simulation model to evaluate the impact of gate operational disruptions and gate-waiting-delay mitigation strategies, including building new gates, implementing common gates, using overnight off-gate parking and adopting self-docking gates. Simulation results show the following effects of disruptions: (i) The impact of arrival delay in a time window (e.g. 7 pm to 9 pm) on gate-waiting delay is bounded. (ii) The impact of longer-than-scheduled gate-occupancy times in a time window on gate-waiting delay can be unbounded and gate-waiting delay can increase linearly as the disruption level increases. (iii) Small reductions in gate availability have a small impact on gate-waiting delay due to slack gate capacity, while larger reductions have a non-linear impact as slack gate capacity is used up. Simulation results show the following effects of mitigation strategies: (i) Implementing common gates is an effective mitigation strategy, especially for airports with a flight schedule not dominated by one carrier, such as LGA. (ii) The overnight off-gate rule is effective in mitigating gate-waiting delay for flights stranded overnight following departure cancellations. This is especially true at airports where the gate utilization is at maximum overnight, such as LGA and DFW. The overnight off-gate rule can also be very effective to mitigate gate-waiting delay due to operational disruptions in evenings. (iii) Self-docking gates are effective in mitigating gate-waiting delay due to reduced gate availability.

Modelling and tuning for a time-delayed vibration absorber with friction

NASA Astrophysics Data System (ADS)

Zhang, Xiaoxu; Xu, Jian; Ji, Jinchen

2018-06-01

This paper presents an integrated analytical and experimental study to the modelling and tuning of a time-delayed vibration absorber (TDVA) with friction. In system modelling, this paper firstly applies the method of averaging to obtain the frequency response function (FRF), and then uses the derived FRF to evaluate the fitness of different friction models. After the determination of the system model, this paper employs the obtained FRF to evaluate the vibration absorption performance with respect to tunable parameters. A significant feature of the TDVA with friction is that its stability is dependent on the excitation parameters. To ensure the stability of the time-delayed control, this paper defines a sufficient condition for stability estimation. Experimental measurements show that the dynamic response of the TDVA with friction can be accurately predicted and the time-delayed control can be precisely achieved by using the modelling and tuning technique provided in this paper.

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

PubMed

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

2016-08-01

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

Organization of Anti-Phase Synchronization Pattern in Neural Networks: What are the Key Factors?

PubMed Central

Li, Dong; Zhou, Changsong

2011-01-01

Anti-phase oscillation has been widely observed in cortical neural network. Elucidating the mechanism underlying the organization of anti-phase pattern is of significance for better understanding more complicated pattern formations in brain networks. In dynamical systems theory, the organization of anti-phase oscillation pattern has usually been considered to relate to time delay in coupling. This is consistent to conduction delays in real neural networks in the brain due to finite propagation velocity of action potentials. However, other structural factors in cortical neural network, such as modular organization (connection density) and the coupling types (excitatory or inhibitory), could also play an important role. In this work, we investigate the anti-phase oscillation pattern organized on a two-module network of either neuronal cell model or neural mass model, and analyze the impact of the conduction delay times, the connection densities, and coupling types. Our results show that delay times and coupling types can play key roles in this organization. The connection densities may have an influence on the stability if an anti-phase pattern exists due to the other factors. Furthermore, we show that anti-phase synchronization of slow oscillations can be achieved with small delay times if there is interaction between slow and fast oscillations. These results are significant for further understanding more realistic spatiotemporal dynamics of cortico-cortical communications. PMID:22232576

Effect of healing time on bone-implant contact of orthodontic micro-implants: a histologic study.

PubMed

Ramazanzadeh, Barat Ali; Fatemi, Kazem; Dehghani, Mahboobe; Mohtasham, Nooshin; Jahanbin, Arezoo; Sadeghian, Hamed

2014-01-01

Objectives. This study aimed to evaluate the effect of immediate and delayed loading of orthodontic micro-implants on bone-implant contact. Materials and Methods. Sixty four micro-implants were implanted in dog's jaw bone. The micro-implants were divided into loaded and unloaded (control) groups. The control group had two subgroups: four and eight weeks being implanted. The loaded group had two subgroups of immediate loading and delayed (after four weeks healing) loading. Loaded samples were subjected to 200g load for four weeks. After sacrificing the animals micro-implants and surrounding tissues were observed histologically. Bone-implant contact ratios (BIC) were calculated and different groups' results were compared by three-way ANOVA. Results. Mean survival rate was 96.7% in general. Survival rates were 96.7%, 94.4% and 100% for control, immediate and delayed loaded groups, respectively. BIC values were not significantly different in loaded and control groups, immediate and delayed loading groups, and pressure and tension sides. Mandibular micro-implants had significantly higher BIC than maxillary ones in immediate loading, 4-weeks control, and 8-weeks control groups (P = 0.021, P = 0.009, P = 0.003, resp.). Conclusion Immediate or delayed loading of micro-implants in dog did not cause significant difference in Bone-implant contact which could be concluded that healing time had not significant effect on micro-implant stability.

Effect of Healing Time on Bone-Implant Contact of Orthodontic Micro-Implants: A Histologic Study

PubMed Central

Ramazanzadeh, Barat Ali; Fatemi, Kazem; Dehghani, Mahboobe; Mohtasham, Nooshin; Jahanbin, Arezoo; Sadeghian, Hamed

2014-01-01

Objectives. This study aimed to evaluate the effect of immediate and delayed loading of orthodontic micro-implants on bone-implant contact. Materials and Methods. Sixty four micro-implants were implanted in dog's jaw bone. The micro-implants were divided into loaded and unloaded (control) groups. The control group had two subgroups: four and eight weeks being implanted. The loaded group had two subgroups of immediate loading and delayed (after four weeks healing) loading. Loaded samples were subjected to 200g load for four weeks. After sacrificing the animals micro-implants and surrounding tissues were observed histologically. Bone-implant contact ratios (BIC) were calculated and different groups' results were compared by three-way ANOVA. Results. Mean survival rate was 96.7% in general. Survival rates were 96.7%, 94.4% and 100% for control, immediate and delayed loaded groups, respectively. BIC values were not significantly different in loaded and control groups, immediate and delayed loading groups, and pressure and tension sides. Mandibular micro-implants had significantly higher BIC than maxillary ones in immediate loading, 4-weeks control, and 8-weeks control groups (P = 0.021, P = 0.009, P = 0.003, resp.). Conclusion Immediate or delayed loading of micro-implants in dog did not cause significant difference in Bone-implant contact which could be concluded that healing time had not significant effect on micro-implant stability. PMID:25006463

Familial diagnostic experiences in paediatric oncology.

PubMed

Evans, N T; Wakefield, C E; McLoone, J K; Cohn, R J

2015-01-06

Diagnostic delays may not have significant prognostic implications in paediatric oncology, but psychological impacts remain understudied. Interviews exploring diagnostic experiences were conducted with childhood cancer survivors (n=19), parents (n=78) and siblings (n=15). Median diagnostic time was 3 weeks. Participants described a mixture of rapid diagnoses (28.9%), plus delayed appraisal intervals (that is, parent- or patient-associated diagnostic delays; 40.0%) and diagnostic intervals (that is, healthcare-associated delays; 46.7%). Families experiencing delays described guilt and anger and deleterious impacts on the family-clinician relationship. Some believed delays impacted on treatment and prognosis. The effect of the diagnostic experience can be considerable.

Stochastic resonance in a time-delayed feedback tristable system and its application in fault diagnosis

NASA Astrophysics Data System (ADS)

Shi, Peiming; Yuan, Danzhen; Han, Dongying; Zhang, Ying; Fu, Rongrong

2018-06-01

Stochastic resonance (SR) phenomena in a time-delayed feedback tristable system driven by Gaussian white noise are investigated by simulating the potential function, mean first-passage time (MFPT), and signal-to-noise ratio (SNR) of the system. Through the use of a short delay time, the generalized potential function and stationary probability density function (PDF) are obtained. The delay feedback term has a significant effect on both equations, and that the parameters b, c, and d have different effects on the three wells of the potential function. The MFPT is calculated, which plays an extremely important role in research on particles escape rates. We find that the delay feedback term can affect the noise enhanced stability (NES). In addition, the SR characteristics are studied by the index of SNR. The simulation demonstrates that SNR is a non-monotonic distributed and that the peak SNR value can be attained by adjusting the appropriate parameters. Finally, the proposed theory is combined with a variable step method and applied to the detection of high frequencies in experiments. The result indicates that the fault frequency can be identified, and that the energy of the fault signal can be enhanced under suitable delay feedback parameters.

Integrated communication and control systems. I - Analysis

NASA Technical Reports Server (NTRS)

Halevi, Yoram; Ray, Asok

1988-01-01

The paper presents the results of an ICCS analysis focusing on discrete-time control systems subject to time-varying delays. The present analytical technique is applicable to integrated dynamic systems such as those encountered in advanced aircraft, spacecraft, and the real-time control of robots and machine tools via a high-speed network within an autonomous manufacturing environment. The significance of data latency and missynchronization between individual system components in ICCS networks is discussed in view of the time-varying delays.

Urban sprawl and delayed ambulance arrival in the U.S.

PubMed

Trowbridge, Matthew J; Gurka, Matthew J; O'Connor, Robert E

2009-11-01

Minimizing emergency medical service (EMS) response time is a central objective of prehospital care, yet the potential influence of built environment features such as urban sprawl on EMS system performance is often not considered. This study measures the association between urban sprawl and EMS response time to test the hypothesis that features of sprawling development increase the probability of delayed ambulance arrival. In 2008, EMS response times for 43,424 motor-vehicle crashes were obtained from the Fatal Analysis Reporting System, a national census of crashes involving > or =1 fatality. Sprawl at each crash location was measured using a continuous county-level index previously developed by Ewing et al. The association between sprawl and the probability of a delayed ambulance arrival (> or =8 minutes) was then measured using generalized linear mixed modeling to account for correlation among crashes from the same county. Urban sprawl is significantly associated with increased EMS response time and a higher probability of delayed ambulance arrival (p=0.03). This probability increases quadratically as the severity of sprawl increases while controlling for nighttime crash occurrence, road conditions, and presence of construction. For example, in sprawling counties (e.g., Fayette County GA), the probability of a delayed ambulance arrival for daytime crashes in dry conditions without construction was 69% (95% CI=66%, 72%) compared with 31% (95% CI=28%, 35%) in counties with prominent smart-growth characteristics (e.g., Delaware County PA). Urban sprawl is significantly associated with increased EMS response time and a higher probability of delayed ambulance arrival following motor-vehicle crashes in the U.S. The results of this study suggest that promotion of community design and development that follows smart-growth principles and regulates urban sprawl may improve EMS performance and reliability.

Micromachined silicon acoustic delay line with 3D-printed micro linkers and tapered input for improved structural stability and acoustic directivity

NASA Astrophysics Data System (ADS)

Cho, Y.; Kumar, A.; Xu, S.; Zou, J.

2016-10-01

Recent studies have shown that micromachined silicon acoustic delay lines can provide a promising solution to achieve real-time photoacoustic tomography without the need for complex transducer arrays and data acquisition electronics. To achieve deeper imaging depth and wider field of view, a longer delay time and therefore delay length are required. However, as the length of the delay line increases, it becomes more vulnerable to structural instability due to reduced mechanical stiffness. In this paper, we report the design, fabrication, and testing of a new silicon acoustic delay line enhanced with 3D printed polymer micro linker structures. First, mechanical deformation of the silicon acoustic delay line (with and without linker structures) under gravity was simulated by using finite element method. Second, the acoustic crosstalk and acoustic attenuation caused by the polymer micro linker structures were evaluated with both numerical simulation and ultrasound transmission testing. The result shows that the use of the polymer micro linker structures significantly improves the structural stability of the silicon acoustic delay lines without creating additional acoustic attenuation and crosstalk. In addition, the improvement of the acoustic acceptance angle of the silicon acoustic delay lines was also investigated to better suppress the reception of unwanted ultrasound signals outside of the imaging plane. These two improvements are expected to provide an effective solution to eliminate current limitations on the achievable acoustic delay time and out-of-plane imaging resolution of micromachined silicon acoustic delay line arrays.

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.

Effect of time between x-irradiation and chemotherapy on the growth of three solid mouse tumors. IV. Actinomycin-d

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

Twentyman, P.R.; Kallman, R.F.; Brown, J.M.

1979-09-01

Experiments have been carried out to determine the effect of different intervals between the administration of x-radiation (1200 rad) and actinomycin-D (200 ..mu..g/kg) on the growth delay produced in three mouse tumors. The tumors used were the EMT6 tumor in BALB/c mice and the KHT and RIF-1 sarcomas in C3H mice. All tumors were grown intramuscularly in the gastrocnemius muscle, and treatment was carried out at a mean tumor weight of 450 mg. Time to reach 2 x (for KHT) or 4 x (for EMT6 and RIF-1) treatment volume was used as the endpoint of response. The drug was administeredmore » intraperitoneally either 24, 6, or 2 hr before radiation, immediately before the start of radiation, or 3, 6, or 24 hr after radiation. All irradiations were carried out in unanesthetized mice. For a single administration at this dose level (close to the maximum tolerated dose) actinomycin-D did not produce a significant delay in the growth of any of the tumors. For the RIF-1 and KHT tumors, the growth delays produced by drug/radiation combinations generally were not significantly greater than that produced by irradiation alone. For the EMT6 tumor, great variability in the growth delays of combined modality groups seen, with mean growth delays significantly longer than predicted by the radiation alone data. No consistent dependence on timing between irradiation and drug administration was seen.« less

Teleoperation in surgical robotics--network latency effects on surgical performance.

PubMed

Lum, Mitchell J H; Rosen, Jacob; King, Hawkeye; Friedman, Diana C W; Lendvay, Thomas S; Wright, Andrew S; Sinanan, Mika N; Hannaford, Blake

2009-01-01

A teleoperated surgical robotic system allows surgical procedures to be conducted across long distances while utilizing wired and wireless communication with a wide spectrum of performance that may affect the outcome. An open architecture portable surgical robotic system (Raven) was developed for both open and minimally invasive surgery. The system has been the subject of an intensive telesurgical experimental protocol aimed at exploring the boundaries of the system and surgeon performance during a series of field experiments in extreme environments (desert and underwater) teleportation between US, Europe, and Japan as well as lab experiments under synthetic fixed time delay. One standard task (block transfer emulating tissue manipulation) of the Fundamentals of Laparoscopic Surgery (FLS) training kit was used for the experimental protocol. Network characterization indicated a typical time delay in the range of 16-172 ms in field experiments. The results of the lab experiments showed that the completion time of the task as well as the length of the tool tip trajectory significantly increased (alpha< 0.02) as time delay increased in the range of 0-0.5 sec increased. For teleoperation with a time delay of 0.25s and 0.5s the task completion time was lengthened by a factor of 1.45 and 2.04 with respect to no time delay, whereas the length of the tools' trajectory was increased by a factor of 1.28 and 1.53 with respect to no time delay. There were no statistical differences between experienced surgeons and non-surgeons in the number of errors (block drooping) as well as the completion time and the tool tip path length at different time delays.

The procrastinators want it now: Behavioral and event-related potential evidence of the procrastination of intertemporal choices.

PubMed

Wu, Haiyan; Gui, Danyang; Lin, Wenzheng; Gu, Ruolei; Zhu, Xiangru; Liu, Xun

2016-08-01

Much past research has focused on the correlation between procrastination and personality traits (e.g., impulsivity). According to the temporal motivation theory, procrastinators are impulsive and sensitive to delays in time. However, there is still a lack of direct evidence of the tendency of procrastinators to prefer immediate over future rewards. To investigate this question, we recorded event-related potentials (ERPs) in the brain while participants performed an intertemporal choice task involving both time delay and reward processing. The participants were assigned to a high procrastination group and a low procrastination group according to their scores on self-report measures. We found that high procrastination participants preferred immediate rewards compared to future ones whereas low procrastination participants did not. High procrastinators also exhibited a larger and delayed P2 component, indicating delay time processing and abnormal reward processing. No significant effect associated with procrastination was found on the P300 component. Taken together, these findings suggest that high procrastinators are more impulsive and encode the information of delay time more slowly but with a higher level of motivation-driven attention. The current study substantiates higher impulsivity in procrastination and verifies that a difference exists in the sensitivity to time delay between high and low procrastinators. Copyright © 2016 Elsevier Inc. All rights reserved.

Parenting Practices and Associations with Development Delays among Young Children in Dominican Republic.

PubMed

Uwemedimo, Omolara Thomas; Howlader, Afrin; Pierret, Giselina

According to the World Health Organization, >200 million children in low- and middle-income countries experience developmental delays. However, household structure and parenting practices have been minimally explored as potential correlates of developmental delay in low- and middle-income countries, despite potential as areas for intervention. The objective of the study was to examine associations of developmental delays with use of World Health Organization-recommended parenting practices among a clinic-based cohort of children aged 6-60 months attending in La Romana, Dominican Republic. This study was conducted among 74 caregiver-child pairs attending the growth-monitoring clinic at Hospital Francisco Gonzalvo in June 2015. The Malawi Developmental Assessment Tool was adapted and performed on each child to assess socioadaptive, fine motor, gross motor, and language development. The IMCI Household Level Survey Questionnaire was used to assess parenting practices. Fisher's exact test was used to determine associations significant at P < .05. Significant variables were then entered into a multivariable logistic regression. Almost two-thirds of children had a delay in at least 1 developmental domain. Most caregivers used scolding (43.2%) or spanking (44%) for child discipline. Children who were disciplined by spanking and scolding were more likely to have language delay (P = .007) and socioadaptive delay (P = .077), respectively. On regression analysis, children with younger primary caregivers had 7 times higher odds of language delay (adjusted odds ratio [AOR]: 7.35, 95% confidence interval [CI]: 1.52-35.61) and 4 times greater odds of any delay (AOR: 4.72, 95% CI: 1.01-22.22). In addition, children punished by spanking had 5 times higher odds of having language delay (AOR: 5.04, 95% CI: 1.13-22.39). Parenting practices such as harsh punishment and lack of positive parental reinforcement were found to have strong associations with language and socioadaptive delays. Likewise, delays were also more common among children with younger caregivers. Copyright © 2017 Icahn School of Medicine at Mount Sinai. Published by Elsevier Inc. All rights reserved.

Delays before Diagnosis and Initiation of Treatment in Patients Presenting to Mental Health Services with Bipolar Disorder

PubMed Central

Patel, Rashmi; Shetty, Hitesh; Jackson, Richard; Broadbent, Matthew; Stewart, Robert; Boydell, Jane; McGuire, Philip; Taylor, Matthew

2015-01-01

Background Bipolar disorder is a significant cause of morbidity and mortality. Although existing treatments are effective, there is often a substantial delay before diagnosis and treatment initiation. We sought to investigate factors associated with the delay before diagnosis of bipolar disorder and the onset of treatment in secondary mental healthcare. Method Retrospective cohort study using anonymised electronic mental health record data from the South London and Maudsley NHS Foundation Trust (SLaM) Biomedical Research Centre (BRC) Case Register on 1364 adults diagnosed with bipolar disorder between 2007 and 2012. The following predictor variables were analysed in a multivariable Cox regression analysis: age, gender, ethnicity, compulsory admission to hospital under the UK Mental Health Act, marital status and other diagnoses prior to bipolar disorder. The outcomes were time to recorded diagnosis from first presentation to specialist mental health services (the diagnostic delay), and time to the start of appropriate therapy (treatment delay). Results The median diagnostic delay was 62 days (interquartile range: 17–243) and median treatment delay was 31 days (4–122). Compulsory hospital admission was associated with a significant reduction in both diagnostic delay (hazard ratio 2.58, 95% CI 2.18–3.06) and treatment delay (4.40, 3.63–5.62). Prior diagnoses of other psychiatric disorders were associated with increased diagnostic delay, particularly alcohol (0.48, 0.33–0.41) and substance misuse disorders (0.44, 0.31–0.61). Prior diagnosis of schizophrenia and psychotic depression were associated with reduced treatment delay. Conclusions Some individuals experience a significant delay in diagnosis and treatment of bipolar disorder after initiation of specialist mental healthcare, particularly those who have prior diagnoses of alcohol and substance misuse disorders. These findings highlight a need for further study on strategies to better identify underlying symptoms and offer appropriate treatment sooner in order to facilitate improved clinical outcomes, such as developing specialist early intervention services to identify and treat people with bipolar disorder. PMID:25992560

Micromachined silicon parallel acoustic delay lines as time-delayed ultrasound detector array for real-time photoacoustic tomography

NASA Astrophysics Data System (ADS)

Cho, Y.; Chang, C.-C.; Wang, L. V.; Zou, J.

2016-02-01

This paper reports the development of a new 16-channel parallel acoustic delay line (PADL) array for real-time photoacoustic tomography (PAT). The PADLs were directly fabricated from single-crystalline silicon substrates using deep reactive ion etching. Compared with other acoustic delay lines (e.g., optical fibers), the micromachined silicon PADLs offer higher acoustic transmission efficiency, smaller form factor, easier assembly, and mass production capability. To demonstrate its real-time photoacoustic imaging capability, the silicon PADL array was interfaced with one single-element ultrasonic transducer followed by one channel of data acquisition electronics to receive 16 channels of photoacoustic signals simultaneously. A PAT image of an optically-absorbing target embedded in an optically-scattering phantom was reconstructed, which matched well with the actual size of the imaged target. Because the silicon PADL array allows a signal-to-channel reduction ratio of 16:1, it could significantly simplify the design and construction of ultrasonic receivers for real-time PAT.

Global exponential stability of inertial memristor-based neural networks with time-varying delays and impulses.

PubMed

Zhang, Wei; Huang, Tingwen; He, Xing; Li, Chuandong

2017-11-01

In this study, we investigate the global exponential stability of inertial memristor-based neural networks with impulses and time-varying delays. We construct inertial memristor-based neural networks based on the characteristics of the inertial neural networks and memristor. Impulses with and without delays are considered when modeling the inertial neural networks simultaneously, which are of great practical significance in the current study. Some sufficient conditions are derived under the framework of the Lyapunov stability method, as well as an extended Halanay differential inequality and a new delay impulsive differential inequality, which depend on impulses with and without delays, in order to guarantee the global exponential stability of the inertial memristor-based neural networks. Finally, two numerical examples are provided to illustrate the efficiency of the proposed methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

Delays in accessing electroconvulsive therapy: a comparison between two urban and two rural populations in Australia.

PubMed

Johnston, Natalie E

2015-10-01

A comparison of the timing, rates and characteristics of electroconvulsive therapy use between urban and rural populations. The medical records of patients who received an acute course of electroconvulsive therapy at two rural and two urban psychiatric hospitals in New South Wales (NSW), Australia, in 2010 were reviewed retrospectively. Main outcome measures were the time from symptom onset, diagnosis and admission to commencing electroconvulsive therapy. Rates of use of electroconvulsive therapy were also compared between rural and urban hospitals using NSW statewide data. There was a significant delay in the time it took for rural patients to receive electroconvulsive therapy compared with urban patients when measured both from the time of symptom onset and from when they received a diagnosis. There were corresponding delays in the time taken for rural patients to be admitted to hospital compared with urban patients. There was no difference in the time it took to commence electroconvulsive therapy once a patient was admitted to hospital. NSW statewide urban-rural comparisons showed rates of electroconvulsive therapy treatment were significantly higher in urban hospitals. Patients in rural areas receive electroconvulsive therapy later in their acute illness due to delays in being admitted to hospital. The rate of use of electroconvulsive therapy also differs geographically. © The Royal Australian and New Zealand College of Psychiatrists 2015.

In-Band Asymmetry Compensation for Accurate Time/Phase Transport over Optical Transport Network

PubMed Central

Siu, Sammy; Hu, Hsiu-fang; Lin, Shinn-Yan; Liao, Chia-Shu; Lai, Yi-Liang

2014-01-01

The demands of precise time/phase synchronization have been increasing recently due to the next generation of telecommunication synchronization. This paper studies the issues that are relevant to distributing accurate time/phase over optical transport network (OTN). Each node and link can introduce asymmetry, which affects the adequate time/phase accuracy over the networks. In order to achieve better accuracy, protocol level full timing support is used (e.g., Telecom-Boundary clock). Due to chromatic dispersion, the use of different wavelengths consequently causes fiber link delay asymmetry. The analytical result indicates that it introduces significant time error (i.e., phase offset) within 0.3397 ns/km in C-band or 0.3943 ns/km in L-band depending on the wavelength spacing. With the proposed scheme in this paper, the fiber link delay asymmetry can be compensated relying on the estimated mean fiber link delay by the Telecom-Boundary clock, while the OTN control plane is responsible for processing the fiber link delay asymmetry to determine the asymmetry compensation in the timing chain. PMID:24982948

Time from symptoms to definitive diagnosis of idiopathic pulmonary arterial hypertension: The delay study

PubMed Central

Strange, Geoff; Gabbay, Eli; Kermeen, Fiona; Williams, Trevor; Carrington, Melinda; Stewart, Simon; Keogh, Anne

2013-01-01

Survival rates for patients with idiopathic pulmonary arterial hypertension (IPAH) have improved with the introduction of PAH-specific therapies. However, the time between patient-reported onset of symptoms and a definitive diagnosis of IPAH is consistently delayed. We conducted a retrospective, multi-center, descriptive investigation in order to (a) understand what factors contribute to persistent diagnostic delays, and (b) examine the time from initial symptom onset to a definitive diagnosis of IPAH. Between January 2007 and December 2008, we enrolled consecutively diagnosed adults with IPAH from four tertiary referral centers in Australia. Screening of patient records and “one-on-one” interviews were used to determine the time from patient-described initial symptoms to a diagnosis of IPAH, confirmed by right heart catheterization (RHC). Thirty-two participants (69% female) were studied. Mean age at symptom onset was 56 ± 16.4 years and 96% reported exertional dyspnea. Mean time from symptom onset to diagnosis was 47 ± 34 months with patients subsequently aged 60 ± 17.3 years. Patients reported 5.3 ± 3.8 GP visits and 3.0 ± 2.1 specialist reviews before being seen at a pulmonary hypertension (PH) center. Advanced age, number of general practitioner (GP) visits, heart rate, and systolic blood pressure at the time of diagnosis were significantly associated with the observed delay. We found a significant delay of 3.9 years from symptom onset to a diagnosis of IPAH in Australia. Exertional dyspnea is the most common presenting symptom. Current practice within Australia does not appear to have the specific capacity for timely, multi-factorial evaluation of breathlessness and potential IPAH. PMID:23662179

Reducing Communication Delays and Improving Quality of Care with a Tuberculosis Laboratory Information System in Resource Poor Environments: A Cluster Randomized Controlled Trial

PubMed Central

Blaya, Joaquín A.; Shin, Sonya S.; Yagui, Martin; Contreras, Carmen; Cegielski, Peter; Yale, Gloria; Suarez, Carmen; Asencios, Luis; Bayona, Jaime; Kim, Jihoon; Fraser, Hamish S. F.

2014-01-01

Background Lost, delayed or incorrect laboratory results are associated with delays in initiating treatment. Delays in treatment for Multi-Drug Resistant Tuberculosis (MDR-TB) can worsen patient outcomes and increase transmission. The objective of this study was to evaluate the impact of a laboratory information system in reducing delays and the time for MDR-TB patients to culture convert (stop transmitting). Methods Setting: 78 primary Health Centers (HCs) in Lima, Peru. Participants lived within the catchment area of participating HCs and had at least one MDR-TB risk factor. The study design was a cluster randomized controlled trial with baseline data. The intervention was the e-Chasqui web-based laboratory information system. Main outcome measures were: times to communicate a result; to start or change a patient's treatment; and for that patient to culture convert. Results 1671 patients were enrolled. Intervention HCs took significantly less time to receive drug susceptibility test (DST) (median 11 vs. 17 days, Hazard Ratio 0.67 [0.62–0.72]) and culture (5 vs. 8 days, 0.68 [0.65–0.72]) results. The time to treatment was not significantly different, but patients in intervention HCs took 16 days (20%) less time to culture convert (p = 0.047). Conclusions The eChasqui system reduced the time to communicate results between laboratories and HCs and time to culture conversion. It is now used in over 259 HCs covering 4.1 million people. This is the first randomized controlled trial of a laboratory information system in a developing country for any disease and the only study worldwide to show clinical impact of such a system. Trial Registration ClinicalTrials.gov NCT01201941 PMID:24721980

Reducing communication delays and improving quality of care with a tuberculosis laboratory information system in resource poor environments: a cluster randomized controlled trial.

PubMed

Blaya, Joaquín A; Shin, Sonya S; Yagui, Martin; Contreras, Carmen; Cegielski, Peter; Yale, Gloria; Suarez, Carmen; Asencios, Luis; Bayona, Jaime; Kim, Jihoon; Fraser, Hamish S F

2014-01-01

Lost, delayed or incorrect laboratory results are associated with delays in initiating treatment. Delays in treatment for Multi-Drug Resistant Tuberculosis (MDR-TB) can worsen patient outcomes and increase transmission. The objective of this study was to evaluate the impact of a laboratory information system in reducing delays and the time for MDR-TB patients to culture convert (stop transmitting). 78 primary Health Centers (HCs) in Lima, Peru. Participants lived within the catchment area of participating HCs and had at least one MDR-TB risk factor. The study design was a cluster randomized controlled trial with baseline data. The intervention was the e-Chasqui web-based laboratory information system. Main outcome measures were: times to communicate a result; to start or change a patient's treatment; and for that patient to culture convert. 1671 patients were enrolled. Intervention HCs took significantly less time to receive drug susceptibility test (DST) (median 11 vs. 17 days, Hazard Ratio 0.67 [0.62-0.72]) and culture (5 vs. 8 days, 0.68 [0.65-0.72]) results. The time to treatment was not significantly different, but patients in intervention HCs took 16 days (20%) less time to culture convert (p = 0.047). The eChasqui system reduced the time to communicate results between laboratories and HCs and time to culture conversion. It is now used in over 259 HCs covering 4.1 million people. This is the first randomized controlled trial of a laboratory information system in a developing country for any disease and the only study worldwide to show clinical impact of such a system. ClinicalTrials.gov NCT01201941.

Association of educational level with delay of prehospital care before reperfusion in STEMI.

PubMed

Heo, Ju Yeon; Hong, Ki Jeong; Shin, Sang Do; Song, Kyoung Jun; Ro, Young Sun

2015-12-01

Rapid access to reperfusion is important in ST-segment elevation myocardial infarction (STEMI). The goal of this study is to assess the association of the educational level of patients with STEMI and prehospital and inhospital delay before reperfusion. We used a nationwide database of 31 emergency departments for cardiovascular disease surveillance operated by the Korean Centers for Disease Control and Prevention. ST-segment elevation myocardial infarction cases registered from November 2007 to December 2012 were enrolled. Cases younger than 18 years old or missing educational history were excluded. Educational level was characterized as low (completion of elementary school or less), medium (completion of middle or high school), and high (completion of a bachelor's degree or higher). We compared prehospital and inhospital delay for 3 educational groups. A general linear regression was used to assess the association of educational level with the time from symptom to hospital arrival. A total of 9028 patients with STEMI were included. The median time from symptom to hospital arrival was 144, 76, and 68 minutes in the low, medium, and high education groups, respectively (P < .01). Educational level had no significant effect on the door-to-balloon time. Low and medium education groups experienced significant delays of symptom to hospital to high education group (low: β = 27.2 minutes; 95% confidence interval, 15.9-38.5; medium: β = 19.1 minutes; 95% confidence interval, 15.9-38.5). In patients with STEMI, the time from symptom to hospital arrival increased as educational level decreased, but educational level had no significant association with the inhospital delay to reperfusion. Copyright © 2015 Elsevier Inc. All rights reserved.

Interpreting the Strongly Lensed Supernova iPTF16geu: Time Delay Predictions, Microlensing, and Lensing Rates

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

More, Anupreeta; Oguri, Masamune; More, Surhud

2017-02-01

We present predictions for time delays between multiple images of the gravitationally lensed supernova, iPTF16geu, which was recently discovered from the intermediate Palomar Transient Factory (iPTF). As the supernova is of Type Ia where the intrinsic luminosity is usually well known, accurately measured time delays of the multiple images could provide tight constraints on the Hubble constant. According to our lens mass models constrained by the Hubble Space Telescope F814W image, we expect the maximum relative time delay to be less than a day, which is consistent with the maximum of 100 hr reported by Goobar et al. but placesmore » a stringent upper limit. Furthermore, the fluxes of most of the supernova images depart from expected values suggesting that they are affected by microlensing. The microlensing timescales are small enough that they may pose significant problems to measure the time delays reliably. Our lensing rate calculation indicates that the occurrence of a lensed SN in iPTF is likely. However, the observed total magnification of iPTF16geu is larger than expected, given its redshift. This may be a further indication of ongoing microlensing in this system.« less

Preventing Delays in First-Case Starts on the Neurosurgery Service: A Resident-Led Initiative at an Academic Institution.

PubMed

Han, Seunggu J; Rolston, John D; Zygourakis, Corinna C; Sun, Matthew Z; McDermott, Michael W; Lau, Catherine Y; Aghi, Manish K

2016-01-01

On-time starts for the first case of the day are critical to maintaining efficiency in operating rooms (ORs). We studied whether a resident-led initiative to ensure on-time site marking and documentation of surgical consent could lead to improved first-case start time. In a resident-led initiative at a large 600-bed academic hospital with 25 ORs, we aimed to complete site marking and surgical consents half an hour before the scheduled start time for all first-case neurosurgical patients. We monitored the occurrence of delayed first starts and the length of delay during our initiative, and compared these cases to neurosurgical cases 3 months before the implementation of the initiative and to first-start nonneurosurgical cases. In the year of the initiative, both site marking and surgical consents were completed 30 minutes before the case start in 97% of neurosurgical cases. The average delay across all first-case starts was reduced to 7.17 minutes (N = 1271), compared with 9.67 minutes before the intervention (N = 345). During the study period, non-neurosurgical cases were delayed on average 10.3 minutes (N = 3592). There was a significant difference in latencies between the study period and the period before the initiative (p < 0.001), and also between neurosurgical cases and nonneurosurgical cases (p < 0.001). There was no reduction in delay times seen on the non-neurosurgical services in the study period when compared to the case 3 months before. Considering its effect across 1271 cases, this initiative over 1 year resulted in a total reduction of 52 hours and 57 minutes in delays. Through a resident-led quality improvement program, neurosurgical trainees successfully reduced delays in first-case starts on a surgical service. Engaging physician trainees in quality improvement and enhancing OR efficiency can be successfully achieved and can have a significant clinical and financial effect. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Delay activity of saccade-related neurons in the caudal dentate nucleus of the macaque cerebellum

PubMed Central

Sommer, Marc A.

2013-01-01

The caudal dentate nucleus (DN) in lateral cerebellum is connected with two visual/oculomotor areas of the cerebrum: the frontal eye field and lateral intraparietal cortex. Many neurons in frontal eye field and lateral intraparietal cortex produce “delay activity” between stimulus and response that correlates with processes such as motor planning. Our hypothesis was that caudal DN neurons would have prominent delay activity as well. From lesion studies, we predicted that this activity would be related to self-timing, i.e., the triggering of saccades based on the internal monitoring of time. We recorded from neurons in the caudal DN of monkeys (Macaca mulatta) that made delayed saccades with or without a self-timing requirement. Most (84%) of the caudal DN neurons had delay activity. These neurons conveyed at least three types of information. First, their activity was often correlated, trial by trial, with saccade initiation. Correlations were found more frequently in a task that required self-timing of saccades (53% of neurons) than in a task that did not (27% of neurons). Second, the delay activity was often tuned for saccade direction (in 65% of neurons). This tuning emerged continuously during a trial. Third, the time course of delay activity associated with self-timed saccades differed significantly from that associated with visually guided saccades (in 71% of neurons). A minority of neurons had sensory-related activity. None had presaccadic bursts, in contrast to DN neurons recorded more rostrally. We conclude that caudal DN neurons convey saccade-related delay activity that may contribute to the motor preparation of when and where to move. PMID:23365182

SU-E-J-141: Assessment of the Magnitude and Impact of Trigger Delay in Respiratory Triggered Real-Time Imaging during Radiotherapy.

PubMed

Duan, J; Shen, S; Popple, R; Wu, X; Cardan, R; Brezovich, I

2012-06-01

To assess the trigger delay in respiratory triggered real-time imaging and its impact on image guided radiotherapy (IGRT) with Varian TrueBeam System. A sinusoidal motion phantom with 2cm motion amplitude was used. The trigger delay was determined directly with video image, and indirectly by the distance between expected and actual triggering phantom positions. For the direct method, a fluorescent screen was placed on the phantom to visualize the x-ray. The motion of the screen was recorded at 60 frames/second. The number of frames between the time when the phantom reached expected triggering position and the time when the screen was illuminated by the x-ray was used to determine the trigger delay. In the indirect method, triggered kV x-ray images were acquired in real-time during 'treatment' with triggers set at 25% and 75% respiratory phases where the phantom moved at the maximum speed. 39-40 triggered images were acquired continuously in each series. The distance between the expected and actual triggering points, d, was measured on the images to determine the delay time t by d=Asin(wt), where w=2π/T, T=period and A=amplitude. Motion periods of 2s and 4s were used in the measurement. The trigger delay time determined with direct video imaging was 125ms (7.5 video frames). The average distance between the expected and actual triggering positions determined by the indirect method was 3.93±0.74mm for T=4s and 7.02±1.25mm for T=2s, yielding mean trigger delay times of 126±24ms and 120±22ms, respectively. Although the mean over-travel distance is significant at 25% and 75% phases, clinically, the target over-travel resulted from the trigger delay at the end of expiration (50% phase) is negligibly small(< 0.5mm). The trigger delay in respiration-triggered imaging is in the range of 120-126ms. This delay has negligible clinical effect on gated IGRT. © 2012 American Association of Physicists in Medicine.

Delayed extubation to nasal continuous positive airway pressure in the immature baboon model of bronchopulmonary dysplasia: lung clinical and pathological findings.

PubMed

Thomson, Merran A; Yoder, Bradley A; Winter, Vicki T; Giavedoni, Luis; Chang, Ling Yi; Coalson, Jacqueline J

2006-11-01

Using the 125-day baboon model of bronchopulmonary dysplasia treated with prenatal steroid and exogenous surfactant, we hypothesized that a delay of extubation from low tidal volume positive pressure ventilation to nasal continuous positive airway pressure at 5 days (delayed nasal continuous positive airway pressure group) would not induce more lung injury when compared with baboons aggressively weaned to nasal continuous positive airway pressure at 24 hours (early nasal continuous positive airway pressure group), because both received positive pressure ventilation. After delivery by cesarean section at 125 days (term: 185 days), infants received 2 doses of Curosurf (Chiesi Farmaceutica S.p.A., Parma, Italy) and daily caffeine citrate. The delay in extubation to 5 days resulted in baboons in the delayed nasal continuous positive airway pressure group having a lower arterial to alveolar oxygen ratio, high PaCO2, and worse respiratory function. The animals in the delayed nasal continuous positive airway pressure group exhibited a poor respiratory drive that contributed to more reintubations and time on mechanical ventilation. A few animals in both groups developed necrotizing enterocolitis and/or sepsis, but infectious pneumonias were not documented. Cellular bronchiolitis and peribronchiolar alveolar wall thickening were more frequently seen in the delayed nasal continuous positive airway pressure group. Bronchoalveolar lavage levels of interleukin-6, interleukin-8, monocyte chemotactic protein-1, macrophage inflammatory protein-1 alpha, and growth-regulated oncogene-alpha were significantly increased in the delayed nasal continuous positive airway pressure group. Standard and digital morphometric analyses showed no significant differences in internal surface area and nodal measurements between the groups. Platelet endothelial cell adhesion molecule vascular staining was not significantly different between the 2 nasal continuous positive airway pressure groups. Volutrauma and/or low-grade colonization of airways secondary to increased reintubations and ventilation times are speculated to play causative roles in the delayed nasal continuous positive airway pressure group findings.

The MMSE orientation for time domain is a strong predictor of subsequent cognitive decline in the elderly.

PubMed

Guerrero-Berroa, Elizabeth; Luo, Xiaodong; Schmeidler, James; Rapp, Michael A; Dahlman, Karen; Grossman, Hillel T; Haroutunian, Vahram; Beeri, Michal Schnaider

2009-12-01

The mini-mental state exam (MMSE) has been used to address questions such as determination of appropriate cutoff scores for differentiation of individuals with intact cognitive function from patients with dementia and rate of cognitive decline. However, little is known about the relationship of performance in specific cognitive domains to subsequent overall decline. To examine the specific and/or combined contribution of four MMSE domains (orientation for time, orientation for place, delayed recall, and attention) to prediction of overall cognitive decline on the MMSE. Linear mixed models were applied to 505 elderly nursing home residents (mean age = 85, > 12 years education = 27%; 79% F, mean follow-up = 3.20 years) to examine the relationship between baseline scores of these domains and total MMSE scores over time. Orientation for time was the only domain significantly associated with MMSE decline over time. Combination of poor delayed recall with either attention or orientation for place was associated with significantly increased decline on the MMSE. The MMSE orientation for time predicts overall decline on MMSE scores over time. A good functioning domain added to good functioning delayed recall was associated with slower rate of decline. Copyright (c) 2009 John Wiley & Sons, Ltd.

A high-resolution time-to-digital converter using a three-level resolution

NASA Astrophysics Data System (ADS)

Dehghani, Asma; Saneei, Mohsen; Mahani, Ali

2016-08-01

In this article, a three-level resolution Vernier delay line time-to-digital converter (TDC) was proposed. The proposed TDC core was based on the pseudo-differential digital architecture that made it insensitive to nMOS and pMOS transistor mismatches. It also employed a Vernier delay line (VDL) in conjunction with an asynchronous read-out circuitry. The time interval resolution was equal to the difference of delay between buffers of upper and lower chains. Then, via the extra chain included in the lower delay line, resolution was controlled and power consumption was reduced. This method led to high resolution and low power consumption. The measurement results of TDC showed a resolution of 4.5 ps, 12-bit output dynamic range, and integral nonlinearity of 1.5 least significant bits. This TDC achieved the consumption of 68.43 µW from 1.1-V supply.

Obtaining Reliable Predictions of Terrestrial Energy Coupling From Real-Time Solar Wind Measurement

NASA Technical Reports Server (NTRS)

Weimer, Daniel R.

2001-01-01

The first draft of a manuscript titled "Variable time delays in the propagation of the interplanetary magnetic field" has been completed, for submission to the Journal of Geophysical Research. In the preparation of this manuscript all data and analysis programs had been updated to the highest temporal resolution possible, at 16 seconds or better. The program which computes the "measured" IMF propagation time delays from these data has also undergone another improvement. In another significant development, a technique has been developed in order to predict IMF phase plane orientations, and the resulting time delays, using only measurements from a single satellite at L1. The "minimum variance" method is used for this computation. Further work will be done on optimizing the choice of several parameters for the minimum variance calculation.

Mass Media Campaigns' Influence on Prehospital Behavior for Acute Coronary Syndromes: An Evaluation of the Australian Heart Foundation's Warning Signs Campaign.

PubMed

Bray, Janet E; Stub, Dion; Ngu, Philip; Cartledge, Susie; Straney, Lahn; Stewart, Michelle; Keech, Wendy; Patsamanis, Harry; Shaw, James; Finn, Judith

2015-07-06

The aim of this study was to examine the awareness of a recent mass media campaign, and its influence on knowledge and prehospital times, in a cohort of acute coronary syndrome (ACS) patients admitted to an Australian hospital. We conducted 199 semistructured interviews with consecutive ACS patients who were aged 35 to 75 years, competent to provide consent, and English speaking. Questions addressed the factors known to predict prehospital delay, awareness of the campaign, and whether it increased knowledge and influenced actions. Multivariable logistic regression was used to examine the association between campaign awareness and a 1-hour delay in deciding to seek medical attention (patient delay) and a 2-hour delay in presenting to hospital (prehospital delay). The median age was 62 years (IQR=53 to 68 years), and 68% (n=136) were male. Awareness of the campaign was reported by 127 (64%) patients, with most of these patients stating the campaign (1) increased their understanding of what is a heart attack (63%), (2) increased their awareness of the signs and symptoms of heart attack (68%), and (3) influenced their actions in response to symptoms (43%). After adjustment for other predictors, awareness of the campaign was significantly associated with patient delay time of ≤1 hour (adjusted odds ratio [AOR]=2.25, 95% CI: 1.03 to 4.91, P=0.04) and prehospital delay time ≤2 hours (AOR=3.11, 95% CI: 1.36 to 7.08, P=0.007). Our study showed reasonably high awareness of the warning signs campaign, which was significantly associated with shorter prehospital decision-making and faster presentation to hospital. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Tolerable hearing-aid delays: IV. effects on subjective disturbance during speech production by hearing-impaired subjects.

PubMed

Stone, Michael A; Moore, Brian C J

2005-04-01

We assessed the effects of time delay in a hearing aid on subjective disturbance and reading rates while the user of the aid was speaking, using hearing-impaired subjects and real-time processing. The time delay was constant across frequency. A digital signal processor was programmed as a four-channel, fast-acting, wide-dynamic-range compression hearing aid. One of four delays could be selected on the aid to produce a total delay of 13, 21, 30, or 40 msec between microphone and receiver. Twenty-five subjects, mostly with near-symmetric hearing impairment of cochlear origin, were fitted bilaterally with behind-the-ear aids connected to the processor. The aids were programmed with insertion gains prescribed by the CAMEQ loudness equalization procedure for each subject and ear. Subjects were asked to read aloud from scripts: speech production rates were measured and subjective ratings of the disturbance of the delay were obtained. Subjects required some training to recognize the effects of the delay to rate it consistently. Subjective disturbance increased progressively with increasing delay and was a nonmonotonic function of low-frequency hearing loss. Subjects with mild or severe low-frequency hearing loss were generally less disturbed by the delay than those with moderate loss. Disturbance ratings tended to decrease over successive tests. Word production rates were not significantly affected by delay over the range of delays tested. The results follow a pattern similar to those presented in , obtained using a simulation of hearing loss and normally hearing subjects, except for the nonmonotonic variation of disturbance with low-frequency hearing loss. We hypothesize that disturbance is maximal when the levels in the ear canal of the low-frequency components are similar for the unaided and aided sounds. A rating of 3, which is probably just acceptable, was obtained for delays ranging from 14 to 30 msec, depending on the hearing loss. Some acclimatization to the subjective disturbance occurred over a time scale of about 1 hour.

Virtual Design of a Controller for a Hydraulic Cam Phasing System

NASA Astrophysics Data System (ADS)

Schneider, Markus; Ulbrich, Heinz

2010-09-01

Hydraulic vane cam phasing systems are nowadays widely used for improving the performance of combustion engines. At stationary operation, these systems should achieve a constant phasing angle, which however is badly disturbed by the alternating torque generated by the valve actuation. As the hydraulic system shows a non-linear characteristic over the full operation range and the inductivity of the hydraulic pipes generates a significant time delay, a full model based control emerges very complex. Therefore a simple feed-forward controller is designed, bridging the time delay of the hydraulic system and improving the system behaviour significantly.

Risk factors for delay in symptomatic presentation: a survey of cancer patients

PubMed Central

Forbes, L J L; Warburton, F; Richards, M A; Ramirez, A J

2014-01-01

Background: Delay in symptomatic presentation leading to advanced stage at diagnosis may contribute to poor cancer survival. To inform public health approaches to promoting early symptomatic presentation, we aimed to identify risk factors for delay in presentation across several cancers. Methods: We surveyed 2371 patients with 15 cancers about nature and duration of symptoms using a postal questionnaire. We calculated relative risks for delay in presentation (time from symptom onset to first presentation >3 months) by cancer, symptoms leading to diagnosis and reasons for putting off going to the doctor, controlling for age, sex and deprivation group. Results: Among 1999 cancer patients reporting symptoms, 21% delayed presentation for >3 months. Delay was associated with greater socioeconomic deprivation but not age or sex. Patients with prostate (44%) and rectal cancer (37%) were most likely to delay and patients with breast cancer least likely to delay (8%). Urinary difficulties, change of bowel habit, systemic symptoms (fatigue, weight loss and loss of appetite) and skin symptoms were all common and associated with delay. Overall, patients with bleeding symptoms were no more likely to delay presentation than patients who did not have bleeding symptoms. However, within the group of patients with bleeding symptoms, there were significant differences in risk of delay by source of bleeding: 35% of patients with rectal bleeding delayed presentation, but only 9% of patients with urinary bleeding. A lump was a common symptom but not associated with delay in presentation. Twenty-eight percent had not recognised their symptoms as serious and this was associated with a doubling in risk of delay. Embarrassment, worry about what the doctor might find, being too busy to go to the doctor and worry about wasting the doctor's time were also strong risk factors for delay, but were much less commonly reported (<6%). Interpretation: Approaches to promote early presentation should aim to increase awareness of the significance of cancer symptoms and should be designed to work for people of the lowest socioeconomic status. In particular, awareness that rectal bleeding is a possible symptom of cancer should be raised. PMID:24918824

Complementary and alternative medicine (CAM) use and delays in presentation and diagnosis of breast cancer patients in public hospitals in Malaysia.

PubMed

Mohd Mujar, Noor Mastura; Dahlui, Maznah; Emran, Nor Aina; Abdul Hadi, Imisairi; Wai, Yan Yang; Arulanantham, Sarojah; Hooi, Chea Chan; Mohd Taib, Nur Aishah

2017-01-01

Complementary and alternative medicine (CAM) is widely used among the breast cancer patients in Malaysia. Delays in presentation, diagnosis and treatment have been shown to impact the disease prognosis. There is considerable use of CAM amongst breast cancer patients. CAM use has been cited as a cause of delay in diagnosis and treatments in qualitative studies, however there had not been any confirmatory study that confirms its impact on delays. The purpose of this study was to evaluate whether the use of CAM among newly diagnosed breast cancer patients was associated with delays in presentation, diagnosis or treatment of breast cancer. This multi-centre cross-sectional study evaluating the time points of the individual breast cancer patients' journey from first visit, resolution of diagnosis and treatments was conducted in six public hospitals in Malaysia. All newly diagnosed breast cancer patients from 1st January to 31st December 2012 were recruited. Data were collected through medical records review and patient interview by using a structured questionnaire. Complementary and alternative medicine (CAM) was defined as the use of any methods and products not included in conventional allopathic medicine before commencement of treatments. Presentation delay was defined as time taken from symptom discovery to first presentation of more than 3 months. The time points were categorised to diagnosis delay was defined as time taken from first presentation to diagnosis of more than 1 month and treatment delay was defined as time taken from diagnosis to initial treatment of more than 1 month. Multiple logistic regression was used for analysis. A total number of 340 patients participated in this study. The prevalence of CAM use was 46.5% (n = 158). Malay ethnicity (OR 3.32; 95% CI: 1.85, 5.97) and not interpreting symptom as cancerous (OR 1.79; 95% CI: 1.10, 2.92) were significantly associated with CAM use. The use of CAM was associated with delays in presentation (OR 1.65; 95% CI: 1.05, 2.59), diagnosis (OR 2.42; 95% CI: 1.56, 3.77) and treatment of breast cancer (OR 1.74; 95% CI: 1.11, 2.72) on univariate analyses. However, after adjusting with other covariates, CAM use was associated with delays in presentation (OR 1.71; 95% CI: 1.05, 2.78) and diagnosis (OR 2.58; 95% CI: 1.59, 4.17) but not for treatment of breast cancer (OR 1.58; 95% CI: 0.98, 2.55). The prevalence of CAM use among the breast cancer patients was high. Women of Malay ethnicity and not interpreting symptom as cancerous were significantly associated with CAM use. The use of CAM is significantly associated with delay in presentation and resolution of diagnosis. This study suggests further evaluation of access to breast cancer care is needed as poor access may cause the use of CAM. However, since public hospitals in Malaysia are heavily subsidized and readily available to the population, CAM use may impact delays in presentation and diagnosis.

Complementary and alternative medicine (CAM) use and delays in presentation and diagnosis of breast cancer patients in public hospitals in Malaysia

PubMed Central

Emran, Nor Aina; Abdul Hadi, Imisairi; Wai, Yan Yang; Arulanantham, Sarojah; Hooi, Chea Chan

2017-01-01

Complementary and alternative medicine (CAM) is widely used among the breast cancer patients in Malaysia. Delays in presentation, diagnosis and treatment have been shown to impact the disease prognosis. There is considerable use of CAM amongst breast cancer patients. CAM use has been cited as a cause of delay in diagnosis and treatments in qualitative studies, however there had not been any confirmatory study that confirms its impact on delays. The purpose of this study was to evaluate whether the use of CAM among newly diagnosed breast cancer patients was associated with delays in presentation, diagnosis or treatment of breast cancer. This multi-centre cross-sectional study evaluating the time points of the individual breast cancer patients’ journey from first visit, resolution of diagnosis and treatments was conducted in six public hospitals in Malaysia. All newly diagnosed breast cancer patients from 1st January to 31st December 2012 were recruited. Data were collected through medical records review and patient interview by using a structured questionnaire. Complementary and alternative medicine (CAM) was defined as the use of any methods and products not included in conventional allopathic medicine before commencement of treatments. Presentation delay was defined as time taken from symptom discovery to first presentation of more than 3 months. The time points were categorised to diagnosis delay was defined as time taken from first presentation to diagnosis of more than 1 month and treatment delay was defined as time taken from diagnosis to initial treatment of more than 1 month. Multiple logistic regression was used for analysis. A total number of 340 patients participated in this study. The prevalence of CAM use was 46.5% (n = 158). Malay ethnicity (OR 3.32; 95% CI: 1.85, 5.97) and not interpreting symptom as cancerous (OR 1.79; 95% CI: 1.10, 2.92) were significantly associated with CAM use. The use of CAM was associated with delays in presentation (OR 1.65; 95% CI: 1.05, 2.59), diagnosis (OR 2.42; 95% CI: 1.56, 3.77) and treatment of breast cancer (OR 1.74; 95% CI: 1.11, 2.72) on univariate analyses. However, after adjusting with other covariates, CAM use was associated with delays in presentation (OR 1.71; 95% CI: 1.05, 2.78) and diagnosis (OR 2.58; 95% CI: 1.59, 4.17) but not for treatment of breast cancer (OR 1.58; 95% CI: 0.98, 2.55). The prevalence of CAM use among the breast cancer patients was high. Women of Malay ethnicity and not interpreting symptom as cancerous were significantly associated with CAM use. The use of CAM is significantly associated with delay in presentation and resolution of diagnosis. This study suggests further evaluation of access to breast cancer care is needed as poor access may cause the use of CAM. However, since public hospitals in Malaysia are heavily subsidized and readily available to the population, CAM use may impact delays in presentation and diagnosis. PMID:28448541

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

PubMed Central

Silverberg, Sarah L.

2018-01-01

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

Dynamical regimes and intracavity propagation delay in external cavity semiconductor diode lasers

NASA Astrophysics Data System (ADS)

Jayaprasath, E.; Sivaprakasam, S.

2017-11-01

Intracavity propagation delay, a delay introduced by a semiconductor diode laser, is found to significantly influence synchronization of multiple semiconductor diode lasers, operated either in stable or in chaotic regime. Two diode lasers coupled in unidirectional scheme is considered in this numerical study. A diode laser subjected to an optical feedback, also called an external cavity diode laser, acts as the transmitter laser (TL). A solitary diode laser acts as the receiver laser (RL). The optical output of the TL is coupled to the RL and laser operating parameters are optimized to achieve synchronization in their output intensities. The time-of-flight between the TL and RL introduces an intercavity time delay in the dynamics of RL. In addition to this, an intracavity propagation delay arises as the TL's field propagated within the RL. This intracavity propagation delay is evaluated by cross-correlation analysis between the output intensities of the lasers. The intracavity propagation delay is found to increase as the external cavity feedback rate of TL is increased, while an increment in the injection rate between the two lasers resulted in a reduction of intracavity propagation delay.

Evaluation of performance of distributed delay model for chemotherapy-induced myelosuppression.

PubMed

Krzyzanski, Wojciech; Hu, Shuhua; Dunlavey, Michael

2018-04-01

The distributed delay model has been introduced that replaces the transit compartments in the classic model of chemotherapy-induced myelosuppression with a convolution integral. The maturation of granulocyte precursors in the bone marrow is described by the gamma probability density function with the shape parameter (ν). If ν is a positive integer, the distributed delay model coincides with the classic model with ν transit compartments. The purpose of this work was to evaluate performance of the distributed delay model with particular focus on model deterministic identifiability in the presence of the shape parameter. The classic model served as a reference for comparison. Previously published white blood cell (WBC) count data in rats receiving bolus doses of 5-fluorouracil were fitted by both models. The negative two log-likelihood objective function (-2LL) and running times were used as major markers of performance. Local sensitivity analysis was done to evaluate the impact of ν on the pharmacodynamics response WBC. The ν estimate was 1.46 with 16.1% CV% compared to ν = 3 for the classic model. The difference of 6.78 in - 2LL between classic model and the distributed delay model implied that the latter performed significantly better than former according to the log-likelihood ratio test (P = 0.009), although the overall performance was modestly better. The running times were 1 s and 66.2 min, respectively. The long running time of the distributed delay model was attributed to computationally intensive evaluation of the convolution integral. The sensitivity analysis revealed that ν strongly influences the WBC response by controlling cell proliferation and elimination of WBCs from the circulation. In conclusion, the distributed delay model was deterministically identifiable from typical cytotoxic data. Its performance was modestly better than the classic model with significantly longer running time.

Effect of work intensity on time delay in mediation of ventilation by arterial carbon dioxide during recovery from impulse exercise.

PubMed

Afroundeh, R; Arimitsu, T; Yamanaka, R; Lian, C S; Shirakawa, K; Yunoki, T; Yano, T

2014-01-01

Time delay in the mediation of ventilation (V(.)E) by arterial CO(2) pressure (PaCO(2)) was studied during recovery from short impulse-like exercises with different work loads of recovery. Subjects performed two tests including 10-s impulse like exercise with work load of 200 watts and 15-min recovery with 25 watts in test one and 50 watts in test two. V(.)E, end tidal CO(2) pressure (PETCO(2)) and heart rate (HR) were measured continuously during rest, warming up, exercise and recovery. PaCO(2) was estimated from PETCO(2) and tidal volume (V(T)). Results showed that predicted arterial CO(2) pressure (PaCO(2 pre)) increased during recovery in both tests. In both tests, V(.)E increased and peaked at the end of exercise. V(.)E decreased in the first few seconds of recovery but started to increase again. The highest correlation coefficient between PaCO(2 pre) and V(.)E was obtained in the time delay of 7 s (r=0.854) in test one and in time delays of 6 s (r=0.451) and 31 s (r=0.567) in test two. HR was significantly higher in test two than in test one. These results indicate that PaCO(2 pre) drives V(.)E with a time delay and that higher work intensity induces a shorter time delay.

Spatio-temporal phenomena in complex systems with time delays

NASA Astrophysics Data System (ADS)

Yanchuk, Serhiy; Giacomelli, Giovanni

2017-03-01

Real-world systems can be strongly influenced by time delays occurring in self-coupling interactions, due to unavoidable finite signal propagation velocities. When the delays become significantly long, complicated high-dimensional phenomena appear and a simple extension of the methods employed in low-dimensional dynamical systems is not feasible. We review the general theory developed in this case, describing the main destabilization mechanisms, the use of visualization tools, and commenting on the most important and effective dynamical indicators as well as their properties in different regimes. We show how a suitable approach, based on a comparison with spatio-temporal systems, represents a powerful instrument for disclosing the very basic mechanism of long-delay systems. Various examples from different models and a series of recent experiments are reported.

Atrial electromechanical conduction delay in patients with neurocardiogenic syncope.

PubMed

Sucu, Murat; Ercan, Suleyman; Uku, Okkes; Davutoglu, Vedat; Altunbas, Gokhan

2014-05-01

We aimed to investigate the presence of atrial electromechanical conduction delay in patients with neurocardiogenic syncope, which was diagnosed with head-up tilt table test (HUTT). A total of 29 patients (mean age: 30.6 ± 15.9 years) with vasovagal syncope, as diagnosed by HUTT, and 23 healthy control subjects (mean age: 34.7 ± 16.3 years) with a negative HUTT were enrolled to the study. Atrial electromechanical conduction delay was defined as the time elapsed from the beginning of the P wave in the electrogardiogram to the beginning of the Am wave in tissue Doppler. There was no statistically significant difference between the groups in terms of interatrial conduction delay, whereas the difference was significant with regard to the right intraatrial electromechanical conduction delay (P < 0.01) and the left intraatrial electromechanical conduction delay (P < 0.0001). There was a negative correlation between the left intraatrial electromechanical conduction delay and the right intraatrial electromechanical conduction delay (r = -0.486, P = 0.001), whereas a positive correlation was present with the interatrial electromechanical conduction delay (r = 0.507, P = 0.001). In this study, the tissue Doppler method revealed that there is left and right intraatrial electromechanical conduction delay in patients with vasovagal syncope. The impact and role of atrial conduction delay as a pathophysiological determinant should be confirmed in further studies. ©2013 Wiley Periodicals, Inc.

High-resolution correlation

NASA Astrophysics Data System (ADS)

Nelson, D. J.

2007-09-01

In the basic correlation process a sequence of time-lag-indexed correlation coefficients are computed as the inner or dot product of segments of two signals. The time-lag(s) for which the magnitude of the correlation coefficient sequence is maximized is the estimated relative time delay of the two signals. For discrete sampled signals, the delay estimated in this manner is quantized with the same relative accuracy as the clock used in sampling the signals. In addition, the correlation coefficients are real if the input signals are real. There have been many methods proposed to estimate signal delay to more accuracy than the sample interval of the digitizer clock, with some success. These methods include interpolation of the correlation coefficients, estimation of the signal delay from the group delay function, and beam forming techniques, such as the MUSIC algorithm. For spectral estimation, techniques based on phase differentiation have been popular, but these techniques have apparently not been applied to the correlation problem . We propose a phase based delay estimation method (PBDEM) based on the phase of the correlation function that provides a significant improvement of the accuracy of time delay estimation. In the process, the standard correlation function is first calculated. A time lag error function is then calculated from the correlation phase and is used to interpolate the correlation function. The signal delay is shown to be accurately estimated as the zero crossing of the correlation phase near the index of the peak correlation magnitude. This process is nearly as fast as the conventional correlation function on which it is based. For real valued signals, a simple modification is provided, which results in the same correlation accuracy as is obtained for complex valued signals.

Multiobjective optimization model of intersection signal timing considering emissions based on field data: A case study of Beijing.

PubMed

Kou, Weibin; Chen, Xumei; Yu, Lei; Gong, Huibo

2018-04-18

Most existing signal timing models are aimed to minimize the total delay and stops at intersections, without considering environmental factors. This paper analyzes the trade-off between vehicle emissions and traffic efficiencies on the basis of field data. First, considering the different operating modes of cruising, acceleration, deceleration, and idling, field data of emissions and Global Positioning System (GPS) are collected to estimate emission rates for heavy-duty and light-duty vehicles. Second, multiobjective signal timing optimization model is established based on a genetic algorithm to minimize delay, stops, and emissions. Finally, a case study is conducted in Beijing. Nine scenarios are designed considering different weights of emission and traffic efficiency. The results compared with those using Highway Capacity Manual (HCM) 2010 show that signal timing optimized by the model proposed in this paper can decrease vehicles delay and emissions more significantly. The optimization model can be applied in different cities, which provides supports for eco-signal design and development. Vehicle emissions are heavily at signal intersections in urban area. The multiobjective signal timing optimization model is proposed considering the trade-off between vehicle emissions and traffic efficiencies on the basis of field data. The results indicate that signal timing optimized by the model proposed in this paper can decrease vehicle emissions and delays more significantly. The optimization model can be applied in different cities, which provides supports for eco-signal design and development.

School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature

PubMed Central

Chapman, Daniel P.; Croft, Janet B.

2015-01-01

BACKGROUND Insufficient sleep in adolescents has been shown to be associated with a wide variety of adverse outcomes, from poor mental and physical health to behavioral problems and lower academic grades. However, most high school students do not get sufficient sleep. Delaying school start times for adolescents has been proposed as a policy change to address insufficient sleep in this population and potentially to improve students’ academic performance, reduce engagement in risk behaviors, and improve health. METHODS This paper reviews 38 reports examining the association between school start times, sleep, and other outcomes among adolescent students. RESULTS Most studies reviewed provide evidence that delaying school start time increases weeknight sleep duration among adolescents, primarily by delaying rise times. Most of the studies saw a significant increase in sleep duration even with relatively small delays in start times of half an hour or so. Later start times also generally correspond to improved attendance, less tardiness, less falling asleep in class, better grades, and fewer motor vehicle crashes. CONCLUSIONS Although additional research is necessary, research results that are already available should be disseminated to stakeholders to enable the development of evidence-based school policies. PMID:27040474

The effects of delay duration on visual working memory for orientation.

PubMed

Shin, Hongsup; Zou, Qijia; Ma, Wei Ji

2017-12-01

We used a delayed-estimation paradigm to characterize the joint effects of set size (one, two, four, or six) and delay duration (1, 2, 3, or 6 s) on visual working memory for orientation. We conducted two experiments: one with delay durations blocked, another with delay durations interleaved. As dependent variables, we examined four model-free metrics of dispersion as well as precision estimates in four simple models. We tested for effects of delay time using analyses of variance, linear regressions, and nested model comparisons. We found significant effects of set size and delay duration on both model-free and model-based measures of dispersion. However, the effect of delay duration was much weaker than that of set size, dependent on the analysis method, and apparent in only a minority of subjects. The highest forgetting slope found in either experiment at any set size was a modest 1.14°/s. As secondary results, we found a low rate of nontarget reports, and significant estimation biases towards oblique orientations (but no dependence of their magnitude on either set size or delay duration). Relative stability of working memory even at higher set sizes is consistent with earlier results for motion direction and spatial frequency. We compare with a recent study that performed a very similar experiment.

Sleep deprivation decreases phase-shift responses of circadian rhythms to light in the mouse: role of serotonergic and metabolic signals.

PubMed

Challet, E; Turek, F W; Laute, M; Van Reeth, O

2001-08-03

The circadian pacemaker in the suprachiasmatic nuclei is primarily synchronized to the daily light-dark cycle. The phase-shifting and synchronizing effects of light can be modulated by non-photic factors, such as behavioral, metabolic or serotonergic cues. The present experiments examine the effects of sleep deprivation on the response of the circadian pacemaker to light and test the possible involvement of serotonergic and/or metabolic cues in mediating the effects of sleep deprivation. Photic phase-shifting of the locomotor activity rhythm was analyzed in mice transferred from a light-dark cycle to constant darkness, and sleep-deprived for 8 h from Zeitgeber Time 6 to Zeitgeber Time 14. Phase-delays in response to a 10-min light pulse at Zeitgeber Time 14 were reduced by 30% in sleep-deprived mice compared to control mice, while sleep deprivation without light exposure induced no significant phase-shifts. Stimulation of serotonin neurotransmission by fluoxetine (10 mg/kg), a serotonin reuptake inhibitor that decreases light-induced phase-delays in non-deprived mice, did not further reduce light-induced phase-delays in sleep-deprived mice. Impairment of serotonin neurotransmission with p-chloroamphetamine (three injections of 10 mg/kg), which did not increase light-induced phase-delays in non-deprived mice significantly, partially normalized light-induced phase-delays in sleep-deprived mice. Injections of glucose increased light-induced phase-delays in control and sleep-deprived mice. Chemical damage of the ventromedial hypothalamus by gold-thioglucose (600 mg/kg) prevented the reduction of light-induced phase-delays in sleep-deprived mice, without altering phase-delays in control mice. Taken together, the present results indicate that sleep deprivation can reduce the light-induced phase-shifts of the mouse suprachiasmatic pacemaker, due to serotonergic and metabolic changes associated with the loss of sleep.

Delay in surgery predisposes to meniscal and chondral injuries in anterior cruciate ligament deficient knees.

PubMed

Gupta, Ravi; Masih, Gladson David; Chander, Gaurav; Bachhal, Vikas

2016-09-01

Despite improvements in instability after anterior cruciate ligament (ACL) reconstruction, associated intraarticular injuries remain a major cause of concern and important prognostic factor for long term results as it may lead to osteoarthritis. Delay in ACL reconstruction has been in variably linked to increase in these injuries but there is lack of consensus regarding optimal timing of reconstruction. The goal of this study was to investigate delay in surgery and other factors, associated with intraarticular injuries in ACL deficient knees. A total of 438 patients (42 females; 396 males) enrolled for this prospective observational study. The average age of patients was 26.43 (range 17-51 years) years with a mean surgical delay of 78.91 (range 1 week - 18 years) weeks after injury. We analyzed the factors of age, sex, surgical delay, instability, and level of activity for possible association with intraarticular injuries. Medial meniscus injuries had a significant association with surgical delay ( P = 0.000) after a delay of 6 months. Lateral meniscus injuries had a significant association with degree of instability ( P = 0.001). Medial-sided articular injuries were significantly affected by age (0.005) with an odds ratio (OR) of 1.048 (95% confidence interval [CI] of 1.014-1.082) reflecting 4.8% rise in incidence with each year. Lateral-sided injuries were associated with female sex ( P = 0.018) with OR of 2.846 (95% CI of 1.200-6.752). The level of activity failed to reveal any significant associations. Surgical delay predicts an increase in medial meniscal and lateral articular injuries justifying early rather than delayed reconstruction in ACL deficient knees. Increasing age is positively related to intraarticular injuries while females are more susceptible to lateral articular injuries.

Corrections of stratified tropospheric delays in SAR interferometry: Validation with global atmospheric models

NASA Astrophysics Data System (ADS)

Doin, Marie-Pierre; Lasserre, Cécile; Peltzer, Gilles; Cavalié, Olivier; Doubre, Cécile

2010-05-01

The main limiting factor on the accuracy of Interferometric SAR measurements (InSAR) comes from phase propagation delays through the troposphere. The delay can be divided into a stratified component, which correlates with the topography and often dominates the tropospheric signal, and a turbulent component. We use Global Atmospheric Models (GAM) to estimate the stratified phase delay and delay-elevation ratio at epochs of SAR acquisitions, and compare them to observed phase delay derived from SAR interferograms. Three test areas are selected with different geographic and climatic environments and with large SAR archive available. The Lake Mead, Nevada, USA is covered by 79 ERS1/2 and ENVISAT acquisitions, the Haiyuan Fault area, Gansu, China, by 24 ERS1/2 acquisitions, and the Afar region, Republic of Djibouti, by 91 Radarsat acquisitions. The hydrostatic and wet stratified delays are computed from GAM as a function of atmospheric pressure P, temperature T, and water vapor partial pressure e vertical profiles. The hydrostatic delay, which depends on ratio P/T, varies significantly at low elevation and cannot be neglected. The wet component of the delay depends mostly on the near surface specific humidity. GAM predicted delay-elevation ratios are in good agreement with the ratios derived from InSAR data away from deforming zones. Both estimations of the delay-elevation ratio can thus be used to perform a first order correction of the observed interferometric phase to retrieve a ground motion signal of low amplitude. We also demonstrate that aliasing of daily and seasonal variations in the stratified delay due to uneven sampling of SAR data significantly bias InSAR data stacks or time series produced after temporal smoothing. In all three test cases, the InSAR data stacks or smoothed time series present a residual stratified delay of the order of the expected deformation signal. In all cases, correcting interferograms from the stratified delay removes all these biases. We quantify the standard error associated with the correction of the stratified atmospheric delay. It varies from one site to another depending on the prevailing atmospheric conditions, but remains bounded by the standard deviation of the daily fluctuations of the stratified delay around the seasonal average. Finally we suggest that the phase delay correction can potentially be improved by introducing a non-linear dependence to the elevation derived from GAM.

Corrections of stratified tropospheric delays in SAR interferometry: Validation with global atmospheric models

NASA Astrophysics Data System (ADS)

Doin, M.-P.; Lasserre, C.; Peltzer, G.; Cavalié, O.; Doubre, C.

2009-09-01

The main limiting factor on the accuracy of Interferometric SAR measurements (InSAR) comes from phase propagation delays through the troposphere. The delay can be divided into a stratified component, which correlates with the topography and often dominates the tropospheric signal, and a turbulent component. We use Global Atmospheric Models (GAM) to estimate the stratified phase delay and delay-elevation ratio at epochs of SAR acquisitions, and compare them to observed phase delay derived from SAR interferograms. Three test areas are selected with different geographic and climatic environments and with large SAR archive available. The Lake Mead, Nevada, USA is covered by 79 ERS1/2 and ENVISAT acquisitions, the Haiyuan Fault area, Gansu, China, by 24 ERS1/2 acquisitions, and the Afar region, Republic of Djibouti, by 91 Radarsat acquisitions. The hydrostatic and wet stratified delays are computed from GAM as a function of atmospheric pressure P, temperature T, and water vapor partial pressure e vertical profiles. The hydrostatic delay, which depends on ratio P/ T, varies significantly at low elevation and cannot be neglected. The wet component of the delay depends mostly on the near surface specific humidity. GAM predicted delay-elevation ratios are in good agreement with the ratios derived from InSAR data away from deforming zones. Both estimations of the delay-elevation ratio can thus be used to perform a first order correction of the observed interferometric phase to retrieve a ground motion signal of low amplitude. We also demonstrate that aliasing of daily and seasonal variations in the stratified delay due to uneven sampling of SAR data significantly bias InSAR data stacks or time series produced after temporal smoothing. In all three test cases, the InSAR data stacks or smoothed time series present a residual stratified delay of the order of the expected deformation signal. In all cases, correcting interferograms from the stratified delay removes all these biases. We quantify the standard error associated with the correction of the stratified atmospheric delay. It varies from one site to another depending on the prevailing atmospheric conditions, but remains bounded by the standard deviation of the daily fluctuations of the stratified delay around the seasonal average. Finally we suggest that the phase delay correction can potentially be improved by introducing a non-linear dependence to the elevation derived from GAM.

A Longitudinal Analysis of PTSD Symptom Course: Delayed-Onset PTSD in Somalia Peacekeepers

ERIC Educational Resources Information Center

Gray, Matt J.; Bolton, Elisa E.; Litz, Brett T.

2004-01-01

Posttraumatic stress disorder (PTSD) typically follows an acute to chronic course. However, some trauma victims do not report significant symptoms until a period of time has elapsed after the event. Although originally dismissed as an artifact of retrospective methodologies, recent prospective studies document apparent instances of delayed-onset…

Predictors of Time to Union After Operative Fixation of Closed Ankle Fractures.

PubMed

Matson, Andrew P; Hamid, Kamran S; Adams, Samuel B

2017-08-01

Ankle fractures are common and represent a significant burden to society. We aim to report the rate of union as determined by clinical and radiographic data, and to identify factors that predict time to union. A cohort of 112 consecutive patients with isolated, closed, operative malleolar ankle fractures treated with open reduction and internal fixation was retrospectively reviewed for time to clinical union. Clinical union was defined based on radiographic and clinical parameters, and delayed union was defined by time to union >12 weeks. Injury characteristics, patient factors and treatment variables were recorded, and statistical techniques employed included the Chi-square test, the Student's T-test, and multivariate linear regression modeling. Forty-two (37.5%) of patients who achieved union did so in less than 12 weeks, and 69 (61.6%) of these patients demonstrated delayed union at a mean of 16.7 weeks (range, 12.1-26.7 weeks), and the remaining patient required revision surgery. Factors associated with higher rates of delayed union or increased time to union included tobacco use, bimalleolar fixation, and high energy mechanism (all p<0.05). In regression analysis, statistically significant negative predictors of time to union were BMI, dislocation of the tibiotalar joint, external fixation for initial stabilization and delay of definitive management (all p<0.05). Patient characteristics, injury factors and treatment variables are predictive of time to union following open reduction and internal fixation of closed ankle fractures. These findings should assist with patient counseling, and help guide the provider when considering adjunctive therapies that promote bone healing. Prognostic, Level IV: Case series.

Autoignition characteristics of aircraft-type fuels

NASA Technical Reports Server (NTRS)

Spadaccini, L. J.; Tevelde, J. A.

1980-01-01

The ignition delay characteristics of Jet A, JP 4, no. 2 diesel, cetane and an experimental referee broad specification (ERBS) fuel in air at inlet temperatures up to 1000 K, pressures of 10, 15, 20, 25 and 30 atm, and fuel air equivalence ratios of 0.3, 0.5, 0.7 and 1.0 were mapped. Ignition delay times in the range of 1 to 50 msec at freestream flow velocities ranging from 20 to 100 m/sec were obtained using a continuous flow test apparatus which permitted independent variation and evaluation of the effect of temperature, pressure, flow rate, and fuel/air ratio. The ignition delay times for all fuels tested appeared to correlate with the inverse of pressure and the inverse exponent of temperature. With the exception of pure cetane, which had the shortest ignition delay times, the differences between the fuels tested did not appear to be significant. The apparent global activation energies for the typical gas turbine fuels ranged from 38 to 40 kcal/mole, while the activation energy determined for cetane was 50 kcal/mole. In addition, the data indicate that for lean mixtures, ignition delay times decrease with increasing equivalence ratio. It was also noted that physical (apparatus dependent) phenomena, such as mixing (i.e., length and number of injection sites) and airstream cooling (due to fuel heating, vaporization and convective heat loss) can have an important effect on the ignition delay.

Limited diagnostic value of Dual-Time-Point (18)F-FDG PET/CT imaging for classifying solitary pulmonary nodules in granuloma-endemic regions both at visual and quantitative analyses.

PubMed

Chen, Song; Li, Xuena; Chen, Meijie; Yin, Yafu; Li, Na; Li, Yaming

2016-10-01

This study is aimed to compare the diagnostic power of using quantitative analysis or visual analysis with single time point imaging (STPI) PET/CT and dual time point imaging (DTPI) PET/CT for the classification of solitary pulmonary nodules (SPN) lesions in granuloma-endemic regions. SPN patients who received early and delayed (18)F-FDG PET/CT at 60min and 180min post-injection were retrospectively reviewed. Diagnoses are confirmed by pathological results or follow-ups. Three quantitative metrics, early SUVmax, delayed SUVmax and retention index(the percentage changes between the early SUVmax and delayed SUVmax), were measured for each lesion. Three 5-point scale score was given by blinded interpretations performed by physicians based on STPI PET/CT images, DTPI PET/CT images and CT images, respectively. ROC analysis was performed on three quantitative metrics and three visual interpretation scores. One-hundred-forty-nine patients were retrospectively included. The areas under curve (AUC) of the ROC curves of early SUVmax, delayed SUVmax, RI, STPI PET/CT score, DTPI PET/CT score and CT score are 0.73, 0.74, 0.61, 0.77 0.75 and 0.76, respectively. There were no significant differences between the AUCs in visual interpretation of STPI PET/CT images and DTPI PET/CT images, nor in early SUVmax and delayed SUVmax. The differences of sensitivity, specificity and accuracy between STPI PET/CT and DTPI PET/CT were not significantly different in either quantitative analysis or visual interpretation. In granuloma-endemic regions, DTPI PET/CT did not offer significant improvement over STPI PET/CT in differentiating malignant SPNs in both quantitative analysis and visual interpretation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The use of a prospective audit proforma to improve door-to-mask times for acute exacerbations chronic obstructive pulmonary disease (COPD) requiring non-invasive ventilation (NIV).

PubMed

Mandal, S; Howes, T Q; Parker, M; Roberts, C M

2014-12-01

Non-invasive ventilation (NIV) is an evidence based management of acidotic, hypercapnic exacerbations of COPD. Previous national and international audits of clinical practice have shown variation against guideline standards with significant delays in initiating NIV. We aimed to map the clinical pathway to better understand delays and reduce the door-to-NIV time to less than 3 hours for all patients with acidotic, hypercapnic exacerbations of COPD requiring this intervention, by mandating the use of a guideline based educational management proforma.The proforma was introduced at 7 acute hospitals in North London and Essex and initiated at admission of the patient. It was used to record the clinical pathway and patient outcomes until the point of discharge or death. Data for 138 patients were collected. 48% of patients commenced NIV within 3 hours with no reduction in door-to-mask time during the study period. Delays in starting NIV were due to: time taken for review by the medical team (101 minutes) and time taken for NIV to be started once a decision had been made (49 minutes). There were significant differences in door-to-NIV decision and mask times between differing respiratory on-call systems, p < 0.05). The introduction of the proforma had no effect on door-to-mask times over the study period. Main reasons for delay were related to timely access to medical staff and to NIV equipment; however, a marked variation in practice within these hospitals was been noted, with a 9-5 respiratory on-call system associated with shorter NIV initiation times.

Replantation surgery in Quebec: The bottlenecks to rapid care

PubMed Central

Borsuk, Daniel E; Zadeh, Teanoosh; Lee, Chen; Moore, Karl; Tan, Grace

2006-01-01

INTRODUCTION Time delays resulting in prolonged ischemia have a significant impact on the successful reattachment of amputated body parts. No studies have addressed the issues surrounding delays from the time of the accident to the start of replantation surgery. The present paper identifies the bottlenecks that prolong the time before patients are able to gain access to a replant team. METHODS A total of 50 patients underwent microsurgical replantation, because of traumatic amputation, at a university-based hospital from 1996 to 2003. The charts were analyzed to ascertain individual time intervals from the onset of injury until the beginning of replant surgery. RESULTS The average length of time for patients who came directly to the replant centre was 3 h 40 min before surgery began. In contrast, for those referred from outlying hospitals, the elapsed time was 6 h 21 min. CONCLUSIONS Two major bottlenecks were found. First, for patients who were referred from other health centres, delays were due to a lack of information as to where patients could receive appropriate replant surgery. Second, delays at the replant centre were primarily due to insufficient physical and human resources in the operating room. PMID:19554107

Is there time discounting for risk premium?

PubMed

Shavit, Tal; Rosenboim, Mosi

2015-03-01

Individuals with a higher subjective discount rate concentrate more on the present and delay is more significant for them. However, when a risky asset is delayed, not only is the outcome delayed but also the risk. In this paper, we suggest a new, two-stage experimental method with real monetary incentives that allows us to distinguish between the effect of the risk and the effect of the time when pricing a risky asset. We show that when individuals have greater preference for the present, their risk aversion for a risky asset realized in the future decreases. We argue that the effect of the risk for future asset is lower for individuals with higher time preference because they discount not only the outcome but also the risks. © Society for the Experimental Analysis of Behavior.

Maximizing the security of chaotic optical communications.

PubMed

Hou, T T; Yi, L L; Yang, X L; Ke, J X; Hu, Y; Yang, Q; Zhou, P; Hu, W S

2016-10-03

The practical application of chaotic optical communications has been limited by two aspects: the difficulty in concealing the time delay - a critical security parameter in feedback chaotic systems, and the difficulty of significantly enlarging the key space without complicating the implementation. Here we propose an architecture to break the above limits. By introducing a frequency-dependent group delay module with frequency tuning resolution of 1 MHz into the chaotic feedback loop, we demonstrate excellent time delay concealment effect, and an additional huge key space of 10⁴⁸ can be achieved at the same time. The effectiveness is proved by both numerical simulation and experiment. Besides, the proposed scheme is compatible with the existing commercial optical communication systems, thus pave the way for high-speed secure optical communications.

Relations among Temperament, Self-regulatory Strategies and Gender in Predicting Delay of Gratification.

PubMed

Hong, Fang; Doan, Stacey N; Lopez, Angelica; Evans, Gary W

2017-01-01

Self-regulation is associated with many positive outcomes, but there is limited information about individual difference regarding children's spontaneous use of strategies to self-regulate and the relative success of those strategies. In the current study, we examined whether temperament and gender are associated with self-regulation and explored the types of spontaneous strategies children use during Mischel's delay of gratification protocol. In addition, we investigated whether spontaneous strategy use during the task could moderate the effects of temperament on self-regulation and whether temperament would mediate the effect of gender on self-regulation. Participants were 349 9-year-olds (182 boys, M age = 9.18, SD = 1.17). Mothers reported on children's temperament and the Delay of Gratification task was used to assess self-regulation. Both temperament and child's gender were significantly associated with children's delay time. Girls were able to delay longer than boys, and children scoring high on activity level were less able to delay. Activity level also mediated the relationship between gender and delay time. Finally, we found an interaction effect between activity level and certain strategies in relation to self-regulatory behavior.

Relations among Temperament, Self-regulatory Strategies and Gender in Predicting Delay of Gratification

PubMed Central

Hong, Fang; Doan, Stacey N.; Lopez, Angelica; Evans, Gary W.

2017-01-01

Self-regulation is associated with many positive outcomes, but there is limited information about individual difference regarding children’s spontaneous use of strategies to self-regulate and the relative success of those strategies. In the current study, we examined whether temperament and gender are associated with self-regulation and explored the types of spontaneous strategies children use during Mischel’s delay of gratification protocol. In addition, we investigated whether spontaneous strategy use during the task could moderate the effects of temperament on self-regulation and whether temperament would mediate the effect of gender on self-regulation. Participants were 349 9-year-olds (182 boys, Mage = 9.18, SD = 1.17). Mothers reported on children’s temperament and the Delay of Gratification task was used to assess self-regulation. Both temperament and child’s gender were significantly associated with children’s delay time. Girls were able to delay longer than boys, and children scoring high on activity level were less able to delay. Activity level also mediated the relationship between gender and delay time. Finally, we found an interaction effect between activity level and certain strategies in relation to self-regulatory behavior. PMID:29163300

Call-to-balloon time dashboard in patients with ST-segment elevation myocardial infarction results in significant improvement in the logistic chain.

PubMed

Hermans, Maaike P J; Velders, Matthijs A; Smeekes, Martin; Drexhage, Olivier S; Hautvast, Raymond W M; Ytsma, Timon; Schalij, Martin J; Umans, Victor A W M

2017-08-04

Timely reperfusion with primary percutaneous coronary intervention (pPCI) in ST-segment elevation myocardial infarction (STEMI) patients is associated with superior clinical outcomes. Aiming to reduce ischaemic time, an innovative system for home-to-hospital (H2H) time monitoring was implemented, which enabled real-time evaluation of ischaemic time intervals, regular feedback and improvements in the logistic chain. The objective of this study was to assess the results after implementation of the H2H dashboard for monitoring and evaluation of ischaemic time in STEMI patients. Ischaemic time in STEMI patients transported by emergency medical services (EMS) and treated with pPCI in the Noordwest Ziekenhuis, Alkmaar before (2008-2009; n=495) and after the implementation of the H2H dashboard (2011-2014; n=441) was compared. Median time intervals were significantly shorter in the H2H group (door-to-balloon time 32 [IQR 25-43] vs. 40 [IQR 28-55] minutes, p-value <0.001, FMC-to-balloon time 62 [IQR 52-75] vs. 80 [IQR 67-103] minutes, p-value <0.001, and treatment delay 142 [IQR 103-221] vs. 159 [IQR 123-253] minutes, p-value <0.001). The H2H time dashboard was independently associated with shorter time delays. Real-time monitoring and feedback on time delay with the H2H dashboard improves the logistic chain in STEMI patients, resulting in shorter ischaemic time intervals.

RF beam transmission of x-band PAA system utilizing large-area, polymer-based true-time-delay module developed using imprinting and inkjet printing

NASA Astrophysics Data System (ADS)

Pan, Zeyu; Subbaraman, Harish; Zhang, Cheng; Li, Qiaochu; Xu, Xiaochuan; Chen, Xiangning; Zhang, Xingyu; Zou, Yi; Panday, Ashwin; Guo, L. Jay; Chen, Ray T.

2016-02-01

Phased-array antenna (PAA) technology plays a significant role in modern day radar and communication networks. Truetime- delay (TTD) enabled beam steering networks provide several advantages over their electronic counterparts, including squint-free beam steering, low RF loss, immunity to electromagnetic interference (EMI), and large bandwidth control of PAAs. Chip-scale and integrated TTD modules promise a miniaturized, light-weight system; however, the modules are still rigid and they require complex packaging solutions. Moreover, the total achievable time delay is still restricted by the wafer size. In this work, we propose a light-weight and large-area, true-time-delay beamforming network that can be fabricated on light-weight and flexible/rigid surfaces utilizing low-cost "printing" techniques. In order to prove the feasibility of the approach, a 2-bit thermo-optic polymer TTD network is developed using a combination of imprinting and ink-jet printing. RF beam steering of a 1×4 X-band PAA up to 60° is demonstrated. The development of such active components on large area, light-weight, and low-cost substrates promises significant improvement in size, weight, and power (SWaP) requirements over the state-of-the-art.

Meeting Air Transportation Demand in 2025 by Using Larger Aircraft and Alternative Routing to Complement NextGen Operational Improvements

NASA Technical Reports Server (NTRS)

Smith, Jeremy C.; Guerreiro, Nelson M.; Viken, Jeffrey K.; Dollyhigh, Samuel M.; Fenbert, James W.

2010-01-01

A study was performed that investigates the use of larger aircraft and alternative routing to complement the capacity benefits expected from the Next Generation Air Transportation System (NextGen) in 2025. National Airspace System (NAS) delays for the 2025 demand projected by the Transportation Systems Analysis Models (TSAM) were assessed using NASA s Airspace Concept Evaluation System (ACES). The shift in demand from commercial airline to automobile and from one airline route to another was investigated by adding the route delays determined from the ACES simulation to the travel times used in the TSAM and re-generating new flight scenarios. The ACES simulation results from this study determined that NextGen Operational Improvements alone do not provide sufficient airport capacity to meet the projected demand for passenger air travel in 2025 without significant system delays. Using larger aircraft with more seats on high-demand routes and introducing new direct routes, where demand warrants, significantly reduces delays, complementing NextGen improvements. Another significant finding of this study is that the adaptive behavior of passengers to avoid congested airline-routes is an important factor when projecting demand for transportation systems. Passengers will choose an alternative mode of transportation or alternative airline routes to avoid congested routes, thereby reducing delays to acceptable levels for the 2025 scenario; the penalty being that alternative routes and the option to drive increases overall trip time by 0.4% and may be less convenient than the first-choice route.

Adding 5 h delayed xenon to delayed hypothermia treatment improves long-term function in neonatal rats surviving to adulthood.

PubMed

Liu, Xun; Dingley, John; Scull-Brown, Emma; Thoresen, Marianne

2015-06-01

We previously reported that combining immediate hypothermia with immediate or 2 h delayed inhalation of an inert gas, xenon, gave additive neuroprotection in rats after a hypoxic-ischemic insult, compared to hypothermia alone. Defining the therapeutic time window for this new combined intervention is crucial in clinical practice when immediate treatment is not always feasible. The aim of this study is to investigate whether combined hypothermia and xenon still provide neuroprotection in rats after a 5 h delay for both hypothermia and xenon. Seven-day-old Wistar rat pups underwent a unilateral hypoxic-ischemic insult. Pups received 5 h of treatment starting 5 h after the insult randomized between normothermia, hypothermia, or hypothermia with 50% xenon. Surviving pups were tested for fine motor function through weeks 8-10 before being euthanized at week 11. Their hemispheric and hippocampal areas were assessed. Both delayed hypothermia-xenon and hypothermia-only treated groups had significantly less brain tissue loss than those which underwent normothermia. The functional performance after 1 wk and adulthood was significantly better after hypothermia-xenon treatment as compared to the hypothermia-only or normothermia groups. Adding 50% xenon to 5 h delayed hypothermia significantly improved functional outcome as compared to delayed hypothermia alone despite similar reductions in brain area.

Women-focused development intervention reduces delays in accessing emergency obstetric care in urban slums in Bangladesh: a cross-sectional study.

PubMed

Nahar, Shamsun; Banu, Morsheda; Nasreen, Hashima E

2011-01-30

Recognizing the burden of maternal mortality in urban slums, in 2007 BRAC (formally known as Bangladesh Rural Advancement Committee) has established a woman-focused development intervention, Manoshi (the Bangla abbreviation of mother, neonate and child), in urban slums of Bangladesh. The intervention emphasizes strengthening the continuum of maternal, newborn and child care through community, delivery centre (DC) and timely referral of the obstetric complications to the emergency obstetric care (EmOC) facilities. This study aimed to assess whether Manoshi DCs reduces delays in accessing EmOC. This cross-sectional study was conducted during October 2008 to January 2009 in the slums of Dhaka city among 450 obstetric complicated cases referred either from DCs of Manoshi or from their home to the EmOC facilities. Trained female interviewers interviewed at their homestead with structured questionnaire. Pearson's chi-square test, t-test and Mann-Whitney test were performed. The median time for making the decision to seek care was significantly longer among women who were referred from home than referred from DCs (9.7 hours vs. 5.0 hours, p < 0.001). The median time to reach a facility and to receive treatment was found to be similar in both groups. Time taken to decide to seek care was significantly shorter in the case of life-threatening complications among those who were referred from DC than home (0.9 hours vs.2.3 hours, p = 0.002). Financial assistance from Manoshi significantly reduced the first delay in accessing EmOC services for life-threatening complications referred from DC (p = 0.006). Reasons for first delay include fear of medical intervention, inability to judge maternal condition, traditional beliefs and financial constraints. Role of gender was found to be an important issue in decision making. First delay was significantly higher among elderly women, multiparity, non life-threatening complications and who were not involved in income-generating activities. Manoshi program reduces the first delay for life-threatening conditions but not non-life-threatening complications even though providing financial assistance. Programme should give more emphasis on raising awareness through couple/family-based education about maternal complications and dispel fear of clinical care to accelerate seeking EmOC.

Response of end tidal CO2 pressure to impulse exercise.

PubMed

Yano, T; Afroundeh, R; Yamanak, R; Arimitsu, T; Lian, C-S; Shirkawa, K; Yunoki, T

2014-03-01

The purpose of the present study was to examine how end tidal CO(2) pressure (PETCO(2)) is controlled in impulse exercise. After pre-exercise at 25 watts for 5 min, impulse exercise for 10 sec with 200 watts followed by post exercise at 25 watts was performed. Ventilation (VE) significantly increased until the end of impulse exercise and significantly re-increased after a sudden decrease. Heart rate (HR) significantly increased until the end of impulse exercise and then decreased to the pre-exercise level. PETCO(2) remained constant during impulse exercise. PETCO(2) significantly increased momentarily after impulse exercise and then significantly decreased to the pre-exercise level. PETCO(2) showed oscillation. The average peak frequency of power spectral density in PETCO(2) appeared at 0.0078 Hz. Cross correlations were obtained after impulse exercise. The peak cross correlations between VE and PETCO(2), HR and PETCO(2), and VE and HR were 0.834 with a time delay of -7 sec, 0.813 with a time delay of 7 sec and 0.701 with a time delay of -15 sec, respectively. We demonstrated that PETCO(2) homeodynamics was interactively maintained by PETCO(2) itself, CO(2) transportation (product of cardiac output and mixed venous CO(2) content) into the lungs by heart pumping and CO(2) elimination by ventilation, and it oscillates as a result of their interactions.

Robust stability of interval bidirectional associative memory neural network with time delays.

PubMed

Liao, Xiaofeng; Wong, Kwok-wo

2004-04-01

In this paper, the conventional bidirectional associative memory (BAM) neural network with signal transmission delay is intervalized in order to study the bounded effect of deviations in network parameters and external perturbations. The resultant model is referred to as a novel interval dynamic BAM (IDBAM) model. By combining a number of different Lyapunov functionals with the Razumikhin technique, some sufficient conditions for the existence of unique equilibrium and robust stability are derived. These results are fairly general and can be verified easily. To go further, we extend our investigation to the time-varying delay case. Some robust stability criteria for BAM with perturbations of time-varying delays are derived. Besides, our approach for the analysis allows us to consider several different types of activation functions, including piecewise linear sigmoids with bounded activations as well as the usual C1-smooth sigmoids. We believe that the results obtained have leading significance in the design and application of BAM neural networks.

Meta-analysis of Timing for Microsurgical Free-Flap Reconstruction for Lower Limb Injury: Evaluation of the Godina Principles.

PubMed

Haykal, Siba; Roy, Mélissa; Patel, Ashit

2018-05-01

 In 1986, Marko Godina published his seminal work regarding the timing of free-flap reconstruction for traumatic extremity defects. Early reconstruction, compared with delayed and late reconstruction resulted in significant decreases in free-flap failure rate, post-operative infections, hospitalization time, bone healing time, and number of additional anesthesias. The objective of this manuscript was to evaluate whether these principles continue to apply.  A meta-analysis was performed analyzing articles from Medline, Embase, and Pubmed. Four hundred and ninety-two articles were screened, and 134 articles were assessed for eligibility. Following full-text review, 43 articles were included in this study.  The exact timing for free-flap reconstruction, free-flap failure rate, infection rate, and follow-up was defined in all 43 articles. Early free-flap reconstruction was found to have significantly lower rates of free-flap failure and infection in comparison to delayed reconstruction ( p  = 0.008; p  = 0.0004). Compared with late reconstruction, early reconstruction was found to have significantly lower infection rates only ( p  = 0.01) with no difference in free-flap failures rates. Early reconstruction was found to lead to fewer additional procedures ( p  = 0.03). No statistical significance was found for bone healing time or hospitalization time.  Early free-flap reconstruction performed within the first 72 hours resulted in a decreased rate of free-flap failures, infection, and additional procedures with no difference in other parameters. The largest majority of free flaps continue to be performed in a delayed time frame. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Methods for analysis of passenger trip performance in a complex networked transportation system

NASA Astrophysics Data System (ADS)

Wang, Danyi

2007-12-01

The purpose of the Air Transportation System (ATS) is to provide safe and efficient transportation service of passengers and cargo. The on-time performance of a passenger's trip is a critical performance measurement of the Quality of Service (QOS) provided by any Air Transportation System. QOS has been correlated with airline profitability, productivity, customer loyalty and customer satisfaction (Heskett et al. 1994). Btatu and Barnhart have shown that official government and airline on-time performance metrics (i.e. flight-centric measures of air transportation) fail to accurately reflect the passenger experience (Btatu and Barnhart, 2005). Flight-based metrics do not include the trip delays accrued by passengers who were re-booked due to cancelled flights or missed connections. Also, flight-based metrics do not quantify the magnitude of the delay (only the likelihood) and thus fails to provide the consumer with a useful assessment of the impact of a delay. Passenger-centric metrics have not been developed because of the unavailability of airline proprietary data, which is also protected by anti-trust collusion concerns and civil liberty privacy restrictions. Moveover, the growth of the ATS is trending out of the historical range. The objectives of this research were to (1) estimate ATS-wide passenger trip delay using publicly accessible flight data, and (2) investigate passenger trip dynamics out of the range of historical data by building a passenger flow simulation model to predict impact on passenger trip time given anticipated changes in the future. The first objective enables researchers to conduct historical analysis on passenger on-time performance without proprietary itinerary data, and the second objective enables researchers to conduct experiments outside the range of historic data. The estimated passenger trip delay was for 1,030 routes between the 35 busiest airports in the United States in 2006. The major findings of this research are listed as follows: 1. High passenger trip delays are disproportionately generated by cancelled flights and missed connections. Passengers scheduled on cancelled flights or missed connections represent 3 percent of total enplanements, but generated 45 percent of total passenger trip delay. On average, passengers scheduled on cancelled flights experienced 607 minutes delay, and passengers who missed the connections experienced 341 minutes delay in 2006. The heavily skewed distribution of passenger trip delay reveals the fact that a small proportion of passengers experience heavy delays, which can not be reflected by flight-based performance metrics. 2. Trend analysis for passenger trip delays from 2000 to 2006 shows the increase in flight operations slowed down and leveled off in 2006, while enplanements kept increasing. This is due to the continuous increase in load factor. Load factor has increased from 69% in 2003 to 80% in 2006. Passenger performance is very sensitive to changes in flight operations: annual total passenger trip delay was increased by 17% and 7% from 2004 to 2005, and from 2005 to 2006, while flight operations barely increased (0.5% from 2004 to 2005, and no increase from 2005 to 2006) during the same time period. 3. Passenger trip delay is shown to have an asymmetric performance of passenger trip delay in terms of routes. Seventeen percent of the 1030 routes generated 50 percent of total passenger trip delays. An interesting observation is that routes between the New York metropolitan area and the Washington D.C. metropolitan area have the highest average passenger trip delays in the system. 4. In terms of airports, there is also an asymmetric performance of passenger trip delay. Nine of the 35 busiest airports generated 50 percent of total passenger trip delays. Some airports, especially major hubs, impact the passenger trip delays significantly more than others. Recognition of this asymmetric performance can help reduce the total passenger trip delay propagation in the air transportation network by making changes primarily in major airports, such as Atlanta, GA (ATL), Chicago O'Hare (ORD) and Newark (EWR) airports. 5. Congestion Flight Delay, Load Factor, Flight Cancellation Time, and Airline Cooperation Policy are the most significant factors affecting total passenger trip delay in the system.

Graphene-based fine-tunable optical delay line for optical beamforming in phased-array antennas.

PubMed

Tatoli, Teresa; Conteduca, Donato; Dell'Olio, Francesco; Ciminelli, Caterina; Armenise, Mario N

2016-06-01

The design of an integrated graphene-based fine-tunable optical delay line on silicon nitride for optical beamforming in phased-array antennas is reported. A high value of the optical delay time (τ_g=920  ps) together with a compact footprint (4.15  mm²) and optical loss <27  dB make this device particularly suitable for highly efficient steering in active phased-array antennas. The delay line includes two graphene-based Mach-Zehnder interferometer switches and two vertically stacked microring resonators between which a graphene capacitor is placed. The tuning range is obtained by varying the value of the voltage applied to the graphene electrodes, which controls the optical path of the light propagation and therefore the delay time. The graphene provides a faster reconfigurable time and low values of energy dissipation. Such significant advantages, together with a negligible beam-squint effect, allow us to overcome the limitations of conventional RF beamformers. A highly efficient fine-tunable optical delay line for the beamsteering of 20 radiating elements up to ±20° in the azimuth direction of a tile in a phased-array antenna of an X-band synthetic aperture radar has been designed.

Evening daylight may cause adolescents to sleep less in spring than in winter

PubMed Central

Figueiro, Mariana G.; Rea, Mark S.

2012-01-01

Sleep restriction commonly experienced by adolescents can stem from greater sleep pressure by the homeostatic processes and from phase delays of the circadian system. With regard to the latter potential cause, we hypothesized that because there is more natural evening light during the spring than winter, a sample of adolescent students would be more phase delayed in spring than in winter, would have later sleep onset times and, because of fixed school schedules, would have shorter sleep durations. Sixteen eighth-grade subjects were recruited for the study. We collected sleep logs and saliva samples to determine their dim light melatonin onset (DLMO), a well-established circadian marker. Actual circadian light exposures experienced by a subset of twelve subjects over the course of seven days in winter and in spring using a personal, head-worn, circadian light measurement device are also reported here. Results showed that this sample of adolescents was exposed to significantly more circadian light in spring than in winter, especially in the evening hours when light exposure would likely delay circadian phase. Consistent with the light data, DLMO and sleep onset times were significantly more delayed, and sleep durations were significantly shorter in spring than in winter. The present ecological study of light, circadian phase, and self-reported sleep suggests that greater access to evening daylight in the spring may lead to sleep restriction in adolescents while attending school. Therefore, lighting schemes that reduce evening light in the spring may encourage longer sleep times in adolescents. PMID:20653452

Local Stability of AIDS Epidemic Model Through Treatment and Vertical Transmission with Time Delay

NASA Astrophysics Data System (ADS)

Novi W, Cascarilla; Lestari, Dwi

2016-02-01

This study aims to explain stability of the spread of AIDS through treatment and vertical transmission model. Human with HIV need a time to positively suffer AIDS. The existence of a time, human with HIV until positively suffer AIDS can be delayed for a time so that the model acquired is the model with time delay. The model form is a nonlinear differential equation with time delay, SIPTA (susceptible-infected-pre AIDS-treatment-AIDS). Based on SIPTA model analysis results the disease free equilibrium point and the endemic equilibrium point. The disease free equilibrium point with and without time delay are local asymptotically stable if the basic reproduction number is less than one. The endemic equilibrium point will be local asymptotically stable if the time delay is less than the critical value of delay, unstable if the time delay is more than the critical value of delay, and bifurcation occurs if the time delay is equal to the critical value of delay.

Improving the timeliness of procedures in a pediatric endoscopy suite.

PubMed

Tomer, Gitit; Choi, Steven; Montalvo, Andrea; Sutton, Sheila; Thompson, John; Rivas, Yolanda

2014-02-01

Pediatric endoscopic procedures are essential in the evaluation and treatment of gastrointestinal diseases in children. Although pediatric endoscopists are greatly interested in increasing efficiency and through-put in pediatric endoscopy units, there is scarcely any literature on this critical process. The goal of this study was to improve the timeliness of pediatric endoscopy procedures at Children's Hospital at Montefiore. In June 2010, a pediatric endoscopy quality improvement initiative was formed at Children's Hospital at Montefiore. We identified patient-, equipment-, and physician-related causes for case delays. Pareto charts, cause and effect diagrams, process flow mapping, and statistical process control charts were used for analysis. From June 2010 to December 2012, we were able to significantly decrease the first case endoscopy delay from an average of 17 to 10 minutes (P < .001), second case delay from 39 to 25 minutes (P = .01), third case delay from 61 to 45 minutes (P = .05), and fourth case delay from 79 to 51 minutes (P = .05). Total delay time decreased from 196 to 131 minutes, resulting in a reduction of 65 minutes (P = .02). From June 2010 to August 2011 (preintervention period), an average of 36% of first endoscopy cases started within 5 minutes, 51% within 10 minutes, and 61% within 15 minutes of the scheduled time. From September 2011 to December 2012 (postintervention period), the percentage of cases starting within 5 minutes, 10 minutes, and 15 minutes increased to 47% (P = .07), 61% (P = .04), and 79% (P = .01), respectively. Applying quality improvement methods and tools helped improve pediatric endoscopy timeliness and significantly decreased total delays.

A counting-weighted calibration method for a field-programmable-gate-array-based time-to-digital converter

NASA Astrophysics Data System (ADS)

Chen, Yuan-Ho

2017-05-01

In this work, we propose a counting-weighted calibration method for field-programmable-gate-array (FPGA)-based time-to-digital converter (TDC) to provide non-linearity calibration for use in positron emission tomography (PET) scanners. To deal with the non-linearity in FPGA, we developed a counting-weighted delay line (CWD) to count the delay time of the delay cells in the TDC in order to reduce the differential non-linearity (DNL) values based on code density counts. The performance of the proposed CWD-TDC with regard to linearity far exceeds that of TDC with a traditional tapped delay line (TDL) architecture, without the need for nonlinearity calibration. When implemented in a Xilinx Vertix-5 FPGA device, the proposed CWD-TDC achieved time resolution of 60 ps with integral non-linearity (INL) and DNL of [-0.54, 0.24] and [-0.66, 0.65] least-significant-bit (LSB), respectively. This is a clear indication of the suitability of the proposed FPGA-based CWD-TDC for use in PET scanners.

Arrival Metering Precision Study

NASA Technical Reports Server (NTRS)

Prevot, Thomas; Mercer, Joey; Homola, Jeffrey; Hunt, Sarah; Gomez, Ashley; Bienert, Nancy; Omar, Faisal; Kraut, Joshua; Brasil, Connie; Wu, Minghong, G.

2015-01-01

This paper describes the background, method and results of the Arrival Metering Precision Study (AMPS) conducted in the Airspace Operations Laboratory at NASA Ames Research Center in May 2014. The simulation study measured delivery accuracy, flight efficiency, controller workload, and acceptability of time-based metering operations to a meter fix at the terminal area boundary for different resolution levels of metering delay times displayed to the air traffic controllers and different levels of airspeed information made available to the Time-Based Flow Management (TBFM) system computing the delay. The results show that the resolution of the delay countdown timer (DCT) on the controllers display has a significant impact on the delivery accuracy at the meter fix. Using the 10 seconds rounded and 1 minute rounded DCT resolutions resulted in more accurate delivery than 1 minute truncated and were preferred by the controllers. Using the speeds the controllers entered into the fourth line of the data tag to update the delay computation in TBFM in high and low altitude sectors increased air traffic control efficiency and reduced fuel burn for arriving aircraft during time based metering.

The NANOGrav 11-year Data Set: High-precision Timing of 45 Millisecond Pulsars

NASA Astrophysics Data System (ADS)

Arzoumanian, Zaven; Brazier, Adam; Burke-Spolaor, Sarah; Chamberlin, Sydney; Chatterjee, Shami; Christy, Brian; Cordes, James M.; Cornish, Neil J.; Crawford, Fronefield; Thankful Cromartie, H.; Crowter, Kathryn; DeCesar, Megan E.; Demorest, Paul B.; Dolch, Timothy; Ellis, Justin A.; Ferdman, Robert D.; Ferrara, Elizabeth C.; Fonseca, Emmanuel; Garver-Daniels, Nathan; Gentile, Peter A.; Halmrast, Daniel; Huerta, E. A.; Jenet, Fredrick A.; Jessup, Cody; Jones, Glenn; Jones, Megan L.; Kaplan, David L.; Lam, Michael T.; Lazio, T. Joseph W.; Levin, Lina; Lommen, Andrea; Lorimer, Duncan R.; Luo, Jing; Lynch, Ryan S.; Madison, Dustin; Matthews, Allison M.; McLaughlin, Maura A.; McWilliams, Sean T.; Mingarelli, Chiara; Ng, Cherry; Nice, David J.; Pennucci, Timothy T.; Ransom, Scott M.; Ray, Paul S.; Siemens, Xavier; Simon, Joseph; Spiewak, Renée; Stairs, Ingrid H.; Stinebring, Daniel R.; Stovall, Kevin; Swiggum, Joseph K.; Taylor, Stephen R.; Vallisneri, Michele; van Haasteren, Rutger; Vigeland, Sarah J.; Zhu, Weiwei; The NANOGrav Collaboration

2018-04-01

We present high-precision timing data over time spans of up to 11 years for 45 millisecond pulsars observed as part of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) project, aimed at detecting and characterizing low-frequency gravitational waves. The pulsars were observed with the Arecibo Observatory and/or the Green Bank Telescope at frequencies ranging from 327 MHz to 2.3 GHz. Most pulsars were observed with approximately monthly cadence, and six high-timing-precision pulsars were observed weekly. All were observed at widely separated frequencies at each observing epoch in order to fit for time-variable dispersion delays. We describe our methods for data processing, time-of-arrival (TOA) calculation, and the implementation of a new, automated method for removing outlier TOAs. We fit a timing model for each pulsar that includes spin, astrometric, and (for binary pulsars) orbital parameters; time-variable dispersion delays; and parameters that quantify pulse-profile evolution with frequency. The timing solutions provide three new parallax measurements, two new Shapiro delay measurements, and two new measurements of significant orbital-period variations. We fit models that characterize sources of noise for each pulsar. We find that 11 pulsars show significant red noise, with generally smaller spectral indices than typically measured for non-recycled pulsars, possibly suggesting a different origin. A companion paper uses these data to constrain the strength of the gravitational-wave background.

The effects of the framing of time on delay discounting.

PubMed

DeHart, William Brady; Odum, Amy L

2015-01-01

We examined the effects of the framing of time on delay discounting. Delay discounting is the process by which delayed outcomes are devalued as a function of time. Time in a titrating delay discounting task is often framed in calendar units (e.g., as 1 week, 1 month, etc.). When time is framed as a specific date, delayed outcomes are discounted less compared to the calendar format. Other forms of framing time; however, have not been explored. All participants completed a titrating calendar unit delay-discounting task for money. Participants were also assigned to one of two delay discounting tasks: time as dates (e.g., June 1st, 2015) or time in units of days (e.g., 5000 days), using the same delay distribution as the calendar delay-discounting task. Time framed as dates resulted in less discounting compared to the calendar method, whereas time framed as days resulted in greater discounting compared to the calendar method. The hyperboloid model fit best compared to the hyperbola and exponential models. How time is framed may alter how participants attend to the delays as well as how the delayed outcome is valued. Altering how time is framed may serve to improve adherence to goals with delayed outcomes. © Society for the Experimental Analysis of Behavior.

Prehospital delay and independent/interdependent construal of self among Japanese patients with acute myocardial infarction.

PubMed

Fukuoka, Yoshimi; Dracup, Kathleen; Rankin, Sally H; Froelicher, Erika Sivarajan; Kobayashi, Fumio; Hirayama, Haro; Ohno, Miyoshi; Matsumoto, David

2005-05-01

Reducing the time from symptom onset to reperfusion therapy is an important approach to minimizing myocardial damage and to preventing death from acute myocardial infarction (AMI). Previous studies suggest that certain ethnic or national groups, such as the Japanese, are more likely to delay in accessing care than other groups. The aims of this paper were the following; (1) to examine whether culture (defined as independent and interdependent construal of self) is associated with delay in accessing medical care in Japanese patients experiencing symptoms of AMI; (2) to determine if the relationship between independent and interdependent construal of self and prehospital delay time is mediated by cognitive responses and/or emotional responses; and (3) to determine if independent and interdependent construal of self independently predicts choice of treatment site (clinic vs. hospital). A cross-sectional study was conducted at hospitals in urban areas in Japan. One hundred and forty-five consecutive patients who were admitted with AMI within 72 h of the onset of symptoms were interviewed using the modified response to symptoms questionnaire and the independent and interdependent construal of self scale. The interdependent construal of self scores were significantly associated with prehospital delay time, controlling for demographics, medical history, and symptoms (p<.001). However, the relationship between independent and interdependent self and prehospital delay times was not mediated by cognitive or emotional responses. In multiple logistic regression analysis, patients with high independent construal of self were more likely to seek care at a hospital rather than a clinic compared to those with lower independent construal of self. In conclusion, cultural variation within this Japanese group was observed and was associated with prehospital delay time.

Air pollution is associated with brainstem auditory nuclei pathology and delayed brainstem auditory evoked potentials

PubMed Central

Calderón-Garcidueñas, Lilian; D’Angiulli, Amedeo; Kulesza, Randy J; Torres-Jardón, Ricardo; Osnaya, Norma; Romero, Lina; Keefe, Sheyla; Herritt, Lou; Brooks, Diane M; Avila-Ramirez, Jose; Delgado-Chávez, Ricardo; Medina-Cortina, Humberto; González-González, Luis Oscar

2011-01-01

We assessed brainstem inflammation in children exposed to air pollutants by comparing brainstem auditory evoked potentials (BAEPs) and blood inflammatory markers in children age 96.3± 8.5 months from highly polluted (n=34) versus a low polluted city (n=17). The brainstems of nine children with accidental deaths were also examined. Children from the highly polluted environment had significant delays in wave III (t(50)=17.038; p<0.0001) and wave V (t(50)=19.730; p<0.0001) but no delay in wave I (p=0.548). They also had significantly longer latencies than controls for interwave intervals I–III, III–V, and I–V (all t(50)> 7.501; p<0.0001), consisting with delayed central conduction time of brainstem neural transmission. Highly exposed children showed significant evidence of inflammatory markers and their auditory and vestibular nuclei accumulated α synuclein and/or β amyloid 1–42. Medial superior olive neurons, critically involved in BAEPs, displayed significant pathology. Children’s exposure to urban air pollution increases their risk for auditory and vestibular impairment. PMID:21458557

[Comparison of effect between early and delayed in primary intramedullary nailing combined with locked plate fixation for the treatment of multi-segments tibial fractures of type].

PubMed

Gao, Wei-qiang; Hu, Jiang-hai; Gu, Zhu-chao; Zhang, Huai-xian; Min, Peng; Zhang, Lin-jun; Yu, Wen-wen; Wang, Guang-lin

2015-02-01

To compare the clinical results of early and delayed intramedullary nailing and locked plating for the treatment of multi-segments tibial fractures of type AO/ASIF-42C2. Between January 2010 and January 2013,45 patients with multi-segments closed tibial fractures of AO/ASIF-42C2 were treated by early primary intramedullary nailing and locked plating in 20 cases as early group and delayed in 25 cases as delayed group. In early group,20 cases included 13 males and 7 females with an average age of (37.9±14.3) years old ranging from 20 to 56 years;according to soft tissue injury Tscherne classification, 8 fractures were frade I,12 were grade II. In delayed group, 25 cases included 17 males and 8 females with an average age of (38.7±17.2) years old ranging from 24 to 55 years,4 fractures were grade I ,19 were grade II ,2 were grade III. The operative time, blood loss, hospital stay,fracture healing time and complications were recorded. At final follow-up, the Johner-Wruhs score were used to evaluate functional efficacy, and the posterior-anterior and lateral X-ray to evaluate fracture reduction and alignment. All the patients were followed up for (12.5±2.5) months in early group and (13.2±2.8) months in delayed group (P>0.05). No wounds infections were happened. At the last follow-up, the mean range of knee joint was 10°-0°-120°. According to Johner-Wruhs scoring,there were 15 cases in excellent,3 in good,fair in 2 in early group; 21 in excellent,2 in good,2 in fair. The average operative time,blood loss had no significant differences between two groups (P>0.05), but hospital stay in early group was significantly shorter than those in delayed group(P<0.05). Average fracture healing time of early group and delayed group were (5.3±2.6) months and (6.0±2.9) months, respectively (P>0.05). For multi-segments tibial fractures of type AO/ASIF-42C2 with preoperative minor soft tissue injuries lighter of Tscherne grade I or II, early primary intramedullary nailing and locked plating does not significantly increase the postoperative incidence of soft tissue complications for patients. The early and delayed primary intramedullary nailing and locked plating for treatment of AO/ASIF-42C2 proximal third tibial fractures can get similar curative effect.

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

NASA Astrophysics Data System (ADS)

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

2009-05-01

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

Real-time correction of beamforming time delay errors in abdominal ultrasound imaging

NASA Astrophysics Data System (ADS)

Rigby, K. W.

2000-04-01

The speed of sound varies with tissue type, yet commercial ultrasound imagers assume a constant sound speed. Sound speed variation in abdominal fat and muscle layers is widely believed to be largely responsible for poor contrast and resolution in some patients. The simplest model of the abdominal wall assumes that it adds a spatially varying time delay to the ultrasound wavefront. The adequacy of this model is controversial. We describe an adaptive imaging system consisting of a GE LOGIQ 700 imager connected to a multi- processor computer. Arrival time errors for each beamforming channel, estimated by correlating each channel signal with the beamsummed signal, are used to correct the imager's beamforming time delays at the acoustic frame rate. A multi- row transducer provides two-dimensional sampling of arrival time errors. We observe significant improvement in abdominal images of healthy male volunteers: increased contrast of blood vessels, increased visibility of the renal capsule, and increased brightness of the liver.

Management of the treatment delay in symptomatic carotid artery stenosis.

PubMed

Stiehm, Markus; Björses, Katarina; Kremer, Christine

2013-01-01

Saving time to intervention is crucial in patients with symptomatic carotid artery stenosis (SCAS). We introduced a fast-track protocol (FTP). Time frames from the onset of symptoms to intervention before and after the introduction of an FTP were analyzed. SCAS patients (403 patients/405 procedures) were evaluated according to whether surgery was performed before (group 1) or after (group 2) the introduction of the FTP. Time frames to surgery, causes of delay and frequency of recurrent events are reported. The median time delay decreased from 17 to 12 days (p<0.001), but time to ultrasound examination remained unchanged. Surgery was within 2 weeks in 41% in group 1 and in 57% in group 2 (p=0.001). Of 181 (30%) patients treated according to the FTP, 54 were operated within 7 days (median), and 80% had the intervention within 2 weeks. Time to surgery decreased significantly after the introduction of the FTP. © 2013 S. Karger AG, Basel.

Religiosity, spirituality, and cancer fatalism beliefs on delay in breast cancer diagnosis in African American women.

PubMed

Gullatte, Mary Magee; Brawley, Otis; Kinney, Anita; Powe, Barbara; Mooney, Kathi

2010-03-01

African American women are more likely than any other racial or ethnic group to present with a later stage of breast cancer at initial diagnosis. Delay in breast cancer detection is a critical factor in diagnosis at a later stage. Available data indicate a delay of 3 months or more is a significant factor in breast cancer mortalty. Numerous factors have been reported as contributing to delay in time to seek medical care including religiosity, spirituality, and fatalistic beliefs. This study examined the influence of religiosity, spirituality, and cancer fatalism on delay in diagnosis and breast cancer stage in African American women with self-detected breast symptoms. A descriptive correlation, retrospective methodology using an open-ended questionnaire and three validated measurement scales were used: the Religious Problem Solving Scale (RPSS), the Religious Coping Activity Scale (RCAS) subscale measuring spiritually based coping, and the modified Powe Fatalism Inventory (mPFI). A convenience sample of 129 women ages between 30 and 84 years who self-reported detecting a breast symptom before diagnosis of breast cancer within the preceding 12 months were included in the study. Outcome variables were time to seek medical care and breast cancer stage. Other variables of interest included marital status, income, education, insurance status, and to whom the women spoke about their breast symptoms. Data were analyzed using descriptive statistics, logistic regression analysis, Pearson r correlations, Mann-Whitney U analysis, and Chi Square analysis. Participants were found to be highly religious and spiritual but not fatalistic. While most women delayed more than 3 months in seeking medical care, no associations were found between the three predictor variables and time to seek medical care. The median delay in time from self detection of a breast symptom to seeking medical care was 5.5 months. Women who were less educated, unmarried, and talked to God only about their breast change were significantly more likely to delay seeking medical care. An association was found between disclosing a breast symptom to God only and delay in seeking medical care. In contrast, women who had told a person about their breast symptom were more likely to seek medical care sooner. African American women who delayed seeking medical care for longer than 3 months were more likely to present with a later stage of breast cancer than women who sought care within 3 months of symptom discovery.

Visualization Improves Supraclavicular Access to the Subclavian Vein in a Mixed Reality Simulator.

PubMed

Sappenfield, Joshua Warren; Smith, William Brit; Cooper, Lou Ann; Lizdas, David; Gonsalves, Drew B; Gravenstein, Nikolaus; Lampotang, Samsun; Robinson, Albert R

2018-07-01

We investigated whether visual augmentation (3D, real-time, color visualization) of a procedural simulator improved performance during training in the supraclavicular approach to the subclavian vein, not as widely known or used as its infraclavicular counterpart. To train anesthesiology residents to access a central vein, a mixed reality simulator with emulated ultrasound imaging was created using an anatomically authentic, 3D-printed, physical mannequin based on a computed tomographic scan of an actual human. The simulator has a corresponding 3D virtual model of the neck and upper chest anatomy. Hand-held instruments such as a needle, an ultrasound probe, and a virtual camera controller are directly manipulated by the trainee and tracked and recorded with submillimeter resolution via miniature, 6 degrees of freedom magnetic sensors. After Institutional Review Board approval, 69 anesthesiology residents and faculty were enrolled and received scripted instructions on how to perform subclavian venous access using the supraclavicular approach based on anatomic landmarks. The volunteers were randomized into 2 cohorts. The first used real-time 3D visualization concurrently with trial 1, but not during trial 2. The second did not use real-time 3D visualization concurrently with trial 1 or 2. However, after trial 2, they observed a 3D visualization playback of trial 2 before performing trial 3 without visualization. An automated scoring system based on time, success, and errors/complications generated objective performance scores. Nonparametric statistical methods were used to compare the scores between subsequent trials, differences between groups (real-time visualization versus no visualization versus delayed visualization), and improvement in scores between trials within groups. Although the real-time visualization group demonstrated significantly better performance than the delayed visualization group on trial 1 (P = .01), there was no difference in gain scores, between performance on the first trial and performance on the final trial, that were dependent on group (P = .13). In the delayed visualization group, the difference in performance between trial 1 and trial 2 was not significant (P = .09); reviewing performance on trial 2 before trial 3 resulted in improved performance when compared to trial 1 (P < .0001). There was no significant difference in median scores (P = .13) between the real-time visualization and delayed visualization groups for the last trial after both groups had received visualization. Participants reported a significant improvement in confidence in performing supraclavicular access to the subclavian vein. Standard deviations of scores, a measure of performance variability, decreased in the delayed visualization group after viewing the visualization. Real-time visual augmentation (3D visualization) in the mixed reality simulator improved performance during supraclavicular access to the subclavian vein. No difference was seen in the final trial of the group that received real-time visualization compared to the group that had delayed visualization playback of their prior attempt. Training with the mixed reality simulator improved participant confidence in performing an unfamiliar technique.

Autism and Classical Eyeblink Conditioning: Performance Changes of the Conditioned Response Related to Autism Spectrum Disorder Diagnosis

PubMed Central

Welsh, John P.; Oristaglio, Jeffrey T.

2016-01-01

Changes in the timing performance of conditioned responses (CRs) acquired during trace and delay eyeblink conditioning (EBC) are presented for diagnostic subgroups of children having autism spectrum disorder (ASD) aged 6–15 years. Children diagnosed with autistic disorder (AD) were analyzed separately from children diagnosed with either Asperger’s syndrome or Pervasive developmental disorder (Asp/PDD) not otherwise specified and compared to an age- and IQ-matched group of children who were typically developing (TD). Within-subject and between-groups contrasts in CR performance on sequential exposure to trace and delay EBC were analyzed to determine whether any differences would expose underlying functional heterogeneities of the cerebral and cerebellar systems, in ASD subgroups. The EBC parameters measured were percentage CRs, CR onset latency, and CR peak latency. Neither AD nor Asp/PDD groups were impaired in CR acquisition during trace or delay EBC. Both AD and Asp/PDD altered CR timing, but not always in the same way. Although the AD group showed normal CR timing during trace EBC, the Asp/PDD group showed a significant 27 and 28 ms increase in CR onset and peak latency, respectively, during trace EBC. In contrast, the direction of the timing change was opposite during delay EBC, during which the Asp/PDD group showed a significant 29 ms decrease in CR onset latency and the AD group showed a larger 77 ms decrease in CR onset latency. Only the AD group showed a decrease in CR peak latency during delay EBC, demonstrating another difference between AD and Asp/PDD. The difference in CR onset latency during delay EBC for both AD and Asp/PDD was due to an abnormal prevalence of early onset CRs that were intermixed with CRs having normal timing, as observed both in CR onset histograms and mean CR waveforms. In conclusion, significant heterogeneity in EBC performance was apparent between diagnostic groups, and this may indicate that EBC performance can report the heterogeneity in the neurobiological predispositions for ASD. The findings will inform further explorations with larger cohorts, different sensory modalities, and different EBC paradigms and provide a reference set for future EBC studies of children having ASD and non-human models. PMID:27563293

Delay to Reconstruction of the Adolescent Anterior Cruciate Ligament: The Socioeconomic Impact on Treatment.

PubMed

Newman, Justin T; Carry, Patrick M; Terhune, Elizabeth B; Spruiell, Murray; Heare, Austin; Mayo, Meredith; Vidal, Armando F

2014-08-01

A delay in pediatric and adolescent anterior cruciate ligament (ACL) reconstruction is associated with an increase in the number of concomitant meniscal and chondral injuries. Factors that contribute to this delay have not been well described. Socioeconomic and demographic factors are related to ACL surgery timing. Cohort study; Level of evidence, 3. All subjects who underwent primary ACL reconstruction at a single tertiary pediatric hospital between 2005 and 2012 were retrospectively reviewed. Variables included concomitant knee injuries (cartilage or meniscus injuries requiring additional operative treatment) and chronologic, demographic, and socioeconomic factors. Multivariable Cox proportional-hazards analyses were used to identify factors related to ACL surgery timing. The mean age of the 272 subjects was 15.2 ± 2.12 years. Time to surgery was significantly different among subjects who required multiple additional surgical procedures at time of ACL reconstruction (median, 3.3 months) compared with subjects with 1 (median, 2.0 months) or no additional injuries (median, 1.6 months). Subjects underwent ACL reconstruction significantly sooner if they were older at the time of injury (hazard ratio [HR], 1.2 per 1 year; 95% CI, 1.1-1.2; P < .0001) or were covered by a commercial insurance plan (HR, 2.0; 95% CI, 1.6-2.6; P < .0001). Median time to ACL surgery was 1.5 months (95% CI, 1.3-1.7) for subjects with commercial insurance plans compared with 3.0 months (95% CI, 2.3-3.3) for subjects with noncommercial insurance coverage. The risk of delayed ACL surgery was significantly higher among pediatric and adolescent subjects who were less affluent, who were covered by a noncommercial insurance plan, and who were younger. This study also confirms previous studies that have reported an association between a delay in ACL surgery and the presence of additional knee injuries requiring operative treatment, accentuating the importance of timely care. Access to care is a current area of research interest and health policy formation. Information in this arena drives 2 important aspects of health: most immediately, care provided to patients, and over a broader scope, the policy that directs health care. The orthopaedic surgeon should be aware of the association between socioeconomic and demographic factors and ACL surgery timing to optimize outcomes.

A Study on Health Seeking Behaviors of Patients of Post-Kala-Azar Dermal Leishmaniasis.

PubMed

Basher, Ariful; Nath, Proggananda; Nabi, Shah Golam; Selim, Shahjada; Rahman, Md Fashiur; Sutradhar, Satya Ranjan; Faiz, Abul; Bhuiyan, Matiur Rahman; Ahmed, Be-Nazir; Rahman, Ridwanur

2015-01-01

Post-Kala-Azar Dermal Leishmaniasis (PKDL) remains a major public health threat in Bangladesh. A cross-sectional study was carried out in Surya Kanta Kala azar Research Centre (SKKRC), Mymensingh, from January 2012 to July 2013 to evaluate the health seeking behaviour and the length of delay of PKDL management. The consecutive 200 diagnosed PKDL cases that got treatment in SKKRC hospital were subjected to evaluation. Most (98%) of the patients were not aware and had no knowledge about PKDL, though 87.5% had a history of history of Kala-azar treatment. Many patients reported first to village doctor (15.5%), the pharmacy shop (10%), or traditional health provider (7.5%) upon recognition of symptom. The time between the initial symptom recognition and first medical consultation (patient delay) ranged from 10 days to 4745 days (13 years) with a median of 373 days (mean: 696; IQR: 138 to 900 days). The time between first medical consultations to definite treatment (system delay) ranged from 0 days to 1971 days (5.4 years), with a median delay of 14 days (mean: 46.48; IQR: 7 to 44 days) that was reported in this study. Age, education, occupation, and residential status had significant association with patient delay (P < 0.05). Educational status, occupation, number of treatment providers, and first health care provider had a significant association with system delay (P < 0.05). Success in PKDL diagnosis and treatment requires specific behavior from patients and health care providers which facilitate those practices.

School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: A Review of the Literature.

PubMed

Wheaton, Anne G; Chapman, Daniel P; Croft, Janet B

2016-05-01

Insufficient sleep in adolescents has been shown to be associated with a wide variety of adverse outcomes, from poor mental and physical health to behavioral problems and lower academic grades. However, most high school students do not get sufficient sleep. Delaying school start times for adolescents has been proposed as a policy change to address insufficient sleep in this population and potentially to improve students' academic performance, reduce engagement in risk behaviors, and improve health. This article reviews 38 reports examining the association between school start times, sleep, and other outcomes among adolescent students. Most studies reviewed provide evidence that delaying school start time increases weeknight sleep duration among adolescents, primarily by delaying rise times. Most of the studies saw a significant increase in sleep duration even with relatively small delays in start times of half an hour or so. Later start times also generally correspond to improved attendance, less tardiness, less falling asleep in class, better grades, and fewer motor vehicle crashes. Although additional research is necessary, research results that are already available should be disseminated to stakeholders to enable the development of evidence-based school policies. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Proton acceleration by a pair of successive ultraintense femtosecond laser pulses

NASA Astrophysics Data System (ADS)

Ferri, J.; Senje, L.; Dalui, M.; Svensson, K.; Aurand, B.; Hansson, M.; Persson, A.; Lundh, O.; Wahlström, C.-G.; Gremillet, L.; Siminos, E.; DuBois, T. C.; Yi, L.; Martins, J. L.; Fülöp, T.

2018-04-01

We investigate the target normal sheath acceleration of protons in thin aluminum targets irradiated at a relativistic intensity by two time-separated ultrashort (35 fs) laser pulses. When the full-energy laser pulse is temporally split into two identical half-energy pulses, and using target thicknesses of 3 and 6 μm, we observe experimentally that the second half-pulse boosts the maximum energy and charge of the proton beam produced by the first half-pulse for time delays below ˜0.6-1 ps. Using two-dimensional particle-in-cell simulations, we examine the variation of the proton energy spectra with respect to the time-delay between the two pulses. We demonstrate that the expansion of the target front surface caused by the first pulse significantly enhances the hot-electron generation by the second pulse arriving after a few hundreds of fs time delay. This enhancement, however, does not suffice to further accelerate the fastest protons driven by the first pulse once three-dimensional quenching effects have set in. This implies a limit to the maximum time delay that leads to proton energy enhancement, which we theoretically determine.

Variable input observer for structural health monitoring of high-rate systems

NASA Astrophysics Data System (ADS)

Hong, Jonathan; Laflamme, Simon; Cao, Liang; Dodson, Jacob

2017-02-01

The development of high-rate structural health monitoring methods is intended to provide damage detection on timescales of 10 µs -10ms where speed of detection is critical to maintain structural integrity. Here, a novel Variable Input Observer (VIO) coupled with an adaptive observer is proposed as a potential solution for complex high-rate problems. The VIO is designed to adapt its input space based on real-time identification of the system's essential dynamics. By selecting appropriate time-delayed coordinates defined by both a time delay and an embedding dimension, the proper input space is chosen which allows more accurate estimations of the current state and a reduction of the convergence rate. The optimal time-delay is estimated based on mutual information, and the embedding dimension is based on false nearest neighbors. A simulation of the VIO is conducted on a two degree-of-freedom system with simulated damage. Results are compared with an adaptive Luenberger observer, a fixed time-delay observer, and a Kalman Filter. Under its preliminary design, the VIO converges significantly faster than the Luenberger and fixed observer. It performed similarly to the Kalman Filter in terms of convergence, but with greater accuracy.

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

Lin, S.; Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi'an Jiaotong University, Xi'an 710049; Beeson, S.

Self-induced gaseous plasma is evaluated as active opening switch medium for pulsed high power microwave radiation. The self-induced plasma switch is investigated for N{sub 2} and Ar environments under pressure conditions ranging from 25 to 700 Torr. A multi-pass TE{sub 111} resonator is used to significantly reduce the delay time inherently associated with plasma generation. The plasma forms under the pulsed excitation of a 4 MW magnetron inside the central dielectric tube of the resonator, which isolates the inner atmospheric gas from the outer vacuum environment. The path from the power source to the load is designed such that the pulse passesmore » through the plasma twice with a 35 ns delay between these two passes. In the first pass, initial plasma density is generated, while the second affects the transition to a highly reflective state with as much as 30 dB attenuation. Experimental data revealed that virtually zero delay time may be achieved for N{sub 2} at 25 Torr. A two-dimensional fluid model was developed to study the plasma formation times for comparison with experimental data. The delay time predicted from this model agrees well with the experimental values in the lower pressure regime (error < 25%), however, due to filamentary plasma formation at higher pressures, simulated delay times may be underestimated by as much as 50%.« less

Advanced Control Algorithms for Compensating the Phase Distortion Due to Transport Delay in Human-Machine Systems

NASA Technical Reports Server (NTRS)

Guo, Liwen; Cardullo, Frank M.; Kelly, Lon C.

2007-01-01

The desire to create more complex visual scenes in modern flight simulators outpaces recent increases in processor speed. As a result, simulation transport delay remains a problem. New approaches for compensating the transport delay in a flight simulator have been developed and are presented in this report. The lead/lag filter, the McFarland compensator and the Sobiski/Cardullo state space filter are three prominent compensators. The lead/lag filter provides some phase lead, while introducing significant gain distortion in the same frequency interval. The McFarland predictor can compensate for much longer delay and cause smaller gain error in low frequencies than the lead/lag filter, but the gain distortion beyond the design frequency interval is still significant, and it also causes large spikes in prediction. Though, theoretically, the Sobiski/Cardullo predictor, a state space filter, can compensate the longest delay with the least gain distortion among the three, it has remained in laboratory use due to several limitations. The first novel compensator is an adaptive predictor that makes use of the Kalman filter algorithm in a unique manner. In this manner the predictor can accurately provide the desired amount of prediction, while significantly reducing the large spikes caused by the McFarland predictor. Among several simplified online adaptive predictors, this report illustrates mathematically why the stochastic approximation algorithm achieves the best compensation results. A second novel approach employed a reference aircraft dynamics model to implement a state space predictor on a flight simulator. The practical implementation formed the filter state vector from the operator s control input and the aircraft states. The relationship between the reference model and the compensator performance was investigated in great detail, and the best performing reference model was selected for implementation in the final tests. Theoretical analyses of data from offline simulations with time delay compensation show that both novel predictors effectively suppress the large spikes caused by the McFarland compensator. The phase errors of the three predictors are not significant. The adaptive predictor yields greater gain errors than the McFarland predictor for short delays (96 and 138 ms), but shows smaller errors for long delays (186 and 282 ms). The advantage of the adaptive predictor becomes more obvious for a longer time delay. Conversely, the state space predictor results in substantially smaller gain error than the other two predictors for all four delay cases.

A money management-based substance use treatment increases valuation of future rewards.

PubMed

Black, Anne C; Rosen, Marc I

2011-01-01

A positive association between delay discounting and substance use has been documented; substance users tend to discount future rewards more than non-users. However, studies detailing the responsiveness of delay discounting to interventions are lacking, and few have examined how any behavioral intervention affects delay discounting and whether these effects moderate changes in substance abuse. This study assesses the effectiveness of a money management intervention, Advisor-Teller Money Manager (ATM), in reducing delay discounting over time and the relationship of these effects to changes in cocaine use. Ninety psychiatric patients with histories of cocaine and/or alcohol use were randomly assigned to 36-weeks of ATM treatment or to a minimal-attention control condition. Delay discounting and cocaine use were measured throughout the intervention with a 52-week follow up measure of cocaine use. Analyses were conducted of (a) the effect of ATM on slopes of delay discounting and cocaine abstinence and (b) the relationship between change in delay discounting and change in cocaine abstinence. The ATM intervention was associated with significantly less delay discounting and less cocaine use over time relative to controls. Increases in delay discounting were associated with decreased abstinence from cocaine. ATM treatment decreased delay discounting rates and these effects extended to cocaine use. Concrete conceptualizations of future events, as occur in financial planning, with higher perceived probability may account for higher valuation of future rewards in counseled patients. Copyright © 2010 Elsevier Ltd. All rights reserved.

Dynamics of scroll waves with time-delay propagation in excitable media

NASA Astrophysics Data System (ADS)

Chen, Jiang-Xing; Xiao, Jie; Qiao, Li-Yan; Xu, Jiang-Rong

2018-06-01

Information transmission delay can be widely observed in various systems. Here, we study the dynamics of scroll waves with time-delay propagation among slices in excitable media. Weak time delay induces scroll waves to meander. Through increasing the time delay, we find a series of dynamical transitions. Firstly, the straight filament of a scroll wave becomes twisted. Then, the scroll wave breaks and forms interesting patterns. With long time delay, loosed scroll waves are maintained while their period are greatly decreased. Also, cylinder waves appears. The influences of diffusively coupling strength on the time-delay-induced scroll waves are studied. It is found that the critical time delay characterizing those transitions decreases as the coupling strength is increased. A phase diagram in the diffusive coupling-time delay plane is presented.

Singer Responses to Sound Fields with a Simulated Reflection

NASA Astrophysics Data System (ADS)

NOSON, D.; SATO, S.; SAKAI, H.; ANDO, Y.

2000-04-01

While numerous recent studies have reported results concerning improvements to stage acoustics for orchestral performers, the preferred acoustical conditions on performing stages for singers has received limited attention in the past 20 years. A series of acoustical modifications have been proposed for a Seattle church to improve the acoustics for both the listeners and the performing choir. An on-site preliminary study was made to determine what acoustical changes might be important to singers. During solo fast-tempo singing and duet singing, singer preference increased with simulated short-delay reflections. The results suggest a potential for new reflectors to produce noticeable improvement in the choir acoustics. Subsequently, a solo singer study was conducted to establish preferred range of time delays for a single-simulated reflection. When singing faster-tempo music, the consensus of preference is statistically significant and the preferred delay averages 20 ms, while with a slow-tempo piece, the singers were not consistent in their judgment of preference and a strong individual variability predominated in the pair-comparison tests. The results point the way for an examination of a wider range of time delays and music motifs to acquire a clearer picture of consensus and individual preference for time-delayed reflections.

Previous Cocaine Exposure Makes Rats Hypersensitive to Both Delay and Reward Magnitude

PubMed Central

Roesch, Matthew R.; Takahashi, Yuji; Gugsa, Nishan; Bissonette, Gregory B.; Schoenbaum, Geoffrey

2008-01-01

Animals prefer an immediate over a delayed reward, just as they prefer a large over a small reward. Exposure to psychostimulants causes long-lasting changes in structures critical for this behavior and might disrupt normal time-discounting performance. To test this hypothesis, we exposed rats to cocaine daily for 2 weeks (30 mg/kg, i.p.). Approximately 6 weeks later, we tested them on a variant of a time-discounting task, in which the rats responded to one of two locations to obtain reward while we independently manipulated the delay to reward and reward magnitude. Performance did not differ between cocaine-treated and saline-treated (control) rats when delay lengths and reward magnitudes were equal at the two locations. However, cocaine-treated rats were significantly more likely to shift their responding when we increased the delay or reward size asymmetrically. Furthermore, they were slower to respond and made more errors when forced to the side associated with the lower value. We conclude that previous exposure to cocaine makes choice behavior hypersensitive to differences in the time to and size of available rewards, consistent with a general effect of cocaine exposure on reward valuation mechanisms. PMID:17202492

Previous cocaine exposure makes rats hypersensitive to both delay and reward magnitude.

PubMed

Roesch, Matthew R; Takahashi, Yuji; Gugsa, Nishan; Bissonette, Gregory B; Schoenbaum, Geoffrey

2007-01-03

Animals prefer an immediate over a delayed reward, just as they prefer a large over a small reward. Exposure to psychostimulants causes long-lasting changes in structures critical for this behavior and might disrupt normal time-discounting performance. To test this hypothesis, we exposed rats to cocaine daily for 2 weeks (30 mg/kg, i.p.). Approximately 6 weeks later, we tested them on a variant of a time-discounting task, in which the rats responded to one of two locations to obtain reward while we independently manipulated the delay to reward and reward magnitude. Performance did not differ between cocaine-treated and saline-treated (control) rats when delay lengths and reward magnitudes were equal at the two locations. However, cocaine-treated rats were significantly more likely to shift their responding when we increased the delay or reward size asymmetrically. Furthermore, they were slower to respond and made more errors when forced to the side associated with the lower value. We conclude that previous exposure to cocaine makes choice behavior hypersensitive to differences in the time to and size of available rewards, consistent with a general effect of cocaine exposure on reward valuation mechanisms.

The impact of command signal power distribution, processing delays, and speed scaling on neurally-controlled devices

NASA Astrophysics Data System (ADS)

Marathe, A. R.; Taylor, D. M.

2015-08-01

Objective. Decoding algorithms for brain-machine interfacing (BMI) are typically only optimized to reduce the magnitude of decoding errors. Our goal was to systematically quantify how four characteristics of BMI command signals impact closed-loop performance: (1) error magnitude, (2) distribution of different frequency components in the decoding errors, (3) processing delays, and (4) command gain. Approach. To systematically evaluate these different command features and their interactions, we used a closed-loop BMI simulator where human subjects used their own wrist movements to command the motion of a cursor to targets on a computer screen. Random noise with three different power distributions and four different relative magnitudes was added to the ongoing cursor motion in real time to simulate imperfect decoding. These error characteristics were tested with four different visual feedback delays and two velocity gains. Main results. Participants had significantly more trouble correcting for errors with a larger proportion of low-frequency, slow-time-varying components than they did with jittery, higher-frequency errors, even when the error magnitudes were equivalent. When errors were present, a movement delay often increased the time needed to complete the movement by an order of magnitude more than the delay itself. Scaling down the overall speed of the velocity command can actually speed up target acquisition time when low-frequency errors and delays are present. Significance. This study is the first to systematically evaluate how the combination of these four key command signal features (including the relatively-unexplored error power distribution) and their interactions impact closed-loop performance independent of any specific decoding method. The equations we derive relating closed-loop movement performance to these command characteristics can provide guidance on how best to balance these different factors when designing BMI systems. The equations reported here also provide an efficient way to compare a diverse range of decoding options offline.

The effect of oral preexposure prophylaxis on the progression of HIV-1 seroconversion

PubMed Central

Donnell, Deborah; Ramos, Eric; Celum, Connie; Baeten, Jared; Dragavon, Joan; Tappero, Jordan; Lingappa, Jairam R.; Ronald, Allan; Fife, Kenneth; Coombs, Robert W.

2017-01-01

Objective: To investigate whether oral preexposure prophylaxis (PrEP) alters timing and patterns of seroconversion when PrEP use continues after HIV-1 infection. Design: Retrospective testing of the timing of Fiebig stage HIV-1 seroconversion in the Partners PrEP Study, a randomized placebo-controlled clinical trial of PrEP conducted in Kenya and Uganda. Methods: Specimens from 138 seroconverters were collected every 3 months and when HIV-1 infection was suspected based on monthly rapid HIV-1 tests. Progression of seroconversion was compared between randomized groups (PrEP versus placebo) and per-protocol groups (placebo versus PrEP participants with detectable tenofovir during the seroconversion period) using laboratory assessment of Fiebig stage. Delay in site-detection of seroconversion and association with PrEP drug-regimen resistant virus were assessed using logistic regression. Analysis of time to each Fiebig stage used maximum likelihood estimation with a parametric model to accommodate the varying lengths of HIV-infection intervals. Results: There was a significant increase in delayed site detection of infection associated with PrEP (odds ratio = 3.49, P = 0.044). Delay in detection was not associated with increased risk of resistance in the PrEP arm (odds ratio = 0.93, P = 0.95). Estimated time to each Fiebig stage was elongated in seroconverters with evidence of ongoing PrEP use, significantly for only Stage 5 (28 versus 17 days, P = 0.05). Adjusted for Fiebig stage, viral RNA was ∼2/3 log lower in those assigned to PrEP compared with placebo; no differences were found in Architect signal to cut-off at any stage. Conclusion: Ongoing PrEP use in seroconverters may delay detection of infection and elongate seroconversion, although the delay does not increase risk of resistance. PMID:28692542

49 CFR 236.563 - Delay time.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Delay time. 236.563 Section 236.563 Transportation... Cab Signal Systems Rules and Instructions; Locomotives § 236.563 Delay time. Delay time of automatic... requirements of § 236.24 shall take into consideration the delay time. ...

49 CFR 236.563 - Delay time.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Delay time. 236.563 Section 236.563 Transportation... Cab Signal Systems Rules and Instructions; Locomotives § 236.563 Delay time. Delay time of automatic... requirements of § 236.24 shall take into consideration the delay time. ...

Comparison of Early and Delayed Open Reduction and Internal Fixation for Treating Closed Tibial Pilon Fractures.

PubMed

Tang, Xin; Liu, Lei; Tu, Chong-qi; Li, Jian; Li, Qi; Pei, Fu-xing

2014-07-01

The timing of surgery for osteosynthesis of type C pilon (AO/OTA) fractures remains controversial. The aim of this study was to determine the outcome of early and delayed open reduction and internal fixation (ORIF) for treating closed type C pilon fractures. Forty-six patients with closed type C pilon fractures matched according to age, gender, soft tissue conditions, and fracture pattern were divided into group A (early group: underwent surgery within 36 hours of the injury) or group B (delayed group: underwent surgery 10 days to 3 weeks postinjury after the soft tissue swelling subsided). In the delayed group, 9 patients were treated first by temporary external fixation. All the closed fractures were managed by ORIF with locking plates. At follow-up, the clinical and radiographic results were retrospectively analyzed. The mean follow-up time was 25.8 months (range, 14 to 48 months) in group A and 26.0 months (range, 15 to 44 months) in group B. There was no significant difference (P > .05) between the 2 groups regarding the rate of soft tissue complication, the rate of fracture union, and the final functional score. The patients in group A had a significantly shorter mean time to fracture union (21.5 ± 4.0 weeks vs 23.3 ± 3.7 weeks, P < .05), operating time (84.3 ± 12.1 months vs 100.6 ± 13.7 months, P < .01), and hospital stay (7.6 ± 2.6 days vs 15.2 ± 4.2 days, P < .01). If soft tissue conditions are acceptable, early ORIF for treating closed type C pilon fractures can be safe and effective, with similar rates of wound complication, fracture union, and final good functional recovery but shorter operative time, union time, and hospital stay. These results favorably compare with delayed ORIF treatment. Level III, retrospective comparative study. © The Author(s) 2014.

Improving first case start times using Lean in an academic medical center.

PubMed

Deldar, Romina; Soleimani, Tahereh; Harmon, Carol; Stevens, Larry H; Sood, Rajiv; Tholpady, Sunil S; Chu, Michael W

2017-06-01

Lean is a process improvement strategy that can improve efficiency of the perioperative process. The purpose of this study was to identify etiologies of late surgery start times, implement Lean interventions, and analyze their effects. A retrospective review of all first-start surgery cases was performed. Lean was implemented in May 2015, and cases 7 months before and after implementation were analyzed. A total of 4,492 first-start cases were included; 2,181 were pre-Lean and 2,311 were post-Lean. The post-Lean group had significantly higher on-time starts than the pre-Lean group (69.0% vs 57.0%, P < .01). The most common delay etiology was surgeon-related for both groups. Delayed post-Lean cases were significantly less likely to be due to preoperative assessment (14.9% vs 9.9%, P < .01) and more likely due to patient-related (16.5% vs 22.3%, P < .01) or chaplain (1.8% vs 4.0%, P < .01) factors. Delayed starts occurred more often on snowy and cold days, and less often on didactic days (P < .01). Modifying preoperative tasks using Lean methods can improve operating room efficiency and increase on-time starts. Copyright © 2016 Elsevier Inc. All rights reserved.

Assessment of Various Risk Factors for Success of Delayed and Immediate Loaded Dental Implants: A Retrospective Analysis.

PubMed

Prasant, M C; Thukral, Rishi; Kumar, Sachin; Sadrani, Sannishth M; Baxi, Harsh; Shah, Aditi

2016-10-01

Ever since its introduction in 1977, a minimum of few months of period is required for osseointegration to take place after dental implant surgery. With the passage of time and advancements in the fields of dental implant, this healing period is getting smaller and smaller. Immediate loading of dental implants is becoming a very popular procedure in the recent time. Hence, we retrospectively analyzed the various risk factors for the failure of delayed and immediate loaded dental implants. In the present study, retrospective analysis of all the patients was done who underwent dental implant surgeries either by immediate loading procedure or by delayed loading procedures. All the patients were divided broadly into two groups with one group containing patients in which delayed loaded dental implants were placed while other consisted of patients in whom immediate loaded dental implants were placed. All the patients in whom follow-up records were missing and who had past medical history of any systemic diseases were excluded from the present study. Evaluation of associated possible risk factors was done by classifying the predictable factors as primary and secondary factors. All the results were analyzed by Statistical Package for the Social Sciences (SPSS) software. Kaplan-Meier survival analyses and chi-square test were used for assessment of level of significance. In delayed and immediate group of dental implants, mean age of the patients was 54.2 and 54.8 years respectively. Statistically significant results were obtained while comparing the clinical parameters of the dental implants in both the groups while demographic parameters showed nonsignificant correlation. Significant higher risk of dental implant failure is associated with immediate loaded dental implants. Tobacco smoking, shorter implant size, and other risk factors play a significant role in predicting the success and failure of dental implants. Delayed loaded dental implant placement should be preferred as they are associated with decreased risk of implant failure.

Delay Discounting as an Index of Sustainable Behavior: Devaluation of Future Air Quality and Implications for Public Health.

PubMed

Berry, Meredith S; Nickerson, Norma P; Odum, Amy L

2017-09-01

Poor air quality and resulting annual deaths represent significant public health concerns. Recently, rapid delay discounting (the devaluation of future outcomes) of air quality has been considered a potential barrier for engaging in long term, sustainable behaviors that might help to reduce emissions (e.g., reducing private car use, societal support for clean air initiatives). Delay discounting has been shown to be predictive of real world behavior outside of laboratory settings, and therefore may offer an important framework beyond traditional variables thought to measure sustainable behavior such as importance of an environmental issue, or environmental attitudes/values, although more research is needed in this area. We examined relations between discounting of air quality, respiratory health, and monetary gains and losses. We also examined, relations between discounting and self-reported importance of air quality and respiratory health, and nature relatedness. Results showed rapid delay discounting of all outcomes across the time frames assessed, and significant positive correlations between delay discounting of air quality, respiratory health, and monetary outcomes. Steeper discounting of monetary outcomes relative to air quality and respiratory health outcomes was observed in the context of gains; however, no differences in discounting were observed across losses of monetary, air quality, and respiratory health. Replicating the sign effect, monetary outcomes were discounted more steeply than monetary losses. Importance of air quality, respiratory health and nature relatedness were significantly and positively correlated with one another, but not with degree of delay discounting of any outcome, demonstrating the need for more comprehensive measures that predict pro-environmental behaviors that might benefit individuals and public health over time. These results add to our understanding of decision-making, and demonstrate alarming rates of delay discounting of air quality and health. These results implicate a major public health concern and potential barriers to individual and societal behavior that reduce pollution and emissions for conservation of clean air.

Delay Discounting as an Index of Sustainable Behavior: Devaluation of Future Air Quality and Implications for Public Health

PubMed Central

Berry, Meredith S.; Nickerson, Norma P.; Odum, Amy L.

2017-01-01

Poor air quality and resulting annual deaths represent significant public health concerns. Recently, rapid delay discounting (the devaluation of future outcomes) of air quality has been considered a potential barrier for engaging in long term, sustainable behaviors that might help to reduce emissions (e.g., reducing private car use, societal support for clean air initiatives). Delay discounting has been shown to be predictive of real world behavior outside of laboratory settings, and therefore may offer an important framework beyond traditional variables thought to measure sustainable behavior such as importance of an environmental issue, or environmental attitudes/values, although more research is needed in this area. We examined relations between discounting of air quality, respiratory health, and monetary gains and losses. We also examined, relations between discounting and self-reported importance of air quality and respiratory health, and nature relatedness. Results showed rapid delay discounting of all outcomes across the time frames assessed, and significant positive correlations between delay discounting of air quality, respiratory health, and monetary outcomes. Steeper discounting of monetary outcomes relative to air quality and respiratory health outcomes was observed in the context of gains; however, no differences in discounting were observed across losses of monetary, air quality, and respiratory health. Replicating the sign effect, monetary outcomes were discounted more steeply than monetary losses. Importance of air quality, respiratory health and nature relatedness were significantly and positively correlated with one another, but not with degree of delay discounting of any outcome, demonstrating the need for more comprehensive measures that predict pro-environmental behaviors that might benefit individuals and public health over time. These results add to our understanding of decision-making, and demonstrate alarming rates of delay discounting of air quality and health. These results implicate a major public health concern and potential barriers to individual and societal behavior that reduce pollution and emissions for conservation of clean air. PMID:28862671

Social time preferences for health and money elicited with a choice experiment.

PubMed

Meerding, Willem Jan; Bonsel, Gouke J; Brouwer, Werner B F; Stuifbergen, Marja C; Essink-Bot, Marie-Louise

2010-01-01

In economic evaluations future health and monetary outcomes are commonly discounted at equal and constant rates. The theoretical foundation of this practice is being debated and appropriate discount rates for costs and health effects are sought. Here, we have derived social discount rates for health, money, and environmental benefits by means of a choice experiment. All choices were framed from a social perspective. We investigated differences in time preference by domain (health, monetary benefits, environmental benefits), time delay (5, 10, and 40 years), and respondent characteristics. Respondents were 173 health-care professionals and 34 health policymakers. Choice titration was used to determine when the respondent was indifferent between future and present benefits. At least two-thirds of respondents preferred an intervention with immediate benefits to delayed benefits in the different domains. The median (mean) yearly discount rates for health benefits were 2.7% (10.7%), 1.3% (3.5%), and 1.1% (2.3%) assuming a 5, 10, and 40 years delay, respectively. Social time preference for monetary benefits was significantly stronger, with median (mean) yearly discount rates of 6.6% (18.7%) and 4.8% (11.2%) assuming a 5 and 10 years delay, respectively. The social time preference with regard to environmental benefits was similar to the monetary benefits. Social time preference for the different domains was significantly correlated at the individual level. The empirically derived social time preference is in line with current theoretical arguments for a lower discount rate for health benefits than for monetary benefits. Moreover, the implied median discount rates for health were lower than those commonly used or advocated in guidelines.

Multiple Time-Point 68Ga-PSMA I&T PET/CT for Characterization of Primary Prostate Cancer: Value of Early Dynamic and Delayed Imaging.

PubMed

Schmuck, Sebastian; Mamach, Martin; Wilke, Florian; von Klot, Christoph A; Henkenberens, Christoph; Thackeray, James T; Sohns, Jan M; Geworski, Lilli; Ross, Tobias L; Wester, Hans-Juergen; Christiansen, Hans; Bengel, Frank M; Derlin, Thorsten

2017-06-01

The aims of this study were to gain mechanistic insights into prostate cancer biology using dynamic imaging and to evaluate the usefulness of multiple time-point Ga-prostate-specific membrane antigen (PSMA) I&T PET/CT for the assessment of primary prostate cancer before prostatectomy. Twenty patients with prostate cancer underwent Ga-PSMA I&T PET/CT before prostatectomy. The PET protocol consisted of early dynamic pelvic imaging, followed by static scans at 60 and 180 minutes postinjection (p.i.). SUVs, time-activity curves, quantitative analysis based on a 2-tissue compartment model, Patlak analysis, histopathology, and Gleason grading were compared between prostate cancer and benign prostate gland. Primary tumors were identified on both early dynamic and delayed imaging in 95% of patients. Tracer uptake was significantly higher in prostate cancer compared with benign prostate tissue at any time point (P ≤ 0.0003) and increased over time. Consequently, the tumor-to-nontumor ratio within the prostate gland improved over time (2.8 at 10 minutes vs 17.1 at 180 minutes p.i.). Tracer uptake at both 60 and 180 minutes p.i. was significantly higher in patients with higher Gleason scores (P < 0.01). The influx rate (Ki) was higher in prostate cancer than in reference prostate gland (0.055 [r = 0.998] vs 0.017 [r = 0.996]). Primary prostate cancer is readily identified on early dynamic and static delayed Ga-PSMA ligand PET images. The tumor-to-nontumor ratio in the prostate gland improves over time, supporting a role of delayed imaging for optimal visualization of prostate cancer.

Examining Delay Intervals in the Diagnosis and Treatment of Primary Open Angle Glaucoma in an Egyptian Population and Its Impact on Lifestyle

PubMed Central

Abu Hussein, Nahla B.; Habib, Ahmed E.; El Sayed, Yasmine M.

2016-01-01

Purpose. To examine causes as well as extent of delay in diagnosis and treatment of primary open angle glaucoma patients in a sample of Egyptians. Patients and Methods. 440 patients with primary open angle glaucoma were interviewed to evaluate delay in their diagnosis and treatment. The extent and cause of delay were investigated. The total delay interval, if any, was correlated with socioeconomic and other factors. Results. The median total delay was one year, with 50% of patients having a total delay of 1 year or less, of which 25% exhibited zero total delay. 25% of patients had a delay ranging from 1 to 3 years, and 25% had a total delay ranging from 3 to 27 years. Diagnostic delay accounted for 43.03% of cases. Longer delays were met in patients with certain socioeconomic factors. Patients with a positive family history of glaucoma displayed shorter delay periods. Conclusion. Significant delay in the diagnosis and treatment of glaucoma was found. Poor socioeconomic status seems to hinder timely diagnosis and treatment of POAG. Certain socioeconomic factors seem to correlate with the extent of delay. More effort is thus needed to subsidize the cost of investigations and treatment for glaucoma patients. PMID:28116140

Role of working memory in transformation of visual and motor representations for use in mental simulation.

PubMed

Gabbard, Carl; Lee, Jihye; Caçola, Priscila

2013-01-01

This study examined the role of visual working memory when transforming visual representations to motor representations in the context of motor imagery. Participants viewed randomized number sequences of three, four, and five digits, and then reproduced the sequence by finger tapping using motor imagery or actually executing the movements; movement duration was recorded. One group viewed the stimulus for three seconds and responded immediately, while the second group had a three-second view followed by a three-second blank screen delay before responding. As expected, delay group times were longer with each condition and digit load. Whereas correlations between imagined and executed actions (temporal congruency) were significant in a positive direction for both groups, interestingly, the delay group's values were significantly stronger. That outcome prompts speculation that delay influenced the congruency between motor representation and actual execution.

Relation between delay and survival in 596 patients with breast cancer.

PubMed

Machiavelli, M; Leone, B; Romero, A; Perez, J; Vallejo, C; Bianco, A; Rodriguez, R; Estevez, R; Chacon, R; Dansky, C

1989-01-01

To evaluate the influence of delay between first symptom and first treatment upon survival the medical records of 596 patients with breast cancer were reviewed. The following intervals were considered: less than 3 months; 3-6 months and greater than 6 months. Patients in the less than 3 months delay group had a better distribution by clinical stages and a 10-year survival rate higher than those in the longer delay groups (p = 0.034). However, within each stage no statistically significant difference in survival according to delay was observed. A Cox multivariate analysis revealed that performance status and stage of disease were independent predictors of survival, but not delay. Assuming the best prognosis for patients with clinical stages I and II and less than 3 months delay, the group with longer delay times had 15 deaths over what would have been predicted. This adverse effect was observed almost exclusively among patients over age 50 (14/15).

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

NASA Technical Reports Server (NTRS)

Walsh, Kevin R.

1992-01-01

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

Factors affecting breast cancer treatment delay in Turkey: a study from Turkish Federation of Breast Diseases Societies

PubMed Central

Boylu, Sukru; Ok, Engin; Canturk, Nuh Zafer; Celik, Varol; Kapkac, Murat; Girgin, Sadullah; Tireli, Mustafa; Ihtiyar, Enver; Demircan, Orhan; Baskan, Mazhar Semih; Koyuncu, Ayhan; Tasdelen, Ismet; Dumanli, Esra; Ozdener, Fatih; Zaborek, Piotr

2015-01-01

Background: One of the most important factors in breast cancer (BC) mortality is treatment delay. The primary goal of this survey was to identify factors affecting the total delay time (TDT) in Turkish BC patients. Methods: A total of 1031 patients with BC were surveyed using a uniform questionnaire. The time between discovering the first symptom and signing up for the first medical visit (patient delay time; PDT) and the time between the first medical visit and the start of therapy (system delay time; SDT) were modelled separately with multilevel regression. Results: The mean PDT, SDT and TDT were 4.8, 10.5 and 13.8 weeks, respectively. In all, 42% of the patients had a TDT >12 weeks. Longer PDT was significantly correlated with disregarding symptoms and having age of between 30 and 39 years. Shorter PDT was characteristic of patients who: had stronger self-examination habits, received more support from family and friends and had at least secondary education. Predictors of longer SDT included disregard of symptoms, distrust in success of therapy and medical system and having PDT in excess of 4 weeks. Shorter SDT was linked to the age of >60 years. Patients who were diagnosed during a periodic check-up or opportunistic mammography displayed shorter SDT compared with those who had symptomatic BC and their first medical examination was by a surgeon. Conclusion: TDT in Turkey is long and remains a major problem. Delays can be reduced by increasing BC awareness, implementing organized population-based screening programmes and founding cancer centres. PMID:25096257

On-demand SSRI treatment of premature ejaculation: pharmacodynamic limitations for relevant ejaculation delay and consequent solutions.

PubMed

Waldinger, Marcel D; Schweitzer, Dave H; Olivier, Berend

2005-01-01

Recently, the idea has emerged that on-demand use of serotonin reuptake inhibitors (SSRIs), particularly short half-life, should be equally effective in delaying ejaculation as daily SSRI treatment of premature ejaculation. To provide evidence that SSRI-induced ejaculation delay is mainly dependent on pharmacodynamic properties of the drug and hardly on pharmacokinetic factors, and that combined SSRI administration with specific 5-hydroxytryptamine (5-HT) receptor antagonism leads acutely to stronger ejaculation delay than acute SSRI monoadministration. We performed a detailed analysis of serotonin neurotransmission and reviewed animal studies with 5-HT(1A) receptor antagonists. In addition, we critically reviewed existing on-demand SSRI treatments publications and the current debate on a definition of premature ejaculation. Intravaginal ejaculation latency time (IELT). Acute SSRI administration leads to only a mild or no increase of 5-HT neurotransmission and concomitant stimulation of postsynaptic 5-HT receptors. Existing on-demand SSRI treatment studies suffer from methodological insufficiencies, and the reported high-fold increases of ejaculation time contradict with neuropharmacological insights from serotonin metabolism. Animal studies show that SSRI coadministration with 5-HT(1A) receptor antagonists significantly increases the ejaculation time acutely compared to acute SSRI monoadministration. On-demand SSRI treatment has less ejaculation-delaying effects than daily SSRI treatment. SSRIs with a short half-life are likely leading to much less ejaculation delay than current registered SSRIs. Combined use of SSRIs with 5-HT(1A) receptor antagonists increases the likelihood of clinically relevant ejaculation delay after on-demand treatment. On-demand SSRIs with short half-life that insufficiently delay ejaculation in men with IELTs less than 1 minute should be called ejaculation-delaying drugs rather than drugs against premature ejaculation.

Effect of time between x-irradiation and chemotherapy on the growth of three solid mouse tumors. V. Bleomycin

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

Twentyman, P.R.; Kallman, R.F.; Brown, J.M.

1979-09-01

Experiments have been carried out to determine the effect of different time intervals between the administration of x-radiation (1200 rad) and bleomycin (20 mg/kg) on the growth delay produced in three mouse tumors. The tumors used were the EMT6 tumor in BALB/c mice and the KHT and RIF-1 sarcomas in C3H mice. All tumors were grown intramuscularly in the gastrocnemius muscle and treatment was carried out at a mean tumor weight of 450 mg. Time to reach 2X (for KHT) or 4X (for EMT6 and RIF-1) treatment volume was used as the endpoint of response. The drug was administered bymore » the intraperitoneal route either 24, 6, or 2 hr before radiation, immediately before the start of radiation, or 3, 6, or 24 hr after radiation. All irradiations were carried out in unanesthetized mice. For a single administration at this dose level, bleomycin alone did not produce a significant growth delay in any of the tumors. In the RIF-1 tumor, growth delays following combination treatments were equal to the addition of the single agent growth delays. In two experiments with EMT6, contrary results were obtained, one producing longer delays following combination treatments than predicted and the other producing shorter delays. This is apparently due to the variability in the growth delay after treatment with radiation alone for this tumor. For the KHT tumor, only small differences from the addition of single agent delays were seen.« less

Critical time delay of the pineal melatonin rhythm in humans due to weak electromagnetic exposure.

PubMed

Halgamuge, Malka N

2013-08-01

Electromagnetic fields (EMFs) can increase free radicals, activate the stress response and alter enzyme reactions. Intracellular signalling is mediated by free radicals and enzyme kinetics is affected by radical pair recombination rates. The magnetic field component of an external EMF can delay the "recombination rate" of free radical pairs. Magnetic fields thus increase radical life-times in biological systems. Although measured in nanoseconds, this extra time increases the potential to do more damage. Melatonin regulates the body's sleep-wake cycle or circadian rhythm. The World Health Organization (WHO) has confirmed that prolonged alterations in sleep patterns suppress the body's ability to make melatonin. Considerable cancer rates have been attributed to the reduction of melatonin production as a result of jet lag and night shift work. In this study, changes in circadian rhythm and melatonin concentration are observed due to the external perturbation of chemical reaction rates. We further analyze the pineal melatonin rhythm and investigate the critical time delay or maturation time of radical pair recombination rates, exploring the impact of the mRNA degradation rate on the critical time delay. The results show that significant melatonin interruption and changes to the circadian rhythm occur due to the perturbation of chemical reaction rates, as also reported in previous studies. The results also show the influence of the mRNA degradation rate on the circadian rhythm's critical time delay or maturation time. The results support the hypothesis that exposure to weak EMFs via melatonin disruption can adversely affect human health.

Stochastic resonance enhancement of small-world neural networks by hybrid synapses and time delay

NASA Astrophysics Data System (ADS)

Yu, Haitao; Guo, Xinmeng; Wang, Jiang

2017-01-01

The synergistic effect of hybrid electrical-chemical synapses and information transmission delay on the stochastic response behavior in small-world neuronal networks is investigated. Numerical results show that, the stochastic response behavior can be regulated by moderate noise intensity to track the rhythm of subthreshold pacemaker, indicating the occurrence of stochastic resonance (SR) in the considered neural system. Inheriting the characteristics of two types of synapses-electrical and chemical ones, neural networks with hybrid electrical-chemical synapses are of great improvement in neuron communication. Particularly, chemical synapses are conducive to increase the network detectability by lowering the resonance noise intensity, while the information is better transmitted through the networks via electrical coupling. Moreover, time delay is able to enhance or destroy the periodic stochastic response behavior intermittently. In the time-delayed small-world neuronal networks, the introduction of electrical synapses can significantly improve the signal detection capability by widening the range of optimal noise intensity for the subthreshold signal, and the efficiency of SR is largely amplified in the case of pure chemical couplings. In addition, the stochastic response behavior is also profoundly influenced by the network topology. Increasing the rewiring probability in pure chemically coupled networks can always enhance the effect of SR, which is slightly influenced by information transmission delay. On the other hand, the capacity of information communication is robust to the network topology within the time-delayed neuronal systems including electrical couplings.

Annual longitudinal survey at up to five time points reveals reciprocal effects of bedtime delay and depression/anxiety in adolescents.

PubMed

Tochigi, Mamoru; Usami, Satoshi; Matamura, Misato; Kitagawa, Yuko; Fukushima, Masako; Yonehara, Hiromi; Togo, Fumiharu; Nishida, Atsushi; Sasaki, Tsukasa

2016-01-01

To investigate the longitudinal relationship between sleep habits and mental health in adolescents. Multipoint observation data of up to five years were employed from a prospective cohort study of sleep habits and mental health status conducted from 2009 to 2013 in a unified junior and senior high school (grades 7-12) in Tokyo, Japan. A total of 1078 students answered a self-report questionnaire, including items on usual bed and wake-up times on school days, and the Japanese version of the 12-item General Health Questionnaire (GHQ-12). Latent growth model (LGM) analysis, which requires three or more time point data, showed that longitudinal changes in bedtime and GHQ-12 score (or score for depression/anxiety) were significantly and moderately correlated (correlation coefficient = 0.510, p < 0.05). Another result of interest was that, using an autoregressive cross-lagged (ARCL) model, bedtime and the depression/anxiety score had reciprocal effects the following year: ie, bedtime significantly affects the following year's depression/anxiety, and vice versa. In addition, the analysis provided estimates of mutually predicted changes: one-hour bedtime delay may worsen the GHQ-12 score by 0.2 points, and one-point worsening of the score may delay bedtime by 2.2 minutes. By using up to five multiple time point data, the present study confirms the correlational and reciprocally longitudinal relationship between bedtime delay and mental health status in Japanese adolescents. The results indicate that preventing late bedtime may have a significant effect on improving mental health in adolescents. Copyright © 2015 Elsevier B.V. All rights reserved.

Time delay in the Einstein ring PKS 1830-211

NASA Technical Reports Server (NTRS)

Van Ommen, T. D.; Jones, D. L.; Preston, R. A.; Jauncey, D. L.

1995-01-01

We present radio observations of the gravitational lens PKS 1830-211 at 8.4 and 15 GHz acquired using the Very Large Array. The observations were made over a 13 month period. Significant flux density changes over this period provide strong constraints on the time delay between the two lensed images and suffest a value of 44 +/- 9 days. This offers new direct evidence that this source is indeed a gravitational lens. The lens distance is dependent upon the model chosen, but reasonable limits on the mass of the lensing galaxy suggest that it is unlikely to be at a redshift less than a few tenths, and may well be significantly more distant.

Low and moderate prenatal ethanol exposures of mice during gastrulation or neurulation delays neurobehavioral development.

PubMed

Schambra, Uta B; Goldsmith, Jeff; Nunley, Kevin; Liu, Yali; Harirforoosh, Sam; Schambra, Heidi M

2015-01-01

Human and animal studies show significant delays in neurobehavioral development in offspring after prolonged prenatal exposure to moderate and high ethanol doses resulting in high blood alcohol concentration (BECs). However, none have investigated the effects of lower ethanol doses given acutely during specific developmental time periods. Here, we sought to create a mouse model for modest and circumscribed human drinking during the 3rd and 4th weeks of pregnancy. We acutely treated mice during embryo gastrulation on gestational day (GD) 7 or neurulation on GD8 with a low or moderate ethanol dose given via gavage that resulted in BECs of 107 and 177 mg/dl, respectively. We assessed neonatal physical development (pinnae unfolding, and eye opening); weight gain from postnatal day (PD) 3-65; and neurobehavioral maturation (pivoting, walking, cliff aversion, surface righting, vertical screen grasp, and rope balance) from PD3 to 17. We used a multiple linear regression model to determine the effects of dose, sex, day of treatment and birth in animals dosed during gastrulation or neurulation, relative to their vehicle controls. We found that ethanol exposure during both time points (GD7 and GD8) resulted in some delays of physical development and significant sensorimotor delays of pivoting, walking, and thick rope balance, as well as additional significant delays in cliff aversion and surface righting after GD8 treatment. We also found that treatment with the low ethanol dose more frequently affected neurobehavioral development of the surviving pups than treatment with the moderate ethanol dose, possibly due to a loss of severely affected offspring. Finally, mice born prematurely were delayed in their physical and sensorimotor development. Importantly, we showed that brief exposure to low dose ethanol, if administered during vulnerable periods of neuroanatomical development, results in significant neurobehavioral delays in neonatal mice. We thus expand concerns about alcohol consumption during the 3rd and 4th weeks of human pregnancy to include occasional light to moderate drinking. Copyright © 2015 Elsevier Inc. All rights reserved.

Memantine for the prevention of cognitive dysfunction in patients receiving whole-brain radiotherapy: a randomized, double-blind, placebo-controlled trial

PubMed Central

Brown, Paul D.; Pugh, Stephanie; Laack, Nadia N.; Wefel, Jeffrey S.; Khuntia, Deepak; Meyers, Christina; Choucair, Ali; Fox, Sherry; Suh, John H.; Roberge, David; Kavadi, Vivek; Bentzen, Soren M.; Mehta, Minesh P.; Watkins-Bruner, Deborah

2013-01-01

Background To determine the protective effects of memantine on cognitive function in patients receiving whole-brain radiotherapy (WBRT). Methods Adult patients with brain metastases received WBRT and were randomized to receive placebo or memantine (20 mg/d), within 3 days of initiating radiotherapy for 24 weeks. Serial standardized tests of cognitive function were performed. Results Of 554 patients who were accrued, 508 were eligible. Grade 3 or 4 toxicities and study compliance were similar in the 2 arms. There was less decline in delayed recall in the memantine arm at 24 weeks (P = .059), but the difference was not statistically significant, possibly because there were only 149 analyzable patients at 24 weeks, resulting in only 35% statistical power. The memantine arm had significantly longer time to cognitive decline (hazard ratio 0.78, 95% confidence interval 0.62–0.99, P = .01); the probability of cognitive function failure at 24 weeks was 53.8% in the memantine arm and 64.9% in the placebo arm. Superior results were seen in the memantine arm for executive function at 8 (P = .008) and 16 weeks (P = .0041) and for processing speed (P = .0137) and delayed recognition (P = .0149) at 24 weeks. Conclusions Memantine was well tolerated and had a toxicity profile very similar to placebo. Although there was less decline in the primary endpoint of delayed recall at 24 weeks, this lacked statistical significance possibly due to significant patient loss. Overall, patients treated with memantine had better cognitive function over time; specifically, memantine delayed time to cognitive decline and reduced the rate of decline in memory, executive function, and processing speed in patients receiving WBRT. RTOG 0614, ClinicalTrials.gov number CT00566852. PMID:23956241

Memantine for the prevention of cognitive dysfunction in patients receiving whole-brain radiotherapy: a randomized, double-blind, placebo-controlled trial.

PubMed

Brown, Paul D; Pugh, Stephanie; Laack, Nadia N; Wefel, Jeffrey S; Khuntia, Deepak; Meyers, Christina; Choucair, Ali; Fox, Sherry; Suh, John H; Roberge, David; Kavadi, Vivek; Bentzen, Soren M; Mehta, Minesh P; Watkins-Bruner, Deborah

2013-10-01

To determine the protective effects of memantine on cognitive function in patients receiving whole-brain radiotherapy (WBRT). Adult patients with brain metastases received WBRT and were randomized to receive placebo or memantine (20 mg/d), within 3 days of initiating radiotherapy for 24 weeks. Serial standardized tests of cognitive function were performed. Of 554 patients who were accrued, 508 were eligible. Grade 3 or 4 toxicities and study compliance were similar in the 2 arms. There was less decline in delayed recall in the memantine arm at 24 weeks (P = .059), but the difference was not statistically significant, possibly because there were only 149 analyzable patients at 24 weeks, resulting in only 35% statistical power. The memantine arm had significantly longer time to cognitive decline (hazard ratio 0.78, 95% confidence interval 0.62-0.99, P = .01); the probability of cognitive function failure at 24 weeks was 53.8% in the memantine arm and 64.9% in the placebo arm. Superior results were seen in the memantine arm for executive function at 8 (P = .008) and 16 weeks (P = .0041) and for processing speed (P = .0137) and delayed recognition (P = .0149) at 24 weeks. Memantine was well tolerated and had a toxicity profile very similar to placebo. Although there was less decline in the primary endpoint of delayed recall at 24 weeks, this lacked statistical significance possibly due to significant patient loss. Overall, patients treated with memantine had better cognitive function over time; specifically, memantine delayed time to cognitive decline and reduced the rate of decline in memory, executive function, and processing speed in patients receiving WBRT. RTOG 0614, ClinicalTrials.gov number CT00566852.

Extended local similarity analysis (eLSA) of microbial community and other time series data with replicates.

PubMed

Xia, Li C; Steele, Joshua A; Cram, Jacob A; Cardon, Zoe G; Simmons, Sheri L; Vallino, Joseph J; Fuhrman, Jed A; Sun, Fengzhu

2011-01-01

The increasing availability of time series microbial community data from metagenomics and other molecular biological studies has enabled the analysis of large-scale microbial co-occurrence and association networks. Among the many analytical techniques available, the Local Similarity Analysis (LSA) method is unique in that it captures local and potentially time-delayed co-occurrence and association patterns in time series data that cannot otherwise be identified by ordinary correlation analysis. However LSA, as originally developed, does not consider time series data with replicates, which hinders the full exploitation of available information. With replicates, it is possible to understand the variability of local similarity (LS) score and to obtain its confidence interval. We extended our LSA technique to time series data with replicates and termed it extended LSA, or eLSA. Simulations showed the capability of eLSA to capture subinterval and time-delayed associations. We implemented the eLSA technique into an easy-to-use analytic software package. The software pipeline integrates data normalization, statistical correlation calculation, statistical significance evaluation, and association network construction steps. We applied the eLSA technique to microbial community and gene expression datasets, where unique time-dependent associations were identified. The extended LSA analysis technique was demonstrated to reveal statistically significant local and potentially time-delayed association patterns in replicated time series data beyond that of ordinary correlation analysis. These statistically significant associations can provide insights to the real dynamics of biological systems. The newly designed eLSA software efficiently streamlines the analysis and is freely available from the eLSA homepage, which can be accessed at http://meta.usc.edu/softs/lsa.

Extended local similarity analysis (eLSA) of microbial community and other time series data with replicates

PubMed Central

2011-01-01

Background The increasing availability of time series microbial community data from metagenomics and other molecular biological studies has enabled the analysis of large-scale microbial co-occurrence and association networks. Among the many analytical techniques available, the Local Similarity Analysis (LSA) method is unique in that it captures local and potentially time-delayed co-occurrence and association patterns in time series data that cannot otherwise be identified by ordinary correlation analysis. However LSA, as originally developed, does not consider time series data with replicates, which hinders the full exploitation of available information. With replicates, it is possible to understand the variability of local similarity (LS) score and to obtain its confidence interval. Results We extended our LSA technique to time series data with replicates and termed it extended LSA, or eLSA. Simulations showed the capability of eLSA to capture subinterval and time-delayed associations. We implemented the eLSA technique into an easy-to-use analytic software package. The software pipeline integrates data normalization, statistical correlation calculation, statistical significance evaluation, and association network construction steps. We applied the eLSA technique to microbial community and gene expression datasets, where unique time-dependent associations were identified. Conclusions The extended LSA analysis technique was demonstrated to reveal statistically significant local and potentially time-delayed association patterns in replicated time series data beyond that of ordinary correlation analysis. These statistically significant associations can provide insights to the real dynamics of biological systems. The newly designed eLSA software efficiently streamlines the analysis and is freely available from the eLSA homepage, which can be accessed at http://meta.usc.edu/softs/lsa. PMID:22784572

Wigner time delay in photodetachment of Tm-and in photoionization of Yb: A comparative study

NASA Astrophysics Data System (ADS)

Saha, Soumyajit; Jose, Jobin; Deshmukh, Pranawa; Dolmatov, Valeriy; Kheifets, Anatoli; Manson, Steven

2017-04-01

Preliminary studies of Wigner time delay in photodetachment spectra of negative ions have been reported. Photodetachment time delay for some dipole channels of Tm- and of Cl- were calculated using relativistic random phase approximation (RRPA). Comparisons between photodetachment time delay of Cl- and photoionization time delay of Ar were made. We investigate the photodetachment time delay for all three relativistically split nd -> ɛ f channels of Tm- and for nd -> ɛ f channels of Yb (isoelectronic to Tm-) using RRPA. We study the effect of the shape resonance, brought about by the centrifugal barrier potential, on photodetachment time delay. A negative ion is a good laboratory for studying the effects of shape resonances on time delay since the phase is unaffected by the Coulomb component. Wigner time delay in photodetachment of Tm- and in photoionization of Yb: A comparative study.

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

PubMed

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

2017-12-05

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

Hospital discharge queues in Massachusetts.

PubMed

Gruenberg, L W; Willemain, T R

1982-02-01

There is growing concern over the inappropriate utilization of health care facilities. The high cost of hospital care and the apparent shortage of nursing home beds have focused attention on one aspect of this problem: the clinically unnecessary days (sometimes called "administrative days" or "ADs") spent in hospitals by patients who are awaiting placement in long-term care facilities. In this study, data from a 1976 Massachusetts Department of Public Health survey of patients backed up in hospitals were analyzed to determine the magnitude of the problem and to examine the influence of several major factors that had been hypothesized in previous studies to contribute to the backup. We demonstrate that the average delay of a patient found waiting in a "snapshot" survey (which is often used to estimate the magnitude of the problem) is significantly greater than the average delay experienced by a typical discharged patient. We show that there are at least two major factors that influence the delay time: nursing home preferences in accepting certain types of patients and nursing home occupancy rates in the hospital service area. Neither medical-surgical occupancy rate nor the number of AD patients waiting in the hospital was significantly correlated with the delay time.

Breast cancer patient delay in Fukushima, Japan following the 2011 triple disaster: a long-term retrospective study.

PubMed

Ozaki, Akihiko; Nomura, Shuhei; Leppold, Claire; Tsubokura, Masaharu; Tanimoto, Tetsuya; Yokota, Takeru; Saji, Shigehira; Sawano, Toyoaki; Tsukada, Manabu; Morita, Tomohiro; Ochi, Sae; Kato, Shigeaki; Kami, Masahiro; Nemoto, Tsuyoshi; Kanazawa, Yukio; Ohira, Hiromichi

2017-06-19

Little information is available concerning how patient delay may be affected by mass disasters. The main objectives of the present study are to identify whether there was a post-disaster increase in the risk of experiencing patient delay among breast cancer patients in an area affected by the 2011 triple disaster in Fukushima, Japan, and to elucidate factors associated with post-disaster patient delay. Sociodemographic factors (age, employment status, cohabitant status and evacuation status), health characteristics, and health access- and disaster-related factors were specifically considered. Records of symptomatic breast cancer patients diagnosed from 2005 to 2016 were retrospectively reviewed to calculate risk ratios (RRs) for patient delay in every year post-disaster compared with the pre-disaster baseline. Total and excessive patient delays were respectively defined as three months or more and twelve months or more from symptom recognition to first medical consultation. Logistic regression analysis was conducted for pre- and post-disaster patient delay in order to reveal any factors potentially associated with patient delay, and changes after the disaster. Two hundred nineteen breast cancer patients (122 pre-disaster and 97 post-disaster) were included. After adjustments for age, significant post-disaster increases in RRs of experiencing both total (RR: 1.66, 95% Confidence Interval (CI): 1.02-2.70, p < 0.05) and excessive patient delay (RR: 4.49, 95% CI: 1.73-11.65, p < 0.01) were observed. The RRs for total patient delay peaked in the fourth year post-disaster, and significant increases in the risk of excessive patient delay were observed in the second, fourth, and fifth years post-disaster, with more than five times the risk observed pre-disaster. A family history of any cancer was the only factor significantly associated with total patient delay post-disaster (odds ratio: 0.38, 95% CI: 0.15-0.95, p < 0.05), while there were no variables associated with delay pre-disaster. The triple disaster in Fukushima appears to have led to an increased risk of patient delay among breast cancer patients, and this trend has continued for five years following the disaster.

Delay-range-dependent chaos synchronization approach under varying time-lags and delayed nonlinear coupling.

PubMed

Zaheer, Muhammad Hamad; Rehan, Muhammad; Mustafa, Ghulam; Ashraf, Muhammad

2014-11-01

This paper proposes a novel state feedback delay-range-dependent control approach for chaos synchronization in coupled nonlinear time-delay systems. The coupling between two systems is esteemed to be nonlinear subject to time-lags. Time-varying nature of both the intrinsic and the coupling delays is incorporated to broad scope of the present study for a better-quality synchronization controller synthesis. Lyapunov-Krasovskii (LK) functional is employed to derive delay-range-dependent conditions that can be solved by means of the conventional linear matrix inequality (LMI)-tools. The resultant control approach for chaos synchronization of the master-slave time-delay systems considers non-zero lower bound of the intrinsic as well as the coupling time-delays. Further, the delay-dependent synchronization condition has been established as a special case of the proposed LK functional treatment. Furthermore, a delay-range-dependent condition, independent of the delay-rate, has been provided to address the situation when upper bound of the delay-derivative is unknown. A robust state feedback control methodology is formulated for synchronization of the time-delay chaotic networks against the L2 norm bounded perturbations by minimizing the L2 gain from the disturbance to the synchronization error. Numerical simulation results are provided for the time-delay chaotic networks to show effectiveness of the proposed delay-range-dependent chaos synchronization methodologies. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Referral-free health care and delay in diagnosis for lung cancer patients.

PubMed

Hsieh, Vivian Chia-Rong; Wu, Trong-Neng; Liu, Shu-Hui; Shieh, Shwn-Huey

2012-10-01

Lung cancer is not only one of the most prevalent cancers but is also a lethal disease with a very low 5-year survival rate. Delay in diagnosis further reduces the chance of early treatment and worsens patients' survival. The purpose of this study was to understand the delay in the diagnosis of lung cancer under the healthcare system in Taiwan, and to identify the factors associated with it. A total of 840 patients diagnosed with lung cancer who had completed or were undergoing cancer treatments were recruited from a medical center in central Taiwan from July 2007 to January 2011. Structured questionnaires were administered regarding demographic characteristics, factors associated with their time to diagnosis and the length of delay in days. Mean age was 62.68 years with 52.16 days to diagnosis on average. Number of hospital visits before confirmation of diagnosis differed significantly with the level of healthcare institution initially visited (P < 0.001). Compared with patients who had three or more hospital visits, patients who only visited two and one hospital(s) had a significant 34.91-day (95% confidence interval: 16.29-53.53) and 42.25-day (95% confidence interval: 20.76-63.76) reduction in their time to diagnosis (P < 0.001). As the number of hospital visits increased, the delay in diagnosis also increased. It is vital to shorten the time to diagnosis for lung cancer patients by limiting the number of medical visits and educating the public to restrict excessive use of medical resources and strengthen their trust in medical professionals.

Effects of delayed finishing/polishing on surface roughness, hardness and gloss of tooth-coloured restorative materials.

PubMed

Yazici, A Ruya; Tuncer, Duygu; Antonson, Sibel; Onen, Alev; Kilinc, Evren

2010-01-01

The aim of this study was to investigate the effect of delayed finishing/polishing on the surface roughness, hardness and gloss of tooth-coloured restorative materials. Four different tooth-coloured restoratives: a flowable resin composite- Tetric Flow, a hybrid resin composite- Venus, a nanohybrid resin composite- Grandio, and a polyacid modified resin composite- Dyract Extra were used. 30 specimens were made for each material and randomly assigned into three groups. The first group was finished/polished immediately and the second group was finished/polished after 24 hours. The remaining 10 specimens served as control. The surface roughness of each sample was recorded using a laser profilometer. Gloss measurements were performed using a small-area glossmeter. Vickers microhardness measurements were performed from three locations on each specimen surface under 100g load and 10s dwell time. Data for surface roughness and hardness were analyzed by Kruskal Wallis test and data for gloss were subjected to one-way ANOVA and Tukey test (P <.05). The smoothest surfaces were obtained under Mylar strip for all materials. While there were no significant differences in surface roughness of immediate and delayed finished/polished Dyract Extra samples, immediately finished/polished Venus and Grandio samples showed significantly higher roughness than the delayed polished samples (P <.05). In Tetric Flow samples, immediately finishing/polishing provided smoother surface than delayed finishing/polishing (P <.05). The highest gloss values were recorded under Mylar strip for all materials. While delayed finishing/polishing resulted in a significantly higher gloss compared to immediate finishing/polishing in Venus samples (P <.05), no differences were observed between delayed or immediate finishing/polishing for the other materials (P>.05). The lowest hardness values were found under Mylar strip. Delayed finishing/polishing significantly increased the hardness of all materials. The effect of delayed finishing/polishing on surface roughness, gloss and hardness appears to be material dependent.

Delay in surgery predisposes to meniscal and chondral injuries in anterior cruciate ligament deficient knees

PubMed Central

Gupta, Ravi; Masih, Gladson David; Chander, Gaurav; Bachhal, Vikas

2016-01-01

Background: Despite improvements in instability after anterior cruciate ligament (ACL) reconstruction, associated intraarticular injuries remain a major cause of concern and important prognostic factor for long term results as it may lead to osteoarthritis. Delay in ACL reconstruction has been in variably linked to increase in these injuries but there is lack of consensus regarding optimal timing of reconstruction. The goal of this study was to investigate delay in surgery and other factors, associated with intraarticular injuries in ACL deficient knees. Materials and Methods: A total of 438 patients (42 females; 396 males) enrolled for this prospective observational study. The average age of patients was 26.43 (range 17–51 years) years with a mean surgical delay of 78.91 (range 1 week - 18 years) weeks after injury. We analyzed the factors of age, sex, surgical delay, instability, and level of activity for possible association with intraarticular injuries. Results: Medial meniscus injuries had a significant association with surgical delay (P = 0.000) after a delay of 6 months. Lateral meniscus injuries had a significant association with degree of instability (P = 0.001). Medial-sided articular injuries were significantly affected by age (0.005) with an odds ratio (OR) of 1.048 (95% confidence interval [CI] of 1.014–1.082) reflecting 4.8% rise in incidence with each year. Lateral-sided injuries were associated with female sex (P = 0.018) with OR of 2.846 (95% CI of 1.200–6.752). The level of activity failed to reveal any significant associations. Conclusion: Surgical delay predicts an increase in medial meniscal and lateral articular injuries justifying early rather than delayed reconstruction in ACL deficient knees. Increasing age is positively related to intraarticular injuries while females are more susceptible to lateral articular injuries. PMID:27746491

Downhole delay assembly for blasting with series delay

DOEpatents

Ricketts, Thomas E.

1982-01-01

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

Psychosocial correlates of immediate versus delayed reconstruction of the breast.

PubMed

Wellisch, D K; Schain, W S; Noone, R B; Little, J W

1985-11-01

Two groups of consecutive patients from two different plastic surgical practice populations were evaluated to determine psychosocial differences between those who underwent immediate (n = 25) versus delayed (n = 38) breast reconstruction. Psychological assessment consisted of a standardized symptom inventory (BSI) and a specially designed self-report questionnaire investigating reactions unique to mastectomy and reconstruction. Both groups were extremely equivalent with regard to sociodemographic data, with the typical subject being a well-educated and employed Caucasian wife. Verbal reports of physical complaints revealed no significant differences between the two groups except for difficulty with arm movement, which was statistically higher for the immediate group (p = 0.006.). This difference most likely was due to the axillary dissection being performed simultaneously at the time of reconstruction. The relationship between timing of reconstruction and self-reported distress over the mastectomy experience revealed that only 25 percent of the women who underwent immediate repair reported "high distress" in recalling their mastectomy surgery compared with 60 percent of the delayed reconstruction group (p = 0.02). In reference to the two scales measuring psychological symptoms, a general trend was present, with the delayed group scoring higher (although not statistically significantly) on 9 of our 12 scales. Ninety-six percent of the immediate group and 89 percent of the delayed group reported satisfaction with results.(ABSTRACT TRUNCATED AT 250 WORDS)

Walking delays anticipatory postural adjustments but not reaction times in a choice reaction task.

PubMed

Haridas, C; Gordon, I T; Misiaszek, J E

2005-06-01

During standing, anticipatory postural adjustments (APAs) and focal movements are delayed while performing a choice reaction task, compared with a simple reaction task. We hypothesized that APAs and focal movements of a choice reaction task would be similarly delayed during walking. Furthermore, reaction times are delayed during walking compared with standing. We further hypothesized that APAs and focal movements would be delayed during walking, compared with standing, for both simple and choice reaction tasks. Subjects either walked or stood on a treadmill while holding on to stable handles. They were asked to push or pull on the handles in response to a visual cue. Muscle activity was recorded from muscles of the leg (APA) and arm (RT). Our results were in agreement with previous work showing APA onset was delayed in the choice reaction task compared with the simple reaction task. In addition, the interval between the onset of APA and focal movement activity increased with choice reaction tasks. The task of walking did not delay the onset of focal movement for either the simple or choice reaction tasks. Walking did delay the onset of the APA, but only during choice reaction tasks. The results suggest the added demand of walking does not significantly modify the control of focal arm movements. However, additional attentional demands while walking may compromise anticipatory postural control.

Can the attention training technique turn one marshmallow into two? Improving children's ability to delay gratification.

PubMed

Murray, Joanne; Theakston, Anna; Wells, Adrian

2016-02-01

The seminal Marshmallow Test (Mischel & Ebbesen, 1970) has reliably demonstrated that children who can delay gratification are more likely to be emotionally stable and successful later in life. However, this is not good news for those children who can't delay. Therefore, this study aimed to explore whether a metacognitive therapy technique, Attention Training (ATT: Wells, 1990) can improve young children's ability to delay gratification. One hundred children participated. Classes of 5-6 year olds were randomly allocated to either the ATT or a no-intervention condition and were tested pre and post-intervention on ability to delay gratification, verbal inhibition (executive control), and measures of mood. The ATT intervention significantly increased (2.64 times) delay of gratification compared to the no-intervention condition. After controlling for age and months in school, the ATT intervention and verbal inhibition task performance were significant independent predictors of delay of gratification. These results provide evidence that ATT can improve children's self-regulatory abilities with the implication that this might reduce psychological vulnerability later in life. The findings highlight the potential contribution that the Self-Regulatory Executive Function (S-REF) model could make to designing techniques to enhance children's self-regulatory processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of comprehensive education protocol in decreasing pre-hospital stroke delay among Chinese urban community population.

PubMed

Chen, Shengyun; Sun, Haixin; Zhao, Xingquan; Fu, Paul; Yan, Wang; Yilong, Wang; Hongyan, Jia; Yan, Zhang; Wenzhi, Wang

2013-06-01

Studies have shown that awareness of early stroke symptoms and the use of ambulances are two important factors in decreasing pre-hospital stroke delay. The purpose of this study is to evaluate a comprehensive educational stroke protocol in improving stroke response times. Two urban communities in Beijing (population ≍50 000), matched in economic status and geography, were enrolled in this study. A comprehensive educational protocol, which included public lectures and distribution of instructive material for the community and its medical staff, was implemented from August 2008 to December 2010. Surveillance of new onset stroke in both communities was carried out during the same period. Pre-hospital delay time and percentage of patients using emergency medical services (EMS) were compared between the two communities. After comprehensive educational protocol, we found that: (i) pre-hospital delay (time from stroke symptom onset to hospital arrival) decreased from 180 to 79 minutes, (ii) the proportion of patients arriving within three hours of stroke onset increased from 55·8% to 80·4%, (iii) pre-hospital delay of stroke patients with symptoms of paralysis, numbness, and speech impediments was decreased, and (iv) the proportion of stroke patients calling for EMS increased from 50·4% to 60·7%. The comprehensive educational stroke protocol was significantly effective in decreasing pre-hospital stroke delay.

Positive parenting mitigates the effects of poor self-regulation on body mass index trajectories from ages 4-15 years.

PubMed

Connell, Lauren E; Francis, Lori A

2014-08-01

This study sought to determine whether parenting style moderates the effects of delay of gratification on body mass index (BMI) trajectories from ages 4-15 years. Longitudinal data were analyzed for 778 children drawn from the Study of Early Child Care and Youth Development. Parenting style (i.e., authoritative, authoritarian, permissive, and neglectful) was created from measures of mothers' sensitivity and expectations for self-control when children were age 4 years. Self-regulation was also measured at 4 years using a well-known delay of gratification protocol. BMI was calculated from measured height and weight at each time point. Mixed modeling was used to test the interaction of parenting styles and ability to delay gratification on BMI trajectories from 4-15 years. There was a significant interaction effect of parenting and ability to delay on BMI growth from 4-15 years for boys. Boys who had authoritarian mothers and failed to delay gratification had a significantly steeper rate of growth in BMI from childhood through adolescence than children in any other parenting by delay group. Authoritative and permissive parenting styles were protective against more rapid BMI gains for boys who could not delay gratification. Ability to delay gratification was protective against BMI gains for boys who had parents with authoritarian or neglectful parenting styles.

Positive parenting mitigates the effects of poor self-regulation on BMI trajectories from age 4 to 15 years

PubMed Central

Connell, Lauren E.; Francis, Lori A.

2014-01-01

Objective This study sought to determine whether parenting style moderated the effects of delay of gratification on BMI trajectories from age 4 to 15 years. Methods Longitudinal data were analyzed on 778 children drawn from the Study of Early Child Care and Youth Development. Parenting style (authoritative, authoritarian, permissive, neglectful) was created from measures of mothers’ sensitivity and expectations for self-control when children were age 4 years. Self-regulation was also measured at 4 years using a well-known delay of gratification protocol. BMI was calculated from measured height and weight at each time point. Mixed modeling was used to test the interaction of parenting styles and ability to delay gratification on BMI trajectories from 4 to 15 years. Results There was a significant interaction effect of parenting and ability to delay on BMI growth from 4 to 15 years for boys. Boys who had authoritarian mothers and failed to delay gratification had a significantly steeper rate of growth in BMI from childhood through adolescence than children in any other parenting x delay group. Conclusions Authoritative and permissive parenting styles were protective against more rapid BMI gains for boys who could not delay gratification. Ability to delay gratification was protective against BMI gains for boys who had parents with authoritarian or neglectful parenting styles. PMID:23977874

Evening daylight may cause adolescents to sleep less in spring than in winter.

PubMed

Figueiro, Mariana G; Rea, Mark S

2010-07-01

Sleep restriction commonly experienced by adolescents can stem from a slower increase in sleep pressure by the homeostatic processes and from phase delays of the circadian system. With regard to the latter potential cause, the authors hypothesized that because there is more natural evening light during the spring than winter, a sample of adolescent students would be more phase delayed in spring than in winter, would have later sleep onset times, and because of fixed school schedules would have shorter sleep durations. Sixteen eighth-grade subjects were recruited for the study. The authors collected sleep logs and saliva samples to determine their dim light melatonin onset (DLMO), a well-established circadian marker. Actual circadian light exposures experienced by a subset of 12 subjects over the course of 7 days in winter and in spring using a personal, head-worn, circadian light measurement device are also reported here. Results showed that this sample of adolescents was exposed to significantly more circadian light in spring than in winter, especially during the evening hours when light exposure would likely delay circadian phase. Consistent with the light data, DLMO and sleep onset times were significantly more delayed, and sleep durations were significantly shorter in spring than in winter. The present ecological study of light, circadian phase, and self-reported sleep suggests that greater access to evening daylight in the spring may lead to sleep restriction in adolescents while attending school. Therefore, lighting schemes that reduce evening light in the spring may encourage longer sleep times in adolescents.

The effects of citalopram and fluoxetine on sexual behavior in healthy men: evidence of delayed ejaculation and unaffected sexual desire. A randomized, placebo-controlled, double-blind, double-dummy, parallel group study.

PubMed

Madeo, Bruno; Bettica, Paolo; Milleri, Stefano; Balestrieri, Antonio; Granata, Antonio R M; Carani, Cesare; Rochira, Vincenzo

2008-10-01

Selective serotonin reuptake inhibitors (SSRIs) are known to induce delayed orgasm and delayed ejaculation, while their effect on other aspects of sexual function, such as sexual motivation, arousal, and erectile function are unclear. In order to evaluate the effect of chronic administration of two SSRIs, citalopram and fluoxetine, on normal sexual function, we studied the parameters of male sexual behavior, erectile function, and ejaculation on 48 healthy male volunteers, aged 29.5 +/- 4.9, in a randomized, placebo-controlled, double-blind, double-dummy study. Methods. The subjects were randomized to receive placebo (16 subjects), or fluoxetine (20 mg/day) (16 subjects) or citalopram (20 mg/day) for the first week, and 40 mg/day in the following 3 weeks (16 subjects). Sexual function was investigated at the screening and at the end of the study by means of test of penile erection (TPE) and masturbation ejaculation latency time (MELT) performed during visual erotic stimulation, and at each visit by self-filled questionnaires (International Index Erectile Function [IIEF-15] and Golombock Rust Inventory of Sexual Satisfaction [GRISS]). All the erectile parameters, evaluated by means of RigiScan Plus during TPE, were not significantly different when both fluoxetine and citalopram were compared with placebo. A delay in the ejaculation time was observed both during citalopram and during fluoxetine treatment when compared with placebo, reaching a statistical significance only with citalopram. During the treatment with citalopram and fluoxetine, the IIEF-15 score of all items decreased except for those items related to sexual desire; however, the scores were significantly lower only for the citalopram treatment. The treatment with citalopram or with fluoxetine was confirmed to delay ejaculation, but was significant only for citalopram. Citalopram and fluoxetine did not affect sexual desire. Citalopram and fluoxetine did not directly affect penile erection as objectively assessed by RigiScan, although an impairment in the subjective assessment of erectile function was observed, but was significant only for citalopram, and it was thought to be a possible consequence of the delayed ejaculation perceived as a trouble.

Time-delayed feedback control of diffusion in random walkers.

PubMed

Ando, Hiroyasu; Takehara, Kohta; Kobayashi, Miki U

2017-07-01

Time delay in general leads to instability in some systems, while specific feedback with delay can control fluctuated motion in nonlinear deterministic systems to a stable state. In this paper, we consider a stochastic process, i.e., a random walk, and observe its diffusion phenomenon with time-delayed feedback. As a result, the diffusion coefficient decreases with increasing delay time. We analytically illustrate this suppression of diffusion by using stochastic delay differential equations and justify the feasibility of this suppression by applying time-delayed feedback to a molecular dynamics model.

Systemic delay propagation in the US airport network

PubMed Central

Fleurquin, Pablo; Ramasco, José J.; Eguiluz, Victor M.

2013-01-01

Technologically driven transport systems are characterized by a networked structure connecting operation centers and by a dynamics ruled by pre-established schedules. Schedules impose serious constraints on the timing of the operations, condition the allocation of resources and define a baseline to assess system performance. Here we study the performance of an air transportation system in terms of delays. Technical, operational or meteorological issues affecting some flights give rise to primary delays. When operations continue, such delays can propagate, magnify and eventually involve a significant part of the network. We define metrics able to quantify the level of network congestion and introduce a model that reproduces the delay propagation patterns observed in the U.S. performance data. Our results indicate that there is a non-negligible risk of systemic instability even under normal operating conditions. We also identify passenger and crew connectivity as the most relevant internal factor contributing to delay spreading. PMID:23362459

Discrimination and Delayed Health Care Among Transgender Women and Men: Implications for Improving Medical Education and Health Care Delivery.

PubMed

Jaffee, Kim D; Shires, Deirdre A; Stroumsa, Daphna

2016-11-01

The transgender community experiences health care discrimination and approximately 1 in 4 transgender people were denied equal treatment in health care settings. Discrimination is one of the many factors significantly associated with health care utilization and delayed care. We assessed factors associated with delayed medical care due to discrimination among transgender patients, and evaluated the relationship between perceived provider knowledge and delayed care using Anderson's behavioral model of health services utilization. Multivariable logistic regression analysis was used to test whether predisposing, enabling, and health system factors were associated with delaying needed care for transgender women and transgender men. A sample of 3486 transgender participants who took part in the National Transgender Discrimination Survey in 2008 and 2009. Predisposing, enabling, and health system environment factors, and delayed needed health care. Overall, 30.8% of transgender participants delayed or did not seek needed health care due to discrimination. Respondents who had to teach health care providers about transgender people were 4 times more likely to delay needed health care due to discrimination. Transgender patients who need to teach their providers about transgender people are significantly more likely to postpone or not seek needed care. Systemic changes in provider education and training, along with health care system adaptations to ensure appropriate, safe, and respectful care, are necessary to close the knowledge and treatment gaps and prevent delayed care with its ensuing long-term health implications.

Reliability and discriminative validity of sudden ankle inversion measurements in patients with chronic ankle instability.

PubMed

Eechaute, Christophe; Vaes, Peter; Duquet, William; Van Gheluwe, Bart

2009-07-01

Studies investigating peroneal muscle reaction times in chronically unstable ankle joints present conflicting results. The degree of reliability and accuracy of these measurements is unknown in patients with chronic ankle instability (CAI). 40 patients with CAI and 30 healthy subjects were tested using a sudden ankle inversion of 50 degrees while standing on a trapdoor device. Sudden ankle inversion measurements were registered using electromyography, accelerometry and electrogoniometry. For reliability testing, intra-class coefficients (ICCs; model 3,1) and standard errors of measurements of the latency time, motor response time and electromechanical delay of the peroneus longus muscle, the time and angular position of onset of decelerations, the mean and maximum inversion speed and the total inversion time were calculated in 15 patients with CAI. To assess between-group differences, t-tests for independent samples (p<.05) were used. ICCs ranged from .20 (angular position of onset of the second deceleration) to .98 (electromechanical delay of the peroneus longus muscle). Significant between-group differences were observed in only 2 of the 12 variables (for the electromechanical delay of the peroneus longus muscle, p=.001; time of onset of the second deceleration, p=.040). The latency time and motor response time of the peroneus longus muscle, the total inversion time and the mean inversion speed demonstrate acceptable reliability in healthy subjects and patients. The latency time and motor response time of the peroneus longus muscle are not delayed in patients with CAI. Ankle inversion measurements are not discriminative for CAI.

Cortical Thickness Changes Correlate with Cognition Changes after Cognitive Training: Evidence from a Chinese Community Study

PubMed Central

Jiang, Lijuan; Cao, Xinyi; Li, Ting; Tang, Yingying; Li, Wei; Wang, Jijun; Chan, Raymond C.; Li, Chunbo

2016-01-01

The aim of this study was to investigate whether changes in cortical thickness correlated with cognitive function changes in healthy older adults after receiving cognitive training interventions. Moreover, it also aimed to examine the differential impacts of a multi-domain and a single-domain cognitive training interventions. Longitudinal magnetic resonance imaging (MRI) scanning was performed on participants 65–75 years of age using the Siemens 3.0 T Trio Tim with the Magnetization Prepared Rapid Gradient Echo (MPRAGE) sequence. The cortical thickness was determined using FreeSurfer Software. Cognitive functioning was evaluated using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). There were significant group × time interaction effects on the left supramarginal, the left frontal pole cortical regions; and a marginal significant group × time interaction effects on visuospatial/constructional and delayed memory scores. In a multi-domain cognitive training group, a number of cortical region changes were significantly positively correlated with changes in attention, delayed memory, and the total score, but significantly negatively correlated with changes in immediate memory and language scores. In the single-domain cognitive training group, some cortical region changes were significantly positively associated with changes in immediate memory, delayed memory, and the total score, while they were significantly negatively associated with changes in visuospatial/constructional, language, and attention scores. Overall, multi-domain cognitive training offered more advantages in visuospatial/constructional, attention, and delayed memory abilities, while single-domain cognitive training benefited immediate memory ability more effectively. These findings suggest that healthy older adults benefit more from the multi-domain cognitive training than single-domain cognitive training. Cognitive training has impacted on cortical thickness changes in healthy elderly. PMID:27252649

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.

Study of Relationship Between Illness Perception and Delay in Seeking Help for Breast Cancer Patients Based on Leventhal's Self-Regulation Model.

PubMed

Attari, Seyedeh Maryam; Ozgoli, Giti; Solhi, Mahnaz; Alavi Majd, Hamid

2016-01-01

One of the major causes of morbidity and mortality in breast cancer patients is delay in seeking help. Leventhal's self-regulation model provides an appropriate framework to assess delay in seeking help. The aim of this study was to investigate the relationship between "illness perception" and "help seeking delay" in breast cancer patients based on Leventhal's self-regulation model. In this correlational descriptive study with convenience sampling conducted in 2013, participants were 120 women with breast cancer who were diagnosed in the last year and referred to chemotherapy and radiotherapy centers in Rasht, Iran. Data collection scales included demographic data, Revised Illness Perception Questionnaire (IPQ-R)and a researcher made questionnaire to measure the delay in seeking help. Pre-hospital delay (help seeking delay) was evaluated in 3 phases (assessment, disease, behavior). The data were analyzed using SPSS-19. The mean (SD) age calculated for the patients was 47.3±10.2. Some 43% of the patients had a high school or higher education level and 82% were married. The "pre-hospital delay" was reported ≥3 months. Logistic regression analysis showed that none of the illness perception components were correlated with appraisal and behavioral delay phases. In the illness delay phase, "time line" (p-value =0.04) and "risk factors"(p-value=0.03) had significant effects on reducing and "psychological attributions" had significant effects on increasing the delay (p-value =0.01). "Illness coherence" was correlated with decreased pre-hospital patient delay (p-value<0.01). Women's perceptions of breast cancer influences delay in seeking help. In addition to verifying the validity of Leventhal's self-regulation model in explaining delay in seeking help, the results signify the importance of the "illness delay phase" (decision to seek help) and educational interventions-counseling for women in the community.

Finite time synchronization of memristor-based Cohen-Grossberg neural networks with mixed delays.

PubMed

Chen, Chuan; Li, Lixiang; Peng, Haipeng; Yang, Yixian

2017-01-01

Finite time synchronization, which means synchronization can be achieved in a settling time, is desirable in some practical applications. However, most of the published results on finite time synchronization don't include delays or only include discrete delays. In view of the fact that distributed delays inevitably exist in neural networks, this paper aims to investigate the finite time synchronization of memristor-based Cohen-Grossberg neural networks (MCGNNs) with both discrete delay and distributed delay (mixed delays). By means of a simple feedback controller and novel finite time synchronization analysis methods, several new criteria are derived to ensure the finite time synchronization of MCGNNs with mixed delays. The obtained criteria are very concise and easy to verify. Numerical simulations are presented to demonstrate the effectiveness of our theoretical results.

Inducing jet-lag in older people: directional asymmetry

NASA Technical Reports Server (NTRS)

Monk, T. H.; Buysse, D. J.; Carrier, J.; Kupfer, D. J.

2000-01-01

Twenty healthy elderly subjects (12 female, 8 male; mean age 81 years, range 67-87 years) each experienced a 15-day time isolation protocol in which they lived individually in a special laboratory apartment in which sleep and circadian rhythm measures could be taken. There were two experiments: one (6 females, 4 males) involved a 6-h phase advance of the sleep/wake cycle, and the other (6 females, 4 males) a 6-h phase delay. Each started with 5 baseline days, immediately followed by the phase shift. The subject was then held to the phase shifted routine for the remainder of the study. Rectal temperatures were recorded minute-by-minute throughout the entire experiment and each night of sleep was recorded using polysomnography. A directional asymmetry in phase-shift effects was apparent, with significantly more sleep disruption and circadian rhythm amplitude disruption after the phase advance than after the phase delay. Sleep disruption was reflected in reduced time spent asleep, and in changed REM latency, which increased in the phase advance direction but decreased in the phase delay direction. Although the phase advance led to a significant increase in wakefulness in the first half of the night, the phase delay did not lead to an equivalent increase in wakefulness during the second half of the night. Examination of both raw and 'demasked' circadian rectal temperature rhythms confirmed that phase adjustment was slow in both directions, but was less slow (and more monotonic) after the phase delay than after the phase advance. Subjective alertness suffered more disruption after the phase advance than after the phase delay.

A Study on Health Seeking Behaviors of Patients of Post-Kala-Azar Dermal Leishmaniasis

PubMed Central

Basher, Ariful; Nath, Proggananda; Nabi, Shah Golam; Selim, Shahjada; Rahman, Md Fashiur; Sutradhar, Satya Ranjan; Faiz, Abul; Bhuiyan, Matiur Rahman; Ahmed, Be-Nazir; Rahman, Ridwanur

2015-01-01

Post-Kala-Azar Dermal Leishmaniasis (PKDL) remains a major public health threat in Bangladesh. A cross-sectional study was carried out in Surya Kanta Kala azar Research Centre (SKKRC), Mymensingh, from January 2012 to July 2013 to evaluate the health seeking behaviour and the length of delay of PKDL management. The consecutive 200 diagnosed PKDL cases that got treatment in SKKRC hospital were subjected to evaluation. Most (98%) of the patients were not aware and had no knowledge about PKDL, though 87.5% had a history of history of Kala-azar treatment. Many patients reported first to village doctor (15.5%), the pharmacy shop (10%), or traditional health provider (7.5%) upon recognition of symptom. The time between the initial symptom recognition and first medical consultation (patient delay) ranged from 10 days to 4745 days (13 years) with a median of 373 days (mean: 696; IQR: 138 to 900 days). The time between first medical consultations to definite treatment (system delay) ranged from 0 days to 1971 days (5.4 years), with a median delay of 14 days (mean: 46.48; IQR: 7 to 44 days) that was reported in this study. Age, education, occupation, and residential status had significant association with patient delay (P < 0.05). Educational status, occupation, number of treatment providers, and first health care provider had a significant association with system delay (P < 0.05). Success in PKDL diagnosis and treatment requires specific behavior from patients and health care providers which facilitate those practices. PMID:26788500

Primary Realignment for Pelvic Fracture Urethral Injury Is Associated With Prolonged Time to Urethroplasty and Increased Stenosis Complexity.

PubMed

Horiguchi, Akio; Shinchi, Masayuki; Masunaga, Ayako; Okubo, Kazuki; Kawamura, Kazuki; Ojima, Kenichiro; Ito, Keiichi; Asano, Tomohiko; Azuma, Ryuichi

2017-10-01

To compare the clinical courses of patients with pelvic fracture urethral injury (PFUI) according to initial management strategy. We reviewed the clinical courses of 63 patients with PFUI who were initially treated elsewhere and underwent delayed anastomotic urethroplasty by a single surgeon between 2008 and 2015. Patients were grouped according to their initial treatment: by suprapubic tube placement alone (49 patients, SPT group) or primary realignment (14 patients, PR group). Time to urethroplasty was defined as the period between injury and delayed urethroplasty. Clinical data regarding the status of urethral stenosis, urethroplasty procedure, and treatment outcome were analyzed. The mean time to urethroplasty in the PR group was about 3 times than that in the SPT group (133 months vs 47 months, P = .035). Fifty percent of the PR group (7 of 14) had a history of repeated urethrotomy or dilation before referral, a percentage significantly higher than that of the SPT group (20.4%, 10 of 49, P = .027). The percentage of patients having a false passage and iatrogenic scar was significantly higher in the PR group (42.9% vs 16.3%, P = .035), but there was no significant between-group difference in urethral stenosis length, operative time, operative blood loss, or the percentage of patients requiring inferior pubectomy or urethral rerouting. PR does not facilitate delayed urethroplasty, and patients who undergo PR are at high risk of having a more complicated stenosis and longer time to urethroplasty, presumably because of repeated transurethral procedures. Copyright © 2017 Elsevier Inc. All rights reserved.

Risk Factors for Speech Delay of Unknown Origin in Three-Year-Old Children.

ERIC Educational Resources Information Center

Campbell, Thomas F.; Dollaghan, Christine A.; Rockette, Howard E.; Paradise, Jack L.; Feldman, Heidi M.; Shriberg, Lawrence D.; Sabo, Diane L.; Kurs-Lasky, Marcia

2003-01-01

Compared 100 three-year-olds with speech delay of unknown origin and 539 same-age peers with respect to 6 speech disorder variables; also examined abnormal hearing in a subset of 279 children. Found significant odds ratios only for low maternal education, male sex, and positive family history; a child with all 3 factors was 7.71 times as likely to…

Time-delayed chameleon: Analysis, synchronization and FPGA implementation

NASA Astrophysics Data System (ADS)

Rajagopal, Karthikeyan; Jafari, Sajad; Laarem, Guessas

2017-12-01

In this paper we report a time-delayed chameleon-like chaotic system which can belong to different families of chaotic attractors depending on the choices of parameters. Such a characteristic of self-excited and hidden chaotic flows in a simple 3D system with time delay has not been reported earlier. Dynamic analysis of the proposed time-delayed systems are analysed in time-delay space and parameter space. A novel adaptive modified functional projective lag synchronization algorithm is derived for synchronizing identical time-delayed chameleon systems with uncertain parameters. The proposed time-delayed systems and the synchronization algorithm with controllers and parameter estimates are then implemented in FPGA using hardware-software co-simulation and the results are presented.

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

PubMed Central

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

2013-01-01

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

Automating individualized coaching and authentic role-play practice for brief intervention training.

PubMed

Hayes-Roth, B; Saker, R; Amano, K

2010-01-01

Brief intervention helps to reduce alcohol abuse, but there is a need for accessible, cost-effective training of clinicians. This study evaluated STAR Workshop , a web-based training system that automates efficacious techniques for individualized coaching and authentic role-play practice. We compared STAR Workshop to a web-based, self-guided e-book and a no-treatment control, for training the Engage for Change (E4C) brief intervention protocol. Subjects were medical and nursing students. Brief written skill probes tested subjects' performance of individual protocol steps, in different clinical scenarios, at three test times: pre-training, post-training, and post-delay (two weeks). Subjects also did live phone interviews with a standardized patient, post-delay. STAR subjects performed significantly better than both other groups. They showed significantly greater improvement from pre-training probes to post-training and post-delay probes. They scored significantly higher on post-delay phone interviews. STAR Workshop appears to be an accessible, cost-effective approach for training students to use the E4C protocol for brief intervention in alcohol abuse. It may also be useful for training other clinical interviewing protocols.

Air pollution is associated with brainstem auditory nuclei pathology and delayed brainstem auditory evoked potentials.

PubMed

Calderón-Garcidueñas, Lilian; D'Angiulli, Amedeo; Kulesza, Randy J; Torres-Jardón, Ricardo; Osnaya, Norma; Romero, Lina; Keefe, Sheyla; Herritt, Lou; Brooks, Diane M; Avila-Ramirez, Jose; Delgado-Chávez, Ricardo; Medina-Cortina, Humberto; González-González, Luis Oscar

2011-06-01

We assessed brainstem inflammation in children exposed to air pollutants by comparing brainstem auditory evoked potentials (BAEPs) and blood inflammatory markers in children age 96.3±8.5 months from highly polluted (n=34) versus a low polluted city (n=17). The brainstems of nine children with accidental deaths were also examined. Children from the highly polluted environment had significant delays in wave III (t(50)=17.038; p<0.0001) and wave V (t(50)=19.730; p<0.0001) but no delay in wave I (p=0.548). They also had significantly longer latencies than controls for interwave intervals I-III, III-V, and I-V (all t(50)>7.501; p<0.0001), consisting with delayed central conduction time of brainstem neural transmission. Highly exposed children showed significant evidence of inflammatory markers and their auditory and vestibular nuclei accumulated α synuclein and/or β amyloid(1-42). Medial superior olive neurons, critically involved in BAEPs, displayed significant pathology. Children's exposure to urban air pollution increases their risk for auditory and vestibular impairment. Copyright © 2011 ISDN. Published by Elsevier Ltd. All rights reserved.

A data-driven search for semen-related phenotypes in conception delay

PubMed Central

Patel, C. J.; Sundaram, R.; Buck Louis, G. M.

2016-01-01

SUMMARY Sperm count, morphology, and motility have been reported to be predictive of pregnancy, although with equivocal basis prompting some authors to question the prognostic value of semen analysis. To assess the utility of including semen quality data in predicting conception delay or requiring >6 cycles to become pregnant (referred to as conception delay), we utilized novel data-driven analytic techniques in a pre-conception cohort of couples prospectively followed up for time-to-pregnancy. The study cohort comprised 402 (80%) male partners who provided semen samples and had time-to-pregnancy information. Female partners used home pregnancy tests and recorded results in daily journals. Odds ratios (OR), false discovery rates, and 95% confidence intervals (CIs) for conception delay (time-to-pregnancy > 6 cycles) were estimated for 40 semen quality phenotypes comprising 35 semen quality endpoints and 5 closely related fecundity determinants (body mass index, time of contraception, lipids, cotinine and seminal white blood cells). Both traditional and strict sperm phenotype measures were associated with lower odds of conception delay. Specifically, for an increase in percent morphologically normal spermatozoa using traditional methods, we observed a 40% decrease in conception delay (OR = 0.6, 95% CI = 0.50, 0.81; p = 0.0003). Similarly, for an increase in strict criteria, we observed a 30% decrease in odds for conception delay (OR = 0.7, 95% CI = 0.52, 0.83; p = 0.001). On the other hand, an increase in percent coiled tail spermatozoa was associated with a 40% increase in the odds for conception delay (OR = 1.4, 95% CI = 1.12, 1.75; p = 0.003). However, our findings suggest that semen phenotypes have little predictive value of conception delay (area under the curve of 73%). In a multivariate model containing significant semen factors and traditional risk factors (i.e. age, body mass index, cotinine and ever having fathered a pregnancy), there was a modest improvement in prediction of conception delay (16% increase in area under the curve, p < 0.0002). PMID:27792860

Does delayed pushing in the second stage of labor impact perinatal outcomes?

PubMed

Frey, Heather A; Tuuli, Methodius G; Cortez, Sarah; Odibo, Anthony O; Roehl, Kimberly A; Shanks, Anthony L; Macones, George A; Cahill, Alison G

2012-11-01

To estimate maternal, neonatal, and labor outcomes associated with delayed pushing. A retrospective cohort study of all consecutive women admitted to a single institution in labor at term who reached the second stage of labor. Pregnancies with multiple fetuses or major anomalies were excluded. Delayed pushing was defined as initiation of pushing ≥60 minutes after complete dilatation. Primary outcome was mode of delivery. Multivariable logistic regression was used to control for confounding. Of the 5290 women who met inclusion criteria, 471 (8.9%) employed delayed pushing, and 4819 (91.1%) pushed immediately. Delayed pushing was associated with increased rates of cesarean, operative vaginal delivery, maternal fever, and lower arterial cord pH. Duration of the second stage and length of time spent pushing were significantly longer with delayed pushing. Delayed pushing is associated with lower rates of spontaneous vaginal delivery and increased adverse maternal and neonatal outcomes. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Minimizing delays in the Jordanian construction industry by adopting BIM technology

NASA Astrophysics Data System (ADS)

Btoush, M.; Harun, A. T.

2017-11-01

The Jordanian construction industry plays a significant role and contributes immensely to the gross domestic product (GDP) of the economy. However, the Jordanian public work and housing ministry and most industry players including engineers and contractors have reported that most of the projects experience delays which lead time and cost overruns, and extra efforts. The main causes of delays identified by researchers include poor scheduling and planning, change orders, site conditions, weather, late deliveries, incompetent technical staff. To address these challenges, the implementation of building information modelling (BIM) is paramount. This paper presents BIM as a powerful tool for reducing delays in Jordan construction projects. The paper focuses on two main parts; the first part involves the identification of the major causes of delays, and the second part is to accurately outline the roles and responsibilities of BIM specialist in construction projects. Finally, the paper matches the roles and responsibilities of BIM specialist and the causes of delays, and how the delays are addressed through BIM specialist.

The time delay in strong gravitational lensing with Gauss-Bonnet correction

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

Man, Jingyun; Cheng, Hongbo, E-mail: jingyunman@mail.ecust.edu.cn, E-mail: hbcheng@ecust.edu.cn

2014-11-01

The time delay between two relativistic images in the strong gravitational lensing governed by Gauss-Bonnet gravity is studied. We make a complete analytical derivation of the expression of time delay in presence of Gauss-Bonnet coupling. With respect to Schwarzschild, the time delay decreases as a consequence of the shrinking of the photon sphere. As the coupling increases, the second term in the time delay expansion becomes more relevant. Thus time delay in strong limit encodes some new information about geometry in five-dimensional spacetime with Gauss-Bonnet correction.

Hospital variation in time to defibrillation after in-hospital cardiac arrest.

PubMed

Chan, Paul S; Nichol, Graham; Krumholz, Harlan M; Spertus, John A; Nallamothu, Brahmajee K

2009-07-27

Delays to defibrillation are associated with worse survival after in-hospital cardiac arrest, but the degree to which hospitals vary in defibrillation response times and hospital predictors of delays remain unknown. Using hierarchical models, we evaluated hospital variation in rates of delayed defibrillation (>2 minutes) and its impact on survival among 7479 adult inpatients with cardiac arrests at 200 hospitals within the National Registry of Cardiopulmonary Resuscitation. Adjusted rates of delayed defibrillation varied substantially among hospitals (range, 2.4%-50.9%), with hospital-level effects accounting for a significant amount of the total variation in defibrillation delays after adjusting for patient factors. We found a 46% greater odds of patients with identical covariates getting delayed defibrillation at one randomly selected hospital compared with another. Among traditional hospital factors evaluated, however, only bed volume (reference category: <200 beds; 200-499 beds: odds ratio [OR], 0.62 [95% confidence interval {CI}, 0.48-0.80]; >or=500 beds: OR, 0.74 [95% CI, 0.53-1.04]) and arrest location (reference category: intensive care unit; telemetry unit: OR, 1.92 [95% CI, 1.65-2.22]; nonmonitored unit: OR, 1.90 [95% CI, 1.61-2.24]) were associated with differences in rates of delayed defibrillation. Wide variation also existed in adjusted hospital rates of survival to discharge (range, 5.3%-49.6%), with higher survival among hospitals in the top-performing quartile for defibrillation time (compared with the bottom quartile: OR for top quartile, 1.41 [95% CI, 1.11-1.77]). Rates of delayed defibrillation vary widely among hospitals but are largely unexplained by traditional hospital factors. Given its association with improved survival, future research is needed to better understand best practices in the delivery of defibrillation at top-performing hospitals.

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

PubMed

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

2016-08-01

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

Factors affecting breast cancer treatment delay in Turkey: a study from Turkish Federation of Breast Diseases Societies.

PubMed

Ozmen, Vahit; Boylu, Sukru; Ok, Engin; Canturk, Nuh Zafer; Celik, Varol; Kapkac, Murat; Girgin, Sadullah; Tireli, Mustafa; Ihtiyar, Enver; Demircan, Orhan; Baskan, Mazhar Semih; Koyuncu, Ayhan; Tasdelen, Ismet; Dumanli, Esra; Ozdener, Fatih; Zaborek, Piotr

2015-02-01

One of the most important factors in breast cancer (BC) mortality is treatment delay. The primary goal of this survey was to identify factors affecting the total delay time (TDT) in Turkish BC patients. A total of 1031 patients with BC were surveyed using a uniform questionnaire. The time between discovering the first symptom and signing up for the first medical visit (patient delay time; PDT) and the time between the first medical visit and the start of therapy (system delay time; SDT) were modelled separately with multilevel regression. The mean PDT, SDT and TDT were 4.8, 10.5 and 13.8 weeks, respectively. In all, 42% of the patients had a TDT >12 weeks. Longer PDT was significantly correlated with disregarding symptoms and having age of between 30 and 39 years. Shorter PDT was characteristic of patients who: had stronger self-examination habits, received more support from family and friends and had at least secondary education. Predictors of longer SDT included disregard of symptoms, distrust in success of therapy and medical system and having PDT in excess of 4 weeks. Shorter SDT was linked to the age of >60 years. Patients who were diagnosed during a periodic check-up or opportunistic mammography displayed shorter SDT compared with those who had symptomatic BC and their first medical examination was by a surgeon. TDT in Turkey is long and remains a major problem. Delays can be reduced by increasing BC awareness, implementing organized population-based screening programmes and founding cancer centres. © The Author 2014. Published by Oxford University Press on behalf of the European Public Health Association.

Determining the VLF/ULF source height using phase measurements

NASA Astrophysics Data System (ADS)

Ryabov, A.; Kotik, D. S.

2012-12-01

Generation of ULF/VLF waves in the ionosphere using powerful RF facilities has been studied for the last 40 years, both theoretically and experimentally. During this time, it was proposed several mechanisms for explaining the experimental results: modulation of ionospheric currents based on thermal nonlinearity, ponderomotive mechanisms for generation both VLF and ULF signals, cubic nonlinearity, etc. According mentioned above mechanisms the VLF/ULF signal source could be located in the lower or upper ionosphere. The group velocity of signal propagation in the ionosphere is significantly smaller than speed of light. As a result the appreciable time delay of the received signals will occur at the earth surface. This time delay could be determine by measuring the phase difference between received and reference signals, which are GPS synchronized. The experiment on determining the time delay of ULF signal propagation from the ionospheric source was carried out at SURA facility in 2012 and the results are presented in this paper. The comparison with numerical simulation of the time delay using the adjusted IRI model and ionosonde data shows well agreement with the experimental observations. The work was supported by RFBR grant 11-02-00419-a and RF Ministry of education and science by state contract 16.518.11.7066.

Spin-dependent delay time and Hartman effect in asymmetrical graphene barrier under strain

NASA Astrophysics Data System (ADS)

Sattari, Farhad; Mirershadi, Soghra

2018-01-01

We study the spin-dependent tunneling time, including group delay and dwell time, in a graphene based asymmetrical barrier with Rashba spin-orbit interaction in the presence of strain, sandwiched between two normal leads. We find that the spin-dependent tunneling time can be efficiently tuned by the barrier width, and the bias voltage. Moreover, for the zigzag direction strain although the oscillation period of the dwell time does not change, the oscillation amplitude increases by increasing the incident electron angle. It is found that for the armchair direction strain unlike the zigzag direction the group delay time at the normal incidence depends on the spin state of electrons and Hartman effect can be observed. In addition, for the armchair direction strain the spin polarization increases with increasing the RSOI strength and the bias voltage. The magnitude and sign of spin polarization can be manipulated by strain. In particular, by applying an external electric field the efficiency of the spin polarization is improved significantly in strained graphene, and a fully spin-polarized current is generated.

An 18-ps TDC using timing adjustment and bin realignment methods in a Cyclone-IV FPGA

NASA Astrophysics Data System (ADS)

Cao, Guiping; Xia, Haojie; Dong, Ning

2018-05-01

The method commonly used to produce a field-programmable gate array (FPGA)-based time-to-digital converter (TDC) creates a tapped delay line (TDL) for time interpolation to yield high time precision. We conduct timing adjustment and bin realignment to implement a TDC in the Altera Cyclone-IV FPGA. The former tunes the carry look-up table (LUT) cell delay by changing the LUT's function through low-level primitives according to timing analysis results, while the latter realigns bins according to the timing result obtained by timing adjustment so as to create a uniform TDL with bins of equivalent width. The differential nonlinearity and time resolution can be improved by realigning the bins. After calibration, the TDC has a 18 ps root-mean-square timing resolution and a 45 ps least-significant bit resolution.

Assessment of atrial electromechanical delay by tissue Doppler echocardiography in obese subjects.

PubMed

Yagmur, Julide; Cansel, Mehmet; Acikgoz, Nusret; Ermis, Necip; Yagmur, Murat; Atas, Halil; Tasolar, Hakan; Karakus, Yasin; Pekdemir, Hasan; Ozdemir, Ramazan

2011-04-01

Our aim was to evaluate whether atrial electromechanical delay measured by tissue Doppler imaging (TDI), which is an early predictor of atrial fibrillation (AF) development, is prolonged in obese subjects. A total of 40 obese and 40 normal-weight subjects with normal coronary angiograms were included in this study. P-wave dispersion (PWD) was calculated on the 12-lead electrocardiogram (ECG). Systolic and diastolic left ventricular (LV) functions, inter- and intra-atrial electromechanical delay were measured by TDI and conventional echocardiography. Inter- and intra-atrial electromechanical delay were significantly longer in the obese subjects compared with the controls (44.08 ± 10.06 vs. 19.35 ± 5.94 ms and 23.63 ± 6.41 vs. 5.13 ± 2.67 ms, P < 0.0001 for both, respectively). PWD was higher in obese subjects (53.40 ± 5.49 vs. 35.95 ± 5.93 ms, P < 0.0001). Left atrial (LA) diameter, LA volume index and LV diastolic parameters were significantly different between the groups. Interatrial electromechanical delay was correlated with PWD (r = 0.409, P = 0.009), high-sensitivity C-reactive protein (hsCRP) levels (r = 0.588, P < 0.0001). Interatrial electromechanical delay was positively correlated with LA diameter, LA volume index, and LV diastolic function parameters consisting of mitral early wave (E) deceleration time (DT) and isovolumetric relaxation time (IVRT; r = 0.323, P = 0.042; r = 0.387, P = 0.014; r = 0.339, P = 0.033; r = 0.325, P = 0.041; respectively) and, negatively correlated with mitral early (E) to late (A) wave ratio (E/A) (r = -0.380, P = 0.016) and myocardial early-to-late diastolic wave ratio (E(m)/A(m)) (r = -0.326, P = 0.040). This study showed that atrial electromechanical delay is prolonged in obese subjects. Prolonged atrial electromechanical delay is due to provoked low-grade inflammation as well as LA enlargement and early LV diastolic dysfunction in obese subjects.

Single-shot gas-phase thermometry using pure-rotational hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering.

PubMed

Miller, Joseph D; Roy, Sukesh; Slipchenko, Mikhail N; Gord, James R; Meyer, Terrence R

2011-08-01

High-repetition-rate, single-laser-shot measurements are important for the investigation of unsteady flows where temperature and species concentrations can vary significantly. Here, we demonstrate single-shot, pure-rotational, hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering (fs/ps RCARS) thermometry based on a kHz-rate fs laser source. Interferences that can affect nanosecond (ns) and ps CARS, such as nonresonant background and collisional dephasing, are eliminated by selecting an appropriate time delay between the 100-fs pump/Stokes pulses and the pulse-shaped 8.4-ps probe. A time- and frequency-domain theoretical model is introduced to account for rotational-level dependent collisional dephasing and indicates that the optimal probe-pulse time delay is 13.5 ps to 30 ps. This time delay allows for uncorrected best-fit N2-RCARS temperature measurements with ~1% accuracy. Hence, the hybrid fs/ps RCARS approach can be performed with kHz-rate laser sources while avoiding corrections that can be difficult to predict in unsteady flows.

Single-shot gas-phase thermometry using pure-rotational hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering

NASA Astrophysics Data System (ADS)

Miller, Joseph D.; Roy, Sukesh; Slipchenko, Mikhail N.; Gord, James R.; Meyer, Terrence R.

2011-08-01

High-repetition-rate, single-laser-shot measurements are important for the investigation of unsteady flows where temperature and species concentrations can vary significantly. Here, we demonstrate single-shot, pure-rotational, hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering (fs/ps RCARS) thermometry based on a kHz-rate fs laser source. Interferences that can affect nanosecond (ns) and ps CARS, such as nonresonant background and collisional dephasing, are eliminated by selecting an appropriate time delay between the 100-fs pump/Stokes pulses and the pulse-shaped 8.4-ps probe. A time- and frequency-domain theoretical model is introduced to account for rotational-level dependent collisional dephasing and indicates that the optimal probe-pulse time delay is 13.5 ps to 30 ps. This time delay allows for uncorrected best-fit N2-RCARS temperature measurements with ~1% accuracy. Hence, the hybrid fs/ps RCARS approach can be performed with kHz-rate laser sources while avoiding corrections that can be difficult to predict in unsteady flows.

Relatively short diagnostic delays (<8 hours) produce morbidity and mortality in blunt small bowel injury: an analysis of time to operative intervention in 198 patients from a multicenter experience.

PubMed

Fakhry, S M; Brownstein, M; Watts, D D; Baker, C C; Oller, D

2000-03-01

Blunt small bowel injury (SBI) is uncommon, and its timely diagnosis may be difficult. The impact of operative delays on morbidity and mortality has been unclear. The purpose of this study was to determine the relationship of diagnostic delays to morbidity and mortality in blunt SBI. Patients with blunt SBI with perforation were identified from the registries of eight trauma centers (1989-1997). Patients with duodenal injuries were excluded. Data were extracted by individual chart review. Patients were classified as multi-trauma (group 1) or near-isolated SBI (group 2 with Abbreviated Injury Scale score < 2 for other body areas). Time to operation and its impact on mortality and morbidity was determined for each patient. A total of 198 patients met inclusion criteria: 66.2% were male, mean age was 35.2 years (range, 1-90 years) and mean Injury Severity Score was 16.7 (range, 9-47). 100 patients had multiple injuries (group 1). There were 21 deaths (10.6%) with 9 (4.5%) attributable to delay in operation for SBI. In patients with near-isolated SBI, the incidence of mortality increased with time to operative intervention (within 8 hours: 2%; 8-16 hours: 9.1%; 16-24 hours: 16.7%; greater than 24 hours: 30.8%, p = 0.009) as did the incidence of complications. Delays as short as 8 hours 5 minutes and 11 hours 15 minutes were associated with mortality attributable to SBI. The rates of delay in diagnosis were not significantly associated with age, gender, intoxication, transfer status, or presence of associated injuries. Delays in the diagnosis of SBI are directly responsible for almost half the deaths in this series. Even relatively brief delays (as little as 8 hours) result in morbidity and mortality directly attributable to "missed" SBI. Further investigation into the prompt diagnosis of this injury is needed.

Research on key technologies of LADAR echo signal simulator

NASA Astrophysics Data System (ADS)

Xu, Rui; Shi, Rui; Ye, Jiansen; Wang, Xin; Li, Zhuo

2015-10-01

LADAR echo signal simulator is one of the most significant components of hardware-in-the-loop (HWIL) simulation systems for LADAR, which is designed to simulate the LADAR return signal in laboratory conditions. The device can provide the laser echo signal of target and background for imaging LADAR systems to test whether it is of good performance. Some key technologies are investigated in this paper. Firstly, the 3D model of typical target is built, and transformed to the data of the target echo signal based on ranging equation and targets reflection characteristics. Then, system model and time series model of LADAR echo signal simulator are established. Some influential factors which could induce fixed delay error and random delay error on the simulated return signals are analyzed. In the simulation system, the signal propagating delay of circuits and the response time of pulsed lasers are belong to fixed delay error. The counting error of digital delay generator, the jitter of system clock and the desynchronized between trigger signal and clock signal are a part of random delay error. Furthermore, these system insertion delays are analyzed quantitatively, and the noisy data are obtained. The target echo signals are got by superimposing of the noisy data and the pure target echo signal. In order to overcome these disadvantageous factors, a method of adjusting the timing diagram of the simulation system is proposed. Finally, the simulated echo signals are processed by using a detection algorithm to complete the 3D model reconstruction of object. The simulation results reveal that the range resolution can be better than 8 cm.

Clinical presentation of retinoblastoma in Alexandria: A step toward earlier diagnosis.

PubMed

Soliman, Sameh E; Eldomiaty, Wesam; Goweida, Mohamed B; Dowidar, Amgad

2017-01-01

To evaluate the clinical presentation of retinoblastoma in Alexandria, Egypt, correlate the timing of accurate diagnosis with the presence of advanced disease and identify causes of delayed presentation. Retrospective noncomparative single institution study reviews demographic and clinical data of all new children with retinoblastoma presenting to Alexandria Main University ocular oncology clinic (OOC) from January 2012 to June 2014. Diagnosis time was from initial parental complaint to retinoblastoma diagnosis and referral time was from retinoblastoma diagnosis to presentation to the Alexandria OCC. Delayed Diagnosis and referral were counted if >2 weeks. Advanced presentation is defined as clinical TNMH (8th edition) staging of cT2 or cT3 (international intraocular retinoblastoma classification group D or E) in at least one eye or the presence of extra-ocular disease (cT4). Seventy eyes of 47 children were eligible: 52% unilateral, 7% with family history and 96% presented with leukocorea. Sixty-four percent of children had advanced intraocular disease and none had extra-ocular disease. Delayed presentation occurred in 58% of children and was significantly associated with advanced disease in both unilaterally and bilaterally affected children (p = 0.003, 0.002 respectively). The delay in diagnosis was more in unilateral cases while the delay in referral was more in bilateral cases. The main cause of delayed presentation in unilateral retinoblastoma was misdiagnosis (30%) while parental shopping for second medical opinion (30%) was the main cause in bilateral children. Delayed diagnosis is a problem affecting retinoblastoma management. Better medical education and training, health education and earlier screening are recommended to achieve earlier diagnosis.

The effect of time postexposure and sex on the horizontal transmission of Metarhizium brunneum conidia between Asian longhorned beetle (Coleoptera: Cerambycidae) mates.

PubMed

Ugine, Todd A; Peters, Kenlyn E; Gardescu, Sana; Hajek, Ann E

2014-12-01

A study using Metarhizium brunneum Petch fungal bands designed to improve delivery of conidia to adult Asian longhorned beetles, Anoplophora glabripennis (Motschulsky), was conducted to determine how a time delay between exposure to infective conidia and pairing of male and female beetles would affect the ability to successfully transfer lethal doses of conidia to a mate. We measured conidial load at the time of mate pairing (0, 4, 24, 48 h postexposure) and assessed its effect on beetle mortality. Conidial load per beetle decreased across the four sampling times, and there was no effect of beetle sex on conidial load. At all time periods postexposure, beetles that climbed across fungal bands carried enough conidia that at least some of their indirectly exposed mates died of mycosis. For indirectly exposed beetles, mortality decreased significantly as the time delay increased from 0 to 48 h, and this was independent of beetle sex. Median survival time was only 11.5 d for females indirectly exposed immediately after their mate had been exposed, but >3 wk when there was a 48-h delay before pairing. Generally, beetles exposed directly to fungal bands died faster than their indirectly exposed mates. In contrast to the pattern seen for indirectly exposed beetles, beetles exposed directly to fungal bands showed no change in survival times with a delay between exposure and pairing. Median survival times of exposed females and males were generally similar, at 10.5-12.5 d.

Audit of thrombolysis initiated in an accident and emergency department.

PubMed Central

Nee, P A; Gray, A J; Martin, M A

1994-01-01

Early thrombolytic therapy after acute myocardial infarction is important in reducing mortality. To evaluate a system for reducing in-hospital delays to thrombolysis pain to needle and door to needle times to thrombolysis were audited in a major accident and emergency (A and E) department of a district general hospital and its coronary care unit (CCU), situated about 5 km away. Baseline performance over six months was assessed retrospectively from notes of 43 consecutive patients (group 1) transferred to the CCU before receiving thrombolysis. Subsequently, selected patients (23) were allowed to receive thrombolysis in the A and E department before transfer to the CCU. The agent was administered by medical staff in the department after receiving oral confirmation of myocardial infarction from the admitting medical officer in the CCU on receipt of fax transmission of the electrocardiogram. A second prospective audit during six months from the start of the new procedure established time intervals in 23 patients eligible to receive thrombolysis in the A and E department (group 2b) and 30 ineligible patients who received thrombolysis in the CCU (group 2a). The groups did not differ significantly in case mix, pre-hospital delay, or transfer time to the CCU. In group 2b door to needle time and pain to needle time were reduced significantly (geometric mean 38 min v 121 min (group 2a) and 128 min (group 1); 141 min v 237 min (group 2a) and 242 min (group 1) respectively, both p < 0.0001). The incidence of adverse effects was not significantly different. Nine deaths occurred (six in group 1, three in group 2b), an in-hospital mortality of 9.9%. Thrombolysis can be safely instituted in the A and E department in selected patients, significantly reducing delay to treatment. PMID:10136256

Influence of Health Insurance Status on the Timing of Surgery and Treatment of Bucket-Handle Meniscus Tears

PubMed Central

Sood, Amit; Gonzalez-Lomas, Guillem; Gehrmann, Robin

2015-01-01

Background Lack of insurance has been shown to lead to delays in seeking care as well as fewer preventive medicine visits and poorer overall health status. Purpose To investigate the effects of insurance status on the timing and treatment of patients with bucket-handle meniscus tears. Study Design Cohort study; Level of evidence, 3. Methods Charts from 2004 to 2013 were retrospectively reviewed for patients diagnosed with bucket-handle meniscus tears. Patients were divided into 2 groups: insured or underinsured. The insured group included patients with commercial insurance or Medicare. The underinsured group included patients with Medicaid or Charity Care. Time intervals were categorized as <6 weeks or ≥6 weeks. Results A total of 52 patients were included in this study: 15 (29%) insured and 37 (71%) underinsured. Underinsured patients experienced delays in initial presentation to an orthopaedic surgeon (P = .004), time from magnetic resonance imaging to surgery (P = .01), and time from injury to surgery (P = .007). Repair rates were 40% and 38% (P > .999) for the insured and underinsured, respectively. Repair rates for <6 weeks from injury to surgery were 75% for insured (P = .007) and 100% for underinsured patients (P = .001). Repair rates for ≥6 weeks from injury to surgery were 0% for insured and 30% for underinsured patients. Overall, patients with an injury-to-surgery time of <6 weeks had a significantly higher repair rate (87%) than those managed >6 weeks (19%) (P < .001). Conclusion Underinsured patients experience significant delays in time to presentation and overall time to surgery. However, the overall repair rate between the insured and underinsured is similar. Regardless of insurance status, patients undergoing arthroscopy within 6 weeks of injury have a significantly higher repair rate than those after 6 weeks. Clinical Relevance Patients undergoing arthroscopy within 6 weeks of injury have a significantly higher repair rate than those after 6 weeks. PMID:26676153

STEPS: lean thinking, theory of constraints and identifying bottlenecks in an emergency department.

PubMed

Ryan, A; Hunter, K; Cunningham, K; Williams, J; O'Shea, H; Rooney, P; Hickey, F

2013-04-01

This study aimed to identify the bottlenecks in patients' journeys through an emergency department (ED). For each stage of the patient journey, the average times were compared between two groups divided according to the four hour time frame and disproportionate delays were identified using a significance test These bottlenecks were evaluated with reference to a lean thinking value-stream map and the five focusing steps of the theory of constraints. A total of 434 (72.5%) ED patients were tracked over one week. Logistic regression showed that patients who had radiological tests, blood tests or who were admitted were 4.4, 4.1 and 7.7 times more likely, respectively, to stay over four hours in the ED than those who didn't The stages that were significantly delayed were the time spent waiting for radiology (p = 0.001), waiting for the in-patient team (p = 0.004), waiting for a bed (p < 0.001) and ED doctor turnaround time (p < 0.001).

Temporal trends and associated factors for pre-hospital and in-hospital delays of stroke patients over a 16-year period: the Athens study.

PubMed

Papapanagiotou, Panagiotis; Iacovidou, Nicoletta; Spengos, Konstantinos; Xanthos, Theodoros; Zaganas, Ioannis; Aggelina, Afrodite; Alegakis, Athanasios; Vemmos, Konstantinos

2011-01-01

The management and outcome of acute ischemic stroke changed dramatically after the introduction of intravenous thrombolysis. However, relatively few patients have received thrombolytic treatment, mainly due to pre-hospital and/or in-hospital delays. Although the causes of these delays have been adequately studied, their change over a long period has not. All acute first-ever stroke patients (n = 2,746) presenting to our academic center from 1993 to 2008 were prospectively documented in a computerized stroke data bank. The time from symptoms onset to presentation at the emergency room and to acquisition of a brain CT was calculated. Time trends over this period as well as the factors affecting them were analyzed. The final study cohort consisted of 2,326 acute stroke patients after excluding 302 patients with an unknown time of stroke onset and 118 who suffered a stroke during hospitalization for another illness. Over the 16-year period, the median time from stroke onset to presentation at the emergency room decreased significantly from 3.15 h (interquartile range 1.30-10.30) to 2.00 h (range 1.00-4.00) (p < 0.001). The median time from emergency room presentation to CT scan completion also decreased significantly (p < 0.001) from 12.3 h (range 4.1-29.8) to 1.0 h (range 0.31-2.77). As a result, the proportion of patients having a CT scan within 4 h of stroke onset increased significantly from 8.6% in 1993-1994 to 53.6% in 2007-2008 (p < 0.001). Thrombolytic treatment was applied in 4.15% of all ischemic stroke patients in the period from 2003 to 2008. Along with other significant factors, use of an emergency medical service was associated with a 57% greater chance of presenting within 3 h after symptoms onset. These results suggest a continued improvement in pre-hospital and in-hospital delays for stroke management. Public awareness and education regarding medical and paramedical services are necessary for the best early management of acute stroke patients. Copyright © 2010 S. Karger AG, Basel.

Revolving Loan Fund: A Novel Approach to Increasing Access to Long-Acting Reversible Contraception Methods in Community Health Centers.

PubMed

Evans, Megan L; Breeze, Janis L; Paulus, Jessica K; Meadows, Audra

The aim of this study was to assess the impact of a revolving loan fund (RLF) on timing of device insertion and long-acting reversible contraception (LARC) access among a high-risk urban population at 3 Boston community health centers. Three health centers were identified to implement a RLF. Each clinic received $5000 from the RLF to purchase LARC devices. Data collected through medical record review retrospectively 1 year prior to start of the RLF and prospectively for 1 year thereafter included patient demographics, type of LARC selected, patient's date of documented interest in a LARC device, and date of insertion. The effect of a RLF on delay to LARC insertion was tested using negative binomial regression, controlling for site and potential confounding variables between the pre- and post-RLF periods. Three urban community health centers. Reproductive-aged women who received family planning services at the 3 participating health centers. Increasing access to LARC and decreasing wait times to LARC insertion after implementation of the RLF. Data on 133 patients in the pre-RLF group and 205 in the post-RLF group were collected. There were no statistically significant differences in demographic or clinical characteristics between the 2 time periods. LARC uptake increased significantly from the pre- to post-RLF period, specifically among implant users. There was a statistically significant decrease in the mean number of days in delay from interest to insertion from the pre- to post-RLF period (pre-RLF: 31.3 ± 50.6 days; post-RLF: 13.6 ± 16.7 days, adjusted P < .001). The reasons for the delay did not differ significantly between the 2 time periods. The RLF decreased wait time for the devices and increased overall insertion rates. This may serve as a promising solution to improve LARC access in community health centers. This project could be expanded to include more health centers, creating a city wide RLF. This expansion could allow for further data analysis, including unintended pregnancy rates with LARC delay, LARC continuation rates, and sustainability of a RLF.

Guided self-help for the treatment of pediatric obesity.

PubMed

Boutelle, Kerri N; Norman, Gregory J; Rock, Cheryl L; Rhee, Kyung E; Crow, Scott J

2013-05-01

Clinic-based programs for childhood obesity are not available to a large proportion of the population. The purpose of this study was to evaluate the efficacy of a guided self-help treatment of pediatric obesity (GSH-PO) compared with a delayed treatment control and to evaluate the impact of GSH-PO 6-months posttreatment. Fifty overweight or obese 8- to 12-year-old children and their parents were randomly assigned to immediate treatment or to delayed treatment. The GSH-PO includes 12 visits over 5 months and addresses key components included in more intensive clinic-based programs. Children and parents in the immediate treatment arm were assessed at time 1 (T1), participated in GSH-PO between T1 and T2, and completed their 6-month posttreatment assessment at T3. Children and parents in the delayed treatment arm were assessed at T1, participated in GSH-PO between T2 and T3, and completed their 6-month posttreatment assessment at T4. The main outcome measures were BMI, BMI z score, and percentage overweight (%OW). Children in the immediate treatment GSH-PO arm decreased their BMI significantly more than did the delayed treatment arm (BMI group × time = -1.39; P < .001). Similar results were found for BMI z score and %OW. At the 6-month posttreatment assessment, changes resulting from GSH-PO were maintained for BMI z score and %OW but not BMI (BMI time effect = -0.06, not significant; BMI z score time effect = -0.10, P < .001; %OW time effect = -4.86, P < .05). The GSH-PO showed initial efficacy in decreasing BMI for children in this study. Additional efficacy and translational studies are needed to additionally evaluate GSH-PO.

Immediate vs delayed repair bond strength of a nanohybrid resin composite.

PubMed

El-Askary, Farid S; El-Banna, Ahmed H; van Noort, Richard

2012-06-01

To evaluate both the immediate and water-stored repair tensile bond strength (TBS) of a nanohybrid resin composite using different bonding protocols. One hundred sixty half hourglass-shaped slabs were prepared. Eighty half-slabs were wet ground immediately after light curing using high-speed abrasive burs, while the other half-slabs were stored in water for one month (delayed) and then wet ground for repair. Each set of the 80 repaired slabs was split into two groups to be tested for TBS after 24 h or 1 month of water storage. For all repaired slabs, either immediate or delayed, four bonding procedures were used involving wet and dry bonding with a 3-step etch-and-rinse adhesive with or without silane pretreatment. TBS tests were performed at a crosshead speed of 0.5 mm/min. To determine the cohesive strength of the resin composite itself, which served as the reference, additional whole slabs were prepared and tested in tension after a 24-h (n = 10) and a 1-month storage period (n = 10). Failure modes were evaluated using a stereomicroscope at 40X magnification. Three-way ANOVA was run to test the effect of water storage, testing time, bonding protocols, and their interactions on the repair TBS, which was given as a percentage of the reference values. For the immediate repair groups, the repair TBS ranged from 40% to 61.9% after 24-h storage and from 26% to 53.1% after 1-month water storage compared to the TBS of the whole slabs. For the delayed repair group, the repaired TBS ranged from 47.2% to 63.6% for the 24-h repairs and from 32.2% to 44.2% for the test groups stored in water for 1 month. Three-way ANOVA revealed that water storage had no significant effect on the repair TBS (p = 0.619). Both testing time and bonding protocols had a significant effect on the repair TBS (p = 0.001). The interactions between the independent variables (water storage, testing time, and bonding protocols) had no significant effect (p = 0.067). The repair bond strength was consistently and highly significantly less than the cohesive strength of the composite. A delay of 1 month before carrying out the repair had no effect on the bond strength, irrespective of the bonding procedure used. Silane treatment did not improve the repair bond strength. In all instances, except for the immediate wet bonding plus silane procedure and delayed dry bonding, the bond strength of the repairs significantly dropped after 1 month of storage in water.

The relationship between obesity and body compositions with respect to the timing of puberty in Chongqing adolescents: a cross-sectional study.

PubMed

He, Fang; Guan, Peiyu; Liu, Qin; Crabtree, Donna; Peng, Linli; Wang, Hong

2017-08-18

It is well known that excess adiposity during childhood may influence pubertal development. However, the extent to which body compositions vary in throughout puberty in boys and girls is currently unknown. The aim of this study was to investigate whether obesity and body compositions correlate with the timing of puberty in boys and girls. By random cluster sampling, our study analyzed data from 1472 students (690 girls, 782 boys) aged 6-17 years from two schools in the Chongqing area. Data were collected by physical examination of weight, height, and skinfold thicknesses. Testicular volume was measured in boys and breast development in girls. By which we got the indicators of obesity, timing of puberty and body compositions. Probit regression analysis was used to group subjects into early puberty (>P 25 ), on-time puberty (P 25  ~ P 75 ), and delayed puberty (

 0.05). In girls, delayed puberty was negatively correlated with Obesity, percentage of body fat, fat mass and fat-free mass, and positively correlated with body density. But in boys, delayed puberty was only negatively correlated with Obesity, the relation between puberty and body compositions was not found.

Factors Associated With Development of Nonunion or Delayed Healing After an Open Long Bone Fracture: A Prospective Cohort Study of 736 Subjects.

PubMed

Westgeest, Joseph; Weber, Donald; Dulai, Sukhdeep K; Bergman, Joseph W; Buckley, Richard; Beaupre, Lauren A

2016-03-01

To determine factors associated with developing nonunion or delayed healing after open fracture. Prospective cohort between 2001 and 2009. Three level 1 Canadian trauma centers. Seven hundred thirty-six (791 fractures) subjects were enrolled. Six hundred eighty-nine (94%) subjects (739 fractures) provided adequate outcome data. Subjects were followed until fracture(s) healed; phone interviews and chart reviews were conducted 1 year after fracture. Patient, fracture, and injury information, and time to surgery and antibiotics were recorded during hospitalization. Nonunion defined as unplanned surgical intervention after definitive wound closure or incomplete radiographic healing at 1 year and delayed healing defined as 2 consecutive clinical assessments showing no radiographic progression or incomplete radiographic healing between 6 months and 1 year. There were 413 (52%) tibia/fibular, 285 (36%) upper extremity, and 93 (13%) femoral fractures. Nonunion developed in 124 (17%) and delayed healing in 63 (8%) fractures. The median time to surgery was not different for fractures that developed nonunion compared with those who did not (P = 0.36). Deep infection [Odd ratio (OR) 12.75; 95% confidence interval (CI) 6.07-26.8], grade 3A fractures (OR 2.49; 95% CI, 1.30-4.78), and smoking (OR 1.73; 95% CI, 1.09-2.76) were significantly associated with developing a nonunion. Delayed healing was also significantly associated with deep infection (OR 4.34; 95% CI, 1.22-15.48) and grade 3B/C fractures (OR 3.69; 95% CI, 1.44-9.44). Multivariate regression found no association between nonunion and time to surgery (P = 0.15) or antibiotics (P = 0.70). Deep infection and higher Gustilo grade fractures were associated with nonunion and delayed healing. Prognostic Level I. See Instructions for Authors for a complete description of levels of evidence.

Canine left ventricle electromechanical behavior under different pacing modes.

PubMed

Vo Thang, Thanh-Thuy; Thibault, Bernard; Finnerty, Vincent; Pelletier-Galarneau, Matthieu; Khairy, Paul; Grégoire, Jean; Harel, François

2012-10-01

Cardiac resynchronization therapy may improve survival and quality of life in patients suffering from heart failure with left ventricular (LV) contraction dyssynchrony. While several studies have investigated electrical or mechanical determinants of synchronous contraction, few have focused on activation contraction coupling at a macroscopic level. The objective of the study was to characterize LV electromechanical behavior and response to pacing in a heart failure model. We analyzed data from 3D electroanatomic non-contact mapping and blood pool SPECT for 12 dogs with right ventricular (RV) tachycardia pacing-induced dilated cardiomyopathy. Surfaces generated by the two modalities were registered. Electrical signals were analyzed, and endocardial wall displacement curves were portrayed. Rapid pacing decreased the mean LV ejection fraction (LVEF) to 20.9 % and prolonged the QRS duration to 79 ± 10 ms (normal range: 40-50 ms). QRS duration remained unchanged with biventricular pacing (88.5 ms), while single site pacing further prolonged the QRS duration (113.3 ms for RV pacing and 111.6 ms for LV pacing). No trend was observed in LV systolic function. Activation duration time was significantly increased with all pacing modes compared to baseline. Finally, electromechanical delay, as defined by the delay between electrical activation and mechanical response, was increased by single site pacing (172.9 ms for RV pacing and 174.6 ms for LV pacing) but not by biventricular pacing (162.4 ms). Combined temporal and spatial coregistration electroanatomic maps and baseline gated blood pool SPECT imaging allowed us to quantify activation duration time, electromechanical delay, and LVEF for different pacing modes. Even if pacing modes did not significantly modify LVEF or activation duration, they produced alterations in electromechanical delay, with biventricular pacing significantly decreasing the electromechanical delay as measured by surface tracings and endocardial non-contact mapping.

Decadal shifts in autumn migration timing by Pacific Arctic beluga whales are related to delayed annual sea ice formation.

PubMed

Hauser, Donna D W; Laidre, Kristin L; Stafford, Kathleen M; Stern, Harry L; Suydam, Robert S; Richard, Pierre R

2017-06-01

Migrations are often influenced by seasonal environmental gradients that are increasingly being altered by climate change. The consequences of rapid changes in Arctic sea ice have the potential to affect migrations of a number of marine species whose timing is temporally matched to seasonal sea ice cover. This topic has not been investigated for Pacific Arctic beluga whales (Delphinapterus leucas) that follow matrilineally maintained autumn migrations in the waters around Alaska and Russia. For the sympatric Eastern Chukchi Sea ('Chukchi') and Eastern Beaufort Sea ('Beaufort') beluga populations, we examined changes in autumn migration timing as related to delayed regional sea ice freeze-up since the 1990s, using two independent data sources (satellite telemetry data and passive acoustics) for both populations. We compared dates of migration between 'early' (1993-2002) and 'late' (2004-2012) tagging periods. During the late tagging period, Chukchi belugas had significantly delayed migrations (by 2 to >4 weeks, depending on location) from the Beaufort and Chukchi seas. Spatial analyses also revealed that departure from Beaufort Sea foraging regions by Chukchi whales was postponed in the late period. Chukchi beluga autumn migration timing occurred significantly later as regional sea ice freeze-up timing became later in the Beaufort, Chukchi, and Bering seas. In contrast, Beaufort belugas did not shift migration timing between periods, nor was migration timing related to freeze-up timing, other than for southward migration at the Bering Strait. Passive acoustic data from 2008 to 2014 provided independent and supplementary support for delayed migration from the Beaufort Sea (4 day yr -1 ) by Chukchi belugas. Here, we report the first phenological study examining beluga whale migrations within the context of their rapidly transforming Pacific Arctic ecosystem, suggesting flexible responses that may enable their persistence yet also complicate predictions of how belugas may fare in the future. © 2016 John Wiley & Sons Ltd.

Delayed school start time is associated with better sleep, daytime functioning, and life satisfaction in residential high-school students.

PubMed

Chan, Christian S; Poon, Cyanea Y S; Leung, Jacklyn C Y; Lau, Kristy N T; Lau, Esther Y Y

2018-05-16

The effects of a delayed school start time by one hour were examined at a boarding school in Hong Kong. Two cohorts of high school students (N = 228; 61.8% female) were recruited respectively before and after a school start time changed from 7:30am to 8:30am. Both cross-cohort and within-cohort longitudinal comparisons yielded significant increase in total sleep time. Cross-cohort comparison yielded improvement in sleep quality, insomnia, life satisfaction, and psychological distress. Longitudinal data suggested that the longer the additional sleep time, the better was sleep quality, day-time functioning, and subjective wellbeing. Copyright © 2018 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Timing of Emergency Medicine Student Evaluation Does Not Affect Scoring.

PubMed

Hiller, Katherine M; Waterbrook, Anna; Waters, Kristina

2016-02-01

Evaluation of medical students rotating through the emergency department (ED) is an important formative and summative assessment method. Intuitively, delaying evaluation should affect the reliability of this assessment method, however, the effect of evaluation timing on scoring is unknown. A quality-improvement project evaluating the timing of end-of-shift ED evaluations at the University of Arizona was performed to determine whether delay in evaluation affected the score. End-of-shift ED evaluations completed on behalf of fourth-year medical students from July 2012 to March 2013 were reviewed. Forty-seven students were evaluated 547 times by 46 residents and attendings. Evaluation scores were means of anchored Likert scales (1-5) for the domains of energy/interest, fund of knowledge, judgment/problem-solving ability, clinical skills, personal effectiveness, and systems-based practice. Date of shift, date of evaluation, and score were collected. Linear regression was performed to determine whether timing of the evaluation had an effect on evaluation score. Data were complete for 477 of 547 evaluations (87.2%). Mean evaluation score was 4.1 (range 2.3-5, standard deviation 0.62). Evaluations took a mean of 8.5 days (median 4 days, range 0-59 days, standard deviation 9.77 days) to complete. Delay in evaluation had no significant effect on score (p = 0.983). The evaluation score was not affected by timing of the evaluation. Variance in scores was similar for both immediate and delayed evaluations. Considerable amounts of time and energy are expended tracking down delayed evaluations. This activity does not impact a student's final grade. Copyright © 2016 Elsevier Inc. All rights reserved.

Cascading Delay Risk of Airline Workforce Deployments with Crew Pairing and Schedule Optimization.

PubMed

Chung, Sai Ho; Ma, Hoi Lam; Chan, Hing Kai

2017-08-01

This article concerns the assignment of buffer time between two connected flights and the number of reserve crews in crew pairing to mitigate flight disruption due to flight arrival delay. Insufficient crew members for a flight will lead to flight disruptions such as delays or cancellations. In reality, most of these disruption cases are due to arrival delays of the previous flights. To tackle this problem, many research studies have examined the assignment method based on the historical flight arrival delay data of the concerned flights. However, flight arrival delays can be triggered by numerous factors. Accordingly, this article proposes a new forecasting approach using a cascade neural network, which considers a massive amount of historical flight arrival and departure data. The approach also incorporates learning ability so that unknown relationships behind the data can be revealed. Based on the expected flight arrival delay, the buffer time can be determined and a new dynamic reserve crew strategy can then be used to determine the required number of reserve crews. Numerical experiments are carried out based on one year of flight data obtained from 112 airports around the world. The results demonstrate that by predicting the flight departure delay as the input for the prediction of the flight arrival delay, the prediction accuracy can be increased. Moreover, by using the new dynamic reserve crew strategy, the total crew cost can be reduced. This significantly benefits airlines in flight schedule stability and cost saving in the current big data era. © 2016 Society for Risk Analysis.

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

PubMed

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

2015-03-01

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

Comparison of Different Control Schemes for Strategic Departure Metering

NASA Technical Reports Server (NTRS)

Idris, Husni; Shen, Ni; Saraf, Aditya; Bertino, Jason; Zelinski, Shannon

2016-01-01

Airports and their terminal airspaces are key choke points in the air transportation system causing major delays and adding to pollution. A solution aimed at mitigating these chokepoints integrates the scheduling of runway operations, flight release from the gates and ramp into the airport movement area, and merging with other traffic competing for downstream airspace points. Within this integrated concept, we present a simulation-based analysis of the departure metering process, which delays the release of flights into the airport movement area while balancing two competing objectives: (1) maintaining large enough queues at the airport resources to maximize throughput and (2) absorbing excess delays at the gates or in ramp areas to save on fuel consumption, emissions, noise, and passenger discomfort. Three metering strategies are compared which respectively attempt to control the number of flights that (1) left the gate but did not take off, (2) left the ramp but did not take off, and (3) spent their unimpeded transit time to the runway but did not take off. It was observed that under deterministic and demand uncertainty conditions, the first strategy performed better than the other two strategies in terms of maintaining the runway throughput while transferring a significant average delay of two minutes to the gate. On the other hand, under uncertainties of flight transit time and runway service rate, all the strategies struggled to delay flights at the gate without a significant impact on the runway throughput.

Deficient neural activity subserving decision-making during reward waiting time in intertemporal choice in adult attention-deficit hyperactivity disorder.

PubMed

Todokoro, Ayako; Tanaka, Saori C; Kawakubo, Yuki; Yahata, Noriaki; Ishii-Takahashi, Ayaka; Nishimura, Yukika; Kano, Yukiko; Ohtake, Fumio; Kasai, Kiyoto

2018-04-24

Impulsivity, which significantly affects social adaptation, is an important target behavioral characteristic in interventions for attention-deficit hyperactivity disorder (ADHD). Typically, people are willing to wait longer to acquire greater rewards. Impulsivity in ADHD may be associated with brain dysfunction in decision-making involving waiting behavior under such situations. We tested the hypothesis that brain circuitry during a period of waiting (i.e., prior to the acquisition of reward) is altered in adults with ADHD. The participants included 14 medication-free adults with ADHD and 16 healthy controls matched for age, sex, IQ, and handedness. The behavioral task had participants choose between a delayed, larger monetary reward and an immediate, smaller monetary reward, where the reward waiting time actually occurred during functional magnetic resonance imaging measurement. We tested for group differences in the contrast values of blood-oxygen-level dependent signals associated with the length of waiting time, calculated using the parametric modulation method. While the two groups did not differ in the time discounting rate, the delay-sensitive contrast values were significantly lower in the caudate and visual cortex in individuals with ADHD. The higher impulsivity scores were significantly associated with lower delay-sensitive contrast values in the caudate and visual cortex. These results suggest that deficient neural activity affects decision-making involving reward waiting time during intertemporal choice tasks, and provide an explanation for the basis of impulsivity in adult ADHD. © 2018 The Author. Psychiatry and Clinical Neurosciences © 2018 Japanese Society of Psychiatry and Neurology.

SSRIs and ejaculation: a double-blind, randomized, fixed-dose study with paroxetine and citalopram.

PubMed

Waldinger, M D; Zwinderman, A H; Olivier, B

2001-12-01

Selective serotonin reuptake inhibitors (SSRIs) are known to induce delayed orgasm and ejaculation. However, different SSRIs may differentially delay ejaculation. A double-blind, fixed-dose study in healthy men with lifelong rapid ejaculation was performed to evaluate potential differences between clinically relevant doses of two selective serotonin reuptake inhibitors, paroxetine and citalopram, in their effects on ejaculation. Thirty men with an intravaginal ejaculation latency time (IELT) less than 1 minute were randomly assigned to receive paroxetine (20 mg/day) and citalopram (20 mg/day) for 5 weeks, after taking half the dosage in the first week. During the 1-month baseline and 6-week treatment period, IELTs were measured at home by using a stopwatch procedure. The trial was completed by 23 men. Analysis of variance revealed a between-group difference in the evolution of IELT delay over time (p = 0.0004); the IELT after paroxetine and citalopram gradually increased from 18 and 21 seconds to approximately 170 and 44 seconds, respectively. Paroxetine 20 mg/day exerted a strong delay (8.9-fold increase), whereas citalopram 20 mg/day mildly delayed ejaculation (1.8-fold increase). These results indicate that paroxetine leads to a significant delay in orgasm and ejaculation, whereas citalopram seems to have less of an effect on it.

Preventing delayed diagnosis of cancer: clinicians’ views on main problems and solutions

PubMed Central

Car, Lorainne Tudor; Papachristou, Nikolaos; Urch, Catherine; Majeed, Azeem; El–Khatib, Mona; Aylin, Paul; Atun, Rifat; Car, Josip; Vincent, Charles

2016-01-01

Background Delayed diagnosis is a major contributing factor to the UK’s lower cancer survival compared to many European countries. In the UK, there is a significant national variation in early cancer diagnosis. Healthcare providers can offer an insight into local priorities for timely cancer diagnosis. In this study, we aimed to identify the main problems and solutions relating to delay cancer diagnosis according to cancer care clinicians. Methods We developed and implemented a new priority–setting approach called PRIORITIZE and invited North West London cancer care clinicians to identify and prioritize main causes for and solutions to delayed diagnosis of cancer care. Results Clinicians identified a number of concrete problems and solutions relating to delayed diagnosis of cancer. Raising public awareness, patient education as well as better access to specialist care and diagnostic testing were seen as the highest priorities. The identified suggestions focused mostly on the delays during referrals from primary to secondary care. Conclusions Many identified priorities were feasible, affordable and converged around common themes such as public awareness, care continuity and length of consultation. As a timely, proactive and scalable priority–setting approach, PRIORITZE could be implemented as a routine preventative system for determining patient safety issues by frontline staff. PMID:28028437

Patterns of postictal cerebral perfusion in idiopathic generalized epilepsy: a multi-delay multi-parametric arterial spin labelling perfusion MRI study.

PubMed

Chen, Guangxiang; Lei, Du; Ren, Jiechuan; Zuo, Panli; Suo, Xueling; Wang, Danny J J; Wang, Meiyun; Zhou, Dong; Gong, Qiyong

2016-07-04

The cerebral haemodynamic status of idiopathic generalized epilepsy (IGE) is a very complicated process. Little attention has been paid to cerebral blood flow (CBF) alterations in IGE detected by arterial spin labelling (ASL) perfusion magnetic resonance imaging (MRI). However, the selection of an optimal delay time is difficult for single-delay ASL. Multi-delay multi-parametric ASL perfusion MRI overcomes the limitations of single-delay ASL. We applied multi-delay multi-parametric ASL perfusion MRI to investigate the patterns of postictal cerebral perfusion in IGE patients with absence seizures. A total of 21 IGE patients with absence seizures and 24 healthy control subjects were enrolled. IGE patients exhibited prolonged arterial transit time (ATT) in the left superior temporal gyrus. The mean CBF of IGE patients was significantly increased in the left middle temporal gyrus, left parahippocampal gyrus and left fusiform gyrus. Prolonged ATT in the left superior temporal gyrus was negatively correlated with the age at onset in IGE patients. This study demonstrated that cortical dysfunction in the temporal lobe and fusiform gyrus may be related to epileptic activity in IGE patients with absence seizures. This information can play an important role in elucidating the pathophysiological mechanism of IGE from a cerebral haemodynamic perspective.

Effects of Delay Duration on the WMS Logical Memory Performance of Older Adults with Probable Alzheimer's Disease, Probable Vascular Dementia, and Normal Cognition.

PubMed

Montgomery, Valencia; Harris, Katie; Stabler, Anthony; Lu, Lisa H

2017-05-01

To examine how the duration of time delay between Wechsler Memory Scale (WMS) Logical Memory I and Logical Memory II (LM) affected participants' recall performance. There are 46,146 total Logical Memory administrations to participants diagnosed with either Alzheimer's disease (AD), vascular dementia (VaD), or normal cognition in the National Alzheimer's Disease Coordinating Center's Uniform Data Set. Only 50% of the sample was administered the standard 20-35 min of delay as specified by WMS-R and WMS-III. We found a significant effect of delay time duration on proportion of information retained for the VaD group compared to its control group, which remained after adding LMI raw score as a covariate. There was poorer retention of information with longer delay for this group. This association was not as strong for the AD and cognitively normal groups. A 24.5-min delay was most optimal for differentiating AD from VaD participants (47.7% classification accuracy), an 18.5-min delay was most optimal for differentiating AD versus normal participants (51.7% classification accuracy), and a 22.5-min delay was most optimal for differentiating VaD versus normal participants (52.9% classification accuracy). Considering diagnostic implications, our findings suggest that test administration should incorporate precise tracking of delay periods. We recommend a 20-min delay with 18-25-min range. Poor classification accuracy based on LM data alone is a reminder that story memory performance is only one piece of data that contributes to complex clinical decisions. However, strict adherence to the recommended range yields optimal data for diagnostic decisions. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Angular dependence of EWS time delay for photoionization of @Xe

NASA Astrophysics Data System (ADS)

Mandal, Ankur; Deshmukh, Pranawa; Kheifets, Anatoli; Dolmatov, Valeriy; Manson, Steven

2017-04-01

Interference between photoionization channels leads to angular dependence in photoionization time delay. Angular dependence is found to be a common effect for two-photon absorption experiments very recently. The effect of confinement on the time delay where each partial wave contributions to the ionization are studied. In this work we report angular dependence and confinement effects on Eisenbud-Wigner-Smith (EWS) time delay in atomic photoionization. Using and we computed the EWS time delay for free and confined Xe atom for photoionization from inner 4d3/2 and 4d5/2 and outer 5p1/2 and 5p3/2 subshells at various angles. The calculated EWS time delay is few tens to few hundreds of attoseconds (10-18 second). The photoionization time delay for @Xe follows that in the free Xe atom on which the confinement oscillations are built. The present work reveals the effect of confinement on the photoionization time delay at different angles between photoelectron ejection and the photon polarization.

Mitigating delay and non-payment in the Malaysian construction industry

NASA Astrophysics Data System (ADS)

Mohamad, N.; Suman, A. S.; Harun, H.; Hashim, H.

2018-02-01

Construction industry is one of the industries that have contributed towards the rapid growth of development and economics in Malaysia. However, the industry is inundated with delay and non-payment issues between the two parties in contract that is the clients and contractors Even though there are contractual and administrative provisions in the standard forms of contract in Malaysia regarding payments, delay and non-payment issues still occur between them. The aim of the study is to develop measures to mitigate delay and non-payment issues between contractors and clients in the Malaysian construction industry. Questionnaire survey was conducted with clients and contractors in Klang Valley. Results from data analysis identified significant measures to mitigate delay and non-payment issues between contractors and clients which include contractors should submit their progress work invoicing with adequate documents; contractors should follow up constantly with client regarding payment; proper understanding of requirements with regards to payment; mutual discussion of problems with client to address problems in a timely manner and proper use of payment provisions in the standard form of contract. This study is significant to contractors and clients and to other construction players in order to reduce and minimise delay and non-payment issues for the growth of economy in the Malaysian construction industry.

Are infants with torticollis at risk of a delay in early motor milestones compared with a control group of healthy infants?

PubMed

Ohman, Anna; Nilsson, Staffan; Lagerkvist, Anna-Lena; Beckung, Eva

2009-07-01

Recently it has been claimed that infants with congenital muscular torticollis (CMT) are at risk of a delay in early motor milestones. The aim of the present study was to investigate whether infants with CMT are indeed at risk in comparison with a control group of healthy infants. A second aim was to investigate whether the time spent in a prone position and plagiocephaly had any influence on motor development. Eighty-two infants with CMT (35 females and 47 males) were compared with 40 healthy infants (18 females and 22 males). Motor development was assessed with the Alberta Infant Motor scale (AIMS). Multiple regression showed that infants in the CMT group had a significantly lower AIMS score than the control group at 2 months (p=0.03) and 6 months of age (p=0.05). Infants who spent at least three occasions daily in a prone position when awake had significantly higher AIMS scores than infants who spent less time prone at 2 months (p=0.001), 6 months (p<0.001), and 10 months of age (p<0.001). The CMT group achieved early motor milestones significantly later than the control group until the age of 10 months, but the risk of delay seems to be more strongly associated with little or no time prone when awake than with CMT.

Crash testing difference-smoothing algorithm on a large sample of simulated light curves from TDC1

NASA Astrophysics Data System (ADS)

Rathna Kumar, S.

2017-09-01

In this work, we propose refinements to the difference-smoothing algorithm for the measurement of time delay from the light curves of the images of a gravitationally lensed quasar. The refinements mainly consist of a more pragmatic approach to choose the smoothing time-scale free parameter, generation of more realistic synthetic light curves for the estimation of time delay uncertainty and using a plot of normalized χ2 computed over a wide range of trial time delay values to assess the reliability of a measured time delay and also for identifying instances of catastrophic failure. We rigorously tested the difference-smoothing algorithm on a large sample of more than thousand pairs of simulated light curves having known true time delays between them from the two most difficult 'rungs' - rung3 and rung4 - of the first edition of Strong Lens Time Delay Challenge (TDC1) and found an inherent tendency of the algorithm to measure the magnitude of time delay to be higher than the true value of time delay. However, we find that this systematic bias is eliminated by applying a correction to each measured time delay according to the magnitude and sign of the systematic error inferred by applying the time delay estimator on synthetic light curves simulating the measured time delay. Following these refinements, the TDC performance metrics for the difference-smoothing algorithm are found to be competitive with those of the best performing submissions of TDC1 for both the tested 'rungs'. The MATLAB codes used in this work and the detailed results are made publicly available.

Protocol Based Real-Time Continuous Electroencephalography for Detecting Vasospasm in Subarachnoid Hemorrhage.

PubMed

Hong, Jeong-Ho; Bang, Jae Seung; Chung, Jin-Heon; Han, Moon-Ku

2016-03-01

A continuous electroencephalography (cEEG) can be helpful in detecting vasospasm and delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage (SAH). We describe a patient with an aneurysmal SAH whose symptomatic vasospasm was detected promptly by using a real-time cEEG. Patient was immediately treated by intraarterial vasodilator therapy. A 50-year-old woman without any significant medical history presented with a severe bifrontal headache due to acute SAH with a ruptured aneurysm on the anterior communicating artery (Fisher grade 3). On bleed day 6, she developed a sudden onset of global aphasia and left hemiparesis preceded by cEEG changes consistent with vasospasm. A stat chemical dilator therapy was performed and she recovered without significant neurological deficits. A real-time and protocol-based cEEG can be utilized in order to avoid any delay in detection of vasospasm in aneurysmal SAH and thereby improve clinical outcomes.

The Roles of Feedback and Feedforward as Humans Learn to Control Unknown Dynamic Systems.

PubMed

Zhang, Xingye; Wang, Shaoqian; Hoagg, Jesse B; Seigler, T Michael

2018-02-01

We present results from an experiment in which human subjects interact with an unknown dynamic system 40 times during a two-week period. During each interaction, subjects are asked to perform a command-following (i.e., pursuit tracking) task. Each subject's performance at that task improves from the first trial to the last trial. For each trial, we use subsystem identification to estimate each subject's feedforward (or anticipatory) control, feedback (or reactive) control, and feedback time delay. Over the 40 trials, the magnitudes of the identified feedback controllers and the identified feedback time delays do not change significantly. In contrast, the identified feedforward controllers do change significantly. By the last trial, the average identified feedforward controller approximates the inverse of the dynamic system. This observation provides evidence that a fundamental component of human learning is updating the anticipatory control until it models the inverse dynamics.

Benefits of Sign Language Interpreting and Text Alternatives for Deaf Students' Classroom Learning

PubMed Central

Marschark, Marc; Leigh, Greg; Sapere, Patricia; Burnham, Denis; Convertino, Carol; Stinson, Michael; Knoors, Harry; Vervloed, Mathijs P. J.; Noble, William

2006-01-01

Four experiments examined the utility of real-time text in supporting deaf students' learning from lectures in postsecondary (Experiments 1 and 2) and secondary classrooms (Experiments 3 and 4). Experiment 1 compared the effects on learning of sign language interpreting, real-time text (C-Print), and both. Real-time text alone led to significantly higher performance by deaf students than the other two conditions, but performance by deaf students in all conditions was significantly below that of hearing peers who saw lectures without any support services. Experiment 2 compared interpreting and two forms of real-time text, C-Print and Communication Access Real-Time Translation, at immediate testing and after a 1-week delay (with study notes). No significant differences among support services were obtained at either testing. Experiment 3 also failed to reveal significant effects at immediate or delayed testing in a comparison of real-time text, direct (signed) instruction, and both. Experiment 4 found no significant differences between interpreting and interpreting plus real-time text on the learning of either new words or the content of television programs. Alternative accounts of the observed pattern of results are considered, but it is concluded that neither sign language interpreting nor real-time text have any inherent, generalized advantage over the other in supporting deaf students in secondary or postsecondary settings. Providing deaf students with both services simultaneously does not appear to provide any generalized benefit, at least for the kinds of materials utilized here. PMID:16928778

Benefits of sign language interpreting and text alternatives for deaf students' classroom learning.

PubMed

Marschark, Marc; Leigh, Greg; Sapere, Patricia; Burnham, Denis; Convertino, Carol; Stinson, Michael; Knoors, Harry; Vervloed, Mathijs P J; Noble, William

2006-01-01

Four experiments examined the utility of real-time text in supporting deaf students' learning from lectures in postsecondary (Experiments 1 and 2) and secondary classrooms (Experiments 3 and 4). Experiment 1 compared the effects on learning of sign language interpreting, real-time text (C-Print), and both. Real-time text alone led to significantly higher performance by deaf students than the other two conditions, but performance by deaf students in all conditions was significantly below that of hearing peers who saw lectures without any support services. Experiment 2 compared interpreting and two forms of real-time text, C-Print and Communication Access Real-Time Translation, at immediate testing and after a 1-week delay (with study notes). No significant differences among support services were obtained at either testing. Experiment 3 also failed to reveal significant effects at immediate or delayed testing in a comparison of real-time text, direct (signed) instruction, and both. Experiment 4 found no significant differences between interpreting and interpreting plus real-time text on the learning of either new words or the content of television programs. Alternative accounts of the observed pattern of results are considered, but it is concluded that neither sign language interpreting nor real-time text have any inherent, generalized advantage over the other in supporting deaf students in secondary or postsecondary settings. Providing deaf students with both services simultaneously does not appear to provide any generalized benefit, at least for the kinds of materials utilized here.

Effects of Gas-Wall Partitioning in Teflon Tubing, Instrumentation and Other Materials on Time-Resolved Measurements of Gas-Phase Organic Compounds

NASA Astrophysics Data System (ADS)

Pagonis, D.; Deming, B.; Krechmer, J. E.; De Gouw, J. A.; Jimenez, J. L.; Ziemann, P. J.

2017-12-01

Recently it has been shown that gas-phase organic compounds partition to and from the walls of Teflon environmental chambers. This process is fast, reversible, and can be modeled as absorptive partitioning. Here these studies were extended to investigate gas-wall partitioning inside Teflon tubing by introducing step function changes in the concentration of compounds being sampled and measuring the delay in the response of a proton transfer reaction-mass spectrometer (PTR-MS). We find that these delays are significant for compounds with a saturation vapor concentration (c*) below 106 μg m-3, and that the Teflon tubing and the PTR-MS both contribute to the delays. Tubing delays range from minutes to hours under common sampling conditions and can be accurately predicted by a simple chromatography model across a range of tubing lengths and diameters, flow rates, compound functional groups, and c*. This method also allows one to determine the volatility-dependent response function of an instrument, which can be convolved with the output of the tubing model to correct for delays in instrument response time for these "sticky" compounds. This correction is expected to be of particular interest to researchers utilizing and developing chemical ionization mass spectrometry (CIMS) techniques, since many of the multifunctional organic compounds detected by CIMS show significant tubing and instrument delays. These results also enable better design of sampling systems, in particular when fast instrument response is needed, such as for rapid transients, aircraft, or eddy covariance measurements. Additional results presented here extend this method to quantify the relative sorptive capacities for other commonly used tubing materials, including PFA, FEP, PTFE, PEEK, glass, copper, stainless steel, and passivated steel.

Comparison of delay enhancement mechanisms for SBS-based slow light systems.

PubMed

Schneider, Thomas; Henker, Ronny; Lauterbach, Kai-Uwe; Junker, Markus

2007-07-23

We compare two simple mechanisms for the enhancement of the time delay in slow light systems. Both are based on the superposition of the Brillouin gain with additional loss. As we will show in theory and experiment if two losses are placed at the wings of a SBS gain, contrary to other methods, the loss power increases the time delay. This leads to higher delay times at lower optical powers and to an increase of the zero gain delay of more than 50%. With this method we achieved a time delay of more than 120ns for pulses with a temporal width of 30ns. To the best of our knowledge, this is the highest time delay in just one fiber spool. Beside the enhancement of the time delay the method could have the potential to decrease the pulse distortions for high bit rate signals.

Parental Delay or Refusal of Vaccine Doses, Childhood Vaccination Coverage at 24 Months of Age, and the Health Belief Model

PubMed Central

Smith, Philip J.; Humiston, Sharon G.; Marcuse, Edgar K.; Zhao, Zhen; Dorell, Christina G.; Howes, Cynthia; Hibbs, Beth

2011-01-01

Objective We evaluated the association between parents' beliefs about vaccines, their decision to delay or refuse vaccines for their children, and vaccination coverage of children at aged 24 months. Methods We used data from 11,206 parents of children aged 24–35 months at the time of the 2009 National Immunization Survey interview and determined their vaccination status at aged 24 months. Data included parents' reports of delay and/or refusal of vaccine doses, psychosocial factors suggested by the Health Belief Model, and provider-reported up-to-date vaccination status. Results In 2009, approximately 60.2% of parents with children aged 24–35 months neither delayed nor refused vaccines, 25.8% only delayed, 8.2% only refused, and 5.8% both delayed and refused vaccines. Compared with parents who neither delayed nor refused vaccines, parents who delayed and refused vaccines were significantly less likely to believe that vaccines are necessary to protect the health of children (70.1% vs. 96.2%), that their child might get a disease if they aren't vaccinated (71.0% vs. 90.0%), and that vaccines are safe (50.4% vs. 84.9%). Children of parents who delayed and refused also had significantly lower vaccination coverage for nine of the 10 recommended childhood vaccines including diphtheria-tetanus-acellular pertussis (65.3% vs. 85.2%), polio (76.9% vs. 93.8%), and measles-mumps-rubella (68.4% vs. 92.5%). After adjusting for sociodemographic differences, we found that parents who were less likely to agree that vaccines are necessary to protect the health of children, to believe that their child might get a disease if they aren't vaccinated, or to believe that vaccines are safe had significantly lower coverage for all 10 childhood vaccines. Conclusions Parents who delayed and refused vaccine doses were more likely to have vaccine safety concerns and perceive fewer benefits associated with vaccines. Guidelines published by the American Academy of Pediatrics may assist providers in responding to parents who may delay or refuse vaccines. PMID:21812176

Electromechanical delay of the knee flexor muscles is impaired after harvesting hamstring tendons for anterior cruciate ligament reconstruction.

PubMed

Ristanis, Stavros; Tsepis, Elias; Giotis, Dimitrios; Stergiou, Nicholas; Cerulli, Guiliano; Georgoulis, Anastasios D

2009-11-01

Changes in electromechanical delay during muscle activation are expected when there are substantial alterations in the structural properties of the musculotendinous tissue. In anterior cruciate ligament reconstruction, specific tendons are being harvested for grafts. Thus, there is an associated scar tissue development at the tendon that may affect the corresponding electromechanical delay. This study was conducted to investigate whether harvesting of semitendinosus and gracilis tendons for anterior cruciate ligament reconstruction will affect the electromechanical delay of the knee flexors. Case-control study; Level of evidence, 3. The authors evaluated 12 patients with anterior cruciate ligament reconstruction with a semitendinosus and gracilis autograft, 2 years after the reconstruction, and 12 healthy controls. Each participant performed 4 maximally explosive isometric contractions with a 1-minute break between contractions. The surface electromyographic activity of the biceps femoris and the semitendinosus was recorded from both legs during the contractions. The statistical comparisons revealed significant increases of the electromechanical delay of the anterior cruciate ligament-reconstructed knee for both investigated muscles. Specifically, the electromechanical delay values were increased for both the biceps femoris (P = .029) and the semitendinosus (P = .005) of the reconstructed knee when compared with the intact knee. Comparing the anterior cruciate ligament-reconstructed knee against healthy controls revealed similar significant differences for both muscles (semitendinosus, P = .011; biceps femoris, P = .024). The results showed that harvesting the semitendinosus and gracilis tendons for anterior cruciate ligament reconstruction significantly increased the electromechanical delay of the knee flexors. Increased hamstring electromechanical delay might impair knee safety and performance by modifying the transfer time of muscle tension to the tibia and therefore affecting muscle response during sudden movements in athletic activities. However, further investigation is required to identify whether the increased electromechanical delay of the hamstrings can actually influence optimal sports performance and increase the risk for knee injury in athletes with anterior cruciate ligament reconstructions.

Impact of Partial Time Delay on Temporal Dynamics of Watts-Strogatz Small-World Neuronal Networks

NASA Astrophysics Data System (ADS)

Yan, Hao; Sun, Xiaojuan

2017-06-01

In this paper, we mainly discuss effects of partial time delay on temporal dynamics of Watts-Strogatz (WS) small-world neuronal networks by controlling two parameters. One is the time delay τ and the other is the probability of partial time delay pdelay. Temporal dynamics of WS small-world neuronal networks are discussed with the aid of temporal coherence and mean firing rate. With the obtained simulation results, it is revealed that for small time delay τ, the probability pdelay could weaken temporal coherence and increase mean firing rate of neuronal networks, which indicates that it could improve neuronal firings of the neuronal networks while destroying firing regularity. For large time delay τ, temporal coherence and mean firing rate do not have great changes with respect to pdelay. Time delay τ always has great influence on both temporal coherence and mean firing rate no matter what is the value of pdelay. Moreover, with the analysis of spike trains and histograms of interspike intervals of neurons inside neuronal networks, it is found that the effects of partial time delays on temporal coherence and mean firing rate could be the result of locking between the period of neuronal firing activities and the value of time delay τ. In brief, partial time delay could have great influence on temporal dynamics of the neuronal networks.

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

NASA Technical Reports Server (NTRS)

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

1987-01-01

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

Amplification of tsunami heights by delayed rupture of great earthquakes along the Nankai trough

NASA Astrophysics Data System (ADS)

Imai, K.; Satake, K.; Furumura, T.

2010-04-01

We investigated the effect of delayed rupture of great earthquakes along the Nankai trough on tsunami heights on the Japanese coast. As the tsunami source, we used a model of the 1707 Hoei earthquake, which consists of four segments: Tokai, Tonankai, and two Nankai segments. We first searched for the worst case, in terms of coastal tsunami heights, of rupture delay time on each segment, on the basis of superposition principle for the linear long wave theory. When the rupture starts on the Tonankai segment, followed by rupture on the Tokai segment 21 min later, as well as the eastern and western Nankai segments 15 and 28 min later, respectively, the average coastal tsunami height becomes the largest. To quantify the tsunami amplification, we compared the coastal tsunami heights from the delayed rupture with those from the simultaneous rupture model. Along the coasts of the sea of Hyu'uga and in the Bungo Channel, the tsunami heights become significantly amplified (>1.4 times larger) relative to the simultaneous rupture. Along the coasts of Tosa Bay and in the Kii Channel, the tsunami heights become amplified about 1.2 times. Along the coasts of the sea of Kumano and Ise Bay, and the western Enshu coast, the tsunami heights become slightly smaller for the delayed rupture. Along the eastern Enshu coast, the coast of Suruga Bay, and the west coast of Sagami Bay, the tsunami heights become amplified about 1.1 times.

Assessment of Appalachian region pediatric hearing healthcare disparities and delays.

PubMed

Bush, Matthew L; Osetinsky, Mariel; Shinn, Jennifer B; Gal, Thomas J; Ding, Xiuhua; Fardo, David W; Schoenberg, Nancy

2014-07-01

The purpose of this study was to examine the timing of diagnostic and therapeutic services in cochlear implant recipients from a rural Appalachian region with healthcare disparity. Retrospective analysis. Cochlear implant recipients from a tertiary referral center born with severe congenital sensorineural hearing loss were examined. Rural status and Appalachian status of their county of origin were recorded. A log-rank test was used to examine differences in the distributions of time to definitive diagnosis of hearing loss, initial amplification fitting, and cochlear implantation in these children. Correlation analysis of the rural status of each county and the timing of services was assessed. A total of 53 children born with congenital hearing loss were included in the study (36 from rural counties and 17 from urban/suburban counties). The distribution of weeks after birth to diagnosis (P=.006), amplification (P=.030), and cochlear implantation (P=.002) was delayed in rural children compared with urban children. An analysis factoring in the effect of implementation of mandatory infant hearing screening in 2000 demonstrated a similar delay in rural children for weeks to diagnosis (P=.028), amplification (P=.087), and cochlear implantation (P<.0001). Children with severe hearing loss in very rural areas, such as Appalachia, may have significant delays in diagnostic and rehabilitative services. Further investigation is warranted to assess causative factors in delays of cochlear implantation and to develop interventions to promote timely diagnosis and care. 3b. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

Optimal Integration of Departure and Arrivals in Terminal Airspace

NASA Technical Reports Server (NTRS)

Xue, Min; Zelinski, Shannon Jean

2012-01-01

Coordination of operations with spatially and temporally shared resources such as route segments, fixes, and runways improves the efficiency of terminal airspace management. Problems in this category include scheduling and routing, thus they are normally difficult to solve compared with pure scheduling problems. In order to reduce the computational time, a fast time algorithm formulation using a non-dominated sorting genetic algorithm (NSGA) was introduced in this work and applied to a test case based on existing literature. The experiment showed that new method can solve the whole problem in fast time instead of solving sub-problems sequentially with a window technique. The results showed a 60% or 406 second delay reduction was achieved by sharing departure fixes (more details on the comparison with MILP results will be presented in the final paper). Furthermore, the NSGA algorithm was applied to a problem in LAX terminal airspace, where interactions between 28% of LAX arrivals and 10% of LAX departures are resolved by spatial segregation, which may introduce unnecessary delays. In this work, spatial segregation, temporal segregation, and hybrid segregation were formulated using the new algorithm. Results showed that spatial and temporal segregation approaches achieved similar delay. Hybrid segregation introduced much less delay than the other two approaches. For a total of 9 interacting departures and arrivals, delay reduction varied from 4 minutes to 6.4 minutes corresponding flight time uncertainty from 0 to 60 seconds. Considering the amount of flights that could be affected, total annual savings with hybrid segregation would be significant.

Application of oil-water discrimination technology in fractured reservoirs using the differences between fast and slow shear-waves

NASA Astrophysics Data System (ADS)

Luo, Cong; Li, Xiangyang; Huang, Guangtan

2017-08-01

Oil-water discrimination is of great significance in the design and adjustment of development projects in oil fields. For fractured reservoirs, based on anisotropic S-wave splitting information, it becomes possible to effectively solve such problems which are difficult to deal with in traditional longitudinal wave exploration, due to the similar bulk modulus and density of these two fluids. In this paper, by analyzing the anisotropic character of the Chapman model (2009 Geophysics 74 97-103), the velocity and reflection coefficient differences between the fast and slow S-wave caused by fluid substitution have been verified. Then, through a wave field response analysis of the theoretical model, we found that water saturation causes a longer time delay, a larger time delay gradient and a lower amplitude difference between the fast and slow S-wave, while the oil case corresponds to a lower time delay, a lower gradient and a higher amplitude difference. Therefore, a new class attribute has been proposed regarding the amplitude energy of the fast and slow shear wave, used for oil-water distinction. This new attribute, as well as that of the time delay gradient, were both applied to the 3D3C seismic data of carbonate fractured reservoirs in the Luojia area of the Shengli oil field in China. The results show that the predictions of the energy attributes are more consistent with the well information than the time delay gradient attribute, hence demonstrating the great advantages and potential of this new attribute in oil-water recognition.

Dancing sprites: Detailed analysis of two case studies

NASA Astrophysics Data System (ADS)

Soula, Serge; Mlynarczyk, Janusz; Füllekrug, Martin; Pineda, Nicolau; Georgis, Jean-François; van der Velde, Oscar; Montanyà, Joan; Fabró, Ferran

2017-03-01

On 29-30 October 2013, a low-light video camera installed at Pic du Midi (2877 m), recorded transient luminous events above a very active storm over the Mediterranean Sea. The minimum cloud top temperature reached -73°C, while its cloud to ground (CG) flash rate exceeded 30 fl min-1. Some sprite events have long duration and resemble to dancing sprites. We analyze in detail the temporal evolution and estimated location of two series of sprite sequences, as well as the cloud structure, the lightning activity, the electric field radiated in a broad range of low frequencies, and the current moment waveform of the lightning strokes. (i) In each series, successive sprite sequences reflect time and location of corresponding positive lightning strokes across the stratiform region. (ii) The longer time-delayed (>20 ms) sprite elements correspond to the lower impulsive charge moment changes (iCMC) of the parent strokes (<200 C km), and they are shifted few tens of kilometers from their SP + CG stroke. However, both short and long time-delayed sprite elements also occur after strokes that produce a large iCMC and that are followed by a continuing current. (iii) The long time-delayed sprite elements during the continuing current correspond to surges in the current moment waveform. They occur sometimes at an altitude apparently lower than the previous short time-delayed sprite elements, possibly because of changes in the local conductivity. (iv) The largest and brightest sprite elements produce significant current signatures, visible when their delay is not too short ( 3-5 ms).

Effect of Photoactivation Timing on the Mechanical Properties of Resin Cements and Bond Strength of Fiberglass Post to Root Dentin.

PubMed

Pereira, R D; Valdívia, A D C M; Bicalho, A A; Franco, S D; Tantbirojn, D; Versluis, A; Soares, C J

2015-01-01

This study tested the hypothesis that photoactivation timing and resin cement affect mechanical properties and bond strength of fiberglass posts to root dentin at different depths. Fiberglass posts (Exacto, Angelus) were luted with RelyX Unicem (3M ESPE), Panavia F 2.0 (Kuraray), or RelyX ARC (3M ESPE) using three photoactivation timings: light curing immediately, after three minutes, or after five minutes. Push-out bonding strength, PBS (n=10) was measured on each root region (coronal, middle, apical). The elastic modulus (E) and Vickers hardness (VHN) of the cement layer along the root canal were determined using dynamic indentation (n=5). A strain-gauge test was used to measure post-gel shrinkage of each cement (n=10). Residual shrinkage stress was assessed with finite element analysis. Data were analyzed with two-way analysis of variance in a split-plot arrangement and a Tukey test (α=0.05). Multiple linear regression analysis was used to determine the influence of study factors. The five-minute delay photoactivation timing significantly increased the PBS for all resin cements evaluated. The PBS decreased significantly from coronal to apical root canal regions. The mean values for E and VHN increased significantly with the delayed photoactivation for RelyX Unicem and decreased from coronal to apical root regions for all resin cements with the immediate-curing timing. The PBS of fiber posts to root dentin, E, and VHN values were affected by the root canal region, photoactivation timing, and resin cement type. Shrinkage stress values decreased gradually with delayed photoactivation for all the cements.

Discovering time-lagged rules from microarray data using gene profile classifiers

PubMed Central

2011-01-01

Background Gene regulatory networks have an essential role in every process of life. In this regard, the amount of genome-wide time series data is becoming increasingly available, providing the opportunity to discover the time-delayed gene regulatory networks that govern the majority of these molecular processes. Results This paper aims at reconstructing gene regulatory networks from multiple genome-wide microarray time series datasets. In this sense, a new model-free algorithm called GRNCOP2 (Gene Regulatory Network inference by Combinatorial OPtimization 2), which is a significant evolution of the GRNCOP algorithm, was developed using combinatorial optimization of gene profile classifiers. The method is capable of inferring potential time-delay relationships with any span of time between genes from various time series datasets given as input. The proposed algorithm was applied to time series data composed of twenty yeast genes that are highly relevant for the cell-cycle study, and the results were compared against several related approaches. The outcomes have shown that GRNCOP2 outperforms the contrasted methods in terms of the proposed metrics, and that the results are consistent with previous biological knowledge. Additionally, a genome-wide study on multiple publicly available time series data was performed. In this case, the experimentation has exhibited the soundness and scalability of the new method which inferred highly-related statistically-significant gene associations. Conclusions A novel method for inferring time-delayed gene regulatory networks from genome-wide time series datasets is proposed in this paper. The method was carefully validated with several publicly available data sets. The results have demonstrated that the algorithm constitutes a usable model-free approach capable of predicting meaningful relationships between genes, revealing the time-trends of gene regulation. PMID:21524308

Ignition and combustion of lunar propellants

NASA Technical Reports Server (NTRS)

Burton, Rodney L.; Roberts, Ted A.; Krier, Herman

1993-01-01

The ignition and combustion of Al, Mg, and Al/Mg alloy particles in 99 percent O2/1 percent N2 mixtures is investigated at high temperatures and pressures for rocket engine applications. The 20 micron particles contain 0, 5, 10, 20, 40, 60, 80, and 100 weight percent Mg alloyed with Al, and are ignited in oxygen using the reflected shock in a shock tube near the endwall. Using this technique, the ignition delay and combustion times of the particles are measured at temperatures up to 3250 K as a function of Mg content for oxygen pressures of 8.5, 17, and 34 atm. An ignition model is developed which employs a simple lumped capacitance energy equation and temperature and pressure dependent particle and gas properties. Good agreement is achieved between the measured and predicted trends in the ignition delay times. For the particles investigated, the contribution of heterogeneous reaction to the heating of the particle is found to be significant at lower temperatures, but may be neglected as gas temperatures above 3000 K. As little as 10 percent Mg reduces the ignition delay time substantially at all pressures tested. The particle ignition delay times decrease with increasing Mg content, and this reduction becomes less pronounced as oxidizer temperature and pressure are increased.

76 FR 68734 - Taking and Importing Marine Mammals: Taking Marine Mammals Incidental to Navy Training Exercises...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-07

... marine mammal is likely to travel during the time associated with the TDFD's time delay, and that... Navy provided the approximate distance that an animal would typically travel within a given time-delay... Speed and Length of Time-Delay Potential distance Species group Swim speed Time-delay traveled Delphinid...

Quantum key distribution with delayed privacy amplification and its application to the security proof of a two-way deterministic protocol

NASA Astrophysics Data System (ADS)

Fung, Chi-Hang Fred; Ma, Xiongfeng; Chau, H. F.; Cai, Qing-Yu

2012-03-01

Privacy amplification (PA) is an essential postprocessing step in quantum key distribution (QKD) for removing any information an eavesdropper may have on the final secret key. In this paper, we consider delaying PA of the final key after its use in one-time pad encryption and prove its security. We prove that the security and the key generation rate are not affected by delaying PA. Delaying PA has two applications: it serves as a tool for significantly simplifying the security proof of QKD with a two-way quantum channel, and also it is useful in QKD networks with trusted relays. To illustrate the power of the delayed PA idea, we use it to prove the security of a qubit-based two-way deterministic QKD protocol which uses four states and four encoding operations.

[Intermodal timing cues for audio-visual speech recognition].

PubMed

Hashimoto, Masahiro; Kumashiro, Masaharu

2004-06-01

The purpose of this study was to investigate the limitations of lip-reading advantages for Japanese young adults by desynchronizing visual and auditory information in speech. In the experiment, audio-visual speech stimuli were presented under the six test conditions: audio-alone, and audio-visually with either 0, 60, 120, 240 or 480 ms of audio delay. The stimuli were the video recordings of a face of a female Japanese speaking long and short Japanese sentences. The intelligibility of the audio-visual stimuli was measured as a function of audio delays in sixteen untrained young subjects. Speech intelligibility under the audio-delay condition of less than 120 ms was significantly better than that under the audio-alone condition. On the other hand, the delay of 120 ms corresponded to the mean mora duration measured for the audio stimuli. The results implied that audio delays of up to 120 ms would not disrupt lip-reading advantage, because visual and auditory information in speech seemed to be integrated on a syllabic time scale. Potential applications of this research include noisy workplace in which a worker must extract relevant speech from all the other competing noises.

Joint Maximum Likelihood Time Delay Estimation of Unknown Event-Related Potential Signals for EEG Sensor Signal Quality Enhancement

PubMed Central

Kim, Kyungsoo; Lim, Sung-Ho; Lee, Jaeseok; Kang, Won-Seok; Moon, Cheil; Choi, Ji-Woong

2016-01-01

Electroencephalograms (EEGs) measure a brain signal that contains abundant information about the human brain function and health. For this reason, recent clinical brain research and brain computer interface (BCI) studies use EEG signals in many applications. Due to the significant noise in EEG traces, signal processing to enhance the signal to noise power ratio (SNR) is necessary for EEG analysis, especially for non-invasive EEG. A typical method to improve the SNR is averaging many trials of event related potential (ERP) signal that represents a brain’s response to a particular stimulus or a task. The averaging, however, is very sensitive to variable delays. In this study, we propose two time delay estimation (TDE) schemes based on a joint maximum likelihood (ML) criterion to compensate the uncertain delays which may be different in each trial. We evaluate the performance for different types of signals such as random, deterministic, and real EEG signals. The results show that the proposed schemes provide better performance than other conventional schemes employing averaged signal as a reference, e.g., up to 4 dB gain at the expected delay error of 10°. PMID:27322267

Diuretic renography in hydronephrosis: delayed tissue tracer transit accompanies both functional decline and tissue reorganization.

PubMed

Schlotmann, Andreas; Clorius, John H; Rohrschneider, Wiltrud K; Clorius, Sandra N; Amelung, Folker; Becker, Kristianna

2008-07-01

The significance of delayed tissue tracer transit (TTT) of (99m)Tc-mercaptoacetyltriglycine ((99m)Tc-MAG3) has not been systematically evaluated in hydronephrosis. We sought to demonstrate that delayed TTT accompanies both functional decline and histomorphologic restructuring. Twenty 2- to 3-mo-old piglets with surgically induced partial unilateral ureteral stenosis were examined with magnetic resonance urography (MRU) to evaluate morphology and with (99m)Tc-MAG3 diuretic renography (DR) to determine single-kidney function (SKF), evaluate the response to furosemide stimulation (RFS), and assess TTT. All animals had DR and MRU before and after surgery and a third DR after surgery. Piglets were sacrificed after the final DR for renal histology. A total histologic score (THS) was generated. Preoperative DR demonstrated nonobstructive RFS, timely TTT, and balanced SKF in all 20 kidneys. After ureteral ligature, MRU demonstrated pelvic dilatation in all piglets. The postoperative DRs revealed 12 kidneys with delayed TTT in one or both follow-ups. In these 12 kidneys, the SKF declined from 51% +/- 4% to 18% +/- 14%, and the THS was 9.0 +/- 4.0. Three kidneys always had timely TTT, balanced SKF, and a THS of 1.8 +/- 0.3. The contralateral, nonoperated kidneys had timely TTT and a THS of 1.2 +/- 0.9. Postoperative scintigrams showed that 3 of 8 kidneys (38%) with an obstructive RFS had timely TTT, which demonstrates that TTT and RFS are not equivalent. In hydronephrosis, a delayed TTT of (99m)Tc-MAG3 accompanies both functional decline and histomorphologic restructuring in obstruction. According to the literature, a delayed TTT is determined by the filtration fraction of the kidneys and appears to identify an obstruction-mediated upregulated renin-angiotensin system.

The Application of MRI for Depiction of Subtle Blood Brain Barrier Disruption in Stroke

PubMed Central

Israeli, David; Tanne, David; Daniels, Dianne; Last, David; Shneor, Ran; Guez, David; Landau, Efrat; Roth, Yiftach; Ocherashvilli, Aharon; Bakon, Mati; Hoffman, Chen; Weinberg, Amit; Volk, Talila; Mardor, Yael

2011-01-01

The development of imaging methodologies for detecting blood-brain-barrier (BBB) disruption may help predict stroke patient's propensity to develop hemorrhagic complications following reperfusion. We have developed a delayed contrast extravasation MRI-based methodology enabling real-time depiction of subtle BBB abnormalities in humans with high sensitivity to BBB disruption and high spatial resolution. The increased sensitivity to subtle BBB disruption is obtained by acquiring T1-weighted MRI at relatively long delays (~15 minutes) after contrast injection and subtracting from them images acquired immediately after contrast administration. In addition, the relatively long delays allow for acquisition of high resolution images resulting in high resolution BBB disruption maps. The sensitivity is further increased by image preprocessing with corrections for intensity variations and with whole body (rigid+elastic) registration. Since only two separate time points are required, the time between the two acquisitions can be used for acquiring routine clinical data, keeping the total imaging time to a minimum. A proof of concept study was performed in 34 patients with ischemic stroke and 2 patients with brain metastases undergoing high resolution T1-weighted MRI acquired at 3 time points after contrast injection. The MR images were pre-processed and subtracted to produce BBB disruption maps. BBB maps of patients with brain metastases and ischemic stroke presented different patterns of BBB opening. The significant advantage of the long extravasation time was demonstrated by a dynamic-contrast-enhancement study performed continuously for 18 min. The high sensitivity of our methodology enabled depiction of clear BBB disruption in 27% of the stroke patients who did not have abnormalities on conventional contrast-enhanced MRI. In 36% of the patients, who had abnormalities detectable by conventional MRI, the BBB disruption volumes were significantly larger in the maps than in conventional MRI. These results demonstrate the advantages of delayed contrast extravasation in increasing the sensitivity to subtle BBB disruption in ischemic stroke patients. The calculated disruption maps provide clear depiction of significant volumes of BBB disruption unattainable by conventional contrast-enhanced MRI. PMID:21209786

The application of MRI for depiction of subtle blood brain barrier disruption in stroke.

PubMed

Israeli, David; Tanne, David; Daniels, Dianne; Last, David; Shneor, Ran; Guez, David; Landau, Efrat; Roth, Yiftach; Ocherashvilli, Aharon; Bakon, Mati; Hoffman, Chen; Weinberg, Amit; Volk, Talila; Mardor, Yael

2010-12-26

The development of imaging methodologies for detecting blood-brain-barrier (BBB) disruption may help predict stroke patient's propensity to develop hemorrhagic complications following reperfusion. We have developed a delayed contrast extravasation MRI-based methodology enabling real-time depiction of subtle BBB abnormalities in humans with high sensitivity to BBB disruption and high spatial resolution. The increased sensitivity to subtle BBB disruption is obtained by acquiring T1-weighted MRI at relatively long delays (~15 minutes) after contrast injection and subtracting from them images acquired immediately after contrast administration. In addition, the relatively long delays allow for acquisition of high resolution images resulting in high resolution BBB disruption maps. The sensitivity is further increased by image preprocessing with corrections for intensity variations and with whole body (rigid+elastic) registration. Since only two separate time points are required, the time between the two acquisitions can be used for acquiring routine clinical data, keeping the total imaging time to a minimum. A proof of concept study was performed in 34 patients with ischemic stroke and 2 patients with brain metastases undergoing high resolution T1-weighted MRI acquired at 3 time points after contrast injection. The MR images were pre-processed and subtracted to produce BBB disruption maps. BBB maps of patients with brain metastases and ischemic stroke presented different patterns of BBB opening. The significant advantage of the long extravasation time was demonstrated by a dynamic-contrast-enhancement study performed continuously for 18 min. The high sensitivity of our methodology enabled depiction of clear BBB disruption in 27% of the stroke patients who did not have abnormalities on conventional contrast-enhanced MRI. In 36% of the patients, who had abnormalities detectable by conventional MRI, the BBB disruption volumes were significantly larger in the maps than in conventional MRI. These results demonstrate the advantages of delayed contrast extravasation in increasing the sensitivity to subtle BBB disruption in ischemic stroke patients. The calculated disruption maps provide clear depiction of significant volumes of BBB disruption unattainable by conventional contrast-enhanced MRI.

Ignition delays, heats of combustion, and reaction rates of aluminum alkyl derivatives used as ignition and combustion enhancers for supersonic combustion

NASA Technical Reports Server (NTRS)

Ryan, Thomas W., III; Schwab, S. T.; Harlowe, W. W.

1992-01-01

The subject of this paper is the design of supersonic combustors which will be required in order to achieve the needed reaction rates in a reasonable sized combustor. A fuel additive approach, which is the focus of this research, is the use of pyrophorics to shorten the ignition delay time and to increase the energy density of the fuel. Pyrophoric organometallic compounds may also provide an ignition source and flame stabilization mechanism within the combustor, thus permitting use of hydrocarbon fuels in supersonic combustion systems. Triethylaluminum (TEA) and trimethylaluminum (TMA) were suggested for this application due to their high energy density and reactivity. The objective here is to provide comparative data for the ignition quality, the energy content, and the reaction rates of several different adducts of both TEA and TMA. The results of the experiments indicate the aluminum alkyls and their more stable derivatives reduce the ignition delay and total reaction time to JP-10 jet fuel. Furthermore, the temperature dependence of ignition delay and total reaction time of the blends of the adducts are significantly lower than in neat JP-10.

Probability of Loss of Assured Safety in Systems with Multiple Time-Dependent Failure Modes: Incorporation of Delayed Link Failure in the Presence of Aleatory Uncertainty.

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

Helton, Jon C.; Brooks, Dusty Marie; Sallaberry, Cedric Jean-Marie.

Probability of loss of assured safety (PLOAS) is modeled for weak link (WL)/strong link (SL) systems in which one or more WLs or SLs could potentially degrade into a precursor condition to link failure that will be followed by an actual failure after some amount of elapsed time. The following topics are considered: (i) Definition of precursor occurrence time cumulative distribution functions (CDFs) for individual WLs and SLs, (ii) Formal representation of PLOAS with constant delay times, (iii) Approximation and illustration of PLOAS with constant delay times, (iv) Formal representation of PLOAS with aleatory uncertainty in delay times, (v) Approximationmore » and illustration of PLOAS with aleatory uncertainty in delay times, (vi) Formal representation of PLOAS with delay times defined by functions of link properties at occurrence times for failure precursors, (vii) Approximation and illustration of PLOAS with delay times defined by functions of link properties at occurrence times for failure precursors, and (viii) Procedures for the verification of PLOAS calculations for the three indicated definitions of delayed link failure.« less

Delayed high school start times later than 8:30am and impact on graduation rates and attendance rates.

PubMed

McKeever, Pamela Malaspina; Clark, Linda

2017-04-01

The first purpose of this study was to investigate changes in high school graduation rates with a delayed school start time of later than 8:30am. The second aim of the study was to analyze the association between a delayed high school start time later than 8:30am and attendance rates. In the current study, a pre-post design using a repeated-measures analysis of variance was used to examine changes in attendance and graduation rates 2 years after a delayed start was implemented. Public high schools from 8 school districts (n=29 high schools) located throughout 7 different states. Schools were identified using previous research from the Children's National Medical Center's Division of Sleep Medicine Research Team. A total membership of more than 30,000 high school students enrolled in the 29 schools identified by the Children's National Medical Center's Research Team. A pre-post design was used for a within-subject design, controlling for any school-to-school difference in the calculation of the response variable. This is the recommended technique for a study that may include data with potential measurement error. Findings from this study linked a start time of later than 8:30am to improved attendance rates and graduation rates. Attendance rates and graduation rates significantly improved in schools with delayed start times of 8:30am or later. School officials need to take special notice that this investigation also raises questions about whether later start times are a mechanism for closing the achievement gap due to improved graduation rates. Copyright © 2017 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.

Time delay can facilitate coherence in self-driven interacting-particle systems

NASA Astrophysics Data System (ADS)

Sun, Yongzheng; Lin, Wei; Erban, Radek

2014-12-01

Directional switching in a self-propelled particle model with delayed interactions is investigated. It is shown that the average switching time is an increasing function of time delay. The presented results are applied to studying collective animal behavior. It is argued that self-propelled particle models with time delays can explain the state-dependent diffusion coefficient measured in experiments with locust groups. The theory is further generalized to heterogeneous groups where each individual can respond to its environment with a different time delay.

Influence of delayed gadolinium enhanced MRI of cartilage (dGEMRIC) protocol on T2-mapping: is it possible to comprehensively assess knee cartilage composition in one post-contrast MR examination at 3 Tesla?

PubMed

Verschueren, J; van Tiel, J; Reijman, M; Bron, E E; Klein, S; Verhaar, J A N; Bierma-Zeinstra, S M A; Krestin, G P; Wielopolski, P A; Oei, E H G

2017-09-01

To evaluate the possibility of assessing knee cartilage with T2-mapping and delayed gadolinium enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) in one post-contrast MR examination at 3 Tesla (T). T2 mapping was performed in 10 healthy volunteers at baseline; directly after baseline; after 10 min of cycling; and after 90 min delay, and in 16 osteoarthritis patients before and after intravenous administration of a double dose gadolinium dimeglumine contrast agent, reflecting key dGEMRIC protocol elements. Differences in T2 relaxation times between each timepoint and baseline were calculated for 6 cartilage regions using paired t tests or Wilcoxon signed-rank tests and the smallest detectable change (SDC). After cycling, a significant change in T2 relaxation times was found in the lateral weight-bearing tibial plateau (+1.0 ms, P = 0.04). After 90 min delay, significant changes were found in the lateral weight-bearing femoral condyle (+1.2 ms, P = 0.03) and the lateral weight-bearing tibial plateau (+1.3 ms, P = 0.01). In these regions of interests (ROIs), absolute differences were small and lower than the corresponding SDCs. T2-mapping after contrast administration only showed statistically significantly lower T2 relaxation times in the medial posterior femoral condyle (-2.4 ms, P < 0.001) with a change exceeding the SDC. Because dGEMRIC protocol elements resulted in only small differences in T2 relaxation times that were not consistent and lower than the SDC in the majority of regions, our results suggest that T2-mapping and dGEMRIC can be performed reliably in a single imaging session to assess cartilage biochemical composition in knee osteoarthritis (OA) at 3 T. Copyright © 2017 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Photonuclear Contributions to SNS Pulse Shapes

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

McClanahan, Tucker C.; Iverson, Erik B.; Gallmeier, Franz X.

Short-pulsed sources like the Spallation Neutron Source (SNS) and ISIS produce bursts of neutron pulses at rates of 10-60 Hz, with sub-microsecond proton pulses impacting on high-Z target materials. Moderators are grouped around the target to receive the fast neutrons generated from spallation reactions to moderate them effciently to thermal and sub-thermal energies and to feed narrow neutron pulses to neutron scattering instruments. The scattering instruments use the neutrons as a probe for material investigations, and make use of time-of-flight (TOF) methods for resolving the neutron energy. The energy resolution of scattering instruments depends on the narrow time-structure of themore » neutron pulses, while neutrons in the long tail of the emission time distributions can degrade the instrument performance and add undesired background to measurements. The SNS neutronics team is investigating a possible source term impacting the background at short-pulsed spallation sources. The ISIS TS2 project claims to have significantly reduced neutron scattering instrument background levels by the elimination or reduction of iron shielding in the target-moderator-reflector assembly. An alternative hypothesis, also proposed by ISIS, suggests that this apparent reduction arises from moving beamline shielding away from the neutron guide channels, reducing albedo down the beamlines. In both hypotheses, the background neutrons in question are believed to be generated by photonuclear reactions. If the background neutrons are indeed generated via photonuclear channels, then they are generated in a time-dependent fashion, since most of the high-energy photons capable of inducing photonuclear production are gone within a few microseconds following the proton pulse. To evaluate this e ect, we have enabled photonuclear reactions in a series of studies for the SNS first target station (FTS) taking advantage of its Monte Carlo model. Using a mixture of ENDF/B VII.0 and TENDL-2014 photonuclear cross sections available and the CEM03 physics model within MCNPX 2.6.0 in the simulation, we are able to estimate the impact of photoneutron production on both overall neutron production and delayed neutron production. We find that a significant number of photon-induced neutrons are produced a few milliseconds after the proton pulse, following prompt gamma emission through the capture of neutrons in the slowing-down and thermalization processes. We name these "slowing-down delayed neutrons" to distinguish them from either "activation-delayed neutrons" or "beta-delayed neutrons." The beta-delayed and activation-delayed neutrons were not part of this study, and will be addressed elsewhere. While these other delayed neutron channels result in the time-independent (constant) production of fast neutrons outside of the prompt pulse, the slowing-down delayed neutrons also a ect the shape of the pulses. Although numerically insignificant in most cases, we describe a set of scenarios related to T0-chopper operation in which the slowing-down delayed neutrons may be important.« less

Delay banking for air traffic management

NASA Technical Reports Server (NTRS)

Green, Steven M. (Inventor)

2007-01-01

A method and associated system for time delay banking for aircraft arrival time, aircraft departure time and/or en route flight position. The delay credit value for a given flight may decrease with passage of time and may be transferred to or traded with other flights having the same or a different user (airline owner or operator). The delay credit value for a given aircraft flight depends upon an initial delay credit value, which is determined by a central system and depends upon one or more other flight characteristics. Optionally, the delay credit value decreases with passage of time. Optionally, a transaction cost is assessed against a delay credit value that is used on behalf of another flight with the same user or is traded with a different user.

General relation between the group delay and dwell time in multicomponent electron systems

NASA Astrophysics Data System (ADS)

Zhai, Feng; Lu, Junqiang

2016-10-01

For multicomponent electron scattering states, we derive a general relation between the Wigner group delay and the Bohmian dwell time. It is found that the definition of group delay should account for the phase of the spinor wave functions of propagating modes. The difference between the group delay and dwell time comes from both the interference delay and the decaying modes. For barrier tunneling of helical electrons on a surface of topological insulators, our calculations including the trigonal-warping term show that the decaying modes can contribute greatly to the group delay. The derived relation between the group delay and the dwell time is helpful to unify the two definitions of tunneling time in a quite general situation.

Forced Incubation.

ERIC Educational Resources Information Center

Wells, Donald H.

1996-01-01

A survey of 98 college professors regarding their creative writing habits and productivity found that creative productivity was significantly correlated with the use of forced incubation (deliberate time delay to allow naturally unenhanced incubation of ideas to occur). Professors who intentionally set aside manuscripts for a period of time to…

Effect of long-time immersion of soft denture liners in water on viscoelastic properties.

PubMed

Iwasaki, Naohiko; Yamaki, Chisato; Takahashi, Hidekazu; Oki, Meiko; Suzuki, Tetsuya

2017-09-26

Aim of this study was to investigate the effect of long-time immersion of soft denture liners in 37°C water on viscoelastic properties. Six silicone-based and two acrylic resin-based soft denture liners were selected. Cylindrical specimens were stored in distilled water at 37°C for 6 months. Viscoelastic properties, which were instantaneous and delayed elastic displacements, viscous flow, and residual displacement, were determined using a creep meter, and analyzed with 2-way analysis of variance and Tukey's comparison (α=0.05). Viscoelastic properties and their time-dependent changes were varied among materials examined. The observed viscoelastic properties of three from six silicone-based liners did not significantly change after 6-month immersion, but those of two acrylic resin-based liners significantly changed with the increase of immersion time. However, the sum of initial instantaneous elastic displacement and delayed elastic displacement of two acrylic resin-based liners during 6-month immersion changed less than 10%, which might indicate clinically sufficient elastic performance.

CAN LARGE TIME DELAYS OBSERVED IN LIGHT CURVES OF CORONAL LOOPS BE EXPLAINED IN IMPULSIVE HEATING?

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

Lionello, Roberto; Linker, Jon A.; Mikić, Zoran

The light curves of solar coronal loops often peak first in channels associated with higher temperatures and then in those associated with lower temperatures. The delay times between the different narrowband EUV channels have been measured for many individual loops and recently for every pixel of an active region observation. The time delays between channels for an active region exhibit a wide range of values. The maximum time delay in each channel pair can be quite large, i.e., >5000 s. These large time delays make-up 3%–26% (depending on the channel pair) of the pixels where a trustworthy, positive time delaymore » is measured. It has been suggested that these time delays can be explained by simple impulsive heating, i.e., a short burst of energy that heats the plasma to a high temperature, after which the plasma is allowed to cool through radiation and conduction back to its original state. In this paper, we investigate whether the largest observed time delays can be explained by this hypothesis by simulating a series of coronal loops with different heating rates, loop lengths, abundances, and geometries to determine the range of expected time delays between a set of four EUV channels. We find that impulsive heating cannot address the largest time delays observed in two of the channel pairs and that the majority of the large time delays can only be explained by long, expanding loops with photospheric abundances. Additional observations may rule out these simulations as an explanation for the long time delays. We suggest that either the time delays found in this manner may not be representative of real loop evolution, or that the impulsive heating and cooling scenario may be too simple to explain the observations, and other potential heating scenarios must be explored.« less

Feedback as Real-Time Constructions

ERIC Educational Resources Information Center

Keiding, Tina Bering; Qvortrup, Ane

2014-01-01

This article offers a re-description of feedback and the significance of time in feedback constructions based on systems theory. It describes feedback as internal, real-time constructions in a learning system. From this perspective, feedback is neither immediate nor delayed, but occurs in the very moment it takes place. This article argues for a…

Contrasting effects of warming and increased snowfall on Arctic tundra plant phenology over the past two decades.

PubMed

Bjorkman, Anne D; Elmendorf, Sarah C; Beamish, Alison L; Vellend, Mark; Henry, Gregory H R

2015-12-01

Recent changes in climate have led to significant shifts in phenology, with many studies demonstrating advanced phenology in response to warming temperatures. The rate of temperature change is especially high in the Arctic, but this is also where we have relatively little data on phenological changes and the processes driving these changes. In order to understand how Arctic plant species are likely to respond to future changes in climate, we monitored flowering phenology in response to both experimental and ambient warming for four widespread species in two habitat types over 21 years. We additionally used long-term environmental records to disentangle the effects of temperature increase and changes in snowmelt date on phenological patterns. While flowering occurred earlier in response to experimental warming, plants in unmanipulated plots showed no change or a delay in flowering over the 21-year period, despite more than 1 °C of ambient warming during that time. This counterintuitive result was likely due to significantly delayed snowmelt over the study period (0.05-0.2 days/yr) due to increased winter snowfall. The timing of snowmelt was a strong driver of flowering phenology for all species - especially for early-flowering species - while spring temperature was significantly related to flowering time only for later-flowering species. Despite significantly delayed flowering phenology, the timing of seed maturation showed no significant change over time, suggesting that warmer temperatures may promote more rapid seed development. The results of this study highlight the importance of understanding the specific environmental cues that drive species' phenological responses as well as the complex interactions between temperature and precipitation when forecasting phenology over the coming decades. As demonstrated here, the effects of altered snowmelt patterns can counter the effects of warmer temperatures, even to the point of generating phenological responses opposite to those predicted by warming alone. © 2015 John Wiley & Sons Ltd.

Property Analysis of the Real-Time Uncalibrated Phase Delay Product Generated by Regional Reference Stations and Its Influence on Precise Point Positioning Ambiguity Resolution

PubMed Central

Zhang, Yong; Wang, Qing; Jiang, Xinyuan

2017-01-01

The real-time estimation of the wide-lane and narrow-lane Uncalibrated Phase Delay (UPD) of satellites is realized by real-time data received from regional reference station networks; The properties of the real-time UPD product and its influence on real-time precise point positioning ambiguity resolution (RTPPP-AR) are experimentally analyzed according to real-time data obtained from the regional Continuously Operating Reference Stations (CORS) network located in Tianjin, Shanghai, Hong Kong, etc. The results show that the real-time wide-lane and narrow-lane UPD products differ significantly from each other in time-domain characteristics; the wide-lane UPDs have daily stability, with a change rate of less than 0.1 cycle/day, while the narrow-lane UPDs have short-term stability, with significant change in one day. The UPD products generated by different regional networks have obvious spatial characteristics, thus significantly influencing RTPPP-AR: the adoption of real-time UPD products employing the sparse stations in the regional network for estimation is favorable for improving the regional RTPPP-AR up to 99%; the real-time UPD products of different regional networks slightly influence PPP-AR positioning accuracy. After ambiguities are successfully fixed, the real-time dynamic RTPPP-AR positioning accuracy is better than 3 cm in the plane and 8 cm in the upward direction. PMID:28534844

Property Analysis of the Real-Time Uncalibrated Phase Delay Product Generated by Regional Reference Stations and Its Influence on Precise Point Positioning Ambiguity Resolution.

PubMed

Zhang, Yong; Wang, Qing; Jiang, Xinyuan

2017-05-19

The real-time estimation of the wide-lane and narrow-lane Uncalibrated Phase Delay (UPD) of satellites is realized by real-time data received from regional reference station networks; The properties of the real-time UPD product and its influence on real-time precise point positioning ambiguity resolution (RTPPP-AR) are experimentally analyzed according to real-time data obtained from the regional Continuously Operating Reference Stations (CORS) network located in Tianjin, Shanghai, Hong Kong, etc. The results show that the real-time wide-lane and narrow-lane UPD products differ significantly from each other in time-domain characteristics; the wide-lane UPDs have daily stability, with a change rate of less than 0.1 cycle/day, while the narrow-lane UPDs have short-term stability, with significant change in one day. The UPD products generated by different regional networks have obvious spatial characteristics, thus significantly influencing RTPPP-AR: the adoption of real-time UPD products employing the sparse stations in the regional network for estimation is favorable for improving the regional RTPPP-AR up to 99%; the real-time UPD products of different regional networks slightly influence PPP-AR positioning accuracy. After ambiguities are successfully fixed, the real-time dynamic RTPPP-AR positioning accuracy is better than 3 cm in the plane and 8 cm in the upward direction.

Firing patterns transition and desynchronization induced by time delay in neural networks

NASA Astrophysics Data System (ADS)

Huang, Shoufang; Zhang, Jiqian; Wang, Maosheng; Hu, Chin-Kun

2018-06-01

We used the Hindmarsh-Rose (HR) model (Hindmarsh and Rose, 1984) to study the effect of time delay on the transition of firing behaviors and desynchronization in neural networks. As time delay is increased, neural networks exhibit diversity of firing behaviors, including regular spiking or bursting and firing patterns transitions (FPTs). Meanwhile, the desynchronization of firing and unstable bursting with decreasing amplitude in neural system, are also increasingly enhanced with the increase of time delay. Furthermore, we also studied the effect of coupling strength and network randomness on these phenomena. Our results imply that time delays can induce transition and desynchronization of firing behaviors in neural networks. These findings provide new insight into the role of time delay in the firing activities of neural networks, and can help to better understand the firing phenomena in complex systems of neural networks. A possible mechanism in brain that can cause the increase of time delay is discussed.

Delay time in a single barrier for a movable quantum shutter

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

Hernandez, Alberto

2010-05-15

The transient solution and delay time for a {delta} potential scatterer with a movable quantum shutter is calculated by solving analytically the time-dependent Schroedinger equation. The delay time is analyzed as a function of the distance between the shutter and the potential barrier and also as a function of the distance between the potential barrier and the detector. In both cases, it is found that the delay time exhibits a dynamical behavior and that it tends to a saturation value {Delta}t{sub sat} in the limit of very short distances, which represents the maximum delay produced by the potential barrier nearmore » the interaction region. The phase time {tau}{sub {theta},} on the other hand, is not an appropriate time scale for measuring the time delay near the interaction region, except if the shutter is moved far away from the potential. The role played by the antibound state of the system on the behavior of the delay time is also discussed.« less

LiDAR-IMU Time Delay Calibration Based on Iterative Closest Point and Iterated Sigma Point Kalman Filter.

PubMed

Liu, Wanli

2017-03-08

The time delay calibration between Light Detection and Ranging (LiDAR) and Inertial Measurement Units (IMUs) is an essential prerequisite for its applications. However, the correspondences between LiDAR and IMU measurements are usually unknown, and thus cannot be computed directly for the time delay calibration. In order to solve the problem of LiDAR-IMU time delay calibration, this paper presents a fusion method based on iterative closest point (ICP) and iterated sigma point Kalman filter (ISPKF), which combines the advantages of ICP and ISPKF. The ICP algorithm can precisely determine the unknown transformation between LiDAR-IMU; and the ISPKF algorithm can optimally estimate the time delay calibration parameters. First of all, the coordinate transformation from the LiDAR frame to the IMU frame is realized. Second, the measurement model and time delay error model of LiDAR and IMU are established. Third, the methodology of the ICP and ISPKF procedure is presented for LiDAR-IMU time delay calibration. Experimental results are presented that validate the proposed method and demonstrate the time delay error can be accurately calibrated.

On Time Delay Margin Estimation for Adaptive Control and Optimal Control Modification

NASA Technical Reports Server (NTRS)

Nguyen, Nhan T.

2011-01-01

This paper presents methods for estimating time delay margin for adaptive control of input delay systems with almost linear structured uncertainty. The bounded linear stability analysis method seeks to represent an adaptive law by a locally bounded linear approximation within a small time window. The time delay margin of this input delay system represents a local stability measure and is computed analytically by three methods: Pade approximation, Lyapunov-Krasovskii method, and the matrix measure method. These methods are applied to the standard model-reference adaptive control, s-modification adaptive law, and optimal control modification adaptive law. The windowing analysis results in non-unique estimates of the time delay margin since it is dependent on the length of a time window and parameters which vary from one time window to the next. The optimal control modification adaptive law overcomes this limitation in that, as the adaptive gain tends to infinity and if the matched uncertainty is linear, then the closed-loop input delay system tends to a LTI system. A lower bound of the time delay margin of this system can then be estimated uniquely without the need for the windowing analysis. Simulation results demonstrates the feasibility of the bounded linear stability method for time delay margin estimation.

Leveraging delay discounting for health: Can time delays influence food choice?

PubMed

Appelhans, Bradley M; French, Simone A; Olinger, Tamara; Bogucki, Michael; Janssen, Imke; Avery-Mamer, Elizabeth F; Powell, Lisa M

2018-07-01

Delay discounting, the tendency to choose smaller immediate rewards over larger delayed rewards, is theorized to promote consumption of immediately rewarding but unhealthy foods at the expense of long-term weight maintenance and nutritional health. An untested implication of delay discounting models of decision-making is that selectively delaying access to less healthy foods may promote selection of healthier (immediately available) alternatives, even if they may be less desirable. The current study tested this hypothesis by measuring healthy versus regular vending machine snack purchasing before and during the implementation of a 25-s time delay on the delivery of regular snacks. Purchasing was also examined under a $0.25 discount on healthy snacks, a $0.25 tax on regular snacks, and the combination of both pricing interventions with the 25-s time delay. Across 32,019 vending sales from three separate vending locations, the 25-s time delay increased healthy snack purchasing from 40.1% to 42.5%, which was comparable to the impact of a $0.25 discount (43.0%). Combining the delay and the discount had a roughly additive effect (46.0%). However, the strongest effects were seen under the $0.25 tax on regular snacks (53.7%) and the combination of the delay and the tax (50.2%). Intervention effects varied substantially between vending locations. Importantly, time delays did not harm overall vending sales or revenue, which is relevant to the real-world feasibility of this intervention. More investigation is needed to better understand how the impact of time delays on food choice varies across populations, evaluate the effects of time delays on beverage vending choices, and extend this approach to food choices in contexts other than vending machines. ClinicalTrials.gov, NCT02359916. Copyright © 2018 Elsevier Ltd. All rights reserved.

Axonal Conduction Delays, Brain State, and Corticogeniculate Communication

PubMed Central

2017-01-01

Thalamocortical conduction times are short, but layer 6 corticothalamic axons display an enormous range of conduction times, some exceeding 40–50 ms. Here, we investigate (1) how axonal conduction times of corticogeniculate (CG) neurons are related to the visual information conveyed to the thalamus, and (2) how alert versus nonalert awake brain states affect visual processing across the spectrum of CG conduction times. In awake female Dutch-Belted rabbits, we found 58% of CG neurons to be visually responsive, and 42% to be unresponsive. All responsive CG neurons had simple, orientation-selective receptive fields, and generated sustained responses to stationary stimuli. CG axonal conduction times were strongly related to modulated firing rates (F1 values) generated by drifting grating stimuli, and their associated interspike interval distributions, suggesting a continuum of visual responsiveness spanning the spectrum of axonal conduction times. CG conduction times were also significantly related to visual response latency, contrast sensitivity (C-50 values), directional selectivity, and optimal stimulus velocity. Increasing alertness did not cause visually unresponsive CG neurons to become responsive and did not change the response linearity (F1/F0 ratios) of visually responsive CG neurons. However, for visually responsive CG neurons, increased alertness nearly doubled the modulated response amplitude to optimal visual stimulation (F1 values), significantly shortened response latency, and dramatically increased response reliability. These effects of alertness were uniform across the broad spectrum of CG axonal conduction times. SIGNIFICANCE STATEMENT Corticothalamic neurons of layer 6 send a dense feedback projection to thalamic nuclei that provide input to sensory neocortex. While sensory information reaches the cortex after brief thalamocortical axonal delays, corticothalamic axons can exhibit conduction delays of <2 ms to 40–50 ms. Here, in the corticogeniculate visual system of awake rabbits, we investigate the functional significance of this axonal diversity, and the effects of shifting alert/nonalert brain states on corticogeniculate processing. We show that axonal conduction times are strongly related to multiple visual response properties, suggesting a continuum of visual responsiveness spanning the spectrum of corticogeniculate axonal conduction times. We also show that transitions between awake brain states powerfully affect corticogeniculate processing, in some ways more strongly than in layer 4. PMID:28559382

Describing-function analysis of a ripple regulator with slew-rate limits and time delays

NASA Technical Reports Server (NTRS)

Wester, Gene W.

1990-01-01

The effects of time delays and slew-rate limits on the steady-state operating points and performance of a free-running ripple regulator are evaluated using describing-function analysis. The describing function of an ideal comparator (no time delays or slew rate limits) has no phase shift and is independent of frequency. It is found that turn-on delay and turn-off delay have different effects on gain and phase and cannot be combined. Comparator hysteresis affects both gain and phase; likewise, time delays generally affect both gain and phase. It is found that the effective time delay around the feedback loop is one half the sum of turn-on and turn-off delays, regardless of whether the delays are caused by storage time or slew rate limits. Expressions are formulated for the switching frequency, switch duty ratio, dc output, and output ripple. For the case of no hysteresis, a simple, graphical solution for the switching frequency is possible, and the resulting switching frequency is independent of first-order variations of input or load.

Determination of differential arrival times by cross-correlating worldwide seismological data

NASA Astrophysics Data System (ADS)

Godano, M.; Nolet, G.; Zaroli, C.

2012-12-01

Cross-correlation delays are the preferred body wave observables in global tomography. Heterogeneity is the main factor influencing delay times found by cross-correlation. Not only the waveform, but also the arrival time itself is affected by differences in seismic velocity encountered along the way. An accurate method for estimating differential times of seismic arrivals across a regional array by cross-correlation was developed by VanDecar and Crosson [1990]. For the estimation of global travel time delays in different frequency bands, Sigloch and Nolet [2006] developed a method for the estimation of body wave delays using a matched filter, which requires the separate estimation of the source time function. Sigloch et al. [2008] found that waveforms often cluster in and opposite the direction of rupture propagation on the fault, confirming that the directivity effect is a major factor in shaping the waveform of large events. We propose a generalization of the VanDecar-Crosson method to which we add a correction for the directivity effect in the seismological data. The new method allows large events to be treated without the need to estimate the source time function for the computation of a matched synthetic waveform. The procedure consists in (1) the detection of the directivity effect in the data and the determination of a rupture model (unilateral or bilateral) explaining the differences in pulse duration among the stations, (2) the determination of an apparent fault rupture length explaining the pulse durations, (3) the removal of the delay due to the directivity effect in the pulse duration , by stretching or contracting the seismograms for directive and anti-directive stations respectively and (4) the application of a generalized VanDecar and Crosson method using only delays between pairs of stations that have an acceptable correlation coefficient. We validate our method by performing tests on synthetic data. Results show that the error between theoretical and measured differential arrival time are significantly reduced for the corrected data. We illustrate our method on data from several real earthquakes.

Modeling tropospheric wet delays with national GNSS reference network in China for BeiDou precise point positioning

NASA Astrophysics Data System (ADS)

Zheng, Fu; Lou, Yidong; Gu, Shengfeng; Gong, Xiaopeng; Shi, Chuang

2017-10-01

During past decades, precise point positioning (PPP) has been proven to be a well-known positioning technique for centimeter or decimeter level accuracy. However, it needs long convergence time to get high-accuracy positioning, which limits the prospects of PPP, especially in real-time applications. It is expected that the PPP convergence time can be reduced by introducing high-quality external information, such as ionospheric or tropospheric corrections. In this study, several methods for tropospheric wet delays modeling over wide areas are investigated. A new, improved model is developed, applicable in real-time applications in China. Based on the GPT2w model, a modified parameter of zenith wet delay exponential decay wrt. height is introduced in the modeling of the real-time tropospheric delay. The accuracy of this tropospheric model and GPT2w model in different seasons is evaluated with cross-validation, the root mean square of the zenith troposphere delay (ZTD) is 1.2 and 3.6 cm on average, respectively. On the other hand, this new model proves to be better than the tropospheric modeling based on water-vapor scale height; it can accurately express tropospheric delays up to 10 km altitude, which potentially has benefits in many real-time applications. With the high-accuracy ZTD model, the augmented PPP convergence performance for BeiDou navigation satellite system (BDS) and GPS is evaluated. It shows that the contribution of the high-quality ZTD model on PPP convergence performance has relation with the constellation geometry. As BDS constellation geometry is poorer than GPS, the improvement for BDS PPP is more significant than that for GPS PPP. Compared with standard real-time PPP, the convergence time is reduced by 2-7 and 20-50% for the augmented BDS PPP, while GPS PPP only improves about 6 and 18% (on average), in horizontal and vertical directions, respectively. When GPS and BDS are combined, the geometry is greatly improved, which is good enough to get a reliable PPP solution, the augmentation PPP improves insignificantly comparing with standard PPP.

Shear Wave Splitting Inversion in a Complex Crust

NASA Astrophysics Data System (ADS)

Lucas, A.

2015-12-01

Shear wave splitting (SWS) inversion presents a method whereby the upper crust can be interrogated for fracture density. It is caused when a shear wave traverses an area of anisotropy, splits in two, with each wave experiencing a different velocity resulting in an observable separation in arrival times. A SWS observation consists of the first arrival polarization direction and the time delay. Given the large amount of data common in SWS studies, manual inspection for polarization and time delay is considered prohibitively time intensive. All automated techniques used can produce high amounts of observations falsely interpreted as SWS. Thus introducing error into the interpretation. The technique often used for removing these false observations is to manually inspect all SWS observations defined as high quality by the automated routine, and remove false identifications. We investigate the nature of events falsely identified compared to those correctly identified. Once this identification is complete we conduct a inversion for crack density from SWS time delay. The current body of work on linear SWS inversion utilizes an equation that defines the time delay between arriving shear waves with respect to fracture density. This equation makes the assumption that no fluid flow occurs as a result of the passing shear wave, a situation called squirt flow. We show that the assumption is not applicable in all geological situations. When it is not true, its use in an inversion produces a result which is negatively affected by the assumptions. This is shown to be the case at the test case of 6894 SWS observations gathered in a small area at Puna geothermal field, Hawaii. To rectify this situation, a series of new time delay formulae, applicable to linear inversion, are derived from velocity equations presented in literature. The new formula use a 'fluid influence parameter' which indicates the degree to which squirt flow is influencing the SWS. It is found that accounting for squirt flow better fits the data and is more applicable. The fluid influence factor that best describes the data can be identified prior to solving the inversion. Implementing this formula in a linear inversion has a significantly improved fit to the time delay observations than that of the current methods.

Tobacco demand, delay discounting, and smoking topography among smokers with and without psychopathology.

PubMed

Farris, Samantha G; Aston, Elizabeth R; Abrantes, Ana M; Zvolensky, Michael J

2017-10-01

Tobacco demand (i.e., relative value attributed to a given reinforcer) and delay discounting (i.e., relative preference for smaller immediate rewards over larger delayed rewards) are two behavioral economic processes that are linked to the progression of problematic substance use. These processes have not been studied among those with psychopathology, a vulnerable group of smokers. The current study examined differences in tobacco demand and delay discounting, and their association with smoking topography among smokers with (n=43) and without (n=64) past-year psychopathology. Adult daily smokers (n=107,M age =43.5; SD=9.7) participated in a study on "smoking behavior." Past-year psychological disorders were assessed via a clinician-administered diagnostic assessment. All subjects participated in an ad libitum smoking trial and then completed an assessment of delay discounting (Monetary Choice Questionnaire) and tobacco demand (Cigarette Purchase Task) approximately 45-60min post-smoking. Smokers with psychopathology, compared to those without, had significantly higher demand intensity and maximum expenditure on tobacco (O max ), but did not differ on other demand indices or delay discounting. Smokers with psychopathology had shorter average inter-puff intervals and shorter time to cigarette completion than smokers without psychopathology. Tobacco demand and delay discounting measures were significantly intercorrelated among smokers with psychopathology, but not those without. Both behavioral economic measures were associated with specific aspects of smoking topography in smokers with psychopathology. The association between tobacco demand and delay discounting is evident among smokers with psychopathology and both measures were most consistently related to smoking behavior. Copyright © 2017 Elsevier B.V. All rights reserved.

Short-term total sleep deprivation alters delay-conditioned memory in the rat.

PubMed

Tripathi, Shweta; Jha, Sushil K

2016-06-01

Short-term sleep deprivation soon after training may impair memory consolidation. Also, a particular sleep stage or its components increase after learning some tasks, such as negative and positive reinforcement tasks, avoidance tasks, and spatial learning tasks, and so forth. It suggests that discrete memory types may require specific sleep stage or its components for their optimal processing. The classical conditioning paradigms are widely used to study learning and memory but the role of sleep in a complex conditioned learning is unclear. Here, we have investigated the effects of short-term sleep deprivation on the consolidation of delay-conditioned memory and the changes in sleep architecture after conditioning. Rats were trained for the delay-conditioned task (for conditioning, house-light [conditioned stimulus] was paired with fruit juice [unconditioned stimulus]). Animals were divided into 3 groups: (a) sleep deprived (SD); (b) nonsleep deprived (NSD); and (c) stress control (SC) groups. Two-way ANOVA revealed a significant interaction between groups and days (training and testing) during the conditioned stimulus-unconditioned stimulus presentation. Further, Tukey post hoc comparison revealed that the NSD and SC animals exhibited significant increase in performances during testing. The SD animals, however, performed significantly less during testing. Further, we observed that wakefulness and NREM sleep did not change after training and testing. Interestingly, REM sleep increased significantly on both days compared to baseline more specifically during the initial 4-hr time window after conditioning. Our results suggest that the consolidation of delay-conditioned memory is sleep-dependent and requires augmented REM sleep during an explicit time window soon after training. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Intraoperative factors associated with delayed recovery of liver function after hepatectomy: analysis of 1969 living donors.

PubMed

Choi, S-S; Cho, S-S; Ha, T-Y; Hwang, S; Lee, S-G; Kim, Y-K

2016-02-01

The safety of healthy living donors who are undergoing hepatic resection is a primary concern. We aimed to identify intraoperative anaesthetic and surgical factors associated with delayed recovery of liver function after hepatectomy in living donors. We retrospectively analysed 1969 living donors who underwent hepatectomy for living donor liver transplantation. Delayed recovery of hepatic function was defined by increases in international normalised ratio of prothrombin time and concomitant hyperbilirubinaemia on or after post-operative day 5. Univariate and multivariate logistic regression analyses were performed to determine the factors associated with delayed recovery of hepatic function after living donor hepatectomy. Delayed recovery of liver function after donor hepatectomy was observed in 213 (10.8%) donors. Univariate logistic regression analysis showed that sevoflurane anaesthesia, synthetic colloid, donor age, body mass index, fatty change and remnant liver volume were significant factors for prediction of delayed recovery of hepatic function. Multivariate logistic regression analysis showed that independent factors significantly associated with delayed recovery of liver function after donor hepatectomy were sevoflurane anaesthesia (odds ratio = 3.514, P < 0.001), synthetic colloid (odds ratio = 1.045, P = 0.033), donor age (odds ratio = 0.970, P = 0.003), female gender (odds ratio = 1.512, P = 0.014) and remnant liver volume (odds ratio = 0.963, P < 0.001). Anaesthesia with sevoflurane was an independent factor in predicting delayed recovery of hepatic function after donor hepatectomy. Although synthetic colloid may be associated with delayed recovery of hepatic function after donor hepatectomy, further study is required. These results can provide useful information on perioperative management of living liver donors. © 2015 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Real-time ultrawide-band group delay profile monitoring through low-noise incoherent temporal interferometry.

PubMed

Park, Yongwoo; Malacarne, Antonio; Azaña, José

2011-02-28

A simple, highly accurate measurement technique for real-time monitoring of the group delay (GD) profiles of photonic dispersive devices over ultra-broad spectral bandwidths (e.g. an entire communication wavelength band) is demonstrated. The technique is based on time-domain self-interference of an incoherent light pulse after linear propagation through the device under test, providing a measurement wavelength range as wide as the source spectral bandwidth. Significant enhancement in the signal-to-noise ratio of the self-interference signal has been observed by use of a relatively low-noise incoherent light source as compared with the theoretical estimate for a white-noise light source. This fact combined with the use of balanced photo-detection has allowed us to significantly reduce the number of profiles that need to be averaged to reach a targeted GD measurement accuracy, thus achieving reconstruction of the device GD profile in real time. We report highly-accurate monitoring of (i) the group-delay ripple (GDR) profile of a 10-m long chirped fiber Bragg grating over the full C band (~42 nm), and (ii) the group velocity dispersion (GVD) and dispersion slope (DS) profiles of a ~2-km long dispersion compensating fiber module over an ~72-nm wavelength range, both captured at a 15 frames/s video rate update, with demonstrated standard deviations in the captured GD profiles as low as ~1.6 ps.

Time course of changes in sperm morphometry and semen variables during testosterone-induced suppression of human spermatogenesis.

PubMed

Garrett, C; Liu, D Y; McLachlan, R I; Baker, H W G

2005-11-01

Quantification of changes in semen may give insight into the testosterone (T)-induced disruption of spermatogenesis in man. A model analogous to flushing of sperm from the genital tract after vasectomy was used to quantify the time course of semen changes in subjects participating in male contraceptive trials using 800 mg T-implant (n = 25) or 200 mg weekly intramuscular injection (IM-T; n = 33). A modified exponential decay model allowed for delayed onset and incomplete disruption to spermatogenesis. Semen variables measured weekly during a 91-day period after initial treatment were fitted to the model. Sperm concentration, total count, motility and morphometry exhibited similar average decay rates (5 day half-life). The mean delay to onset of decline in concentration was 15 (IM-T) and 18 (T-implant) days. The significantly longer (P < 0.005) delays deduced for the commencement of fall in normal morphology (41 days), normal morphometry (40 days) and sperm viability (43 and 55 days), and the change of morphometry to smaller more compact sperm heads are consistent with sperm being progressively cleared from the genital tract rather than continued shedding of immature or abnormal sperm by the seminiferous epithelium. A significant negative relationship was found between lag time and baseline sperm concentration, consistent with longer sperm-epididymal transit times associated with lower daily production rates.

Stage at diagnosis and delay in seeking medical care among women with breast cancer, delhi, India.

PubMed

Pakseresht, Sedigheh; Ingle, Gopal Krishna; Garg, Suneela; Sarafraz, Nahid

2014-12-01

Patients with cancer often delay seeking medical advice in developing countries. It can adversely influence the outcome of disease. The present study was performed to determine the stage at diagnosis and delay in seeking medical care among women with breast cancer in Delhi, India. This was a cross-sectional study based on a census (case series) approach to reach all women (172) diagnosed with primary breast cancer "detected in surgery Out Patient Department (OPD) from January 2007 to December 2009" at Lok Nayak Hospital, Delhi, India. Patients were interviewed using a self-structure questionnaire. Seeking behavior variables were awareness of problem, first consultation, followed physician's advice, detection of problem, system of medicine and gap between knowing the problem and consultation (patient delay). Statistical Analysis was performed using the Microsoft SPSS-pc version 14.0 statistical program. The analytic methods were used (mean, standard deviation, X(2), Fisher's Exact Test, K-S, Kruskal-Wallis) for variables. All statistical tests were performed at a significance level of 5% (P < 0.05). the mean age of women was 46.99 years. 38.4% of women were ≤ 40 years. 61% of women were in stage IV of cancer at the time of diagnosis. The mean duration of gap between knowing the problem and consulting a physician (patients delay) was 10.90 months. There was no significant association between stage of cancer and consultation gap. A significant association was found between the stage of breast cancer and income; women with lower income had a higher stage of breast cancer (P < 005). A significant association was found between ages of women with their delays in consultation. Delay is still prevalent amongst women with breast cancer. It seems necessary to design educating programs for women in both clinical and community settings, about breast cancer and early detection practices.

[Association of pubertal timing and the different dimensionality of adolescents' aggressive behavior].

PubMed

Han, Hui; Wang, Gengfu; Su, Puyu

2016-01-01

To explore the relationship between pubertal timing and aggressive behaviors. Stratified random sampling was used to choose 5760 students from one junior high school and one high school. The pubertal development scale (PDS) questionnaire and perceived pubertal timing were used to evaluate the pubertal timing, and the Buss-Perry questionnaire was used to explore the students' aggressive behaviors. The score of aggressive behavior was significantly different in junior high school students with different perceived pubertal timing, the score of early pubertal timing was highest and the score of delay pubertal timing was lowest, and the score of physical aggression and verbal aggression of schoolboy in early pubertal timing and normal pubertal timing in high school was higher than the delay pubertal timing (P < 0.05). The score of physical aggression, anger and hostility of schoolgirl in early pubertal timing was highest, there was significant difference between them. The relationship between the perceived pubertal timing and the aggressive behavior was the physical aggression, anger and hostility score was highest in schoolgirls both in junior high school and high school, and the score of verbal aggression was higher in normal pubertal timing and early pubertal timing in schoolboys (P < 0.05), there was significant difference between them. There are closely relationship between the early pubertal timing and aggressive behaviors by used the PDS questionnaire, and the perceived pubertal timing is in a relatively large impact on girls' aggressive behaviors.

Delay time and Hartman effect in strain engineered graphene

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

Chen, Xi, E-mail: xchen@shu.edu.cn; Deng, Zhi-Yong; Ban, Yue, E-mail: yban@shu.edu.cn

2014-05-07

Tunneling times, including group delay and dwell time, are studied for massless Dirac electrons transmitting through a one-dimensional barrier in strain-engineered graphene. The Hartman effect, the independence of group delay on barrier length, is induced by the strain effect, and associated with the transmission gap and the evanescent mode. The influence of barrier height/length and strain modulus/direction on the group delay is also discussed, which provides the flexibility to control the group delay with applications in graphene-based devices. The relationship between group delay and dwell time is finally derived to clarify the nature of the Hartman effect.

Predictors of delayed disclosure of rape in female adolescents and young adults

PubMed Central

Bicanic, Iva A. E.; Hehenkamp, Lieve M.; van de Putte, Elise M.; van Wijk, Arjen J.; de Jongh, Ad

2015-01-01

Background Delayed disclosure of rape has been associated with impaired mental health; it is, therefore, important to understand which factors are associated with disclosure latency. The purpose of this study was to compare various demographics, post-rape characteristics, and psychological functioning of early and delayed disclosers (i.e., more than 1-week post-rape) among rape victims, and to determine predictors for delayed disclosure. Methods Data were collected using a structured interview and validated questionnaires in a sample of 323 help-seeking female adolescents and young adults (12–25 years), who were victimized by rape, but had no reported prior chronic child sexual abuse. Results In 59% of the cases, disclosure occurred within 1 week. Delayed disclosers were less likely to use medical services and to report to the police than early disclosers. No significant differences were found between delayed and early disclosers in psychological functioning and time to seek professional help. The combination of age category 12–17 years [odds ratio (OR) 2.05, confidence intervals (CI) 1.13–3.73], penetration (OR 2.36, CI 1.25–4.46), and closeness to assailant (OR 2.64, CI 1.52–4.60) contributed significantly to the prediction of delayed disclosure. Conclusion The results point to the need of targeted interventions that specifically encourage rape victims to disclose early, thereby increasing options for access to health and police services. PMID:25967381

The study on achievement of motor milestones and associated factors among children in rural North India

PubMed Central

Gupta, Arti; Kalaivani, Mani; Gupta, Sanjeev Kumar; Rai, Sanjay K.; Nongkynrih, Baridalyne

2016-01-01

Background: Nearly 14% of children worldwide do not reach their developmental potential in early childhood. The early identification of delays in achieving milestones is critical. The World Health Organization (WHO) has developed normal age ranges for the achievement of motor milestones by healthy children. This study aimed to assess the gross motor developmental achievements and associated factors among children in rural India. Materials and Methods: A cross-sectional study was conducted with rural children in North India. A pretested questionnaire was used to collect the data. The median age at the time of the highest observed milestone was calculated and compared with the WHO windows of achievement. Results: Overall, 221 children aged 4–18 months were included in the study. The median age of motor development exhibited a 0.1–2.1-month delay compared to the WHO median age of motor milestone achievement. The prevalence of the gross motor milestone achievements for each of the six milestones ranged from 91.6% to 98.4%. Developmental delay was observed in 6.3% of the children. After adjusting for different variables, children with birth order of second or more were found to be significantly associated with the timely achievement of gross motor milestones. Conclusion: The apparently healthy children of the rural area of Haryana achieved gross motor milestones with some delay with respect to the WHO windows of achievement. Although the median value of this delay was low, awareness campaigns should be implemented to promote timely identification of children with development delays. PMID:27843845

Is delayed surgery related to worse outcomes in native left-sided endocarditis?

PubMed

Tepsuwan, Thitipong; Rimsukcharoenchai, Chartaroon; Tantraworasin, Apichat; Woragidpoonpol, Surin; Schuarattanapong, Suphachai; Nawarawong, Weerachai

2016-05-01

Timing of surgery in the management of infective endocarditis is controversial, and there is still no definite conclusion on how early the surgery should be performed. This study focuses on the outcomes of surgery during the active period of infective endocarditis in consideration of the duration after diagnosis. One hundred and thirty-four patients with active native valve infective endocarditis who underwent surgery from January 2006 to December 2013 were reviewed retrospectively. They were divided in 2 groups based on timing of surgery: early group (first week after diagnosis, n = 37) and delayed group (2 to 6 weeks after diagnosis, n = 97). Compared to the delayed group, the early group had significantly more patients in New York Heart Association class IV (81% vs. 43.3%), more mechanically ventilated (54.1% vs. 18.6%), more on inotropic support (62.2% vs. 38.1%), and hence a worse EuroSCORE II (14.8% vs. 8.8%). Operative mortality was comparable (5.4% vs. 10.3%) and 7-year survival was similar (77.4% vs. 74.6%). On multivariable regression analysis, delayed surgery did not impact on short- and long-term outcomes. Preoperative cardiac arrest and infection with Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, or Kingella were risk factors for higher operative mortality. Predictors of poor 7-year survival were diabetes mellitus and acute renal failure. Delayed surgery is not associated with worse outcomes. Both early and delayed approaches are safe and provide acceptable results. Timing of surgery should be tailored to each patient's clinical status, not based on duration of endocarditis alone. © The Author(s) 2016.

Reconstructions of parameters of radiophysical chaotic generator with delayed feedback from short time series

NASA Astrophysics Data System (ADS)

Ishbulatov, Yu. M.; Karavaev, A. S.; Kiselev, A. R.; Semyachkina-Glushkovskaya, O. V.; Postnov, D. E.; Bezruchko, B. P.

2018-04-01

A method for the reconstruction of time-delayed feedback system is investigated, which is based on the detection of synchronous response of a slave time-delay system with respect to the driving from the master system under study. The structure of the driven system is similar to the structure of the studied time-delay system, but the feedback circuit is broken in the driven system. The method efficiency is tested using short and noisy data gained from an electronic chaotic oscillator with time-delayed feedback.

Process improvement to enhance existing stroke team activity toward more timely thrombolytic treatment.

PubMed

Cho, Han-Jin; Lee, Kyung Yul; Nam, Hyo Suk; Kim, Young Dae; Song, Tae-Jin; Jung, Yo Han; Choi, Hye-Yeon; Heo, Ji Hoe

2014-10-01

Process improvement (PI) is an approach for enhancing the existing quality improvement process by making changes while keeping the existing process. We have shown that implementation of a stroke code program using a computerized physician order entry system is effective in reducing the in-hospital time delay to thrombolysis in acute stroke patients. We investigated whether implementation of this PI could further reduce the time delays by continuous improvement of the existing process. After determining a key indicator [time interval from emergency department (ED) arrival to intravenous (IV) thrombolysis] and conducting data analysis, the target time from ED arrival to IV thrombolysis in acute stroke patients was set at 40 min. The key indicator was monitored continuously at a weekly stroke conference. The possible reasons for the delay were determined in cases for which IV thrombolysis was not administered within the target time and, where possible, the problems were corrected. The time intervals from ED arrival to the various evaluation steps and treatment before and after implementation of the PI were compared. The median time interval from ED arrival to IV thrombolysis in acute stroke patients was significantly reduced after implementation of the PI (from 63.5 to 45 min, p=0.001). The variation in the time interval was also reduced. A reduction in the evaluation time intervals was achieved after the PI [from 23 to 17 min for computed tomography scanning (p=0.003) and from 35 to 29 min for complete blood counts (p=0.006)]. PI is effective for continuous improvement of the existing process by reducing the time delays between ED arrival and IV thrombolysis in acute stroke patients.

Temporal response improvement for computed tomography fluoroscopy

NASA Astrophysics Data System (ADS)

Hsieh, Jiang

1997-10-01

Computed tomography fluoroscopy (CTF) has attracted significant attention recently. This is mainly due to the growing clinical application of CTF in interventional procedures, such as guided biopsy. Although many studies have been conducted for its clinical efficacy, little attention has been paid to the temporal response and the inherent limitations of the CTF system. For example, during a biopsy operation, when needle is inserted at a relatively high speed, the true needle position will not be correctly depicted in the CTF image due to the time delay. This could result in an overshoot or misplacement of the biopsy needle by the operator. In this paper, we first perform a detailed analysis of the temporal response of the CTF by deriving a set of equations to describe the average location of a moving object observed by the CTF system. The accuracy of the equations is verified by computer simulations and experiments. We show that the CT reconstruction process acts as a low pass filter to the motion function. As a result, there is an inherent time delay in the CTF process to the true biopsy needle motion and locations. Based on this study, we propose a generalized underscan weighting scheme which significantly improve the performance of CTF in terms of time lag and delay.

Stability of Nonlinear Systems with Unknown Time-varying Feedback Delay

NASA Astrophysics Data System (ADS)

Chunodkar, Apurva A.; Akella, Maruthi R.

2013-12-01

This paper considers the problem of stabilizing a class of nonlinear systems with unknown bounded delayed feedback wherein the time-varying delay is 1) piecewise constant 2) continuous with a bounded rate. We also consider application of these results to the stabilization of rigid-body attitude dynamics. In the first case, the time-delay in feedback is modeled specifically as a switch among an arbitrarily large set of unknown constant values with a known strict upper bound. The feedback is a linear function of the delayed states. In the case of linear systems with switched delay feedback, a new sufficiency condition for average dwell time result is presented using a complete type Lyapunov-Krasovskii (L-K) functional approach. Further, the corresponding switched system with nonlinear perturbations is proven to be exponentially stable inside a well characterized region of attraction for an appropriately chosen average dwell time. In the second case, the concept of the complete type L-K functional is extended to a class of nonlinear time-delay systems with unknown time-varying time-delay. This extension ensures stability robustness to time-delay in the control design for all values of time-delay less than the known upper bound. Model-transformation is used in order to partition the nonlinear system into a nominal linear part that is exponentially stable with a bounded perturbation. We obtain sufficient conditions which ensure exponential stability inside a region of attraction estimate. A constructive method to evaluate the sufficient conditions is presented together with comparison with the corresponding constant and piecewise constant delay. Numerical simulations are performed to illustrate the theoretical results of this paper.

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.

Quantifying travel time variability in transportation networks.

DOT National Transportation Integrated Search

2010-03-01

Nonrecurring congestion creates significant delay on freeways in urban areas, lending importance : to the study of facility reliability. In locations where traffic detectors record and archive data, : approximate probability distributions for travel ...

Defective sensorimotor integration in preparation for reaction time tasks in patients with multiple sclerosis.

PubMed

Cabib, Christopher; Llufriu, Sara; Casanova-Molla, Jordi; Saiz, Albert; Valls-Solé, Josep

2015-03-01

Slowness of voluntary movements in patients with multiple sclerosis (MS) may be due to various factors, including attentional and cognitive deficits, delays in motor conduction time, and impairment of specific central nervous system circuits. In 13 healthy volunteers and 20 mildly disabled, relapsing-remitting MS patients, we examined simple reaction time (SRT) tasks requiring sensorimotor integration in circuits involving the corpus callosum and the brain stem. A somatosensory stimulus was used as the imperative signal (IS), and subjects were requested to react with either the ipsilateral or the contralateral hand (uncrossed vs. crossed SRT). In 33% of trials, a startling auditory stimulus was presented together with the IS, and the percentage reaction time change with respect to baseline SRT trials was measured (StartReact effect). The difference between crossed and uncrossed SRT, which requires interhemispheric conduction, was significantly larger in patients than in healthy subjects (P = 0.021). The StartReact effect, which involves activation of brain stem motor pathways, was reduced significantly in patients with respect to healthy subjects (uncrossed trials: P = 0.015; crossed trials: P = 0.005). In patients, a barely significant correlation was found between SRT delay and conduction abnormalities in motor and sensory pathways (P = 0.02 and P = 0.04, respectively). The abnormalities found specifically in trials reflecting interhemispheric transfer of information, as well as the evidence for reduced subcortical motor preparation, indicate that a delay in reaction time execution in MS patients cannot be explained solely by conduction slowing in motor and sensory pathways but suggest, instead, defective sensorimotor integration mechanisms in at least the two circuits examined. Copyright © 2015 The American Physiological Society.

Mortality in patients with TIMI 3 flow after PCI in relation to time delay to reperfusion.

PubMed

Vichova, Teodora; Maly, Marek; Ulman, Jaroslav; Motovska, Zuzana

2016-03-01

Percutaneous coronary intervention (PCI) performed within 12 h from symptom onset enables complete blood flow restoration in infarct-related artery in 90% of patients. Nevertheless, even with complete restoration of epicardial blood flow in culprit vessel (postprocedural Thrombolysis in Myocardial Infarction (TIMI) flow grade 3), myocardial perfusion at tissue level may be insufficient. We hypothesized that the outcome of patients with STEMI/bundle branch block (BBB)-myocardial infarction and post-PCI TIMI 3 flow is related to the time to reperfusion. Observational study based on a retrospective analysis of population of 635 consecutive patients with STEMI/BBB-MI and post-PCI TIMI 3 flow from January 2009 to December 2011 (mean age 63 years, 69.6% males). Mortality of patients was evaluated in relation to the time from symptom onset to reperfusion. A total of 83 patients (13.07%) with postprocedural TIMI 3 flow after PCI had died at 1-year follow-up. Median TD in patients who survived was 3.92 h (iqr 5.43), in patients who died 6.0 h (iqr 11.42), P = 0.004. Multiple logistic regression analysis identified time delay ≥ 9 h as significantly related to 1-year mortality of patients with STEMI/BBB-MI and post-PCI TIMI 3 flow (OR 1.958, P = 0.026). Other significant variables associated with mortality in multivariate regression analysis were: left ventricle ejection fraction < 30% (P = 0.006), age > 65 years (P < 0.001), Killip class >2 (P <0.001), female gender (P = 0.019), and creatinine clearance < 30 mL/min (P < 0.001). Time delay to reperfusion is significantly related to 1-year mortality of patients with STEMI/BBB-MI and complete restoration of epicardial blood flow in culprit vessel after PCI.

Traversal of electromagnetic pulses through dispersive media with negative refractive index

NASA Astrophysics Data System (ADS)

Nanda, L.; Ramakrishna, S. A.

2017-05-01

We investigate the traversal of electromagnetic pulses through dispersive media with negative refractive index in such a way that no resonant effects come into play. It has been verified that for evanescent waves, the definitions of the group delay and the reshaping delay times get interchanged in comparison to the propagating waves. We show that for a negative refractive index medium (NRM) with ɛ(ω)=μ(ω), the reshaping delay time identically vanishes for propagating waves. The total delay time in NRM is otherwise contributed by both the group and the reshaping delay times, whereas for the case of broadband pulses in NRM the total delay time is always subluminal.

Prospective Memory Deficits in Ecstasy Users: Effects of Longer Ongoing Task Delay Interval

PubMed Central

WEINBORN, MICHAEL; WOODS, STEVEN PAUL; NULSEN, CLAIRE; PARK, KATHERINE

2011-01-01

Ecstasy use has been associated with neurotoxicity and neurocognitive impairment in a variety of domains, including prospective memory (ProM), which involves the delayed execution of a previously encoded intention in response to a specific cue. The present study adopted the multiprocess theory of ProM to evaluate the hypothesis that ecstasy users would evidence differentially impaired ProM on longer versus shorter ongoing task delays. Ecstasy (n = 31) users, high-risk alcohol users (n = 21) and healthy nonusers (n = 31) completed the short (2-min) and long (15-min) delay ProM scales of the Memory for Intentions Screening Test. Results showed a significant group by ProM delay interaction, such that ecstasy users performed comparably to the comparison groups on short-delay trials, but were impaired on long-delay ProM, particularly for time-based cues. Among the ecstasy users, long-delay ProM was positively associated with risky decision-making, but not with retrospective memory or other aspects of executive functions. These findings suggest that ecstasy users may be particularly susceptible to deficits in strategic target monitoring and maintenance of cue-intention pairings over longer ProM delays. Findings are discussed in the context of their potential everyday functioning (e.g., academic, vocational) and treatment implications for ecstasy users. PMID:22047194

Defining the Ideal Time Interval Between Planned Induction Therapy and Surgery for Stage IIIA Non-Small Cell Lung Cancer.

PubMed

Samson, Pamela; Crabtree, Traves D; Robinson, Cliff G; Morgensztern, Daniel; Broderick, Stephen; Krupnick, A Sasha; Kreisel, Daniel; Patterson, G Alexander; Meyers, Bryan; Puri, Varun

2017-04-01

Induction therapy leads to significant improvement in survival for selected patients with stage IIIA non-small cell lung cancer. The ideal time interval between induction therapy and surgery remains unknown. Clinical stage IIIA non-small cell lung cancer patients receiving induction therapy and surgery were identified in the National Cancer Database. Delayed surgery was defined as greater than or equal to 3 months after starting induction therapy. A logistic regression model identified variables associated with delayed surgery. Cox proportional hazards modeling and Kaplan-Meier analysis were performed to evaluate variables independently associated with overall survival. From 2006 to 2010, 1,529 of 2,380 (64.2%) received delayed surgery. Delayed surgery patients were older (61.2 ± 10.0 years versus 60.3 ± 9.2; p = 0.03), more likely to be non-white (12.4% versus 9.7%; p = 0.046), and less likely to have private insurance (50% versus 58.2%; p = 0.002). Delayed surgery patients were also more likely to have a sublobar resection (6.3% versus 2.9%). On multivariate analysis, age greater than 68 years (odds ratio [OR], 1.37; 95% confidence interval [CI], 1.1 to 1.7) was associated with delayed surgery, whereas white race (OR, 0.75; 95% CI, 0.57 to 0.99) and private insurance status (OR, 0.82; 95% CI, 0.68 to 0.99) were associated with early surgery. Delayed surgery was associated with higher risk of long-term mortality (hazard ratio, 1.25; 95% CI, 1.07 to 1.47). Delayed surgery after induction therapy for stage IIIA lung cancer is associated with shorter survival, and is influenced by both social and physiologic factors. Prospective work is needed to further characterize the relationship between patient comorbidities and functional status with receipt of timely surgery. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

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.

Simulation analysis of the effect of initial delay on flight delay diffusion

NASA Astrophysics Data System (ADS)

Que, Zufu; Yao, Hongguang; Yue, Wei

2018-01-01

The initial delay of the flight is an important factor affecting the spread of flight delays, so clarifying their relationship conduces to control flight delays in the aeronautical network. Through establishing a model of the chain aviation network and making simulation analysis of the effects of initial delay on the delay longitudinal diffusion, it’s found that the number of delayed airports in the air network, the total delay time and the average delay time of the delayed airport are generally positively correlated with the initial delay. This indicates that the occurrence of the initial delay should be avoided or reduced as much as possible to improve the punctuality of the flight.

Cronobiologic analysis of abortions in two related populations of teenager girls during two decades.

PubMed

Mikulechý, M; Soltés, L; Valachová, A

1994-06-01

To identify and compare the time dynamics of artificial abortions in two (Czech and Slovak) ethnically, historically and socially closely related populations. Data have been taken separately for 12-15 and 16-18 year age girls from official exhaustive statistical sources and processed by advanced procedures of time series analysis. Czech and Slovak Republics. All girls of the given age. Legislative liberalization of abortions 1987. Estimated starting values of relative numbers of abortions by 1971, increasing linear trends, period lengths of fluctuation, coefficients of determination and those of cross-correlation. Level of significance alpha = 0.05. The Czech figures are significantly higher than the Slovak. Thus, estimated abortion percentage (from pregnancies) for 1971 was for younger Czech girls 53%, and for those from Slovakia 29%. All estimated trends were increasing significantly in all cases for the Czech population (by 1.5% per year in the younger group) and in one case for Slovakia. The estimated period lengths were usually 10-12 years. Czech and Slovak data display significant positive mutual cross-correlation, the delay being 1-3 years in Slovak girls. Surprisingly, all data significantly cross-correlate with the geomagnetic index value Ap, acting as lead-lag, with 3-6-year delay for abortions. Despite living in the same federal state--the former Czechoslovak Republic, both Czech and Slovak populations do differ in starting values and general trends of abortions in teenagers. This can be due to historical, racial and religious peculiarities as well as a more advanced process of industrialization in the western part--the Czech Republic. The latter hypothesis is corroborated by strong dynamism of changes and by the time delay in Slovakia. The periodicity exhibits a frequency resembling that known for solar motion round barycenter of solar system, for sunspots and geomagnetism.

Effects of additional food in a delayed predator-prey model.

PubMed

Sahoo, Banshidhar; Poria, Swarup

2015-03-01

We examine the effects of supplying additional food to predator in a gestation delay induced predator-prey system with habitat complexity. Additional food works in favor of predator growth in our model. Presence of additional food reduces the predatory attack rate to prey in the model. Supplying additional food we can control predator population. Taking time delay as bifurcation parameter the stability of the coexisting equilibrium point is analyzed. Hopf bifurcation analysis is done with respect to time delay in presence of additional food. The direction of Hopf bifurcations and the stability of bifurcated periodic solutions are determined by applying the normal form theory and the center manifold theorem. The qualitative dynamical behavior of the model is simulated using experimental parameter values. It is observed that fluctuations of the population size can be controlled either by supplying additional food suitably or by increasing the degree of habitat complexity. It is pointed out that Hopf bifurcation occurs in the system when the delay crosses some critical value. This critical value of delay strongly depends on quality and quantity of supplied additional food. Therefore, the variation of predator population significantly effects the dynamics of the model. Model results are compared with experimental results and biological implications of the analytical findings are discussed in the conclusion section. Copyright © 2015 Elsevier Inc. All rights reserved.

A randomized controlled trial of qigong for fibromyalgia

PubMed Central

2012-01-01

Introduction Fibromyalgia is difficult to treat and requires the use of multiple approaches. This study is a randomized controlled trial of qigong compared with a wait-list control group in fibromyalgia. Methods One hundred participants were randomly assigned to immediate or delayed practice groups, with the delayed group receiving training at the end of the control period. Qigong training (level 1 Chaoyi Fanhuan Qigong, CFQ), given over three half-days, was followed by weekly review/practice sessions for eight weeks; participants were also asked to practice at home for 45 to 60 minutes per day for this interval. Outcomes were pain, impact, sleep, physical function and mental function, and these were recorded at baseline, eight weeks, four months and six months. Immediate and delayed practice groups were analyzed individually compared to the control group, and as a combination group. Results In both the immediate and delayed treatment groups, CFQ demonstrated significant improvements in pain, impact, sleep, physical function and mental function when compared to the wait-list/usual care control group at eight weeks, with benefits extending beyond this time. Analysis of combined data indicated significant changes for all measures at all times for six months, with only one exception. Post-hoc analysis based on self-reported practice times indicated greater benefit with the per protocol group compared to minimal practice. Conclusions This study demonstrates that CFQ, a particular form of qigong, provides long-term benefits in several core domains in fibromyalgia. CFQ may be a useful adjuvant self-care treatment for fibromyalgia. Trial registration clinicaltrials.gov NCT00938834. PMID:22863206

Drift in Neural Population Activity Causes Working Memory to Deteriorate Over Time.

PubMed

Schneegans, Sebastian; Bays, Paul M

2018-05-23

Short-term memories are thought to be maintained in the form of sustained spiking activity in neural populations. Decreases in recall precision observed with increasing number of memorized items can be accounted for by a limit on total spiking activity, resulting in fewer spikes contributing to the representation of each individual item. Longer retention intervals likewise reduce recall precision, but it is unknown what changes in population activity produce this effect. One possibility is that spiking activity becomes attenuated over time, such that the same mechanism accounts for both effects of set size and retention duration. Alternatively, reduced performance may be caused by drift in the encoded value over time, without a decrease in overall spiking activity. Human participants of either sex performed a variable-delay cued recall task with a saccadic response, providing a precise measure of recall latency. Based on a spike integration model of decision making, if the effects of set size and retention duration are both caused by decreased spiking activity, we would predict a fixed relationship between recall precision and response latency across conditions. In contrast, the drift hypothesis predicts no systematic changes in latency with increasing delays. Our results show both an increase in latency with set size, and a decrease in response precision with longer delays within each set size, but no systematic increase in latency for increasing delay durations. These results were quantitatively reproduced by a model based on a limited neural resource in which working memories drift rather than decay with time. SIGNIFICANCE STATEMENT Rapid deterioration over seconds is a defining feature of short-term memory, but what mechanism drives this degradation of internal representations? Here, we extend a successful population coding model of working memory by introducing possible mechanisms of delay effects. We show that a decay in neural signal over time predicts that the time required for memory retrieval will increase with delay, whereas a random drift in the stored value predicts no effect of delay on retrieval time. Testing these predictions in a multi-item memory task with an eye movement response, we identified drift as a key mechanism of memory decline. These results provide evidence for a dynamic spiking basis for working memory, in contrast to recent proposals of activity-silent storage. Copyright © 2018 Schneegans and Bays.

Estimation of coupling between time-delay systems from time series

NASA Astrophysics Data System (ADS)

Prokhorov, M. D.; Ponomarenko, V. I.

2005-07-01

We propose a method for estimation of coupling between the systems governed by scalar time-delay differential equations of the Mackey-Glass type from the observed time series data. The method allows one to detect the presence of certain types of linear coupling between two time-delay systems, to define the type, strength, and direction of coupling, and to recover the model equations of coupled time-delay systems from chaotic time series corrupted by noise. We verify our method using both numerical and experimental data.

LiDAR-IMU Time Delay Calibration Based on Iterative Closest Point and Iterated Sigma Point Kalman Filter

PubMed Central

Liu, Wanli

2017-01-01

The time delay calibration between Light Detection and Ranging (LiDAR) and Inertial Measurement Units (IMUs) is an essential prerequisite for its applications. However, the correspondences between LiDAR and IMU measurements are usually unknown, and thus cannot be computed directly for the time delay calibration. In order to solve the problem of LiDAR-IMU time delay calibration, this paper presents a fusion method based on iterative closest point (ICP) and iterated sigma point Kalman filter (ISPKF), which combines the advantages of ICP and ISPKF. The ICP algorithm can precisely determine the unknown transformation between LiDAR-IMU; and the ISPKF algorithm can optimally estimate the time delay calibration parameters. First of all, the coordinate transformation from the LiDAR frame to the IMU frame is realized. Second, the measurement model and time delay error model of LiDAR and IMU are established. Third, the methodology of the ICP and ISPKF procedure is presented for LiDAR-IMU time delay calibration. Experimental results are presented that validate the proposed method and demonstrate the time delay error can be accurately calibrated. PMID:28282897

Characteristics of lightning flashes generating dancing sprites above thunderstorms

NASA Astrophysics Data System (ADS)

Soula, Serge; Mlynarczyk, Janusz; Füllekrug, Martin; Pineda, Nicolau; Georgis, Jean-François; van der Velde, Oscar; Montanyà, Joan; Fabro, Ferran

2017-04-01

During the night of October 29-30, 2013, a low-light video camera at Pic du Midi (2877 m) in the French Pyrénées, recorded TLEs above a very active storm over the Mediterranean Sea. The minimum cloud top temperature reached -73˚ C at ˜1600 UTC while its cloud to ground (CG) flash rate reached ˜30 fl min-1. Some sprite events with long duration are classified as dancing sprites. We analyze in detail the temporal evolution and estimated location of sprite elements for two cases of these events. They consist in series of sprite sequences with a duration that exceeds 1 second. By associating the cloud structure, the lightning activity, the electric field radiated in a broad range of low frequencies and the current moment waveform of the lightning strokes, some findings are highlighted: (i) In each series, successive sprite sequences reflect the occurrence time and location of individual positive lightning strokes across the stratiform region. (ii) The longer time-delayed (> 20 ms) sprite elements correspond to the lower impulsive charge moment changes (iCMC) of the parent stroke (< 200 C km) and they are shifted few tens of kilometres from their SP+CG stroke. However, both short and long time-delayed sprite elements also occur after strokes that produce a large iCMC and that are followed by a continuing current. (iii) The long time-delayed sprite elements produced during the continuing current correspond to surges in the current moment waveform. They occur sometimes at an altitude apparently lower than the previous short time-delayed sprite elements, possibly because of the lowered altitude of the ionosphere potential. (iv) The largest and brightest sprite elements produce significant current signatures, visible when their delay is not too short (˜3-5 ms).

JNDS of interaural time delay (ITD) of selected frequency bands in speech and music signals

NASA Astrophysics Data System (ADS)

Aliphas, Avner; Colburn, H. Steven; Ghitza, Oded

2002-05-01

JNDS of interaural time delay (ITD) of selected frequency bands in the presence of other frequency bands have been reported for noiseband stimuli [Zurek (1985); Trahiotis and Bernstein (1990)]. Similar measurements will be reported for speech and music signals. When stimuli are synthesized with bandpass/band-stop operations, performance with complex stimuli are similar to noisebands (JNDS in tens or hundreds of microseconds); however, the resulting waveforms, when viewed through a model of the auditory periphery, show distortions (irregularities in phase and level) at the boundaries of the target band of frequencies. An alternate synthesis method based upon group-delay filtering operations does not show these distortions and is being used for the current measurements. Preliminary measurements indicate that when music stimuli are created using the new techniques, JNDS of ITDs are increased significantly compared to previous studies, with values on the order of milliseconds.

Two-color pump-probe laser spectroscopy instrument with picosecond time-resolved electronic delay and extended scan range

NASA Astrophysics Data System (ADS)

Yu, Anchi; Ye, Xiong; Ionascu, Dan; Cao, Wenxiang; Champion, Paul M.

2005-11-01

An electronically delayed two-color pump-probe instrument was developed using two synchronized laser systems. The instrument has picosecond time resolution and can perform scans over hundreds of nanoseconds without the beam divergence and walk-off effects that occur using standard spatial delay systems. A unique picosecond Ti :sapphire regenerative amplifier was also constructed without the need for pulse stretching and compressing optics. The picosecond regenerative amplifier has a broad wavelength tuning range, which suggests that it will make a significant contribution to two-color pump-probe experiments. To test this instrument we studied the rotational correlation relaxation of myoglobin (τr=8.2±0.5ns) in water as well as the geminate rebinding kinetics of oxygen to myoglobin (kg1=1.7×1011s-1, kg2=3.4×107s-1). The results are consistent with, and improve upon, previous studies.

A Novel IEEE 802.15.4e DSME MAC for Wireless Sensor Networks

PubMed Central

Sahoo, Prasan Kumar; Pattanaik, Sudhir Ranjan; Wu, Shih-Lin

2017-01-01

IEEE 802.15.4e standard proposes Deterministic and Synchronous Multichannel Extension (DSME) mode for wireless sensor networks (WSNs) to support industrial, commercial and health care applications. In this paper, a new channel access scheme and beacon scheduling schemes are designed for the IEEE 802.15.4e enabled WSNs in star topology to reduce the network discovery time and energy consumption. In addition, a new dynamic guaranteed retransmission slot allocation scheme is designed for devices with the failure Guaranteed Time Slot (GTS) transmission to reduce the retransmission delay. To evaluate our schemes, analytical models are designed to analyze the performance of WSNs in terms of reliability, delay, throughput and energy consumption. Our schemes are validated with simulation and analytical results and are observed that simulation results well match with the analytical one. The evaluated results of our designed schemes can improve the reliability, throughput, delay, and energy consumptions significantly. PMID:28275216

A Novel IEEE 802.15.4e DSME MAC for Wireless Sensor Networks.

PubMed

Sahoo, Prasan Kumar; Pattanaik, Sudhir Ranjan; Wu, Shih-Lin

2017-01-16

IEEE 802.15.4e standard proposes Deterministic and Synchronous Multichannel Extension (DSME) mode for wireless sensor networks (WSNs) to support industrial, commercial and health care applications. In this paper, a new channel access scheme and beacon scheduling schemes are designed for the IEEE 802.15.4e enabled WSNs in star topology to reduce the network discovery time and energy consumption. In addition, a new dynamic guaranteed retransmission slot allocation scheme is designed for devices with the failure Guaranteed Time Slot (GTS) transmission to reduce the retransmission delay. To evaluate our schemes, analytical models are designed to analyze the performance of WSNs in terms of reliability, delay, throughput and energy consumption. Our schemes are validated with simulation and analytical results and are observed that simulation results well match with the analytical one. The evaluated results of our designed schemes can improve the reliability, throughput, delay, and energy consumptions significantly.

Energy conservation in ad hoc multimedia networks using traffic-shaping mechanisms

NASA Astrophysics Data System (ADS)

Chandra, Surendar

2003-12-01

In this work, we explore network traffic shaping mechanisms that deliver packets at pre-determined intervals; allowing the network interface to transition to a lower power consuming sleep state. We focus our efforts on commodity devices, IEEE 802.11b ad hoc mode and popular streaming formats. We argue that factors such as the lack of scheduling clock phase synchronization among the participants and scheduling delays introduced by back ground tasks affect the potential energy savings. Increasing the periodic transmission delays to transmit data infrequently can offset some of these effects at the expense of flooding the wireless channel for longer periods of time; potentially increasing the time to acquire the channel for non-multimedia traffic. Buffering mechanisms built into media browsers can mitigate the effects of these added delays from being mis-interpreted as network congestion. We show that practical implementations of such traffic shaping mechanisms can offer significant energy savings.

[Time perception in depressed and manic patients].

PubMed

Zhao, Qi-yuan; Ji, Yi-fu; Wang, Kai; Zhang, Lei; Liu, Ping; Jiang, Yu-bao

2010-02-02

To investigate the time perception in affective disorders by using neuropsychological tests and to try to elucidate its neurobiochemical mechanism. Using a time reproduction task, a comparative study was conducted for 28 depressive patients, 22 manic patients, and 26 age and education level matched healthy persons as healthy controls. Both depressive patients and manic patients are abnormal (P < 0.001), depressive patients over-reproduced the time interval than healthy controls (600 ms/delay 1 s: 1.6 +/- 0.6, P < 0.001; 600 ms/delay 5 s: 1.7 +/- 0.6, P < 0.001; 3 s/delay 1 s: 3.9 +/- 0.9, P < 0.001; 3 s/delay 5 s: 3.9 +/- 0.7, P < 0.001; 5 s/delay 1 s: 5.9 +/- 1.3, P < 0.001; 5 s/delay 5 s: 6.1 +/- 1.3, P < 0.001), yet manic patients under-reproduced the time interval (600 ms/delay 1 s: 0.7 +/- 0.2, P < 0.01; 600 ms/delay 5 s: 0.6 +/- 0.3, P < 0.001; 3 s/delay 1 s: 1.7 +/- 0.5, P < 0.001; 3 s/delay 5 s: 1.8 +/- 0.6, P < 0.001; 5 s/delay 1 s: 2.9 +/- 0.7, P < 0.001; 5 s/delay 5 s: 3.0 +/- 0.8, P < 0.001). The results of time reproduction task in patients were not related to age, education, duration of illness, number of admission (P > 0.05), but had some relation to severity of illness.And the results were positively correlated with the score of HAMD in depressive patients (six times: r = 0.44, 0.46, 0.73, 0.61, 0.55, 0.50, P < 0.05), but negatively with the score of BRMS in manic patients (six times: r = -0.57, -0.54, -0.71, -0.69, -0.80, -0.71, P < 0.05). Emotion will affect one's time perception. And the neurotransmitter in brain may participate in the processes of time perception.

Addressing the third delay: implementing a novel obstetric triage system in Ghana.

PubMed

Goodman, David M; Srofenyoh, Emmanuel K; Ramaswamy, Rohit; Bryce, Fiona; Floyd, Liz; Olufolabi, Adeyemi; Tetteh, Cecilia; Owen, Medge D

2018-01-01

Institutional delivery has been proposed as a method for reducing maternal morbidity and mortality, but little is known about how referral hospitals in low-resource settings can best manage the expected influx of patients. In this study, we assess the impact of an obstetric triage improvement programme on reducing hospital-based delay in a referral hospital in Accra, Ghana. An Active Implementation Framework is used to describe a 5-year intervention to introduce and monitor obstetric triage capabilities. Baseline data, collected from September to November 2012, revealed significant delays in patient assessment on arrival. A triage training course and monitoring of quality improvement tools occurred in 2013 and 2014. Implementation barriers led to the construction of a free-standing obstetric triage pavilion, opened January 2015, with dedicated midwives. Data were collected at three time intervals following the triage pavilion opening and compared with baseline including: referral indications, patient and labour characteristics, waiting time from arrival to assessment and the documentation of a care plan. An obstetric triage improvement programme reduced the median (IQR) patient waiting time from facility arrival to first assessment by a midwife from 40 min (15-100) to 5 min (2-6) (p<0.001) over the 5-year intervention. The triage pavilion enhanced performance resulting in the elimination of previous delays associated with the time of admission and disease acuity. Care plan documentation increased from 51% to 96%. Obstetric triage, when properly implemented, reduced delay in a busy, low-resource hospital. The implementation process was sustained under local leadership during transition to a new hospital.

TIME DELAY AND ACCRETION DISK SIZE MEASUREMENTS IN THE LENSED QUASAR SBS 0909+532 FROM MULTIWAVELENGTH MICROLENSING ANALYSIS

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

Hainline, Laura J.; Morgan, Christopher W.; MacLeod, Chelsea L.

2013-09-01

We present three complete seasons and two half-seasons of Sloan Digital Sky Survey (SDSS) r-band photometry of the gravitationally lensed quasar SBS 0909+532 from the U.S. Naval Observatory, as well as two seasons each of SDSS g-band and r-band monitoring from the Liverpool Robotic Telescope. Using Monte Carlo simulations to simultaneously measure the system's time delay and model the r-band microlensing variability, we confirm and significantly refine the precision of the system's time delay to {Delta}t{sub AB} = 50{sub -4}{sup +2} days, where the stated uncertainties represent the bounds of the formal 1{sigma} confidence interval. There may be a conflictmore » between the time delay measurement and a lens consisting of a single galaxy. While models based on the Hubble Space Telescope astrometry and a relatively compact stellar distribution can reproduce the observed delay, the models have somewhat less dark matter than we would typically expect. We also carry out a joint analysis of the microlensing variability in the r and g bands to constrain the size of the quasar's continuum source at these wavelengths, obtaining log {l_brace}(r{sub s,r}/cm)[cos i/0.5]{sup 1/2}{r_brace} = 15.3 {+-} 0.3 and log {l_brace}(r{sub s,g}/cm)[cos i/0.5]{sup 1/2}{r_brace} = 14.8 {+-} 0.9, respectively. Our current results do not formally constrain the temperature profile of the accretion disk but are consistent with the expectations of standard thin disk theory.« less

Bounded Linear Stability Analysis - A Time Delay Margin Estimation Approach for Adaptive Control

NASA Technical Reports Server (NTRS)

Nguyen, Nhan T.; Ishihara, Abraham K.; Krishnakumar, Kalmanje Srinlvas; Bakhtiari-Nejad, Maryam

2009-01-01

This paper presents a method for estimating time delay margin for model-reference adaptive control of systems with almost linear structured uncertainty. The bounded linear stability analysis method seeks to represent the conventional model-reference adaptive law by a locally bounded linear approximation within a small time window using the comparison lemma. The locally bounded linear approximation of the combined adaptive system is cast in a form of an input-time-delay differential equation over a small time window. The time delay margin of this system represents a local stability measure and is computed analytically by a matrix measure method, which provides a simple analytical technique for estimating an upper bound of time delay margin. Based on simulation results for a scalar model-reference adaptive control system, both the bounded linear stability method and the matrix measure method are seen to provide a reasonably accurate and yet not too conservative time delay margin estimation.

Decreased head circumference velocity as related to developmental deficit in infancy.

PubMed

Tal, Galit; Cohen, Ayala; Habib, Sonia; Tirosh, Emanuel

2012-11-01

We evaluated the significance of head circumference growth velocity as related to developmental deficits during infancy. Head circumferences, lengths, and developmental diagnoses were retrieved in a standard manner at ≥ 2 time points from 437 infants with developmental deficits, and 3909 normally developing infants. Infants' ages ranged from 1-24 months, with final diagnoses ascertained at age 24 months. Increased velocity during the first 2 months in typical infants was evident in the study group during the period 2-4 months. A differential head circumference growth velocity was observed, and infants diagnosed with motor delay presented decreased velocity between ages 2-4 months, compared with infants receiving other nonmotor developmental diagnoses. These differences remained after controlling for birth weight and length. No significant sex effect was evident. Infants with developmental deficits demonstrate delayed acceleration of head circumference velocity, compared with typical infants in the first 2 months. Infants with motor delay manifest decreased velocity, compared with infants presenting other developmental deficits. These differences may be related to delayed white matter maturation. Copyright © 2012 Elsevier Inc. All rights reserved.

Visual event-related potential changes in multiple system atrophy: delayed N2 latency in selective attention to a color task.

PubMed

Kamitani, Toshiaki; Kuroiwa, Yoshiyuki

2009-01-01

Recent studies demonstrated an altered P3 component and prolonged reaction time during the visual discrimination tasks in multiple system atrophy (MSA). In MSA, however, little is known about the N2 component which is known to be closely related to the visual discrimination process. We therefore compared the N2 component as well as the N1 and P3 components in 17 MSA patients with these components in 10 normal controls, by using a visual selective attention task to color or to shape. While the P3 in MSA was significantly delayed in selective attention to shape, the N2 in MSA was significantly delayed in selective attention to color. N1 was normally preserved both in attention to color and in attention to shape. Our electrophysiological results indicate that the color discrimination process during selective attention is impaired in MSA.

Broadband true time delay for microwave signal processing, using slow light based on stimulated Brillouin scattering in optical fibers.

PubMed

Chin, Sanghoon; Thévenaz, Luc; Sancho, Juan; Sales, Salvador; Capmany, José; Berger, Perrine; Bourderionnet, Jérôme; Dolfi, Daniel

2010-10-11

We experimentally demonstrate a novel technique to process broadband microwave signals, using all-optically tunable true time delay in optical fibers. The configuration to achieve true time delay basically consists of two main stages: photonic RF phase shifter and slow light, based on stimulated Brillouin scattering in fibers. Dispersion properties of fibers are controlled, separately at optical carrier frequency and in the vicinity of microwave signal bandwidth. This way time delay induced within the signal bandwidth can be manipulated to correctly act as true time delay with a proper phase compensation introduced to the optical carrier. We completely analyzed the generated true time delay as a promising solution to feed phased array antenna for radar systems and to develop dynamically reconfigurable microwave photonic filters.

Finite-Time Stabilization and Adaptive Control of Memristor-Based Delayed Neural Networks.

PubMed

Wang, Leimin; Shen, Yi; Zhang, Guodong

Finite-time stability problem has been a hot topic in control and system engineering. This paper deals with the finite-time stabilization issue of memristor-based delayed neural networks (MDNNs) via two control approaches. First, in order to realize the stabilization of MDNNs in finite time, a delayed state feedback controller is proposed. Then, a novel adaptive strategy is applied to the delayed controller, and finite-time stabilization of MDNNs can also be achieved by using the adaptive control law. Some easily verified algebraic criteria are derived to ensure the stabilization of MDNNs in finite time, and the estimation of the settling time functional is given. Moreover, several finite-time stability results as our special cases for both memristor-based neural networks (MNNs) without delays and neural networks are given. Finally, three examples are provided for the illustration of the theoretical results.Finite-time stability problem has been a hot topic in control and system engineering. This paper deals with the finite-time stabilization issue of memristor-based delayed neural networks (MDNNs) via two control approaches. First, in order to realize the stabilization of MDNNs in finite time, a delayed state feedback controller is proposed. Then, a novel adaptive strategy is applied to the delayed controller, and finite-time stabilization of MDNNs can also be achieved by using the adaptive control law. Some easily verified algebraic criteria are derived to ensure the stabilization of MDNNs in finite time, and the estimation of the settling time functional is given. Moreover, several finite-time stability results as our special cases for both memristor-based neural networks (MNNs) without delays and neural networks are given. Finally, three examples are provided for the illustration of the theoretical results.

Application of troposphere model from NWP and GNSS data into real-time precise positioning

NASA Astrophysics Data System (ADS)

Wilgan, Karina; Hadas, Tomasz; Kazmierski, Kamil; Rohm, Witold; Bosy, Jaroslaw

2016-04-01

The tropospheric delay empirical models are usually functions of meteorological parameters (temperature, pressure and humidity). The application of standard atmosphere parameters or global models, such as GPT (global pressure/temperature) model or UNB3 (University of New Brunswick, version 3) model, may not be sufficient, especially for positioning in non-standard weather conditions. The possible solution is to use regional troposphere models based on real-time or near-real time measurements. We implement a regional troposphere model into the PPP (Precise Point Positioning) software GNSS-WARP (Wroclaw Algorithms for Real-time Positioning) developed at Wroclaw University of Environmental and Life Sciences. The software is capable of processing static and kinematic multi-GNSS data in real-time and post-processing mode and takes advantage of final IGS (International GNSS Service) products as well as IGS RTS (Real-Time Service) products. A shortcoming of PPP technique is the time required for the solution to converge. One of the reasons is the high correlation among the estimated parameters: troposphere delay, receiver clock offset and receiver height. To efficiently decorrelate these parameters, a significant change in satellite geometry is required. Alternative solution is to introduce the external high-quality regional troposphere delay model to constrain troposphere estimates. The proposed model consists of zenith total delays (ZTD) and mapping functions calculated from meteorological parameters from Numerical Weather Prediction model WRF (Weather Research and Forecasting) and ZTDs from ground-based GNSS stations using the least-squares collocation software COMEDIE (Collocation of Meteorological Data for Interpretation and Estimation of Tropospheric Pathdelays) developed at ETH Zurich.

Robust stability bounds for multi-delay networked control systems

NASA Astrophysics Data System (ADS)

Seitz, Timothy; Yedavalli, Rama K.; Behbahani, Alireza

2018-04-01

In this paper, the robust stability of a perturbed linear continuous-time system is examined when controlled using a sampled-data networked control system (NCS) framework. Three new robust stability bounds on the time-invariant perturbations to the original continuous-time plant matrix are presented guaranteeing stability for the corresponding discrete closed-loop augmented delay-free system (ADFS) with multiple time-varying sensor and actuator delays. The bounds are differentiated from previous work by accounting for the sampled-data nature of the NCS and for separate communication delays for each sensor and actuator, not a single delay. Therefore, this paper expands the knowledge base in multiple inputs multiple outputs (MIMO) sampled-data time delay systems. Bounds are presented for unstructured, semi-structured, and structured perturbations.

Clinical Characteristics and Lesions Responsible for Swallowing Hesitation After Acute Cerebral Infarction.

PubMed

Saito, Tsukasa; Hayashi, Keisuke; Nakazawa, Hajime; Ota, Tetsuo

2016-08-01

Some stroke patients with a unilateral lesion demonstrate acute dysphagia characterized by a markedly prolonged swallowing time, making us think they are reluctant to swallow. In order to clarify the clinical characteristics and causative lesions of delayed swallowing, we conducted a retrospective analysis of 20 right-handed patients without a history of swallowing dysfunction who underwent videofluorography on suspicion of dysphagia after a first ischemic stroke. The oral processing time plus the postfaucial aggregation time required to swallow jelly for patients classified as having delayed swallowing was over 10 s. The time required for swallowing jelly was significantly longer than that without the hesitation (median value, 24.1 vs. 8.9 s, P < 0.001). The oral processing time plus the postfaucial aggregation time required for patients with delayed swallowing to swallow thickened water was largely over 5 s and significantly longer than that of patients without swallowing hesitation (median value, 10.2 vs. 3.3 s, P < 0.001). Swallowing hesitation caused by acute unilateral infarction could be separated into two different patterns. Because four of the five patients with a rippling tongue movement in the swallowing hesitation pattern had a lesion in the left primary motor cortex, which induces some kinds of apraxia, swallowing hesitation with a rippling tongue movement seems to be a representative characteristic of apraxia. The patients with swallowing hesitation with a temporary stasis of the tongue in this study tended to have broad lesions in the frontal lobe, especially in the middle frontal gyrus, which is thought to be involved in higher cognition.

Discrete-time BAM neural networks with variable delays

NASA Astrophysics Data System (ADS)

Liu, Xin-Ge; Tang, Mei-Lan; Martin, Ralph; Liu, Xin-Bi

2007-07-01

This Letter deals with the global exponential stability of discrete-time bidirectional associative memory (BAM) neural networks with variable delays. Using a Lyapunov functional, and linear matrix inequality techniques (LMI), we derive a new delay-dependent exponential stability criterion for BAM neural networks with variable delays. As this criterion has no extra constraints on the variable delay functions, it can be applied to quite general BAM neural networks with a broad range of time delay functions. It is also easy to use in practice. An example is provided to illustrate the theoretical development.

Local Bifurcations and Optimal Theory in a Delayed Predator-Prey Model with Threshold Prey Harvesting

NASA Astrophysics Data System (ADS)

Tankam, Israel; Tchinda Mouofo, Plaire; Mendy, Abdoulaye; Lam, Mountaga; Tewa, Jean Jules; Bowong, Samuel

2015-06-01

We investigate the effects of time delay and piecewise-linear threshold policy harvesting for a delayed predator-prey model. It is the first time that Holling response function of type III and the present threshold policy harvesting are associated with time delay. The trajectories of our delayed system are bounded; the stability of each equilibrium is analyzed with and without delay; there are local bifurcations as saddle-node bifurcation and Hopf bifurcation; optimal harvesting is also investigated. Numerical simulations are provided in order to illustrate each result.

Internet Teleprescence by Real-Time View-Dependent Image Generation with Omnidirectional Video Camera

NASA Astrophysics Data System (ADS)

Morita, Shinji; Yamazawa, Kazumasa; Yokoya, Naokazu

2003-01-01

This paper describes a new networked telepresence system which realizes virtual tours into a visualized dynamic real world without significant time delay. Our system is realized by the following three steps: (1) video-rate omnidirectional image acquisition, (2) transportation of an omnidirectional video stream via internet, and (3) real-time view-dependent perspective image generation from the omnidirectional video stream. Our system is applicable to real-time telepresence in the situation where the real world to be seen is far from an observation site, because the time delay from the change of user"s viewing direction to the change of displayed image is small and does not depend on the actual distance between both sites. Moreover, multiple users can look around from a single viewpoint in a visualized dynamic real world in different directions at the same time. In experiments, we have proved that the proposed system is useful for internet telepresence.

Time-varying delays compensation algorithm for powertrain active damping of an electrified vehicle equipped with an axle motor during regenerative braking

NASA Astrophysics Data System (ADS)

Zhang, Junzhi; Li, Yutong; Lv, Chen; Gou, Jinfang; Yuan, Ye

2017-03-01

The flexibility of the electrified powertrain system elicits a negative effect upon the cooperative control performance between regenerative and hydraulic braking and the active damping control performance. Meanwhile, the connections among sensors, controllers, and actuators are realized via network communication, i.e., controller area network (CAN), that introduces time-varying delays and deteriorates the control performances of the closed-loop control systems. As such, the goal of this paper is to develop a control algorithm to cope with all these challenges. To this end, the models of the stochastic network induced time-varying delays, based on a real in-vehicle network topology and on a flexible electrified powertrain, were firstly built. In order to further enhance the control performances of active damping and cooperative control of regenerative and hydraulic braking, the time-varying delays compensation algorithm for the electrified powertrain active damping during regenerative braking was developed based on a predictive scheme. The augmented system is constructed and the H∞ performance is analyzed. Based on this analysis, the control gains are derived by solving a nonlinear minimization problem. The simulations and hardware-in-loop (HIL) tests were carried out to validate the effectiveness of the developed algorithm. The test results show that the active damping and cooperative control performances are enhanced significantly.

The effect of antithyroid treatment on atrial conduction times in patients with subclinical hyperthyroidism.

PubMed

Nacar, Alper Buğra; Acar, Gürkan; Yorgun, Hikmet; Akçay, Ahmet; Özkaya, Mesut; Canpolat, Uğur; Akkoyun, Murat; Tuncer, Cemal

2012-09-01

Prolonged atrial conduction time measured by tissue Doppler imaging (TDI) has been associated with increased risk of atrial fibrillation. We aimed to evaluate the effect of subclinical hyperthyroidism (SH) and antithyroid treatment on atrial conduction time. A total of 30 patients with SH (26 females; mean age 34.8 ± 8.5 years) and 30 age- and gender-matched controls were included. Using TDI, atrial conduction time was measured from the lateral mitral annulus, septal mitral annulus, and lateral tricuspid annulus. Intra- and interatrial conduction delay were calculated. TDI and thyroid hormone levels were studied at the time of enrollment and after achievement of euthyroid state with propylthiouracil treatment. Patients were followed for 14 ± 3 weeks. Atrial conduction time at the lateral and septal mitral annulus were significantly higher in patients with SH compared to controls. Both inter-, right, and left intraatrial electromechanical delay were prolonged in patients with SH compared to control subjects (21.3 ± 6.1 vs. 13.9 ± 4.3, P < 0.001 and 4.2 ± 3.5 vs. 2.3 ± 1.9, P = 0.014 and 17.1 ± 6.0 vs. 11.6 ± 3.8, P < 0.001, respectively). After achievement of euthyroid state, inter- and left intraatrial electromechanical delay were significantly decreased compared to baseline values and approximated to the values of the control group (P < 0.001). SH is associated with prolonged atrial conduction time. After achievement of euthyroid state, decrement in atrial conduction time may reveal how the antithyroid treatment may prevent the development of atrial fibrillation in these patients. © 2012, Wiley Periodicals, Inc.

Cost Averted With Timely Fecal Microbiota Transplantation in the Management of Recurrent Clostridium difficile Infection in Alberta, Canada.

PubMed

Waye, Arianna; Atkins, Kerry; Kao, Dina

2016-10-01

Fecal microbiota transplantation (FMT) is highly effective in treating recurrent Clostridium difficile infection (RCDI). However, the ideal timing for offering FMT remains to be determined. Furthermore, the direct medical costs averted with timely FMT have not been examined. A retrospective review of the Edmonton FMT program database included patients who received FMT for RCDI (October 2012 to September 2014). They were divided into 2 groups: those who received FMT after 2 recurrences (the timely FMT group) and those who received FMT after at least 3 recurrences (the delayed FMT group). The primary outcome was the difference in direct medical costs related to hospital admissions and emergency room visits due to CDI between the 2 groups. The secondary outcomes were RCDI cure rate and duration of RCDI in each group. A total of 75 patients were included: 30 received timely FMT, whereas 45 received delayed FMT. The mean difference in hospital length of stay and emergency room visits related to CDI were 13.8 days shorter and 1.3 visits fewer with timely FMT, associated with a mean cost saving of $29,842 per patient. Sensitivity analysis was performed to examine the effect of outliers and comorbities on the differential costs, and it was found that the differences in average cost per patient were more pronounced in those with Charlson comorbidity index ≥3 compared with those with scores of 0 to 2. The cure rate was 94% (timely FMT group) and 93% (delayed FMT group). The mean duration of RCDI was 109 days (timely FMT group) and 281 days (delayed FMT group). Timely FMT can provide significant cost savings to health-care systems, especially for patients with multiple comorbidities.

Do presenting symptoms explain sex differences in emergency department delays among patients with acute stroke?

PubMed

Gargano, Julia Warner; Wehner, Susan; Reeves, Mathew J

2009-04-01

Previous studies report that women with stroke may experience longer delays in diagnostic workup than men after arriving at the emergency department. We hypothesized that presenting symptom differences could explain these delays. Data were collected on 1922 acute stroke cases who presented to 15 hospitals participating in a statewide stroke registry. We evaluated 2 in-hospital time intervals: emergency department arrival to physician examination ("door-to-doctor") and emergency department arrival to brain imaging ("door-to-image"). We used parametric survival models to estimate time ratios, which represent the ratio of average times comparing women to men, after adjusting for symptom presentation and other confounders. Women were significantly less likely than men to present with any stroke warning sign or suspected stroke (87.5% versus 91.4%) or to report trouble with walking, balance, or dizziness (9.5% versus 13.7%). Difficulty speaking and loss of consciousness were associated with shorter door-to-doctor times. Weakness, facial droop, difficulty speaking, and loss of consciousness were associated with shorter door-to-image times, whereas difficulty with walking/balance was associated with longer door-to-image times. In adjusted analyses, women had 11% longer door-to-doctor intervals (time ratio, 1.11; 95%, CI 1.02 to 1.22) and 15% longer door-to-image intervals (time ratio, 1.15; 95% CI, 1.08 to 1.25) after accounting for presenting symptoms, age, and other confounders. Furthermore, these sex differences remained evident after restricting to patients who arrived within 6 or within 2 hours of symptom onset. Women with acute stroke experienced greater emergency department delays than men, which were not attributable to differences in presenting symptoms, time of arrival, age, or other confounders.

A Strain-Sonde Technique for the Measurement of Mechanical Time-Delay Fuze Function Times and Performance

DTIC Science & Technology

1983-09-01

AD IV) MEMORANDUM REPORT ARBRL-MR-03309 N(Supersedes IMR No. 760) A STRAIN -SONDE TECHNIQUE FOR THE MEASUREMENT OF MECHANICAL TIME- DELAY FUZE...and BkuWel) S. TYPE OF REPORT & PERIOD COVERED A STRAIN -SONDE TECHNIQUE FOR THE MEASUREMENT OF Final MECHANICAL TIME-DELAY FUZE FUNCTION TIMES AND S...nmber) M577 Mechanical Time-Delay Fuze F"/FM Telemeter Interlock Pin Release Semiconductor Strain Gage Rotor Signal Condition Amplifier Firing Pin In

Robust optimization for nonlinear time-delay dynamical system of dha regulon with cost sensitivity constraint in batch culture

NASA Astrophysics Data System (ADS)

Yuan, Jinlong; Zhang, Xu; Liu, Chongyang; Chang, Liang; Xie, Jun; Feng, Enmin; Yin, Hongchao; Xiu, Zhilong

2016-09-01

Time-delay dynamical systems, which depend on both the current state of the system and the state at delayed times, have been an active area of research in many real-world applications. In this paper, we consider a nonlinear time-delay dynamical system of dha-regulonwith unknown time-delays in batch culture of glycerol bioconversion to 1,3-propanediol induced by Klebsiella pneumonia. Some important properties and strong positive invariance are discussed. Because of the difficulty in accurately measuring the concentrations of intracellular substances and the absence of equilibrium points for the time-delay system, a quantitative biological robustness for the concentrations of intracellular substances is defined by penalizing a weighted sum of the expectation and variance of the relative deviation between system outputs before and after the time-delays are perturbed. Our goal is to determine optimal values of the time-delays. To this end, we formulate an optimization problem in which the time delays are decision variables and the cost function is to minimize the biological robustness. This optimization problem is subject to the time-delay system, parameter constraints, continuous state inequality constraints for ensuring that the concentrations of extracellular and intracellular substances lie within specified limits, a quality constraint to reflect operational requirements and a cost sensitivity constraint for ensuring that an acceptable level of the system performance is achieved. It is approximated as a sequence of nonlinear programming sub-problems through the application of constraint transcription and local smoothing approximation techniques. Due to the highly complex nature of this optimization problem, the computational cost is high. Thus, a parallel algorithm is proposed to solve these nonlinear programming sub-problems based on the filled function method. Finally, it is observed that the obtained optimal estimates for the time-delays are highly satisfactory via numerical simulations.

Comparison of noninvasive pulse transit time estimates as markers of blood pressure using invasive pulse transit time measurements as a reference.

PubMed

Gao, Mingwu; Olivier, N Bari; Mukkamala, Ramakrishna

2016-05-01

Pulse transit time (PTT) measured as the time delay between invasive proximal and distal blood pressure (BP) or flow waveforms (invasive PTT [I-PTT]) tightly correlates with BP PTT estimated as the time delay between noninvasive proximal and distal arterial waveforms could therefore permit cuff-less BP monitoring. A popular noninvasive PTT estimate for this application is the time delay between ECG and photoplethysmography (PPG) waveforms (pulse arrival time [PAT]). Another estimate is the time delay between proximal and distal PPG waveforms (PPG-PTT). PAT and PPG-PTT were assessed as markers of BP over a wide physiologic range using I-PTT as a reference. Waveforms for determining I-PTT, PAT, and PPG-PTT through central arteries were measured from swine during baseline conditions and infusions of various hemodynamic drugs. Diastolic, mean, and systolic BP varied widely in each subject (group average (mean ± SE) standard deviation between 25 ± 2 and 36 ± 2 mmHg). I-PTT correlated well with all BP levels (group average R(2) values between 0.86 ± 0.03 and 0.91 ± 0.03). PPG-PTT also correlated well with all BP levels (group average R(2) values between 0.81 ± 0.03 and 0.85 ± 0.02), and its R(2) values were not significantly different from those of I-PTT PAT correlated best with systolic BP (group average R(2) value of 0.70 ± 0.04), but its R(2) values for all BP levels were significantly lower than those of I-PTT (P < 0.005) and PPG-PTT (P < 0.02). The pre-ejection period component of PAT was responsible for its inferior correlation with BP In sum, PPG-PTT was not different from I-PTT and superior to the popular PAT as a marker of BP. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Time delay and noise explaining the behaviour of the cell growth in fermentation process

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

Ayuobi, Tawfiqullah; Rosli, Norhayati; Bahar, Arifah

2015-02-03

This paper proposes to investigate the interplay between time delay and external noise in explaining the behaviour of the microbial growth in batch fermentation process. Time delay and noise are modelled jointly via stochastic delay differential equations (SDDEs). The typical behaviour of cell concentration in batch fermentation process under this model is investigated. Milstein scheme is applied for solving this model numerically. Simulation results illustrate the effects of time delay and external noise in explaining the lag and stationary phases, respectively for the cell growth of fermentation process.

Time delay and noise explaining the behaviour of the cell growth in fermentation process

NASA Astrophysics Data System (ADS)

Ayuobi, Tawfiqullah; Rosli, Norhayati; Bahar, Arifah; Salleh, Madihah Md

2015-02-01

This paper proposes to investigate the interplay between time delay and external noise in explaining the behaviour of the microbial growth in batch fermentation process. Time delay and noise are modelled jointly via stochastic delay differential equations (SDDEs). The typical behaviour of cell concentration in batch fermentation process under this model is investigated. Milstein scheme is applied for solving this model numerically. Simulation results illustrate the effects of time delay and external noise in explaining the lag and stationary phases, respectively for the cell growth of fermentation process.

The Effects of Financial Education on Impulsive Decision Making

PubMed Central

DeHart, William B.; Friedel, Jonathan E.; Lown, Jean M.; Odum, Amy L.

2016-01-01

Delay discounting, as a behavioral measure of impulsive choice, is strongly related to substance abuse and other risky behaviors. Therefore, effective techniques that alter delay discounting are of great interest. We explored the ability of a semester long financial education course to change delay discounting. Participants were recruited from a financial education course (n = 237) and an abnormal psychology course (n = 80). Both groups completed a delay-discounting task for $100 during the first two weeks (Time 1) of the semester as well as during the last two weeks (Time 2) of the semester. Participants also completed a personality inventory and financial risk tolerance scale both times and a delay-discounting task for $1,000 during Time 2. Delay discounting decreased in the financial education group at the end of the semester whereas there was no change in delay discounting in the abnormal psychology group. Financial education may be an effective method for reducing delay discounting. PMID:27442237

The Effects of Financial Education on Impulsive Decision Making.

PubMed

DeHart, William B; Friedel, Jonathan E; Lown, Jean M; Odum, Amy L

2016-01-01

Delay discounting, as a behavioral measure of impulsive choice, is strongly related to substance abuse and other risky behaviors. Therefore, effective techniques that alter delay discounting are of great interest. We explored the ability of a semester long financial education course to change delay discounting. Participants were recruited from a financial education course (n = 237) and an abnormal psychology course (n = 80). Both groups completed a delay-discounting task for $100 during the first two weeks (Time 1) of the semester as well as during the last two weeks (Time 2) of the semester. Participants also completed a personality inventory and financial risk tolerance scale both times and a delay-discounting task for $1,000 during Time 2. Delay discounting decreased in the financial education group at the end of the semester whereas there was no change in delay discounting in the abnormal psychology group. Financial education may be an effective method for reducing delay discounting.

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

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

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

2015-08-15

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

The rates and time-delay distribution of multiply imaged supernovae behind lensing clusters

NASA Astrophysics Data System (ADS)

Li, Xue; Hjorth, Jens; Richard, Johan

2012-11-01

Time delays of gravitationally lensed sources can be used to constrain the mass model of a deflector and determine cosmological parameters. We here present an analysis of the time-delay distribution of multiply imaged sources behind 17 strong lensing galaxy clusters with well-calibrated mass models. We find that for time delays less than 1000 days, at z = 3.0, their logarithmic probability distribution functions are well represented by P(log Δt) = 5.3 × 10-4Δttilde beta/M2502tilde beta, with tilde beta = 0.77, where M250 is the projected cluster mass inside 250 kpc (in 1014M⊙), and tilde beta is the power-law slope of the distribution. The resultant probability distribution function enables us to estimate the time-delay distribution in a lensing cluster of known mass. For a cluster with M250 = 2 × 1014M⊙, the fraction of time delays less than 1000 days is approximately 3%. Taking Abell 1689 as an example, its dark halo and brightest galaxies, with central velocity dispersions σ>=500kms-1, mainly produce large time delays, while galaxy-scale mass clumps are responsible for generating smaller time delays. We estimate the probability of observing multiple images of a supernova in the known images of Abell 1689. A two-component model of estimating the supernova rate is applied in this work. For a magnitude threshold of mAB = 26.5, the yearly rate of Type Ia (core-collapse) supernovae with time delays less than 1000 days is 0.004±0.002 (0.029±0.001). If the magnitude threshold is lowered to mAB ~ 27.0, the rate of core-collapse supernovae suitable for time delay observation is 0.044±0.015 per year.

Elapsed Time Between the First Symptoms of Breast Cancer and Medical Help-Seeking Behavior and the Affecting Factors.

PubMed

Gözüm, Sebahat; Tuzcu, Ayla

Many studies have determined that the time between women's realization of first symptoms and seeking help from a healthcare professional is more than 1 month. The situation is defined as delay in medical help-seeking behavior (MHSB). The purpose of this study was to determine the time elapsed between the first symptoms of breast cancer and MHSB, as well as the factors contributing to the delay. In this descriptive study, the data were collected from 132 patients who received a diagnosis of breast cancer and are receiving treatment in the Oncology Clinic of Akdeniz University Hospital. The questionnaire used in the study was structured in 3 parts: sociodemographic characteristics, breast cancer history/screening behaviors, and psychological factors affecting MHSB. The elapsed time between patients' first symptoms and MHSB was classified into "normal" when it was less than 1 month, "delay" when it was between 1 and 3 months, "long-term delay" when it was more than 3 months, and "very serious delay" when it was more than 6 months. A total of 59.8% were classified as normal, 16.7% as delayed, 5.3% as a long-term delay, and 18.2% as a very serious delay after first symptoms. The delay in MHSB time was affected 18.55 times by "not caring/minding," 10.73 times by "fear," 7.13 times by "having more important problems," and 4.23 times by "realization of first symptoms" by themselves. Psychological factors were the most important determinants in delay. The MHSB time was less if those first realizing the symptoms were healthcare professionals. Healthcare professionals should direct women to screenings and train them to interpret symptoms correctly.

Autapse-induced multiple stochastic resonances in a modular neuronal network

NASA Astrophysics Data System (ADS)

Yang, XiaoLi; Yu, YanHu; Sun, ZhongKui

2017-08-01

This study investigates the nontrivial effects of autapse on stochastic resonance in a modular neuronal network subjected to bounded noise. The resonance effect of autapse is detected by imposing a self-feedback loop with autaptic strength and autaptic time delay to each constituent neuron. Numerical simulations have demonstrated that bounded noise with the proper level of amplitude can induce stochastic resonance; moreover, the noise induced resonance dynamics can be significantly shaped by the autapse. In detail, for a specific range of autaptic strength, multiple stochastic resonances can be induced when the autaptic time delays are appropriately adjusted. These appropriately adjusted delays are detected to nearly approach integer multiples of the period of the external weak signal when the autaptic strength is very near zero; otherwise, they do not match the period of the external weak signal when the autaptic strength is slightly greater than zero. Surprisingly, in both cases, the differences between arbitrary two adjacent adjusted autaptic delays are always approximately equal to the period of the weak signal. The phenomenon of autaptic delay induced multiple stochastic resonances is further confirmed to be robust against the period of the external weak signal and the intramodule probability of subnetwork. These findings could have important implications for weak signal detection and information propagation in realistic neural systems.

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

PubMed Central

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

2016-01-01

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

Effects of computing time delay on real-time control systems

NASA Technical Reports Server (NTRS)

Shin, Kang G.; Cui, Xianzhong

1988-01-01

The reliability of a real-time digital control system depends not only on the reliability of the hardware and software used, but also on the speed in executing control algorithms. The latter is due to the negative effects of computing time delay on control system performance. For a given sampling interval, the effects of computing time delay are classified into the delay problem and the loss problem. Analysis of these two problems is presented as a means of evaluating real-time control systems. As an example, both the self-tuning predicted (STP) control and Proportional-Integral-Derivative (PID) control are applied to the problem of tracking robot trajectories, and their respective effects of computing time delay on control performance are comparatively evaluated. For this example, the STP (PID) controller is shown to outperform the PID (STP) controller in coping with the delay (loss) problem.

The influences of delay time on the stability of a market model with stochastic volatility

NASA Astrophysics Data System (ADS)

Li, Jiang-Cheng; Mei, Dong-Cheng

2013-02-01

The effects of the delay time on the stability of a market model are investigated, by using a modified Heston model with a cubic nonlinearity and cross-correlated noise sources. These results indicate that: (i) There is an optimal delay time τo which maximally enhances the stability of the stock price under strong demand elasticity of stock price, and maximally reduces the stability of the stock price under weak demand elasticity of stock price; (ii) The cross correlation coefficient of noises and the delay time play an opposite role on the stability for the case of the delay time <τo and the same role for the case of the delay time >τo. Moreover, the probability density function of the escape time of stock price returns, the probability density function of the returns and the correlation function of the returns are compared with other literatures.

Clinical efficacy of dim light melatonin onset testing in diagnosing delayed sleep phase syndrome.

PubMed

Rahman, Shadab A; Kayumov, Leonid; Tchmoutina, Ekaterina A; Shapiro, Colin M

2009-05-01

Delayed Sleep Phase Syndrome (DSPS) arises from biological clock desynchrony and accounts for 10% of chronic insomnia patients. Currently DSPS is diagnosed based on sleep/wake cycle disruptions rather than examining the underlying biological clock alterations. The objective of the study was to determine the sensitivity and specificity of the Dim Light Melatonin Onset (DLMO) Test in diagnosing DSPS in a clinical setting. Fifty-six patients (mean age 28 years) symptomatic of DSPS participated in the study. Following an initial assessment of DSPS using sleep diaries, participants underwent two consecutive nights of polysomnography (PSG), with an imposed sleep period on the second night to demonstrate the delay in the timing of habitual sleep period and to thereby confirm DSPS. Circadian phase delays were also measured using melatonin secretion profiles, and the efficacy of diagnosing DSPS using DLMO was compared to using sleep diaries and PSG. Melatonin secretion was assayed for each individual by ELISA using saliva samples. Main outcome measures included the time of melatonin secretion onset, clinical sensitivity and specificity of the DLMO test. The time of melatonin secretion onset was significantly delayed in DSPS patients. Clinical sensitivity and specificity of the DLMO test in diagnosing DSPS were 90.3% and 84.0%, respectively. The DLMO test is an accurate tool for differentiating between sleep disorder patients with or without underlying circadian rhythm disruption. It is effective for phase typing DSPS patients in a clinical setting.

Early diagnosis of post-varicella necrotising fasciitis: A medical and surgical emergency

PubMed Central

Xavier, Rose; Abraham, Bobby; Cherian, Vinod Jacob; Joseph, Jobin I.

2016-01-01

Necrotising fasciitis (NF) is an extremely rare complication of a rather common paediatric viral exanthem varicella. Delayed diagnosis and treatment can lead to significant morbidity and mortality. Laboratory risk indicator of NF score aids in early clinical diagnosis in suspected cases of post-varicella NF thus enabling timely intervention. Surgery delayed for more than 24 hours, is an independent risk factor for death. Surgical debridement with good antibiotic coverage is the definitive treatment for NF. PMID:27251524

Immersive visualization for navigation and control of the Mars Exploration Rovers

NASA Technical Reports Server (NTRS)

Hartman, Frank R.; Cooper, Brian; Maxwell, Scott; Wright, John; Yen, Jeng

2004-01-01

The Rover Sequencing and Visualization Program (RSVP) is a suite of tools for sequencing of planetary rovers, which are subject to significant light time delay and thus are unsuitable for teleoperation.

Traffic signal coordination and queue management in oversaturated intersection.

DOT National Transportation Integrated Search

2011-03-18

Traffic signal timing optimization when done properly, could significantly improve network : performance by reducing delay, increasing network throughput, reducing number of stops, or : increasing average speed in the network. The optimization can be...

Traffic signal coordination and queue management in oversaturated intersections.

DOT National Transportation Integrated Search

2011-03-18

Traffic signal timing optimization when done properly, could significantly improve network performance by reducing delay, increasing network throughput, reducing number of stops, or increasing average speed in the network. The optimization can become...

Comparison of the Delay in Processing Time and Protective Plastic Cases in Two Phosphor Plate Systems

PubMed Central

Aktan, Ali Murat; Çiftçi, Mehmet Ertuğrul; Akgünlü, Faruk

2012-01-01

Objective. The purpose of this study was to analyze two phosphor plate systems (PSPs) (Dürr Dental, Digora Optime) according to their scanning delay and protective plastic case performances. Methods. Two PSPs using an aluminum step wedge were exposed. These plates were placed in three different protective plastic cases (manufacturers' original cases, black case, and white case) before obtaining the radiographs and were then processed immediately and 1, 5, 10, 30, 60, 120, 240, and 480 min after exposure. Mean gray values (MGVs) of the 3rd, 5th, 7th, and 9th steps of the wedges were compared using ANOVA. Results. Statistically significant differences were found between the two PSPs (P < 0.001). ANOVA revealed that the MGVs of four steps of the wedges were significantly different from each other for all scan delays (P < 0.001). MGVs increased with increasing scanning delay, except the group with Dürr plates in their original cases. Reduction in image quality began 5 min after exposure in the other Dürr plate groups. Conclusions. Within the limitations of the current study, it can be concluded that scanning delay causes a reduction in image quality, and using the manufacturer's original protective case will result in better performance of PSPs. PMID:23213301

Comparison of the delay in processing time and protective plastic cases in two phosphor plate systems.

PubMed

Aktan, Ali Murat; Ciftçi, Mehmet Ertuğrul; Akgünlü, Faruk

2012-01-01

The purpose of this study was to analyze two phosphor plate systems (PSPs) (Dürr Dental, Digora Optime) according to their scanning delay and protective plastic case performances. Two PSPs using an aluminum step wedge were exposed. These plates were placed in three different protective plastic cases (manufacturers' original cases, black case, and white case) before obtaining the radiographs and were then processed immediately and 1, 5, 10, 30, 60, 120, 240, and 480 min after exposure. Mean gray values (MGVs) of the 3rd, 5th, 7th, and 9th steps of the wedges were compared using ANOVA. Statistically significant differences were found between the two PSPs (P < 0.001). ANOVA revealed that the MGVs of four steps of the wedges were significantly different from each other for all scan delays (P < 0.001). MGVs increased with increasing scanning delay, except the group with Dürr plates in their original cases. Reduction in image quality began 5 min after exposure in the other Dürr plate groups. Within the limitations of the current study, it can be concluded that scanning delay causes a reduction in image quality, and using the manufacturer's original protective case will result in better performance of PSPs.

Management Strategies to Facilitate Optimal Outcomes for Patients Treated with Delayed-release Dimethyl Fumarate.

PubMed

Mayer, Lori; Fink, Mary Kay; Sammarco, Carrie; Laing, Lisa

2018-04-01

Delayed-release dimethyl fumarate is an oral disease-modifying therapy that has demonstrated significant efficacy in adults with relapsing-remitting multiple sclerosis. Incidences of flushing and gastrointestinal adverse events are common in the first month after delayed-release dimethyl fumarate initiation. Our objective was to propose mitigation strategies for adverse events related to initiation of delayed-release dimethyl fumarate in the treatment of patients with multiple sclerosis. Studies of individually developed mitigation strategies and chart reviews were evaluated. Those results, as well as mitigation protocols developed at multiple sclerosis care centers, are summarized. Key steps to optimize the effectiveness of delayed-release dimethyl fumarate treatment include education prior to and at the time of delayed-release dimethyl fumarate initiation, initiation dose protocol gradually increasing to maintenance dose, dietary suggestions for co-administration with food, gastrointestinal symptom management with over-the-counter medications, flushing symptom management with aspirin, and temporary dose reduction. Using the available evidence from clinical trials and evaluations of post-marketing studies, these strategies to manage gastrointestinal and flushing symptoms can be effective and helpful to the patient when initiating delayed-release dimethyl fumarate.

Acute ethanol does not always affect delay discounting in rats selected to prefer or avoid ethanol.

PubMed

Wilhelm, Clare J; Mitchell, Suzanne H

2012-01-01

The purpose of this study was to determine whether animals predisposed to prefer alcohol possess an altered acute response to alcohol on a delay discounting task relative to animals predisposed to avoid alcohol. We used rats selected to prefer or avoid alcohol to assess whether genotype moderates changes in delay discounting induced by acute ethanol exposure. Selectively bred rat lines of Sardinian alcohol-preferring (sP; n = 8) and non-preferring (sNP; n = 8) rats, and alko alcohol (AA, n = 8) and alko non-alcohol (ANA, n = 8) rats were trained in an adjusting amount task to assess delay discounting. There were no significant effects of line on baseline discounting; however, both lines of alcohol-preferring rats exhibit slowed reaction times. Acute ethanol (0, 0.25, 0.5 g/kg) treatment also had no effect on delay discounting in any of the selectively bred rat lines. Our data indicate that in these lines of animals, alcohol preference or avoidance has no impact on delay discounting following acute ethanol exposure. It is possible that other genetic models or lines may be differentially affected by alcohol and exhibit qualitatively and quantitatively different responses in delay discounting tasks.

Timing of umbilical cord-clamping and infant anaemia: the role of maternal anaemia.

PubMed

Blouin, Brittany; Penny, Mary E; Maheu-Giroux, Mathieu; Casapía, Martín; Aguilar, Eder; Silva, Hermánn; Creed-Kanashiro, Hilary M; Joseph, Serene A; Gagnon, Anita; Rahme, Elham; Gyorkos, Theresa W

2013-05-01

Evidence from randomized controlled trials has shown that delayed cord-clamping is beneficial to infant iron status. The role of maternal anaemia in this relationship, however, has not been established. To determine the effect of maternal anaemia at delivery on the association between timing of umbilical cord-clamping and infant anaemia at 4 and 8 months of age. A cohort of pregnant women admitted to the labour room of Hospital Iquitos (Iquitos, Peru) and their newborns were recruited into the study during two time periods (18 May to 3 June and 6-20 July 2009). Between the two recruitment periods, the hospital's policy changed from early to delayed umbilical cord-clamping. Maternal haemoglobin levels were measured before delivery, and the time between delivery and cord-clamping was recorded at delivery for the entire cohort. Mother-infant pairs were followed-up at 4 (n = 207) and 8 months (n = 184) post partum. Infant haemoglobin levels were measured at follow-up visits. Data were analysed using logistic regression models. The prevalence of maternal anaemia (Hb <11.0 g/dl) at delivery was 22%. Infant haemoglobin levels at 4 and 8 months of age were 10.4 g/dl and 10.3 g/dl, respectively. Infant haemoglobin levels did not differ significantly between infants born to anaemic mothers and those born to non-anaemic mothers at either 4 or 8 months of age. However, the association between the timing of cord-clamping and infant anaemia was modified by the mother's anaemia status. Significant benefits of delayed cord-clamping in preventing anaemia were found in infants born to anaemic mothers at both 4 months (aOR = 0.59, 95% CI 0.36-0.99) and 8 months (aOR = 0.38, 95% CI 0.19-0.76) of age. The study contributes additional evidence in support of delayed cord-clamping. This intervention is likely to have most public health impact in areas with a high prevalence of anaemia during pregnancy.

Cardiac-driven Pulsatile Motion of Intracranial Cerebrospinal Fluid Visualized Based on a Correlation Mapping Technique.

PubMed

Yatsushiro, Satoshi; Sunohara, Saeko; Hayashi, Naokazu; Hirayama, Akihiro; Matsumae, Mitsunori; Atsumi, Hideki; Kuroda, Kagayaki

2018-04-10

A correlation mapping technique delineating delay time and maximum correlation for characterizing pulsatile cerebrospinal fluid (CSF) propagation was proposed. After proofing its technical concept, this technique was applied to healthy volunteers and idiopathic normal pressure hydrocephalus (iNPH) patients. A time-resolved three dimensional-phase contrast (3D-PC) sampled the cardiac-driven CSF velocity at 32 temporal points per cardiac period at each spatial location using retrospective cardiac gating. The proposed technique visualized distributions of propagation delay and correlation coefficient of the PC-based CSF velocity waveform with reference to a waveform at a particular point in the CSF space. The delay time was obtained as the amount of time-shift, giving the maximum correlation for the velocity waveform at an arbitrary location with that at the reference location. The validity and accuracy of the technique were confirmed in a flow phantom equipped with a cardiovascular pump. The technique was then applied to evaluate the intracranial CSF motions in young, healthy (N = 13), and elderly, healthy (N = 13) volunteers and iNPH patients (N = 13). The phantom study demonstrated that root mean square error of the delay time was 2.27%, which was less than the temporal resolution of PC measurement used in this study (3.13% of a cardiac cycle). The human studies showed a significant difference (P < 0.01) in the mean correlation coefficient between the young, healthy group and the other two groups. A significant difference (P < 0.05) was also recognized in standard deviation of the correlation coefficients in intracranial CSF space among all groups. The result suggests that the CSF space compliance of iNPH patients was lower than that of healthy volunteers. The correlation mapping technique allowed us to visualize pulsatile CSF velocity wave propagations as still images. The technique may help to classify diseases related to CSF dynamics, such as iNPH.

Time delay and long-range connection induced synchronization transitions in Newman-Watts small-world neuronal networks.

PubMed

Qian, Yu

2014-01-01

The synchronization transitions in Newman-Watts small-world neuronal networks (SWNNs) induced by time delay τ and long-range connection (LRC) probability P have been investigated by synchronization parameter and space-time plots. Four distinct parameter regions, that is, asynchronous region, transition region, synchronous region, and oscillatory region have been discovered at certain LRC probability P = 1.0 as time delay is increased. Interestingly, desynchronization is observed in oscillatory region. More importantly, we consider the spatiotemporal patterns obtained in delayed Newman-Watts SWNNs are the competition results between long-range drivings (LRDs) and neighboring interactions. In addition, for moderate time delay, the synchronization of neuronal network can be enhanced remarkably by increasing LRC probability. Furthermore, lag synchronization has been found between weak synchronization and complete synchronization as LRC probability P is a little less than 1.0. Finally, the two necessary conditions, moderate time delay and large numbers of LRCs, are exposed explicitly for synchronization in delayed Newman-Watts SWNNs.

Time Delay and Long-Range Connection Induced Synchronization Transitions in Newman-Watts Small-World Neuronal Networks

PubMed Central

Qian, Yu

2014-01-01

The synchronization transitions in Newman-Watts small-world neuronal networks (SWNNs) induced by time delay and long-range connection (LRC) probability have been investigated by synchronization parameter and space-time plots. Four distinct parameter regions, that is, asynchronous region, transition region, synchronous region, and oscillatory region have been discovered at certain LRC probability as time delay is increased. Interestingly, desynchronization is observed in oscillatory region. More importantly, we consider the spatiotemporal patterns obtained in delayed Newman-Watts SWNNs are the competition results between long-range drivings (LRDs) and neighboring interactions. In addition, for moderate time delay, the synchronization of neuronal network can be enhanced remarkably by increasing LRC probability. Furthermore, lag synchronization has been found between weak synchronization and complete synchronization as LRC probability is a little less than 1.0. Finally, the two necessary conditions, moderate time delay and large numbers of LRCs, are exposed explicitly for synchronization in delayed Newman-Watts SWNNs. PMID:24810595

The Effect of Spatial Heterogeneities on Nucleation Kinetics in Amorphous Aluminum Alloys

NASA Astrophysics Data System (ADS)

Shen, Ye

The mechanical property of the Al based metallic glass could be enhanced significantly by introducing the high number density of Al-fcc nanocrystals (1021 ˜1023 m-3) to the amorphous matrix through annealing treatments, which motivates the study of the nucleation kinetics for the microstructure control. With the presence of a high number density (1025 m-3) of aluminum-like medium range order (MRO), the Al-Y-Fe metallic glass is considered to be spatially heterogeneous. Combining the classical nucleation theory with the structural configuration, a MRO seeded nucleation model has been proposed and yields theoretical steady state nucleation rates consistent with the experimental results. In addition, this model satisfies all the thermodynamic and kinetic constraints to be reasonable. Compared with the Al-Y-Fe system, the primary crystallization onset temperature decreases significantly and the transient delay time (tau) is shorter in the Al-Y-Fe-Pb(In) systems because the insoluble Pb and In nanoparticles in the amorphous matrix served as extrinsic spatial heterogeneity to provide the nucleation sites for Al-fcc precipitation and the high-resolution transmission electron microscopy (HRTEM) images of the Pb-Al interface revealed a good wetting behavior between the Al and Pb nanoparticles. The study of the transient delay time (tau) could provide insight on the transport behavior during the nucleation and a more convenient approach to evaluate the delay time has been developed by measuring the Al-Y-Fe amorphous alloy glass transition temperature (Tg) shift with the increasing annealing time (tannealing) in FlashDSC. The break point in the Tg vs. log(tannealing) plot has been identified to correspond to the delay time by the TEM characterization. FlashDSC tests with different heating rates and different compositions (Al-Y-Fe-Pb and Zn-Mg-Ca-Yb amorphous alloys) further confirmed the break point and delay time relationship. The amorphous matrix composition and the enthalpy analysis indicates that there are different mechanisms leading to the Tg shift before and after the break point. Before the break point, Tg shifts solely due to the increased glass stability through a relaxation process. However, after the break point, Tg shifts to higher temperatures because of both the relaxation and the composition change effects.

LMI designmethod for networked-based PID control

NASA Astrophysics Data System (ADS)

Souza, Fernando de Oliveira; Mozelli, Leonardo Amaral; de Oliveira, Maurício Carvalho; Palhares, Reinaldo Martinez

2016-10-01

In this paper, we propose a methodology for the design of networked PID controllers for second-order delayed processes using linear matrix inequalities. The proposed procedure takes into account time-varying delay on the plant, time-varying delays induced by the network and packed dropouts. The design is carried on entirely using a continuous-time model of the closed-loop system where time-varying delays are used to represent sampling and holding occurring in a discrete-time digital PID controller.

Accurate time delay technology in simulated test for high precision laser range finder

NASA Astrophysics Data System (ADS)

Chen, Zhibin; Xiao, Wenjian; Wang, Weiming; Xue, Mingxi

2015-10-01

With the continuous development of technology, the ranging accuracy of pulsed laser range finder (LRF) is higher and higher, so the maintenance demand of LRF is also rising. According to the dominant ideology of "time analog spatial distance" in simulated test for pulsed range finder, the key of distance simulation precision lies in the adjustable time delay. By analyzing and comparing the advantages and disadvantages of fiber and circuit delay, a method was proposed to improve the accuracy of the circuit delay without increasing the count frequency of the circuit. A high precision controllable delay circuit was designed by combining the internal delay circuit and external delay circuit which could compensate the delay error in real time. And then the circuit delay accuracy could be increased. The accuracy of the novel circuit delay methods proposed in this paper was actually measured by a high sampling rate oscilloscope actual measurement. The measurement result shows that the accuracy of the distance simulated by the circuit delay is increased from +/- 0.75m up to +/- 0.15m. The accuracy of the simulated distance is greatly improved in simulated test for high precision pulsed range finder.

Kalman filters for fractional discrete-time stochastic systems along with time-delay in the observation signal

NASA Astrophysics Data System (ADS)

Torabi, H.; Pariz, N.; Karimpour, A.

2016-02-01

This paper investigates fractional Kalman filters when time-delay is entered in the observation signal in the discrete-time stochastic fractional order state-space representation. After investigating the common fractional Kalman filter, we try to derive a fractional Kalman filter for time-delay fractional systems. A detailed derivation is given. Fractional Kalman filters will be used to estimate recursively the states of fractional order state-space systems based on minimizing the cost function when there is a constant time delay (d) in the observation signal. The problem will be solved by converting the filtering problem to a usual d-step prediction problem for delay-free fractional systems.

Reliability of biologic indicators in a mail-return sterilization-monitoring service: a review of 3 years.

PubMed

Andrés, M T; Tejerina, J M; Fierro, J F

1995-12-01

Most mail-return sterilization-monitoring services use spore strips to test sterilizers in dental clinics, but factors such as delay caused by mailing to the laboratory could cause false negatives. The aims of this study were to determine the influence of poststerilization time and temperature on the biologic indicator recovery system and to evaluate sterilization failure and its possible causes in dental clinics subscribing to a mail-return sterilization-monitoring service. Spore strips used in independent tests revealed the poststerilization time and temperature after a 7-day delay to have no significant influence. Sixty-six dental clinics that received quarterly biologic indicators to evaluate the effectiveness of their sterilizers had sterilization failure rates of 28.7% in 1992, 18.1% in 1993, and 9.1% in 1994, a statistically significant decrease in sterilization failure during the 3-year period. The usual causes of failure were operator error in wrapping of instruments, loading, operating temperature, or exposure time.

A comparison of control modes for time-delayed remote manipulation

NASA Technical Reports Server (NTRS)

Starr, G. P.

1982-01-01

Transmission time delay in the communication channel of a manual control system is investigated. A time delay can exist in remote manipulation systems, caused by long communication distances or bandwidth limitations. Ferrell 1 conducted the first research in time-delayed manipulation using a two degree-of-freedom manipulator. His subjects, working at time delays of 1.0, 2.1, and 3.2 s, could accomplish tasks even requiring great accuracy. The subjects spontaneously adopted a pattern of moving cautiously, then waiting to see the results of their actions. In experiments with a six degree-of-freedom master-slave manipulator system and time delays of 1.0 to 6 s, Black 2 saw that subjects tried to use the move-and-wait strategy; but there were often difficulties. The subjects seemed to have a problem in holding the master arm stationary while waiting for feedback. Any undesired drifting of the master arm introduced a discrepancy between the positions of the master and slave. This discrepancy was not perceived because of the time delay. The subject would then begin his next move with an inherent error. The difficulty of effectively using the move-and-wait strategy with a master-slave manipulator suggested that rate control might be a more effective control mode with time delay.

TIMEDELN: A programme for the detection and parametrization of overlapping resonances using the time-delay method

NASA Astrophysics Data System (ADS)

Little, Duncan A.; Tennyson, Jonathan; Plummer, Martin; Noble, Clifford J.; Sunderland, Andrew G.

2017-06-01

TIMEDELN implements the time-delay method of determining resonance parameters from the characteristic Lorentzian form displayed by the largest eigenvalues of the time-delay matrix. TIMEDELN constructs the time-delay matrix from input K-matrices and analyses its eigenvalues. This new version implements multi-resonance fitting and may be run serially or as a high performance parallel code with three levels of parallelism. TIMEDELN takes K-matrices from a scattering calculation, either read from a file or calculated on a dynamically adjusted grid, and calculates the time-delay matrix. This is then diagonalized, with the largest eigenvalue representing the longest time-delay experienced by the scattering particle. A resonance shows up as a characteristic Lorentzian form in the time-delay: the programme searches the time-delay eigenvalues for maxima and traces resonances when they pass through different eigenvalues, separating overlapping resonances. It also performs the fitting of the calculated data to the Lorentzian form and outputs resonance positions and widths. Any remaining overlapping resonances can be fitted jointly. The branching ratios of decay into the open channels can also be found. The programme may be run serially or in parallel with three levels of parallelism. The parallel code modules are abstracted from the main physics code and can be used independently.

Appropriate antimicrobial therapy in the era of multidrug-resistant human pathogens.

PubMed

Pogue, J M; Kaye, K S; Cohen, D A; Marchaim, D

2015-04-01

The past decade has brought a significant rise in antimicrobial resistance, and the ESKAPE pathogens have become a significant threat to public health. Three epidemiological features that negatively impact patients, which are consistently seen with the ESKAPE pathogens, are the following: 1) there has been a rise in incidence of these organisms as causative human pathogens, 2) there has been a significant increase in antimicrobial resistance in these bacterial species, and 3) the infections caused by these resistant strains are associated with worse outcomes when compared with infections caused by their susceptible counterparts. Significant delays in time to appropriate antimicrobial therapy of up to 5 days have been reported in infections due to these organisms and this is the strongest predictor of mortality with ESKAPE pathogens, particular in critically ill patients, where every hour delay has an incremental survival disadvantage for patients. Strategies to decrease these delays are urgently needed. Although routine broad-spectrum empiric coverage for these organisms would ideally limit this delay, agents with activity against these organisms are sometimes less effective, have significant toxicity risk, and their use can result in the development of resistance. Therefore, strategies to optimize therapy, although limiting unnecessary use of broad-spectrum antimicrobials, are urgently needed. This review will discuss potential strategies to optimize empiric therapy in the age of multi-drug resistance, the limitations of these strategies, and will discuss future directions and opportunities. Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Individuals with chronic low back pain demonstrate delayed onset of the back muscle activity during prone hip extension.

PubMed

Suehiro, Tadanobu; Mizutani, Masatoshi; Ishida, Hiroshi; Kobara, Kenichi; Osaka, Hiroshi; Watanabe, Susumu

2015-08-01

Prone hip extension (PHE) is commonly used in the evaluation of the stability of the lumbopelvic region. There is little evidence of difference in muscle activity onset timing between healthy individuals and individuals with chronic low back pain (CLBP) during PHE. The purpose of this study was to determine if individuals with and without CLBP differ in the onset time of the trunk and hip extensor muscles activity during PHE. The participants were 20 patients with CLBP and 20 healthy individuals. Electromyography data of the erector spinae, multifidus, gluteus maximus, and semitendinosus were collected during PHE using a surface electromyograph. Relative differences in the onset times between each muscle and the prime mover (i.e., the semitendinosus) were calculated. The onsets of the bilateral multifidus and contralateral erector spinae were significantly delayed in the CLBP group compared with the healthy group (p<0.001), despite the onset timings of leg movement not being significantly different between the groups. The onset times of the gluteus maximus and ipsilateral erector spinae showed no significant differences between the groups. These results suggest that individuals with CLBP use an altered, and possibly inadequate, trunk muscle recruitment pattern. Copyright © 2015 Elsevier Ltd. All rights reserved.

14 CFR 417.221 - Time delay analysis.

Code of Federal Regulations, 2010 CFR

2010-01-01

... OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.221 Time delay analysis. (a) General. A flight safety analysis must include a time delay analysis that establishes the mean elapsed time between the violation of a flight termination rule and the time when the flight safety system is...

14 CFR 417.221 - Time delay analysis.

Code of Federal Regulations, 2011 CFR

2011-01-01

... OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.221 Time delay analysis. (a) General. A flight safety analysis must include a time delay analysis that establishes the mean elapsed time between the violation of a flight termination rule and the time when the flight safety system is...

49 CFR 236.831 - Time, delay.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Time, delay. 236.831 Section 236.831 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Time, delay. As applied to an automatic train stop or train control system, the time which elapses...

Delay of gratification: a comparison study of children with Down syndrome, moderate intellectual disability and typical development.

PubMed

Cuskelly, M; Gilmore, L; Glenn, S; Jobling, A

2016-09-01

Self-regulation has been found to be an important contributor to a range of outcomes, with delay of gratification (a self-regulatory skill) predicting better academic, social and personal functioning. There is some evidence that individuals with Down syndrome have difficulty with delay of gratification. We investigated the question of whether this difficulty is common to intellectual disability irrespective of aetiology, or whether it presents a particular problem for those with Down syndrome. The latter was considered a possibility because of language difficulties in this group. Three groups of children with a mean MA between 36 and 60 months participated in the study: children with Down syndrome (n = 32), children with a moderate intellectual disability from a cause other than Down syndrome (n = 26) and typically developing children (n = 50). Children completed a series of measures of language and cognitive functioning and participated in a delay of gratification task. The group of children with Down syndrome delayed for a significantly shorter time than either of the other two groups that did not differ from each other. Receptive language was associated with delay time for the children with Down syndrome but not for the typically developing group, nor for the group with moderate intellectual disability. Children with Down syndrome appear to have a particular difficulty with delay of gratification. Language abilities would seem to be implicated in this difficulty, although further examination of this hypothesis is required. © 2016 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.

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

NASA Technical Reports Server (NTRS)

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

1977-01-01

An experimental study was made to determine the effect on pilot performance of time delays in the visual and motion feedback loops of a simulated pursuit tracking task. Three major interrelated factors were identified: task difficulty either in the form of airplane handling qualities or target frequency, the amount and type of motion cues, and time delay itself. In general, the greater the task difficulty, the smaller the time delay that could exist without degrading pilot performance. Conversely, the greater the motion fidelity, the greater the time delay that could be tolerated. The effect of motion was, however, pilot dependent.

Optimal estimation of parameters and states in stochastic time-varying systems with time delay

NASA Astrophysics Data System (ADS)

Torkamani, Shahab; Butcher, Eric A.

2013-08-01

In this study estimation of parameters and states in stochastic linear and nonlinear delay differential systems with time-varying coefficients and constant delay is explored. The approach consists of first employing a continuous time approximation to approximate the stochastic delay differential equation with a set of stochastic ordinary differential equations. Then the problem of parameter estimation in the resulting stochastic differential system is represented as an optimal filtering problem using a state augmentation technique. By adapting the extended Kalman-Bucy filter to the resulting system, the unknown parameters of the time-delayed system are estimated from noise-corrupted, possibly incomplete measurements of the states.

Opto-VLSI-based photonic true-time delay architecture for broadband adaptive nulling in phased array antennas.

PubMed

Juswardy, Budi; Xiao, Feng; Alameh, Kamal

2009-03-16

This paper proposes a novel Opto-VLSI-based tunable true-time delay generation unit for adaptively steering the nulls of microwave phased array antennas. Arbitrary single or multiple true-time delays can simultaneously be synthesized for each antenna element by slicing an RF-modulated broadband optical source and routing specific sliced wavebands through an Opto-VLSI processor to a high-dispersion fiber. Experimental results are presented, which demonstrate the principle of the true-time delay unit through the generation of 5 arbitrary true-time delays of up to 2.5 ns each. (c) 2009 Optical Society of America

Solar oscillation time delay measurement assisted celestial navigation method

NASA Astrophysics Data System (ADS)

Ning, Xiaolin; Gui, Mingzhen; Zhang, Jie; Fang, Jiancheng; Liu, Gang

2017-05-01

Solar oscillation, which causes the sunlight intensity and spectrum frequency change, has been studied in great detail, both observationally and theoretically. In this paper, owing to the existence of solar oscillation, the time delay between the sunlight coming from the Sun directly and the sunlight reflected by the other celestial body such as the satellite of planet or asteroid can be obtained with two optical power meters. Because the solar oscillation time delay is determined by the relative positions of the spacecraft, reflective celestial body and the Sun, it can be adopted as the navigation measurement to estimate the spacecraft's position. The navigation accuracy of single solar oscillation time delay navigation system depends on the time delay measurement accuracy, and is influenced by the distance between spacecraft and reflective celestial body. In this paper, we combine it with the star angle measurement and propose a solar oscillation time delay measurement assisted celestial navigation method for deep space exploration. Since the measurement model of time delay is an implicit function, the Implicit Unscented Kalman Filter (IUKF) is applied. Simulations demonstrate the effectiveness and superiority of this method.

System for sensing droplet formation time delay in a flow cytometer

DOEpatents

Van den Engh, Ger; Esposito, Richard J.

1997-01-01

A droplet flow cytometer system which includes a system to optimize the droplet formation time delay based on conditions actually experienced includes an automatic droplet sampler which rapidly moves a plurality of containers stepwise through the droplet stream while simultaneously adjusting the droplet time delay. Through the system sampling of an actual substance to be processed can be used to minimize the effect of the substances variations or the determination of which time delay is optimal. Analysis such as cell counting and the like may be conducted manually or automatically and input to a time delay adjustment which may then act with analysis equipment to revise the time delay estimate actually applied during processing. The automatic sampler can be controlled through a microprocessor and appropriate programming to bracket an initial droplet formation time delay estimate. When maximization counts through volume, weight, or other types of analysis exists in the containers, the increment may then be reduced for a more accurate ultimate setting. This may be accomplished while actually processing the sample without interruption.

[Cohort study on the prevalence and risk factors of late pulmonary complications in adults following a closed minor chest trauma].

PubMed

Plourde, Miville; Émond, Marcel; Lavoie, André; Guimont, Chantal; Le Sage, Natalie; Chauny, Jean-Marc; Bergeron, Éric; Vanier, Laurent; Moore, Lynne; Allain-Boulé, Nadine; Fratu, Ramona-Florina; Dufresne, Maryline

2013-11-01

The objectives of this study are to determine the prevalence, risk factors, and time to onset of delayed hemothorax and pneumothorax in adults who experienced a minor blunt thoracic trauma. A prospective cohort of 450 consecutive patients was recruited. Eligible patients had to be over 16 years of age, consulted within 72 hours for a trauma, and available for outpatient follow-up at 2, 7, and 14 days posttrauma. The clinical outcome investigated was the presence of delayed pneumothorax or hemothorax on the follow-up chest x-ray. Delayed hemothorax occurred in 11.8% (95% CI 8.8-14.8), and delayed pneumothorax occurred in 0.9% (95% CI 0.2-2.3) of participants. During the 14-day follow-up period, 87.0% of these delayed complications developed in the first week. In the multivariate analysis, the only statistically significant risk factor for delayed complications was the location of fractures on the x-ray of the hemithorax. The adjusted odds ratio was 1.52 (95% CI 0.62-3.73) for the lower ribs (tenth to twelfth rib), 3.11 (95% CI 1.60-6.08) for the midline ribs (sixth to ninth rib), and 5.05 (95% CI 1.80-14.19) for the upper ribs (third to fifth rib) versus patients with no fractures. The presence of at least one rib fracture between the third and ninth rib on the x-ray of the hemithorax is a significant risk factor for delayed hemothorax and pneumothorax.

Neurokinin B is critical for normal timing of sexual maturation but dispensable for adult reproductive function in female mice.

PubMed

True, Cadence; Nasrin Alam, Sayeda; Cox, Kimberly; Chan, Yee-Ming; Seminara, Stephanie B

2015-04-01

Humans carrying mutations in neurokinin B (NKB) or the NKB receptor fail to undergo puberty due to decreased secretion of GnRH. Despite this pubertal delay, many of these patients go on to achieve activation of their hypothalamic-pituitary-gonadal axis in adulthood, a phenomenon termed reversal, indicating that NKB signaling may play a more critical role for the timing of pubertal development than adult reproductive function. NKB receptor-deficient mice are hypogonadotropic but have no defects in the timing of sexual maturation. The current study has performed the first phenotypic evaluation of mice bearing mutations in Tac2, the gene encoding the NKB ligand, to determine whether they have impaired sexual development similar to their human counterparts. Male Tac2-/- mice showed no difference in the timing of sexual maturation or fertility compared with wild-type littermates and were fertile. In contrast, Tac2-/- females had profound delays in sexual maturation, with time to vaginal opening and first estrus occurring significantly later than controls, and initial abnormalities in estrous cycles. However, cycling recovered in adulthood and Tac2-/- females were fertile, although they produced fewer pups per litter. Thus, female Tac2-/- mice parallel humans harboring NKB pathway mutations, with delayed sexual maturation and activation of the reproductive cascade later in life. Moreover, direct comparison of NKB ligand and receptor-deficient females confirmed that only NKB ligand-deficient animals have delayed sexual maturation, suggesting that in the absence of the NKB receptor, NKB may regulate the timing of sexual maturation through other tachykinin receptors.

Tunable delay time and Hartman effect in graphene magnetic barriers

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

Ban, Yue; Wang, Lin-Jun; Chen, Xi, E-mail: xchen@shu.edu.cn

2015-04-28

Tunable group delay and Hartman effect have been investigated for massless Dirac electrons in graphene magnetic barriers. In the presence of magnetic field, dwell time is found to be equal to net group delay plus the group delay contributing from the lateral shifts. The group delay times are discussed in both cases of normal and oblique incidence, to clarify the nature of Hartman effect. In addition, the group delay in transmission can be modulated from subluminality to superluminality by adjusting the magnetic field, which may also lead to potential applications in graphene-based microelectronics.

Causes of delay in door-to-balloon time in south-east Asian patients undergoing primary percutaneous coronary intervention.

PubMed

Sim, Wen Jun; Ang, An Shing; Tan, Mae Chyi; Xiang, Wen Wei; Foo, David; Loh, Kwok Kong; Jafary, Fahim Haider; Watson, Timothy James; Ong, Paul Jau Lueng; Ho, Hee Hwa

2017-01-01

To evaluate causes and impact of delay in the door-to-balloon (D2B) time for patients undergoing primary percutaneous coronary intervention (PPCI). From January 2009 to December 2012, 1268 patients (86% male, mean age of 58 ± 12 years) presented to our hospital for ST-elevation myocardial infarction (STEMI) and underwent PPCI. They were divided into two groups: Non-delay defined as D2B time ≤ 90 mins and delay group defined as D2B time > 90 mins. Data were collected retrospectively on baseline clinical characteristics, mode of presentation, angiographic findings, therapeutic modality and inhospital outcome. 202 patients had delay in D2B time. There were more female patients in the delay group. They were older and tend to self-present to hospital. They were less likely to be smokers and have a higher prevalence of prior MI. The incidence of posterior MI was higher in the delay group. They also had a higher incidence of triple vessel disease. The 3 most common reasons for D2B delay was delay in the emergency department (39%), atypical clinical presentation (37.6%) and unstable medical condition requiring stabilisation/computed tomographic imaging (26.7%). The inhospital mortality was numerically higher in the delay group (7.4% versus 4.8%, p = 0.12). Delay in D2B occurred in 16% of our patients undergoing PPCI. Several key factors for delay were identified and warrant further intervention.

An Energy Scaled and Expanded Vector-Based Forwarding Scheme for Industrial Underwater Acoustic Sensor Networks with Sink Mobility.

PubMed

Wadud, Zahid; Hussain, Sajjad; Javaid, Nadeem; Bouk, Safdar Hussain; Alrajeh, Nabil; Alabed, Mohamad Souheil; Guizani, Nadra

2017-09-30

Industrial Underwater Acoustic Sensor Networks (IUASNs) come with intrinsic challenges like long propagation delay, small bandwidth, large energy consumption, three-dimensional deployment, and high deployment and battery replacement cost. Any routing strategy proposed for IUASN must take into account these constraints. The vector based forwarding schemes in literature forward data packets to sink using holding time and location information of the sender, forwarder, and sink nodes. Holding time suppresses data broadcasts; however, it fails to keep energy and delay fairness in the network. To achieve this, we propose an Energy Scaled and Expanded Vector-Based Forwarding (ESEVBF) scheme. ESEVBF uses the residual energy of the node to scale and vector pipeline distance ratio to expand the holding time. Resulting scaled and expanded holding time of all forwarding nodes has a significant difference to avoid multiple forwarding, which reduces energy consumption and energy balancing in the network. If a node has a minimum holding time among its neighbors, it shrinks the holding time and quickly forwards the data packets upstream. The performance of ESEVBF is analyzed through in network scenario with and without node mobility to ensure its effectiveness. Simulation results show that ESEVBF has low energy consumption, reduces forwarded data copies, and less end-to-end delay.

Early versus delayed rehabilitation treatment in hemiplegic patients with ischemic stroke: proprioceptive or cognitive approach?

PubMed

Morreale, Manuela; Marchione, Pasquale; Pili, Antonio; Lauta, Antonella; Castiglia, Stefano F; Spallone, Aldo; Pierelli, Francesco; Giacomini, Patrizia

2016-02-01

Early/intensive mobilization may improve functional recovery after stroke but it is not clear which kind of "mobilization" is more effective. Proprioceptive neuromuscular facilitation (PNF) and cognitive therapeutic exercise (CTE) are widespread applied in post-stroke rehabilitation but their efficacy and safety have not been systematically investigated. To compare PNF and CTE methods in a two different time setting (early versus standard approach) in order to evaluate different role of time and techniques in functional recovery after acute ischemic stroke. We designed a prospectical multicenter blinded interventional study of early versus standard approach with two different methods by means of both PNF and CTE. A discrete stroke-dedicated area for out-of-thrombolysis patients, connected with two different comprehensive stroke centres in two different catchment areas. Three hundred and forty consecutive stroke patient with first ever sub-cortical ischemic stroke in the mean cerebral artery (MCA) territory and contralateral hemiplegia admitted within 6 and 24 hours from symptoms onset. All patients were randomly assigned by means of a computer generated randomization sequence in blocks of 4 to one to the 4 interventional groups: early versus delayed rehabilitation programs with Kabat's schemes or Perfetti's technique. Patients in both delayed group underwent to a standard protocol in the acute phase. disability at 3-12 months. Disability measures: modified Rankin Score and Barthel Index. Safety outcome: immobility-related adverse events. Six-Minute Walking Test, Motricity Index, Mini-Mental State Examination, Beck Depression Inventory. Disability was not different between groups at 3 months but Barthel Index significantly changed between early versus delayed groups at 12 months (P=0.01). Six-Minute Walking Test (P=0.01) and Motricity Index in both upper (P=0.01) and lower limbs (P=0.001) increased in early versus delayed groups regardless rehabilitation schedule. A time-dependent effect of rehabilitation on post stroke motor recovery was observed, particularly in lower limb improvement. According to our results, rehabilitation technique seems not to affect long term motor recovery. These results show a significant effect of time but not of technique that may impact the decision making in the acute phase of care.

Delay-correlation landscape reveals characteristic time delays of brain rhythms and heart interactions

PubMed Central

Lin, Aijing; Liu, Kang K. L.; Bartsch, Ronny P.; Ivanov, Plamen Ch.

2016-01-01

Within the framework of ‘Network Physiology’, we ask a fundamental question of how modulations in cardiac dynamics emerge from networked brain–heart interactions. We propose a generalized time-delay approach to identify and quantify dynamical interactions between physiologically relevant brain rhythms and the heart rate. We perform empirical analysis of synchronized continuous EEG and ECG recordings from 34 healthy subjects during night-time sleep. For each pair of brain rhythm and heart interaction, we construct a delay-correlation landscape (DCL) that characterizes how individual brain rhythms are coupled to the heart rate, and how modulations in brain and cardiac dynamics are coordinated in time. We uncover characteristic time delays and an ensemble of specific profiles for the probability distribution of time delays that underly brain–heart interactions. These profiles are consistently observed in all subjects, indicating a universal pattern. Tracking the evolution of DCL across different sleep stages, we find that the ensemble of time-delay profiles changes from one physiologic state to another, indicating a strong association with physiologic state and function. The reported observations provide new insights on neurophysiological regulation of cardiac dynamics, with potential for broad clinical applications. The presented approach allows one to simultaneously capture key elements of dynamic interactions, including characteristic time delays and their time evolution, and can be applied to a range of coupled dynamical systems. PMID:27044991

Delay-correlation landscape reveals characteristic time delays of brain rhythms and heart interactions

NASA Astrophysics Data System (ADS)

Lin, Aijing; Liu, Kang K. L.; Bartsch, Ronny P.; Ivanov, Plamen Ch.

2016-05-01

Within the framework of `Network Physiology', we ask a fundamental question of how modulations in cardiac dynamics emerge from networked brain-heart interactions. We propose a generalized time-delay approach to identify and quantify dynamical interactions between physiologically relevant brain rhythms and the heart rate. We perform empirical analysis of synchronized continuous EEG and ECG recordings from 34 healthy subjects during night-time sleep. For each pair of brain rhythm and heart interaction, we construct a delay-correlation landscape (DCL) that characterizes how individual brain rhythms are coupled to the heart rate, and how modulations in brain and cardiac dynamics are coordinated in time. We uncover characteristic time delays and an ensemble of specific profiles for the probability distribution of time delays that underly brain-heart interactions. These profiles are consistently observed in all subjects, indicating a universal pattern. Tracking the evolution of DCL across different sleep stages, we find that the ensemble of time-delay profiles changes from one physiologic state to another, indicating a strong association with physiologic state and function. The reported observations provide new insights on neurophysiological regulation of cardiac dynamics, with potential for broad clinical applications. The presented approach allows one to simultaneously capture key elements of dynamic interactions, including characteristic time delays and their time evolution, and can be applied to a range of coupled dynamical systems.

Time-shifted synchronization of chaotic oscillator chains without explicit coupling delays.

PubMed

Blakely, Jonathan N; Stahl, Mark T; Corron, Ned J

2009-12-01

We examine chains of unidirectionally coupled oscillators in which time-shifted synchronization occurs without explicit delays in the coupling. In numerical simulations and in an experimental system of electronic oscillators, we examine the time shift and the degree of distortion (primarily in the form of attenuation) of the waveforms of the oscillators located far from the drive oscillator. Surprisingly, under weak coupling we observe minimal attenuation in spite of a significant total time shift. In contrast, at higher coupling strengths the observed attenuation increases dramatically and approaches the value predicted by an analytically derived estimate. In this regime, we verify directly that generalized synchronization is maintained over the entire chain length despite severe attenuation. These results suggest that weak coupling generally may produce higher quality synchronization in systems for which truly identical synchronization is not possible.

Accurate, fast, and secure biometric fingerprint recognition system utilizing sensor fusion of fingerprint patterns

NASA Astrophysics Data System (ADS)

El-Saba, Aed; Alsharif, Salim; Jagapathi, Rajendarreddy

2011-04-01

Fingerprint recognition is one of the first techniques used for automatically identifying people and today it is still one of the most popular and effective biometric techniques. With this increase in fingerprint biometric uses, issues related to accuracy, security and processing time are major challenges facing the fingerprint recognition systems. Previous work has shown that polarization enhancementencoding of fingerprint patterns increase the accuracy and security of fingerprint systems without burdening the processing time. This is mainly due to the fact that polarization enhancementencoding is inherently a hardware process and does not have detrimental time delay effect on the overall process. Unpolarized images, however, posses a high visual contrast and when fused (without digital enhancement) properly with polarized ones, is shown to increase the recognition accuracy and security of the biometric system without any significant processing time delay.

Intersection delay estimation from floating car data via principal curves: a case study on Beijing's road network

NASA Astrophysics Data System (ADS)

Liu, Xiliang; Lu, Feng; Zhang, Hengcai; Qiu, Peiyuan

2013-06-01

It is a pressing task to estimate the real-time travel time on road networks reliably in big cities, even though floating car data has been widely used to reflect the real traffic. Currently floating car data are mainly used to estimate the real-time traffic conditions on road segments, and has done little for turn delay estimation. However, turn delays on road intersections contribute significantly to the overall travel time on road networks in modern cities. In this paper, we present a technical framework to calculate the turn delays on road networks with float car data. First, the original floating car data collected with GPS equipped taxies was cleaned and matched to a street map with a distributed system based on Hadoop and MongoDB. Secondly, the refined trajectory data set was distributed among 96 time intervals (from 0: 00 to 23: 59). All of the intersections where the trajectories passed were connected with the trajectory segments, and constituted an experiment sample, while the intersections on arterial streets were specially selected to form another experiment sample. Thirdly, a principal curve-based algorithm was presented to estimate the turn delays at the given intersections. The algorithm argued is not only statistically fitted the real traffic conditions, but also is insensitive to data sparseness and missing data problems, which currently are almost inevitable with the widely used floating car data collecting technology. We adopted the floating car data collected from March to June in Beijing city in 2011, which contains more than 2.6 million trajectories generated from about 20000 GPS-equipped taxicabs and accounts for about 600 GB in data volume. The result shows the principal curve based algorithm we presented takes precedence over traditional methods, such as mean and median based approaches, and holds a higher estimation accuracy (about 10%-15% higher in RMSE), as well as reflecting the changing trend of traffic congestion. With the estimation result for the travel delay at intersections, we analyzed the spatio-temporal distribution of turn delays in three time scenarios (0: 00-0: 15, 8: 15-8: 30 and 12: 00-12: 15). It indicates that during one's single trip in Beijing, average 60% of the travel time on the road networks is wasted on the intersections, and this situation is even worse in daytime. Although the 400 main intersections take only 2.7% of all the intersections, they occupy about 18% travel time.

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

PubMed

Rebelo, Joao; Schiele, Andre

2015-01-01

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

75 FR 41438 - Stainless Steel Bar from India: Extension of Time Limit for the Final Results of the 2008-2009...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-16

..., following the preliminary results, the Department received additional cost information from Venus, as... a comprehensive cost analysis, significantly delaying the briefing schedule. See Memorandum from..., the Department requires additional time to review and address the detail and complexity of the cost...

Validation of early image acquisitions following Tc-99 m sestamibi injection using a semiconductors camera of cadmium-zinc-telluride.

PubMed

Meyer, Celine; Weinmann, Pierre

2017-08-01

Cadmium-zinc-telluride (CZT) cameras allow to decrease significantly the acquisition time of myocardial perfusion imaging (MPI), but the duration of the examination is still long. Therefore, this study was performed to test the feasibility of early imaging following injection of Tc-99 m sestamibi using a CZT camera. Seventy patients underwent both an early and a delayed image acquisition after exercise stress test (n = 30), dipyridamole stress test (n = 20), and at rest (n = 20). After injection of Tc-99 m sestamibi, the early image acquisition started on average within 5 minutes for the exercise and rest groups, and 3 minutes 30 seconds for the dipyridamole group. Two independent observers evaluated image quality and extracardiac uptake on four-point scales. The difference between early and later images for each patient was scored on a five-point scale. The image quality and extracardiac uptake of early and delayed image acquisitions were not different for the three groups (P > .05). There was no significant difference between early and delayed image acquisitions in the exercise, dipyridamole, and rest groups, respectively, in 63%, 40%, and 80% of cases. In the exercise group and rest group, a defect was only present in early MPI, respectively, in 13% and 20% of cases. A defect was only present in delayed images in 10% of cases in the exercise group and in 45% of cases in the dipyridamole group. There was no difference between early and later image acquisitions in terms of quality. This protocol reduces the length of the procedure for the patient. Beginning with early image acquisitions may help to overcome the artifacts that are observed at the delayed time.

Typical teleoperator time delay profiles, phase 2. [remotely controlled manipulator arms

NASA Technical Reports Server (NTRS)

Wetherington, R. D.; Walsh, J. R.

1974-01-01

The results of the second phase of a study on time delays in communications systems applicable to the teleoperator program are presented. Estimates of the maximum time delays that will be encountered and presents time delay profiles are given for (1) ground control to teleoperator in low earth orbit, (2) ground control to teleoperator in geosynchronous orbit, and (3) low earth orbit control to teleoperator in low earth orbit.

VARIABLE TIME DELAY MEANS

DOEpatents

Clemensen, R.E.

1959-11-01

An electrically variable time delay line is described which may be readily controlled simuitaneously with variable impedance matching means coupied thereto such that reflections are prevented. Broadly, the delay line includes a signal winding about a magnetic core whose permeability is electrically variable. Inasmuch as the inductance of the line varies directly with the permeability, the time delay and characteristic impedance of the line both vary as the square root of the permeability. Consequently, impedance matching means may be varied similariy and simultaneously w:th the electrically variable permeability to match the line impedance over the entire range of time delay whereby reflections are prevented.

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

NASA Technical Reports Server (NTRS)

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

1978-01-01

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

Wigner time delay and spin-orbit activated confinement resonances

NASA Astrophysics Data System (ADS)

Keating, D. A.; Deshmukh, P. C.; Manson, S. T.

2017-09-01

A study of the photoionization of spin-orbit split subshells of high-Z atoms confined in C60 has been performed using the relativistic-random-phase approximation. Specifically, Hg@C60 5p, Rn@C60 6p and Ra@C60 5d were investigated and the near-threshold confinement resonances in the j = l - 1/2 channels were found to engender structures in the j = l + 1/2 cross sections via correlation in the form of interchannel coupling. These structures are termed spin-orbit induced confinement resonances and they are found to profoundly influence the Wigner time delay spectrum resulting in time delays of tens or hundreds of attoseconds along with dramatic swings in time delay over small energy intervals. Pronounced relativistic effects in time delay are also found. These structures, including their manifestation in time delay spectra, are expected to be general phenomena in the photoionization of spin-orbit doublets in confined high-Z atoms.

Synchronization in a chaotic neural network with time delay depending on the spatial distance between neurons

NASA Astrophysics Data System (ADS)

Tang, Guoning; Xu, Kesheng; Jiang, Luoluo

2011-10-01

The synchronization is investigated in a two-dimensional Hindmarsh-Rose neuronal network by introducing a global coupling scheme with time delay, where the length of time delay is proportional to the spatial distance between neurons. We find that the time delay always disturbs synchronization of the neuronal network. When both the coupling strength and length of time delay per unit distance (i.e., enlargement factor) are large enough, the time delay induces the abnormal membrane potential oscillations in neurons. Specifically, the abnormal membrane potential oscillations for the symmetrically placed neurons form an antiphase, so that the large coupling strength and enlargement factor lead to the desynchronization of the neuronal network. The complete and intermittently complete synchronization of the neuronal network are observed for the right choice of parameters. The physical mechanism underlying these phenomena is analyzed.

Dissipativity and stability analysis of fractional-order complex-valued neural networks with time delay.

PubMed

Velmurugan, G; Rakkiyappan, R; Vembarasan, V; Cao, Jinde; Alsaedi, Ahmed

2017-02-01

As we know, the notion of dissipativity is an important dynamical property of neural networks. Thus, the analysis of dissipativity of neural networks with time delay is becoming more and more important in the research field. In this paper, the authors establish a class of fractional-order complex-valued neural networks (FCVNNs) with time delay, and intensively study the problem of dissipativity, as well as global asymptotic stability of the considered FCVNNs with time delay. Based on the fractional Halanay inequality and suitable Lyapunov functions, some new sufficient conditions are obtained that guarantee the dissipativity of FCVNNs with time delay. Moreover, some sufficient conditions are derived in order to ensure the global asymptotic stability of the addressed FCVNNs with time delay. Finally, two numerical simulations are posed to ensure that the attention of our main results are valuable. Copyright © 2016 Elsevier Ltd. All rights reserved.

Factors associated with long diagnostic delay in celiac disease.

PubMed

Fuchs, Valma; Kurppa, Kalle; Huhtala, Heini; Collin, Pekka; Mäki, Markku; Kaukinen, Katri

2014-11-01

Here, we investigated the factors associated with long diagnostic delay in celiac disease and the impact of the national Current Care Guidelines in reducing the delay. This population-based study involved 825 adult celiac disease patients. The diagnosis was considered delayed when the interval between first symptoms and diagnosis was >10 years. The patients were asked about the duration and type of symptoms before diagnosis, time and site (tertiary, secondary, or primary care) of the diagnosis, family history of the disease, and presence of significant comorbidities. Analysis was performed by binary logistic regression. Altogether, 261 (32%) out of 825 participants reported a diagnostic delay of >10 years. Female gender, neurological or musculoskeletal disorders and presence of diarrhea, abdominal pain, and malabsorption were associated with prolonged delay. Male gender, diagnosis after the introduction of the first Current Care Guidelines in 1997, and being detected by serological screening, and family history of celiac disease were associated with a lower risk of delayed diagnosis. Factors not associated with the delay were site of diagnosis, age, and presence of dermatitis herpetiformis, type 1 diabetes, or thyroidal disease. The number of long diagnostic delays in celiac disease has decreased over the past decades. The shift of diagnostics from secondary and tertiary care to primary care has not been detrimental. National guidelines together with increased awareness and active screening in at-risk groups of celiac disease are important in these circumstances.

[Overall treatment time assessment of radiotherapy delivered in a curative intent: A prospective study].

PubMed

Petit, C; Suissa, A; Finet, A; Comte, A; Soltys, B; Daveau, C; Ali, D; Dessard-Diana, B; Giraud, P; Housset, M; Durdux, C

2015-12-01

To assess the overall treatment time of radiotherapy delivered with curative intent in a cohort of 185 consecutive patients and the causes of this possible delay. If delay, to propose corrective actions. We report a single-center prospective study including all consecutive patients receiving a radiation therapy with curative intent, from 1st December 2013 to 28th February 2014, on the three linear accelerators of the radiotherapy department. For each fraction missed, the causes of non-completion were prospectively collected. This analysis took into account the following parameters: age, sex, occupation, transport type and duration, tumour localization, radiation dose, concomitant chemotherapy, hospitalization, type of linear accelerator. One hundred and fifty-five patients were included in the study (183 evaluable, two did not complete treatment). The overall treatment time was respected for 31 patients (17%). It was lengthened on 4.6 days (d) (0-29 d; median: 3d). The mean number of delayed fractions was 3.4 (0-17; median: 2). The reasons of delay were: breakdown 32.2%; maintenance 29.3%; holiday 11%; treatment toxicity 9.4%; inadequate planning 8.6%; other disease 3.9%; treatment refusal 2.1%; unspecified personal reasons 1.5%; refusal to wait 0.8%; transportation 0.3%; error of communication 0.3%; other 0.6%. Two parameters had a significant impact on the overall treatment time: the type of linear accelerator in relation to breakdown occurrence (P<0.001) and transportation duration (more or less than 40 min, P=0.022). One hundred and thirty-eight patients (75%) and 79 patients (43%) were treated on one or more than two Saturdays. Treatment on Saturday significantly reduced the overall treatment time (median, 1.9 d; P<0.001). The overall treatment time was globally respected excluding break down and maintenance. Their impact on the overall treatment time is minimized by the systematic opening of the department on Saturdays. Copyright © 2015 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

External fixation combined with delayed internal fixation in treatment of tibial plateau fractures with dislocation

PubMed Central

Tao, Xingguang; Chen, Nong; Pan, Fugen; Cheng, Biao

2017-01-01

Abstract The aim of this study was to evaluate the clinical efficacy of external fixation, delayed open reduction, and internal fixation in treating tibial plateau fracture with dislocation. Clinical data of 34 patients diagnosed with tibial plateau fracture complicated with dislocation between January 2009 and May 2015 were retrospectively analyzed. Fifteen patients in group A underwent early calcaneus traction combined with open reduction and internal fixation and 19 in group B received early external fixation combined with delayed open reduction and internal fixation. Operation time, postoperative complication, bone healing time, knee joint range of motion, initial weight-bearing time, Rasmussen tibial plateau score, and knee function score (HSS) were statistically compared between 2 groups. The mean follow-up time was 18.6 months (range: 5–24 months). The mean operation time in group A was 96 minutes, significantly longer than 71 minutes in group B (P < .05). In group A, 5 cases had postoperative complications and 1 in group B (P < .05). The mean bone healing time in group A was 6.9 months (range: 5–9 months) and 6.0 months (range: 5–8 months) in group B (P > .05). In group A, initial weight-bearing time in group A was (14.0 ± 3.6) weeks, significantly differing from (12.9 ± 2.8) weeks in group B (P < 0.05). In group A, the mean knee joint range of motion was 122° (range: 95°–150°) and 135° (range: 100°–160°) in group B (P > 0.05). Rasmussen tibial plateau score in group A was slightly lower than that in group B (P > .05). The excellent rate of knee joint function in group A was 80% and 84.21% in group B (P > .05). External fixation combined with delayed open reduction and internal fixation is a safer and more efficacious therapy of tibial plateau fracture complicated with dislocation compared with early calcaneus traction and open reduction and internal fixation. PMID:29019890

External fixation combined with delayed internal fixation in treatment of tibial plateau fractures with dislocation.

PubMed

Tao, Xingguang; Chen, Nong; Pan, Fugen; Cheng, Biao

2017-10-01

The aim of this study was to evaluate the clinical efficacy of external fixation, delayed open reduction, and internal fixation in treating tibial plateau fracture with dislocation.Clinical data of 34 patients diagnosed with tibial plateau fracture complicated with dislocation between January 2009 and May 2015 were retrospectively analyzed. Fifteen patients in group A underwent early calcaneus traction combined with open reduction and internal fixation and 19 in group B received early external fixation combined with delayed open reduction and internal fixation. Operation time, postoperative complication, bone healing time, knee joint range of motion, initial weight-bearing time, Rasmussen tibial plateau score, and knee function score (HSS) were statistically compared between 2 groups.The mean follow-up time was 18.6 months (range: 5-24 months). The mean operation time in group A was 96 minutes, significantly longer than 71 minutes in group B (P < .05). In group A, 5 cases had postoperative complications and 1 in group B (P < .05). The mean bone healing time in group A was 6.9 months (range: 5-9 months) and 6.0 months (range: 5-8 months) in group B (P > .05). In group A, initial weight-bearing time in group A was (14.0 ± 3.6) weeks, significantly differing from (12.9 ± 2.8) weeks in group B (P < 0.05). In group A, the mean knee joint range of motion was 122° (range: 95°-150°) and 135° (range: 100°-160°) in group B (P > 0.05). Rasmussen tibial plateau score in group A was slightly lower than that in group B (P > .05). The excellent rate of knee joint function in group A was 80% and 84.21% in group B (P > .05).External fixation combined with delayed open reduction and internal fixation is a safer and more efficacious therapy of tibial plateau fracture complicated with dislocation compared with early calcaneus traction and open reduction and internal fixation.

Developing and Evaluating Computer-Based Teamwork Skills Training for Long-Duration Spaceflight Crews

ERIC Educational Resources Information Center

Hixson, Katharine

2013-01-01

Due to the long-duration and long distance nature of future exploration missions, coupled with significant communication delays from ground-based personnel, NASA astronauts will be living and working within confined, isolated environments for significant periods of time. This extreme environment poses concerns for the flight crews' ability to…

Delayed Post-ischemic Conditioning Significantly Improves the Outcome after Retinal Ischemia

PubMed Central

Dreixler, John C.; Poston, Jacqueline N.; Shaikh, Afzhal R.; Alexander, Michael; Tupper, Kelsey Y.; Marcet, Marcus M.; Bernaudin, Myriam; Roth, Steven

2011-01-01

In previous studies, it was shown that post-conditioning, a transient period of brief ischemia following prolonged severe ischemia in the retina, could provide significant improvement in post-ischemic recovery, attenuation of cell loss, and decreased apoptosis. These studies showed that post-conditioning effectively prevented damage after retinal ischemia when it was instituted early (within one hour) in the post-ischemic period. While post-ischemic conditioning holds high promise of clinical translation, patients often present late after the onset of retinal ischemia and therefore immediate application of this anti-ischemic maneuver is generally not feasible. In this study, we examined the hypothesis that application of a post-conditioning stimulus at 24 h or greater following the end of prolonged ischemia would decrease the extent of ischemic injury. Ischemia was induced in rat retina in vivo. Recovery after ischemia followed by 5 minutes of post-conditioning brief ischemia 24 or 48 h after prolonged ischemia was assessed functionally (electroretinography) and histologically at 7 days after ischemia and post-conditioning or sham post-conditioning. We found that the brief ischemic stimulus applied 24, but not 48 h after prolonged ischemia significantly improved functional recovery and decreased histological damage induced by prolonged ischemia. We conclude that within a defined time window, delayed post-ischemic conditioning ameliorated post-ischemic injury in rats. Compared to earlier studies, the present work demonstrates for the first time the novel ability of a significantly delayed ischemic stimulus to provide robust neuroprotection in the retina following ischemia. PMID:21501608

Comparison of filgrastim and pegfilgrastim to prevent neutropenia and maintain dose intensity of adjuvant chemotherapy in patients with breast cancer.

PubMed

Kourlaba, Georgia; Dimopoulos, Meletios A; Pectasides, Dimitrios; Skarlos, Dimosthenis V; Gogas, Helen; Pentheroudakis, George; Koutras, Angelos; Fountzilas, George; Maniadakis, Nikos

2015-07-01

The aim of this study was to compare the effectiveness of prophylactic single fixed dose of pegfilgrastim and daily administration of filgrastim on febrile neutropenia (FN), severe neutropenia, treatment delay, and dose reduction in patients with breast cancer receiving dose-dense adjuvant chemotherapy. A retrospective cohort study with 1058 breast cancer patients matched by age and chemotherapy was conducted. The primary endpoints were FN, severe (grade 3, 4) neutropenia, dose reduction (>10 % reduction of the dose planned), and treatment delay (dose given more than 2 days later). Eighteen episodes of FN (3.4%) in the filgrastim group and 23 (4.3%) in the pegfilgrastim group (p = 0.500) were recorded. More than half of the total episodes (27/41) occurred during the first 4 cycles of treatment. Patients who received filgrastim were almost three times more likely to experience a severe neutropenia episode and were significantly more likely to experience a dose reduction (18.5%) compared to those who received pegfilgrastim (10.8%) (p < 0.001). The percentage of patients, who received their planned dose on time, was significantly lower in patients receiving filgrastim (58%) compared to those receiving pegfilgrastim (72.4%, p < 0.001). No significant difference was detected on FN rate between daily administration of filgrastim and single administration of pegfilgrastim. However, patients receiving pegfilgrastim had a significantly lower rate of severe neutropenia, as well as dose reduction and treatment delay, thus, achieving a higher dose density.

Influence of postmortem time on the outcome of blood cultures among cadaveric tissue donors.

PubMed

Saegeman, V; Verhaegen, J; Lismont, D; Verduyckt, B; De Rijdt, T; Ectors, N

2009-02-01

Tissue banks provide tissues of human cadaver donors for transplantation. The maximal time limit for tissue retrieval has been set at 24 h postmortem. This study aimed at evaluating the evidence for this limit from a microbiological point of view. The delay of growth in postmortem blood cultures, the identification of the species isolated and clinical/environmental factors were investigated among 100 potential tissue donors. No significant difference was found in the rate of donors with grown blood cultures within (25/65=38%) compared with after (24/65=37%) 24 h of death. Coagulase-negative staphylococci and gastro-intestinal microorganisms were isolated within and after 24 h of death. Two factors--antimicrobial therapy and "delay before body cooling"--were significantly inversely related with donors' blood culture results. From a microbiological point of view, there is no evidence for avoiding tissue retrieval among donors after 24 h of death.

Diagnostic Delay Is Associated with a Greater Risk of Early Surgery in a French Cohort of Crohn's Disease Patients.

PubMed

Nahon, Stéphane; Lahmek, Pierre; Paupard, Thierry; Lesgourgues, Bruno; Chaussade, Stanislas; Peyrin-Biroulet, Laurent; Abitbol, Vered

2016-11-01

To investigate whether a diagnostic delay is associated with a poor outcome in Crohn's disease (CD). Medical and socioeconomic characteristics as well as medications and need for surgery of consecutive CD adults patients followed in three referral centers were prospectively recorded using an electronic database (Focus_MICI ® ). A long diagnostic delay was defined by the upper quartile. We compared patients with long diagnostic delay to those with earlier diagnosis regarding the time to: (1) first intestinal surgery, (2) first use of immunosuppressants (IMSs), and (3) first use of anti-tumor necrosis factor (anti-TNF) therapy using the Kaplan-Meier test and the log-rank test. A total of 497 patients with CD (53.6 % women) were analyzed. Median diagnostic delay was 5 months (IQR 25-75 %: 2-13 months). Median follow-up was 9 years (IQR 4-16.2), and 148 (29.8 %) patients had major surgery. There were no significant differences between patients with late and early diagnosis regarding age at diagnosis, disease phenotype, need for IMS therapy, and need for anti-TNF therapy. Time to first major surgery was shorter in patients with late diagnosis (p = 0.05). In this large multicenter prospective cohort of French CD patients, a long diagnostic delay (>13 months) increased the risk of early surgery. No associated factors could be identified in this study.

Pastoralism and delay in diagnosis of TB in Ethiopia

PubMed Central

Gele, Abdi A; Bjune, Gunnar; Abebe, Fekadu

2009-01-01

Background Tuberculosis (TB) is a major public health problem in the Horn of Africa with Ethiopia being the most affected where TB cases increase at the rate of 2.6% each year. One of the main contributing factors for this rise is increasing transmission due to large number of untreated patients, serving as reservoirs of the infection within the communities. Reduction of the time between onset of TB symptoms to diagnosis is therefore a prerequisite to bring the TB epidemic under control. The aim of this study was to measure duration of delay among pastoralist TB patients at TB management units in Somali Regional State (SRS) of Ethiopia. Methods A cross sectional study of 226 TB patients with pastoralist identity was conducted in SRS of Ethiopia from June to September 2007. Patients were interviewed using questionnaire based interview. Time between onset of TB symptoms and first visit to a professional health care provider (patient delay), and the time between first visits to the professional health care provider to the date of diagnosis (medical provider's delay) were analyzed. Both pulmonary and extrapulmonary TB patients were included in the study. Result A total of 226 pastoralist TB patients were included in this study; 93 (41.2%) were nomadic pastoralists and 133 (58.8%) were agro-pastoralists. Median patient delay was found to be 60 days with range of 10–1800 days (83 days for nomadic pastoralists and 57 days for agro-pastoralists). Median health care provider's delay was 6 days and median total delay was 70 days in this study. Patient delay constituted 86% of the total delay. In multivariate logistic regression analysis, nomadic pastoralism (aOR. 2.69, CI 1.47–4.91) and having low biomedical knowledge on TB (aOR. 2.02, CI 1.02–3.98) were significantly associated with prolonged patient delay. However, the only observed risk factor for very long patient delay >120 days was distance to health facility (aOR.4.23, CI 1.32–13.54). Extra-pulmonary TB was the only observed predictor for health care providers' delay (aOR. 3.39, CI 1.68–6.83). Conclusion Patient delay observed among pastoralist TB patients in SRS is one of the highest reported so far from developing countries, exceeding two years in some patients. This long patient delay appears to be associated with patient's inadequate knowledge of the disease and distance to health care facility with nomadic pastoralists being the most affected. Regional TB control programmes need to consider the exceptional circumstances of pastoralists, to maximise their access to TB services. PMID:19128498

Resolution of tracheal aspiration after the acute phase of stroke-related oropharyngeal Dysphagia.

PubMed

Terré, Rosa; Mearin, Fermín

2009-04-01

We set out to ascertain the evolution and the clinical and videofluoroscopic (VFS) prognostic factors of aspiration recovery and return to oral intake in patients with stroke and VFS diagnosis of tracheal aspiration. Twenty patients with stroke and VFS diagnosis of tracheal aspiration were prospectively evaluated. Clinical evaluation of oropharyngeal dysphagia and VFS examination were performed at admission and repeated at 1, 3, 6 and 12 months of follow-up. At admission, videofluoroscopy showed 40% of patients to have an increase in oral transit time and 65% impaired tongue control; in the pharyngeal phase, mean pharyngeal transit time was increased in 70% of patients and the time required to trigger the swallowing reflex was delayed in 70%. During follow-up, an improvement was observed, and the number of patients with aspiration decreased progressively (the most significant change occurred at 6 months). Evolution was related to the vascular territory affected: at 1 year, aspiration persisted in 12% of anterior territory lesions vs. 58% of posterior territory lesions. Also, the number of silent aspirators decreased from 35% at baseline to no patients after 3 months. Persistent aspiration at 1 year of follow-up significantly correlated with the following baseline variables: vascular territory, gag reflex abolition, palatoglossal seal alteration and pharyngeal delay time. Swallowing physiology in stroke greatly improved during follow-up, mainly between 3 and 6 months, and the number of aspirations decreased progressively. Prognostic factors for persisting aspiration are posterior vascular territory lesions, oropharyngeal reflex abolition, palatoglossal seal alteration and pharyngeal delay time at baseline.

The impact of command signal power distribution, processing delays, and speed scaling on neurally-controlled devices.

PubMed

Marathe, A R; Taylor, D M

2015-08-01

Decoding algorithms for brain-machine interfacing (BMI) are typically only optimized to reduce the magnitude of decoding errors. Our goal was to systematically quantify how four characteristics of BMI command signals impact closed-loop performance: (1) error magnitude, (2) distribution of different frequency components in the decoding errors, (3) processing delays, and (4) command gain. To systematically evaluate these different command features and their interactions, we used a closed-loop BMI simulator where human subjects used their own wrist movements to command the motion of a cursor to targets on a computer screen. Random noise with three different power distributions and four different relative magnitudes was added to the ongoing cursor motion in real time to simulate imperfect decoding. These error characteristics were tested with four different visual feedback delays and two velocity gains. Participants had significantly more trouble correcting for errors with a larger proportion of low-frequency, slow-time-varying components than they did with jittery, higher-frequency errors, even when the error magnitudes were equivalent. When errors were present, a movement delay often increased the time needed to complete the movement by an order of magnitude more than the delay itself. Scaling down the overall speed of the velocity command can actually speed up target acquisition time when low-frequency errors and delays are present. This study is the first to systematically evaluate how the combination of these four key command signal features (including the relatively-unexplored error power distribution) and their interactions impact closed-loop performance independent of any specific decoding method. The equations we derive relating closed-loop movement performance to these command characteristics can provide guidance on how best to balance these different factors when designing BMI systems. The equations reported here also provide an efficient way to compare a diverse range of decoding options offline.

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

NASA Technical Reports Server (NTRS)

Walsh, Kevin R.

1993-01-01

A flight evaluation was conducted to determine the effect of engine throttle response characteristics on precision formation-flying qualities. A variable electronic throttle control system was developed and flight-tested on a TF-104G airplane with a J79-11B engine at the NASA Dryden Flight Research Facility. This airplane was chosen because of its known, very favorable thrust response characteristics. Ten research flights were flown to evaluate the effects of throttle gain, time delay, and fuel control rate limiting on engine handling qualities during a demanding precision wing formation task. Handling quality effects of lag filters and lead compensation time delays were also evaluated. The Cooper and Harper Pilot Rating Scale was used to assign levels of handling quality. Data from pilot ratings and comments indicate that throttle control system time delays and rate limits cause significant degradations in handling qualities. Threshold values for satisfactory (level 1) and adequate (level 2) handling qualities of these key variables are presented. These results may provide engine manufacturers with guidelines to assure satisfactory handling qualities in future engine designs.

Managing Science Operations during Planetary Surface Operations at Long Light Delay-Time Targets: The 2011 Desert RATS Test

NASA Technical Reports Server (NTRS)

Eppler, D. B.

2012-01-01

Desert Research and Technology Studies (Desert RATS) is a multi-year series of hardware and operations tests carried out annually in the high desert of Arizona in the San Francisco Volcanic Field. Conducted since 1997, these activities are designed to exercise planetary surface hardware and operations in conditions where multi-day tests are achievable. Desert RATS 2011 Science Operations Test simulated the management of crewed science operations at targets that were beyond the light delay time experienced during Low-Earth Orbit (LEO) and lunar surface missions, such as a mission to a Near-Earth Object (NEO) or the martian surface. Operations at targets at these distances are likely to be the norm as humans move out of the Earth-Moon system. Operating at these distances places significant challenges on mission operations, as the imposed light-delay time makes normal, two-way conversations extremely inefficient. Consequently, the operations approach for space missions that has been exercised during the first half-century of human space operations is no longer viable, and new approaches must be devised.

Treatment of psychosis in prisons and violent recidivism

PubMed Central

Kallis, Constantinos; Coid, Jeremy

2015-01-01

Background Violence among released prisoners with psychosis is an important public health problem. It is unclear whether treatment in prison can influence criminal behaviour subsequent to release. Aims To investigate whether treatment in prison can delay time to reoffending. Method Our sample consisted of 1717 adult prisoners in England and Wales convicted of a serious violent or sexual offence. We used Cox regression to investigate the effects of treatment received in prison on associations between mental illness and time to first reconviction following release. Results Prisoners with current symptoms of schizophrenia reoffended quicker following release. Nevertheless, treatment with medication significantly delayed time to violence (18% reduction). Treatment for substance dependence delayed violent and non-violent reoffending among prisoners with drug-induced psychosis. Conclusions Identifying prisoners with psychosis and administering treatment in prison have important protective effects against reoffending. Repeated screening with improved accuracy in identification is necessary to prevent cases being missed. Declaration of interest None. Copyright and usage © The Royal College of Psychiatrists 2015. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) licence. PMID:27703740

[Changes in clinic-epidemiological characteristics of new cases of HIV-1 infection in Castellón (Spain), and its impact on delayed presentation (1987-2011)].

PubMed

Mínguez-Gallego, Carlos; Vera-Remartinez, Enrique J; Albert-Coll, Monica; Roldán-Puchalt, M Concepción; Aguilar-Climent, Manuel; Rovira-Ferrando, Rosa E; Andrés-Soler, Jorge; Roig-Espert, Belén; Penadés-Vidal, María; Usó-Blasco, Jorge

2015-03-01

To describe the trend of the clinical and epidemiological characteristics of a cohort of HIV-1 infected patients in Castellón (Spain), and its impact on the delayed presentation. Data from HIV-1 infected outpatients presenting for care for the first time between 1987 and 2011 were retrospectively analyzed. There have been significant changes in the characteristics of the 1001 newly presented patients during the period studied. An increase in the mean age was observed (increasing from about 30 years before 1996, to approximately 35 after the 2000-2002 period), as well as an increase in the percentage of immigrants (<2% before 1997, to 50% in the 2009-2011 period), and a decline in the proportion of intravenous drug use as the main transmission route (changing from being 92.3% before 1988 to below 20% after the 2003-2005 period), together with a decrease in the proportion of hepatitis-C coinfection. The rate of late presentation has not significantly changed, being 47.1% in the period studied. Factors associated with this late presentation were: older age, hospital diagnosis, an increased delay between estimated infection time and diagnosis, and between diagnosis and initial presentation. The epidemiology of HIV-1 infection in our area has dramatically changed since the beginning of the disease. The increasing delay between estimated infection time and diagnosis is an important cause of the lack of variation in the late presentation rate, and highlights the low impact of early diagnosis strategies. Copyright © 2013 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Timeliness of lung cancer care in Victoria: a retrospective cohort study.

PubMed

Evans, Sue M; Earnest, Arul; Bower, Wendy; Senthuren, Meera; McLaughlin, Peta; Stirling, Rob

2016-02-01

To assess factors associated with second-line delays in the management of patients diagnosed with lung cancer. A retrospective cohort study, conducted in six public and two private Victorian hospitals, of 1417 patients aged 18 years or more who were diagnosed between July 2011 and October 2014 with an incident case of lung cancer identified by International Classification of Diseases, 10th revision codes (C34.0-C34.9, Z85.1, Z85.2) on the basis of either a clinical or pathological diagnosis. Time intervals between referral, diagnosis and initial definitive management. The median time from referral to diagnosis was 15 days (interquartile range [IQR], 5-36); from diagnosis to initial definitive management, 30 days (IQR, 6-84); and from referral to initial definitive management, 53 days (IQR, 25-106). Factors that were significantly associated with delay between referral and initial definitive management include declining or not being referred to palliative care (hazard ratio [HR], v patients referred for palliation, 0.73; 95% CI, 0.62-0.86; P < 0.001), and being treated in a public hospital (HR, v patients managed in a private hospital, 0.55; 95% CI, 0.48-0.64; P < 0.001). The median time from referral to initial definitive management in public and private hospitals was 61 days (IQR, 35-118) and 30 days (IQR, 13-76) respectively; 48% of patients in public hospitals waited longer than the British National Health Service target of a maximum 62 days between referral and first definitive treatment. There are significant delays at various stages of the patient journey after referral for initial definitive management. Having a greater understanding of these delays will enable strategies to be developed that improve the timeliness of care for patients with lung cancer.

Estimating tropospheric phase delay in SAR interferograms using Global Atmospheric Models

NASA Astrophysics Data System (ADS)

Doin, M.; Lasserre, C.; Peltzer, G.; Cavalie, O.; Doubre, C.

2008-12-01

The main limiting factor on the accuracy of Interferometric SAR (InSAR) measurements comes from phase propagation delays through the Earth's troposphere. The delay can be divided into a stratified component, which correlates with the topography and often dominates the tropospheric signal in InSAR data, and a turbulent component. The stratified delay can be expressed as a function of atmospheric pressure P, temperature T, and water vapor partial pressure e vertical profiles. We compare the stratified delay computed using results from global atmospheric models with the topography-dependent signal observed in interferograms covering three test areas in different geographic and climatic environments: Lake Mead, Nevada, USA, the Haiyuan fault area, Gansu, China, and Afar, Republic of Djibouti. For each site we compute a multi-year series of interferograms. The phase-elevation ratio is estimated for each interferogram and the series is inverted to form a timeline of delay-elevation ratios characterizing each epoch of data acquisition. InSAR derived ratios are in good agreement with the ratios computed from global atmospheric models. This agreement shows that both estimations of the delay-elevation ratio can be used to perform a first order correction of the InSAR phase. Seasonal variations of the atmosphere significantly affect the phase delay throughout the year, aliasing the results of time series inversions using temporal smoothing or data stacking when the acquisitions are not evenly distributed in time. This is particularly critical when the spatial shape of the signal of interest correlates with topography. In the Lake Mead area, the irregular temporal sampling of our SAR data results in an interannual bias of amplitude ~2~cm on range change estimates. In the Haiyuan Fault area, the coarse and uneven data sampling results in a bias of up to ~0.5~cm/yr on the line of sight velocity across the fault. In the Afar area, the seasonal signal exceeds the deformation signal in the phase time series. In all cases, correcting interferograms from the stratified delay helps removing these biases. Finally we suggest that the phase delay correction can potentially be improved by introducing a non-linear dependance to the elevation, as consistent non-linear relationships are observed in many interferograms as well as in global atmospheric models.

A New Zenith Tropospheric Delay Grid Product for Real-Time PPP Applications over China.

PubMed

Lou, Yidong; Huang, Jinfang; Zhang, Weixing; Liang, Hong; Zheng, Fu; Liu, Jingnan

2017-12-27

Tropospheric delay is one of the major factors affecting the accuracy of electromagnetic distance measurements. To provide wide-area real-time high precision zenith tropospheric delay (ZTD), the temporal and spatial variations of ZTD with altitude were analyzed on the bases of the latest meteorological reanalysis product (ERA-Interim) provided by the European Center for Medium-Range Weather Forecasts (ECMWF). An inverse scale height model at given locations taking latitude, longitude and day of year as inputs was then developed and used to convert real-time ZTD at GPS stations in Crustal Movement Observation Network of China (CMONOC) from station height to mean sea level (MSL). The real-time ZTD grid product (RtZTD) over China was then generated with a time interval of 5 min. Compared with ZTD estimated in post-processing mode, the bias and error RMS of ZTD at test GPS stations derived from RtZTD are 0.39 and 1.56 cm, which is significantly more accurate than commonly used empirical models. In addition, simulated real-time kinematic Precise Point Positioning (PPP) tests show that using RtZTD could accelerate the BDS-PPP convergence time by up to 32% and 65% in the horizontal and vertical components (set coordinate error thresholds to 0.4 m), respectively. For GPS-PPP, the convergence time using RtZTD can be accelerated by up to 29% in the vertical component (0.2 m).

Long-time behavior for suspension bridge equations with time delay

NASA Astrophysics Data System (ADS)

Park, Sun-Hye

2018-04-01

In this paper, we consider suspension bridge equations with time delay of the form u_{tt}(x,t) + Δ ^2 u (x,t) + k u^+ (x,t) + a_0 u_t (x,t) + a_1 u_t (x, t- τ ) + f(u(x,t)) = g(x). Many researchers have studied well-posedness, decay rates of energy, and existence of attractors for suspension bridge equations without delay effects. But, as far as we know, there is no work about suspension equations with time delay. In addition, there are not many studies on attractors for other delayed systems. Thus we first provide well-posedness for suspension equations with time delay. And then show the existence of global attractors and the finite dimensionality of the attractors by establishing energy functionals which are related to the norm of the phase space to our problem.

Robust outer synchronization between two nonlinear complex networks with parametric disturbances and mixed time-varying delays

NASA Astrophysics Data System (ADS)

Zhang, Chuan; Wang, Xingyuan; Luo, Chao; Li, Junqiu; Wang, Chunpeng

2018-03-01

In this paper, we focus on the robust outer synchronization problem between two nonlinear complex networks with parametric disturbances and mixed time-varying delays. Firstly, a general complex network model is proposed. Besides the nonlinear couplings, the network model in this paper can possess parametric disturbances, internal time-varying delay, discrete time-varying delay and distributed time-varying delay. Then, according to the robust control strategy, linear matrix inequality and Lyapunov stability theory, several outer synchronization protocols are strictly derived. Simple linear matrix controllers are designed to driver the response network synchronize to the drive network. Additionally, our results can be applied on the complex networks without parametric disturbances. Finally, by utilizing the delayed Lorenz chaotic system as the dynamics of all nodes, simulation examples are given to demonstrate the effectiveness of our theoretical results.

Autonomous Mission Operations Roadmap

NASA Technical Reports Server (NTRS)

Frank, Jeremy David

2014-01-01

As light time delays increase, the number of such situations in which crew autonomy is the best way to conduct the mission is expected to increase. However, there are significant open questions regarding which functions to allocate to ground and crew as the time delays increase. In situations where the ideal solution is to allocate responsibility to the crew and the vehicle, a second question arises: should the activity be the responsibility of the crew or an automated vehicle function? More specifically, we must answer the following questions: What aspects of mission operation responsibilities (Plan, Train, Fly) should be allocated to ground based or vehicle based planning, monitoring, and control in the presence of significant light-time delay between the vehicle and the Earth?How should the allocated ground based planning, monitoring, and control be distributed across the flight control team and ground system automation? How should the allocated vehicle based planning, monitoring, and control be distributed between the flight crew and onboard system automation?When during the mission should responsibility shift from flight control team to crew or from crew to vehicle, and what should the process of shifting responsibility be as the mission progresses? NASA is developing a roadmap of capabilities for Autonomous Mission Operations for human spaceflight. This presentation will describe the current state of development of this roadmap, with specific attention to in-space inspection tasks that crews might perform with minimum assistance from the ground.

Switchgrass Biomass Quality as Affected by Nitrogen Rate, Harvest Time, and Storage

DOE PAGES

Ibrahim, Mostafa; Hong, Chang Oh.; Singh, Shikha; ...

2017-01-25

The purpose of this study was to assess the changes in switchgrass (Panicum virgatum L.) biomass quality as affected by N rate, harvest time, and storage. This research was conducted near Bristol, SD, in 2010 and 2011. Treatments included three N rates (0, 56, and 112 kg N ha –1) applied annually and each N rate replicated four times. After a killing frost, all of the plots were harvested and baled in large round bales in October 2010 and November 2011. An area of about 30 m 2 from each plot was left unharvested to represent storage of standing switchgrassmore » over the winter and to determine dry matter yields. Switchgrass was analyzed for hemicellulose, cellulose, lignin, mineral elements, N, and C. In the first season, storage of the fall harvested switchgrass bales numerically increased the concentrations of hemicellulose, lignin, and N. In the second season, they increased significantly. Mineral elements significantly increased in both sampling seasons. Delaying harvest until spring decreased lignin, N, and mineral elements concentration, and increased cellulose and hemicellulose concentrations, but also reduced biomass yield. Results from this study suggest that delaying the switchgrass harvest until spring increased the overall feedstock quality for ethanol production, but yield reductions must be considered to determine the overall economic impact of a delayed harvest.« less

Switchgrass Biomass Quality as Affected by Nitrogen Rate, Harvest Time, and Storage

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

Ibrahim, Mostafa; Hong, Chang Oh.; Singh, Shikha

The purpose of this study was to assess the changes in switchgrass (Panicum virgatum L.) biomass quality as affected by N rate, harvest time, and storage. This research was conducted near Bristol, SD, in 2010 and 2011. Treatments included three N rates (0, 56, and 112 kg N ha –1) applied annually and each N rate replicated four times. After a killing frost, all of the plots were harvested and baled in large round bales in October 2010 and November 2011. An area of about 30 m 2 from each plot was left unharvested to represent storage of standing switchgrassmore » over the winter and to determine dry matter yields. Switchgrass was analyzed for hemicellulose, cellulose, lignin, mineral elements, N, and C. In the first season, storage of the fall harvested switchgrass bales numerically increased the concentrations of hemicellulose, lignin, and N. In the second season, they increased significantly. Mineral elements significantly increased in both sampling seasons. Delaying harvest until spring decreased lignin, N, and mineral elements concentration, and increased cellulose and hemicellulose concentrations, but also reduced biomass yield. Results from this study suggest that delaying the switchgrass harvest until spring increased the overall feedstock quality for ethanol production, but yield reductions must be considered to determine the overall economic impact of a delayed harvest.« less

Effects of delayed cord clamping on the third stage of labour, maternal haematological parameters and acid-base status in fetuses at term.

PubMed

De Paco, Catalina; Herrera, Javier; Garcia, Carolina; Corbalán, Shiana; Arteaga, Alicia; Pertegal, Miriam; Checa, Rosario; Prieto, María Teresa; Nieto, Aníbal; Delgado, Juan Luis

2016-12-01

To compare the time in the third stage of labour, differences in maternal hematologic parameters 48h after birth and acid-base status in the umbilical cord between the early cord clamping (ECC) and delayed cord clamping (DCC). 97 healthy pregnancies at term and a spontaneous vertex delivery at Clinic University Hospital "Virgen de la Arrixaca" (Murcia, Spain), were randomized to ECC group (<10s post-delivery) or to DCC group (2min post-delivery). Duration of the third stage of labour was measured. Samples for acid-base status were taken both from the umbilical artery and vein. Blood samples were taken from the mothers 48h after birth. No statistical differences were found in the time of the third stage of labour (p=0.35). No statiscally significant differences were found between the number of red cells (p=0.25), hemoglobin (p=0.08) or hematocrit (p=0.15) in mothers. Umbilical acid-base status or gas analysis did not show any differences between the two groups CONCLUSIONS: Delayed cord clamping does not affect significantly the time of the third stage of labour. It does not show either any effect on the hematological parameters in the mother 48h after birth. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Biphasic Effects of Alcohol on Delay and Probability Discounting

PubMed Central

Bidwell, L. Cinnamon; MacKillop, James; Murphy, James G.; Grenga, Andrea; Swift, Robert M.; McGeary, John E.

2014-01-01

Delay discounting and probability discounting are behavioral economic indices of impulsive and risky decision making that have been associated with addictive behavior, but the acute biphasic effects of alcohol on these decision-making processes are not well understood. This study sought to investigate the biphasic effects of alcohol on delay and probability discounting across the ascending and descending limbs of the breath alcohol concentration (BAC) curve, which are respectively characterized by the stimulant and sedative effects of alcohol. Delay and probability discounting were measured at four time points (Baseline, Ascending, Descending, and Endpoint) across the BAC curve at two target alcohol doses (40 mg/dl and 80 mg/dl) in healthy adults (N = 23 and 27, for both doses, respectively). There was no significant effect of alcohol on delay discounting at either dose. Alcohol significantly affected probability discounting, such that reduced discounting for uncertain rewards was evident during the descending limb of the BAC curve at the lower dose (p<.05) and during both the ascending and descending limb of the BAC curve at the higher dose (p<.05). Thus, alcohol resulted in increased risky decision making, particularly during the descending limb which is primarily characterized by the sedative effects of alcohol. These findings suggest that the biphasic effects of alcohol across the ascending and descending limbs of the BAC have differential effects on behavior related to decision-making for probabilistic, but not delayed, rewards. Parallels to and distinctions from previous findings are discussed. PMID:23750692

Mental and physical activities delay cognitive decline in older persons with dementia.

PubMed

Cheng, Sheung-Tak; Chow, Pizza K; Song, You-Qiang; Yu, Edwin C S; Chan, Alfred C M; Lee, Tatia M C; Lam, John H M

2014-01-01

To examine the effects of cognitive stimulation (mahjong) and physical exercise (tai chi [TC]) on cognitive performance in persons with dementia. Cluster-randomized open-label controlled design. Nursing homes. One hundred ten residents, most of whom were cholinesterase-inhibitor naive. Inclusion criteria were Mini-Mental State Examination (MMSE) = 10-24 and suffering from at least very mild dementia (Clinical Dementia Rating ≥ 0.5). Exclusion criteria were being bedbound, audio/visual impairment, regular activity participation before study, or contraindications for physical or group activities. Homes were randomized into three conditions (mahjong, TC, and simple handicrafts [control]). Activities were conducted three times weekly for 12 weeks. Primary outcome was MMSE. Secondary outcomes were immediate/delayed recall, categorical fluency, and digit span. Various biological risk factors, including apolipoprotein E ε4 allele, were included as covariates. Measures were collected at 0 (baseline), 3 (posttreatment), 6, and 9 months. Intent-to-treat analyses were performed using mixed-effects regression. Mahjong's effect varied by time for MMSE, delayed recall, and forward digit span. TC had similar effects but not for delayed recall. The typical pattern was that control participants deteriorated while mahjong and TC participants maintained their abilities over time, leading to enlarged treatment effects as time progressed. By 9 months, mahjong and TC differed from control by 4.5 points (95% confidence interval: 2.0-6.9; d = 0.48) and 3.7 points (95% confidence interval: 1.4-6.0; d = 0.40), respectively, on MMSE. No treatment effects were observed for immediate recall and backward digit span. Mahjong and TC can preserve functioning or delay decline in certain cognitive domains, even in those with significant cognitive impairment. Copyright © 2014 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

Durations and Delays in Care Seeking, Diagnosis and Treatment Initiation in Uncomplicated Pulmonary Tuberculosis Patients in Mumbai, India.

PubMed

Mistry, Nerges; Rangan, Sheela; Dholakia, Yatin; Lobo, Eunice; Shah, Shimoni; Patil, Akshaya

2016-01-01

Timely diagnosis and treatment initiation are critical to reduce the chain of transmission of Tuberculosis (TB) in places like Mumbai, where almost 60% of the inhabitants reside in overcrowded slums. This study documents the pathway from the onset of symptoms suggestive of TB to initiation of TB treatment and examines factors responsible for delay among uncomplicated pulmonary TB patients in Mumbai. A population-based retrospective survey was conducted in the slums of 15 high TB burden administrative wards to identify 153 self-reported TB patients. Subsequently in-depth interviews of 76 consenting patients that fit the inclusion criteria were undertaken using an open-ended interview schedule. Mean total, first care seeking, diagnosis and treatment initiation duration and delays were computed for new and retreatment patients. Patients showing defined delays were divided into outliers and non-outliers for all three delays using the median values. The mean duration for the total pathway was 65 days with 29% of patients being outliers. Importantly the mean duration of first care seeking was similar in new (24 days) and retreatment patients (25 days). Diagnostic duration contributed to 55% of the total pathway largely in new patients. Treatment initiation was noted to be the least among the three durations with mean duration in retreatment patients twice that of new patients. Significantly more female patients experienced diagnostic delay. Major shift of patients from the private to public sector and non-allopaths to allopaths was observed, particularly for treatment initiation. Achieving positive behavioural changes in providers (especially non-allopaths) and patients needs to be considered in TB control strategies. Specific attention is required in counselling of TB patients so that timely care seeking is effected at the time of relapse. Prioritizing improvement of environmental health in vulnerable locations and provision of point of care diagnostics would be singularly effective in curbing pathway delays.

Durations and Delays in Care Seeking, Diagnosis and Treatment Initiation in Uncomplicated Pulmonary Tuberculosis Patients in Mumbai, India

PubMed Central

Mistry, Nerges; Rangan, Sheela; Dholakia, Yatin; Lobo, Eunice; Shah, Shimoni; Patil, Akshaya

2016-01-01

Background Timely diagnosis and treatment initiation are critical to reduce the chain of transmission of Tuberculosis (TB) in places like Mumbai, where almost 60% of the inhabitants reside in overcrowded slums. This study documents the pathway from the onset of symptoms suggestive of TB to initiation of TB treatment and examines factors responsible for delay among uncomplicated pulmonary TB patients in Mumbai. Methods A population-based retrospective survey was conducted in the slums of 15 high TB burden administrative wards to identify 153 self-reported TB patients. Subsequently in-depth interviews of 76 consenting patients that fit the inclusion criteria were undertaken using an open-ended interview schedule. Mean total, first care seeking, diagnosis and treatment initiation duration and delays were computed for new and retreatment patients. Patients showing defined delays were divided into outliers and non-outliers for all three delays using the median values. Results The mean duration for the total pathway was 65 days with 29% of patients being outliers. Importantly the mean duration of first care seeking was similar in new (24 days) and retreatment patients (25 days). Diagnostic duration contributed to 55% of the total pathway largely in new patients. Treatment initiation was noted to be the least among the three durations with mean duration in retreatment patients twice that of new patients. Significantly more female patients experienced diagnostic delay. Major shift of patients from the private to public sector and non-allopaths to allopaths was observed, particularly for treatment initiation. Conclusion Achieving positive behavioural changes in providers (especially non-allopaths) and patients needs to be considered in TB control strategies. Specific attention is required in counselling of TB patients so that timely care seeking is effected at the time of relapse. Prioritizing improvement of environmental health in vulnerable locations and provision of point of care diagnostics would be singularly effective in curbing pathway delays. PMID:27018589

Delayed antimicrobial therapy increases mortality and organ dysfunction duration in pediatric sepsis.

PubMed

Weiss, Scott L; Fitzgerald, Julie C; Balamuth, Fran; Alpern, Elizabeth R; Lavelle, Jane; Chilutti, Marianne; Grundmeier, Robert; Nadkarni, Vinay M; Thomas, Neal J

2014-11-01

Delayed antimicrobials are associated with poor outcomes in adult sepsis, but data relating antimicrobial timing to mortality and organ dysfunction in pediatric sepsis are limited. We sought to determine the impact of antimicrobial timing on mortality and organ dysfunction in pediatric patients with severe sepsis or septic shock. Retrospective observational study. PICU at an academic medical center. One hundred thirty patients treated for severe sepsis or septic shock. None. We determined if hourly delays from sepsis recognition to initial and first appropriate antimicrobial administration were associated with PICU mortality (primary outcome); ventilator-free, vasoactive-free, and organ failure-free days; and length of stay. Median time from sepsis recognition to initial antimicrobial administration was 140 minutes (interquartile range, 74-277 min) and to first appropriate antimicrobial was 177 minutes (90-550 min). An escalating risk of mortality was observed with each hour delay from sepsis recognition to antimicrobial administration, although this did not achieve significance until 3 hours. For patients with more than 3-hour delay to initial and first appropriate antimicrobials, the odds ratio for PICU mortality was 3.92 (95% CI, 1.27-12.06) and 3.59 (95% CI, 1.09-11.76), respectively. These associations persisted after adjustment for individual confounders and a propensity score analysis. After controlling for severity of illness, the odds ratio for PICU mortality increased to 4.84 (95% CI, 1.45-16.2) and 4.92 (95% CI, 1.30-18.58) for more than 3-hour delay to initial and first appropriate antimicrobials, respectively. Initial antimicrobial administration more than 3 hours was also associated with fewer organ failure-free days (16 [interquartile range, 1-23] vs 20 [interquartile range, 6-26]; p = 0.04). Delayed antimicrobial therapy was an independent risk factor for mortality and prolonged organ dysfunction in pediatric sepsis.

Delayed Antimicrobial Therapy Increases Mortality and Organ Dysfunction Duration in Pediatric Sepsis

PubMed Central

Weiss, Scott L.; Fitzgerald, Julie C.; Balamuth, Fran; Alpern, Elizabeth R.; Lavelle, Jane; Chilutti, Marianne; Grundmeier, Robert; Nadkarni, Vinay M.; Thomas, Neal J.

2014-01-01

Objectives Delayed antimicrobials are associated with poor outcomes in adult sepsis, but data relating antimicrobial timing to mortality and organ dysfunction in pediatric sepsis are limited. We sought to determine the impact of antimicrobial timing on mortality and organ dysfunction in pediatric patients with severe sepsis or septic shock. Design Retrospective observational study. Setting PICU at an academic medical center. Patients One hundred thirty patients treated for severe sepsis or septic shock. Interventions None. Measurements and Main Results We determined if hourly delays from sepsis recognition to initial and first appropriate antimicrobial administration were associated with PICU mortality (primary outcome); ventilator-free, vasoactive-free, and organ failure–free days; and length of stay. Median time from sepsis recognition to initial antimicrobial administration was 140 minutes (interquartile range, 74–277 min) and to first appropriate antimicrobial was 177 minutes (90–550 min). An escalating risk of mortality was observed with each hour delay from sepsis recognition to antimicrobial administration, although this did not achieve significance until 3 hours. For patients with more than 3-hour delay to initial and first appropriate antimicrobials, the odds ratio for PICU mortality was 3.92 (95% CI, 1.27–12.06) and 3.59 (95% CI, 1.09–11.76), respectively. These associations persisted after adjustment for individual confounders and a propensity score analysis. After controlling for severity of illness, the odds ratio for PICU mortality increased to 4.84 (95% CI, 1.45–16.2) and 4.92 (95% CI, 1.30–18.58) for more than 3-hour delay to initial and first appropriate antimicrobials, respectively. Initial antimicrobial administration more than 3 hours was also associated with fewer organ failure–free days (16 [interquartile range, 1–23] vs 20 [interquartile range, 6–26]; p = 0.04). Conclusions Delayed antimicrobial therapy was an independent risk factor for mortality and prolonged organ dysfunction in pediatric sepsis. PMID:25148597

Traveltime delay relative to the maximum energy of the wave train for dispersive tsunamis propagating across the Pacific Ocean: the case of 2010 and 2015 Chilean Tsunamis

NASA Astrophysics Data System (ADS)

Poupardin, A.; Heinrich, P.; Hébert, H.; Schindelé, F.; Jamelot, A.; Reymond, D.; Sugioka, H.

2018-05-01

This paper evaluates the importance of frequency dispersion in the propagation of recent trans-Pacific tsunamis. Frequency dispersion induces a time delay for the most energetic waves, which increases for long propagation distances and short source dimensions. To calculate this time delay, propagation of tsunamis is simulated and analyzed from spectrograms of time-series at specific gauges in the Pacific Ocean. One- and two-dimensional simulations are performed by solving either shallow water or Boussinesq equations and by considering realistic seismic sources. One-dimensional sensitivity tests are first performed in a constant-depth channel to study the influence of the source width. Two-dimensional tests are then performed in a simulated Pacific Ocean with a 4000-m constant depth and by considering tectonic sources of 2010 and 2015 Chilean earthquakes. For these sources, both the azimuth and the distance play a major role in the frequency dispersion of tsunamis. Finally, simulations are performed considering the real bathymetry of the Pacific Ocean. Multiple reflections, refractions as well as shoaling of waves result in much more complex time series for which the effects of the frequency dispersion are hardly discernible. The main point of this study is to evaluate frequency dispersion in terms of traveltime delays by calculating spectrograms for a time window of 6 hours after the arrival of the first wave. Results of the spectral analysis show that the wave packets recorded by pressure and tide sensors in the Pacific Ocean seem to be better reproduced by the Boussinesq model than the shallow water model and approximately follow the theoretical dispersion relationship linking wave arrival times and frequencies. Additionally, a traveltime delay is determined above which effects of frequency dispersion are considered to be significant in terms of maximum surface elevations.

The impact of social isolation on delayed hospital discharges of older hip fracture patients and associated costs.

PubMed

Landeiro, F; Leal, J; Gray, A M

2016-02-01

Delayed discharges represent an inefficient use of acute hospital beds. Social isolation and referral to a public-funded rehabilitation unit were significant predictors of delayed discharges while admission from an institution was a protective factor for older hip fracture patients. Preventing delays could save between 11.2 and 30.7 % of total hospital costs for this patient group. Delayed discharges of older patients from acute care hospitals are a major challenge for administrative, humanitarian, and economic reasons. At the same time, older people are particularly vulnerable to social isolation which has a detrimental effect on their health and well-being with cost implications for health and social care services. The purpose of the present study was to determine the impact and costs of social isolation on delayed hospital discharge. A prospective study of 278 consecutive patients aged 75 or older with hip fracture admitted, as an emergency, to the Orthopaedics Department of Hospital Universitário de Santa Maria, Portugal, was conducted. A logistic regression model was used to examine the impact of relevant covariates on delayed discharges, and a negative binomial regression model was used to examine the main drivers of days of delayed discharges. Costs of delayed discharges were estimated using unit costs from national databases. Mean age at admission was 85.5 years and mean length of stay was 13.1 days per patient. Sixty-two (22.3 %) patients had delayed discharges, resulting in 419 bed days lost (11.5 % of the total length of stay). Being isolated or at a high risk of social isolation, measured with the Lubben social network scale, was significantly associated with delayed discharges (odds ratio (OR) 3.5) as was being referred to a public-funded rehabilitation unit (OR 7.6). These two variables also increased the number of days of delayed discharges (2.6 and 4.9 extra days, respectively, holding all else constant). Patients who were admitted from an institution were less likely to have delayed discharges (OR 0.2) with 5.5 fewer days of delay. Total costs of delayed discharges were between 11.2 and 30.7 % of total costs (€2352 and €9317 per patient with delayed discharge) conditional on whether waiting costs for placement in public-funded rehabilitation unit were included. High risk of social isolation, social isolation and referral to public-funded rehabilitation units increase delays in patients' discharges from acute care hospitals.

A comprehensive review of prehospital and in-hospital delay times in acute stroke care.

PubMed

Evenson, K R; Foraker, R E; Morris, D L; Rosamond, W D

2009-06-01

The purpose of this study was to systematically review and summarize prehospital and in-hospital stroke evaluation and treatment delay times. We identified 123 unique peer-reviewed studies published from 1981 to 2007 of prehospital and in-hospital delay time for evaluation and treatment of patients with stroke, transient ischemic attack, or stroke-like symptoms. Based on studies of 65 different population groups, the weighted Poisson regression indicated a 6.0% annual decline (P<0.001) in hours/year for prehospital delay, defined from symptom onset to emergency department arrival. For in-hospital delay, the weighted Poisson regression models indicated no meaningful changes in delay time from emergency department arrival to emergency department evaluation (3.1%, P=0.49 based on 12 population groups). There was a 10.2% annual decline in hours/year from emergency department arrival to neurology evaluation or notification (P=0.23 based on 16 population groups) and a 10.7% annual decline in hours/year for delay time from emergency department arrival to initiation of computed tomography (P=0.11 based on 23 population groups). Only one study reported on times from arrival to computed tomography scan interpretation, two studies on arrival to drug administration, and no studies on arrival to transfer to an in-patient setting, precluding generalizations. Prehospital delay continues to contribute the largest proportion of delay time. The next decade provides opportunities to establish more effective community-based interventions worldwide. It will be crucial to have effective stroke surveillance systems in place to better understand and improve both prehospital and in-hospital delays for acute stroke care.

Exact synchronization bound for coupled time-delay systems.

PubMed

Senthilkumar, D V; Pesquera, Luis; Banerjee, Santo; Ortín, Silvia; Kurths, J

2013-04-01

We obtain an exact bound for synchronization in coupled time-delay systems using the generalized Halanay inequality for the general case of time-dependent delay, coupling, and coefficients. Furthermore, we show that the same analysis is applicable to both uni- and bidirectionally coupled time-delay systems with an appropriate evolution equation for their synchronization manifold, which can also be defined for different types of synchronization. The exact synchronization bound assures an exponential stabilization of the synchronization manifold which is crucial for applications. The analytical synchronization bound is independent of the nature of the modulation and can be applied to any time-delay system satisfying a Lipschitz condition. The analytical results are corroborated numerically using the Ikeda system.

Time delay induced different synchronization patterns in repulsively coupled chaotic oscillators

NASA Astrophysics Data System (ADS)

Yao, Chenggui; Yi, Ming; Shuai, Jianwei

2013-09-01

Time delayed coupling plays a crucial role in determining the system's dynamics. We here report that the time delay induces transition from the asynchronous state to the complete synchronization (CS) state in the repulsively coupled chaotic oscillators. In particular, by changing the coupling strength or time delay, various types of synchronous patterns, including CS, antiphase CS, antiphase synchronization (ANS), and phase synchronization, can be generated. In the transition regions between different synchronous patterns, bistable synchronous oscillators can be observed. Furthermore, we show that the time-delay-induced phase flip bifurcation is of key importance for the emergence of CS. All these findings may light on our understanding of neuronal synchronization and information processing in the brain.

Stability analysis of fractional-order Hopfield neural networks with time delays.

PubMed

Wang, Hu; Yu, Yongguang; Wen, Guoguang

2014-07-01

This paper investigates the stability for fractional-order Hopfield neural networks with time delays. Firstly, the fractional-order Hopfield neural networks with hub structure and time delays are studied. Some sufficient conditions for stability of the systems are obtained. Next, two fractional-order Hopfield neural networks with different ring structures and time delays are developed. By studying the developed neural networks, the corresponding sufficient conditions for stability of the systems are also derived. It is shown that the stability conditions are independent of time delays. Finally, numerical simulations are given to illustrate the effectiveness of the theoretical results obtained in this paper. Copyright © 2014 Elsevier Ltd. All rights reserved.